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JOURNAL
OF THE
ASSOCIATION OF OFFICIAL
AGRICULTURAL CHEMISTS
BOARD OF EDITORS
R. W. Batcom, Chairman
R. E. DoouitTLe R. B. DEEMER
W. W. RANDALL W. F. Hann
Marian E. Lapp, Associate Editor
VOLUME VI
1922-1923
\qisol
dae
1923
ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS
BOX 290, PENNSYLVANIA AVENUE STATION
WASHINGTON, D. C.
Copyricnt, 1923,
BY
Tue AssocrATION oF OFFICIAL AGRICULTURAL CHEMISTS
CONTENTS
PROCEEDINGS OF THE THIRTY-SEVENTH ANNUAL CONVENTION,
OCTOBER, 1921
TurspAY—Morninc SEssion PAGE
Report on Chemical Reagents. By G. C. Spencer................0.c0ceeccees 1
Report on Non-Alcoholic Beverages. By W. W. Skinner...................... 3
Report on Eggs and Egg Products. By H. L. Lourie.......................+- 4
Report on Preservatives (Saccharin). By M. G. Wolf........................5 14
Report on Food Colors. By W. E. Mathewson...................0cc0scceeees 15
Use of Sodium-Alpha-Naphthol-2-Sulfonate for the Spectrophotometric Estimation
of Aromatic Amino Compounds. By W. E. Mathewson................... 16
eport.on Metalsin Poods:.,,by W. PF. Glarke ico... ec 4 acs ais joie ins eauelew ie a 28
meport on Asseniciim Foods, iBy RR. Mi Hani.) oo. os os. ues ss Gia nie a oe yon ss ole 31
Report on Determination of Pectin in Fruit and Fruit Products. By H. J. Wich-
THEI ase ae ean ARAN I ran ra SNS ee i iby ines ned ade See DEO i 34
Report on Determination of Moisture in Dried Fruits. By R. W. Hilts......... 40
ikeport.on Canned Foods. ‘By Rew: Balcomaeenoe. . es... 3 250.66 eo) bee vee 49
A Net Micrometer for Use in Making Mold Counts. By B. J. Howard......... 50
Address by the Honorary President. By H. W. Wiley.....................05. 51
TUESDAY—AFTERNOON SESSION
ieeport on’ Cereal Boods. ..ByiG. Ei. Batley i es ele a oo pects a iui ele eto aidlbgeduiel poate 60
Studies on Wheat Flour Grades, III—Effect of Chlorine Bleaching upon the Elec-
trolytic Resistance and Hydrogen Ion Concentration of Water Extracts. By
Creide ellen ANG, ATOM GUTSON: co 3' 0a)5 cS aie Ga cee pe has Oa ad cine an eee 63
Quantitative Determination of Chlorine in Bleached and Natural Flours. By
ECAR tee ee Ne MO TIN SOU een 2 Seen Oe. 68
Microscopic Method for the Quantitative Determination of Rice Hulls in Rice
rane, ys Eibls SUEDE. 28.5 n i ese eee oo 6 Lk a eNOS « SURE Oe Sa ae see ae
Report on Meat and Meat Products. By C. Robert Moulton.................. 72
Separation of Meat Proteins. By C. Robert Moulton......................... 76
Amino Acids in the Globulin-Albumin Fraction of Beef Flesh. By C. Robert
Moilion 5.) 3:5 213... d tae eee oe ess cE ee i AIL, RIEL es SI 86
Address by the Secretary of Agriculture. By Henry C. Wallace................ 90
Report on Spices and Other Condiments. By A. E. Paul...................... 92
Report on Determination of Shell in Cacao Products. By B. H. Silberberg. ..... 98
Report on Methods for Examination of Cacao Butter. By W. F. Baughman.... 101
ieenort on Conce.. Biv Hi Ameer ris. io 4o crore uicaey deters els ciei ds swale tse 106
PPCpOr, OW Leas. sy i. E. Aiidmewmee ne sc. cir de the.. sieietonusatictevsienrec cation ciae 107
WEDNESDAY—MornNING SESSION
Report of Committee on Editing Methods of Analysis........................- 113
enone of Board ot Editors: - “By fe. W. Baleom..../.0.. =)... ..:+.sc0e+s aeons 119
Report of Committee on Vegetation Tests on the Availability of Phosphoric Acid
STYLE TS ips! Fe apie MER aii SR ee OE Aa A 123
Report of Committee to Cooperate with the American Society for Testing Ma-
SEAER ee TNs LAA OL PERE IAS MIL AMEE CSS. 1. 104, MONEE DURE gad FM 124
Report of Committee on Recommendations of Referees. By R. E. Doolittle.... 125
iii
iv CONTENTS
Report of Committee A on Recommendations of Referees. By B. B. Ross...... 127
Report of Committee B on Recommendations of Referees. By H. C. Lythgoe... 133
Report of Committee C on Recommendations of Referees. By R. E. Doolittle... 144
WEDNESDAY—AFTERNOON SESSION
Report of Representative to Cooperate with the United States Pharmacopceia
Revision Gommittee! ) Byrbahe Keblersat)o i atten). one eee le eee 152
Report of Representatives on the Board of Governors of the Crop Protection
Institute of the National Research Council....................0e cece cece 154
Report of Secretary-Freasurer.” “By C.L. Alsbergo."47- >, eee oe eee 158
Report of Secretary-Treasurer.' ‘By Rh. W.Baleom. 0. 62. Seer oen eae ane 160
Financial Report on Publications... By C. L. Alsberg. 7). 0. ooo eens ee 162
Financial Report on Publications. By R. W. Balcom:........................ 164
Report of ‘Auditing Conimittes 5. ). ooo he = ota he soe reece cca eke ened ee 168
Report of Committee to Cooperate with Other Committees on Food Definitions.. 169
Report.of-Nominating;Gommittee: ... 54 sae eee ence Cee ocr ee 171
Report of; Committee on) Resolutions, «(pec eer eee ee En eee 172
Obituary—Bert..Holmes Fite. 330/25 shes 5s Sas weal ees eee een © eS ee 174
CONTRIBUTED PAPERS
Methods for the Estimation of Small Amounts of Starch in Plant Tissues. By
FBS Denny. see fe AT es Re eee Te 175
Analysis of Licorice Root and Licorice Extract. By Percy A. Houseman....... 191
Variations in the Concord Grape During Ripening. By H. A. Noyes, H. T. King,
and J. Ei Miartsolf yo: 25.3.4 ee a Cc nn Ss Ee 197
Determination of Crude Fiber in Prepared Mustard. By C. A. Clemens....... 205
PROCEEDINGS OF THE THIRTY-EIGHTH ANNUAL CONVENTION,
NOVEMBER, 1922
Obituary on Dr. Fritz Wilhelm Woll. By M. E. Jaffa...................... No. 3, i
Officers, Committees, Referees, and Associate Referees of the Association of Official
Agricultural Chemists, for the Year ending November, 1923.............. 209
Members and Visitors Present, 1922 Meeting .: ... 2. .-...6..2.00.5 00s oe Me eee 216
President's Address... By(F. /P. Veitel! ci... Apes sd. oe eee ee 223
Change in Order of Publication.'s..0. 4:70; Lele) SE eee eee 229
FrmAay—MorninG SESSION
Report of Committee on Editing Methods of Analysis. By R. E. Doolittle..... 229
Report of Board of Editors. By BR: W.iBaleom. 2020.5 eee ee 241
Financial Report on Publications from October 16, 1921 to November 1, 1922.
By 'R.‘W. Balcom...... e422 Se ER sh cane eee 244
Financial Report of the Secretary-Treasurer from October 16, 1921 to November
41,1922. By We W. Skimmers) cc5 ic eis) sen oy eee ee a 248
Address by the Secretary of Agriculture. Hon. Henry C. Wallace............. 251
Report of Committee on Vegetation Tests on the Availability of Phosphoric Acid
in.Basic Slag. “By B.D, Haskins ob viis ei eter oa OR once SU 254
Report of Committee to Cooperate with the American Society for Testing Materials
A Regard to Methods of Analysis for Liming Materials. By W. H. Mac-
MUG oe iss dia cthe oo kevin beclgualt ATR <del eR ERROR erent RR entire rt 255
CONTENTS v
PAGE
Report of Committee A on Recommendations of Referees. By B. B. Ross....... 258
Report of Committee B on Recommendations of Referees. By H. C. Lythgoe... 262
Report of Committee C on Recommendations of Referees. By R. E. Doolittle.... 272
FripAY—AFTERNOON SESSION
Report of Committee to Cooperate with the Revision Committee of the United
States Pharmacopocia. By L. Fi: Kebleniit...i2).') Rot ited. watgeld ise a 281
Report of Representatives on the Board of Governors of the Crop Protection Insti-
tute of the National Research Council. By B. L. Hartwell................ 286
Report of Secretary-Treasurer. By W. W. Skinner.................0ceeeceees 227
Report of Committee to Cooperate with other Committees on Food Definitions.
Woy, Mul HoOrtyet.. ce oi6 oie «oc an a, ora oie US ck ohor= OES ER oe 292
Report of Committee on Definitions of Terms and Interpretation of Results on
Fertilizers. (By Hy Di Haskomsy: sys: 5 eee) Ce Nps eve co ai, heeanroyf alia haiatayee bean 302
demons, of: Aviad ri trag: Covent BOG a 25) my, ooh nc sed Beta Ruse ee as -+, 9, SST SUSAR Bh ta Ps 303
eport.ol: Nominating, Commithees: a51</).05- 23 oie 3 bpd «sia oathya'd's Hed bia eenataiolare We 305
ieport. of Committee on Resolutions... 2) 2...) 22 FF PS, Ss eT oes Pe 305
WeEDNESDAY—MoRrnNING SESSION
enor. on Water... By.J. Wi Salegee: ase big Pid. ist. ee oe on saeiaus lsichoyih oud ected 307
Report on Tanning Materials and Leather. By F. P. Veitch................... 309
Report on Insecticides and Fungicides. By J. J.T. Graham................... 313
ipeport on sons: ey W. EH. Mackntime 5212) 28icc% 2 vayhhs sisi payer ary ok taraid eualolayeee 320
neport ion. colfur.in Soils. (By) Wo Hi. Maclntires. .)!)2). 92.1.2 sind. WP RIGE Ds PEG es 320
Effect of Cropping Upon the Active Potash of the Soil. By G. S. Fraps....... 329
Report on Foods and Feeding Stuffs. By J. B. Reed.......................45. 332
meporvem Grune Biber. > Dyes: Ptapay 2". 2.5 Se ee ote ete cwesice ty mee 333
Report on Stock Feed Adulteration. By H. E. Gensler....................44. 345
The Determination of Starch Content in the Presence of Interfering Polysaccha-
rides, as in Impure Linseed Products. By G. P. Walton and M. R. Coe.... 350
Reading the Fat Column in the Babcock Test for Milk. By C. F. Hoyt........ 354
Report. on saccharine Products, By HOS: Paine: 6257.55 2. tos See ah 363
Report on Maltose’/Prodacts. byiie 'G_ Gores (0/0) 22.0. 24s ahs ask wae ots A 364
The Determination of Ash in Cane Sirup and Molasses. By J. F. Brewster..... 365
The Use of Nickel Dishes for Ashing Saccharine Products. By W. L. O. Whaley.. 370
WEDNESDAY—AFTERNOON SESSION
eenor ton Fertilizers: iy yiian INS ET AGROEL jo) 5 61s) 5.9 aiiayere nae os She wd)niare loge la pin's vlefbie. aye 375
Summary of Work on the Determination of Iron and Alumina in Phosphate Rock by
the Association of Official Agricultural Chemists. By R. N. Brackett...... 377
ineport on Boron in Fertilizers.» By Jd. Ms Bartletts: 3 9... .0a0h. oicie a's os sales Waele 381
Report on the Preparation of a Neutral Solution of Ammonium Citrate. By C.
SR CGIAITISO ai...) ge hee os ON Ie Sas Vereen 2 ek atc a Auta ae 384
enartion: Nitrogen. |) By l. IC qe Menge sicc ols ss cc ak ete co eiare sce cai w'st ere shat are 391
Pencrion rotasa., (by.o. Ps Bomar ye es Bek re ah ce cL OS 399
Summary Relating to Strength and Kind of Alcohol Used in Official Potash Methods,
184 1O2 IES UB wane CAL EhUStOmMuaw arin. ce run en tual, oliayc) Ais a\tay's gale oyaenes coeie eee 403
Availability of Potash in Mixed Fertilizers. By N. E. Gordon.................. 407
The Volumetric Determination of Phosphorus. By W. A. Turner.............. 409
A’ New Pextihzer Sampling Tube.’ By'h’D. Haigh 2). 2 Oe ae 410
Report on Inorganic Constituents. By A: J. Patten. 2.0003... 000. bod, 414
Report on Sulfur and Phosphorus in the Seeds of Plants. By W. L. Latshaw.... 414
Vi CONTENTS
PAGE
Report on the Determination of ron and Aluminium, Calcium and Magnesium in
the Ash of Seeds. By A: J. Patten «...... os pres ae: coop pik tiny ok ne en 418
Report on Dairy Products... By Julius Hortyets son. «si. ope se's so = avr ssn eee 422
Cryoscopy of Milks) By EB. M. Bailey. oo ts ictec. es taye oo enya « choy, eee ee 429
Methods for Fat in Malted Milk and Dried Milk. By J. T. Keister........... 435
Data Secured with the “Turbidity Point” of Butter Fat. By Armin Seidenberg. 437
Report,on‘Fats‘and Oils; By G. S.,Janiieson 2) 24). 7teeiawae 2.08 enh ees ee 440
Heport:on: Baking Powder. - By LH. Bailey). 3. 2202. - PPR ee 445
Report on Fluorides in Baking Powder. By J. K. Morton..................... 457
DruG SECTION
Report on Drugs. | By 'G: ‘W. Hoover’. «6:6... 5.0 sete in os ce a ee 460
Report on Methods of Qualitative and Quantitative Analysis of Arsphenamine
(Salvarsan) and Neoarsphenamine (Neosalvarsan).................0.00-00-
Report on:Turpentine.:. By JO. Clarke. 2.-..600:22.0..\.0.0./ 4. eee ee 465
A New Sedimentation Tube and Its Use in Determining the Cleanliness of Drugs
and Spices. By Arno Viehoever............5....5 <1: ).4) Sep ee ate enter eee 466
Sublimation of Plant and Animal Products—Third Report. By Arno Viehoever.. 473
Sublimation as an Analytical Procedure. By Julius Hortvet................... 481
Domestic Sources of Cantharidin. By Viehoever and Capen................... 489
Quantitative Determination of Acetic Anhydride. By G. C. Spencer........... 493
CONTRIBUTED PAPERS
Martin: 06 icc) ous edinety ton bamee) oot bog
Nut: Margarines: By Ja; Keister. 4/4045 .4) oso. shijoe Cee ee eee eee 502
Determination of Fat in Alimentary Paste. Flour and Dried Egg. By R. Hertwig.. 508
SECOND DAY.
TUESDAY—MORNING SESSION.
REPORT ON CHEMICAL REAGENTS.
By G. C. Spencer (Bureau of Chemistry, Washington, D. C.), Referee.
Under date of May 25, 1921, the referee sent out 119 copies of a circu-
lar letter to members of the association who would be concerned with
buying or testing the chemical reagents in their respective organiza-
tions. In this letter correspondence was requested relating to cases of
unsatisfactory chemical reagents and the action which had been taken
by the institution to secure a satisfactory adjustment of the trouble.
Only seventeen replies were received, and twelve of these had no
suggestions or comments on the quality of reagents used. From the
lack of response to this letter among the association members at large,
it is assumed that the quality of reagents generally purchasable in this
country is satisfactory. It is also assumed that in many of the chemical
stations represented in this body the C. P. reagents are taken on faith
and used without further testing; otherwise there would have been a
keener interest manifested.
It is true that, taken altogether, the American manufacturers are
putting out chemicals which can be accepted to a great extent on their
face value and that they are keenly interested in bringing their prod-
ucts up to the highest possible standard of purity. To this end they
have met in conference with each other and with members of the Com-
mittee on Guaranteed Reagents and Standard Apparatus of the
American Chemical Society and have exchanged and considered sug-
gestions relative to reagent standards.
No collaborative work was attempted as it was deemed advisable
first to quicken an interest among the members in the quality of their
reagents and especially to emphasize the desirability of reporting com-
plaints regarding chemicals to the manufacturers. No such complaints
were reported during the past year. If, however, they were made in
the proper spirit, these complaints would be appreciated by the fair-
minded dealers who would seek thereafter to give satisfaction, not only
to the correspondent but to other purchasers.
Unfortunately, the analyses printed on the chemical labels are not
always reliable, as the Bureau of Chemistry has learned during the
eighteen years that it has been testing its purchased chemicals. This
statement is not intended as a reflection on the honesty of the dealer, as
1
2 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 7
it is appreciated that it is impossible to state correctly the analysis of
every bottle among the thousands that are daily shipped from the big
factories; but in fairness to producer and consumer the fact should be
plainly understood that the results on the labels are not dependable in
every case.
The following criticisms of chemical reagents were received from
association members during the past summer:
Acetone.—A sample was reported as containing about 40% of methyl] alcohol.
Amyl Acetate—This sample consisted largely of butyl and propyl acetates.
Calcium Carbonate, precipitated, of “‘tested purity’.—The dealer’s analysis showed
the absence of potash, but potash was nevertheless found. The correspondent also
complained that a heavy variety of calcium carbonate was difficult to obtain from
dealers.
Todine.—One sample was found to contain sulfur.
Powdered Iron.—This contained no impurities but was not properly screened.
Tron Reduced by Hydrogen and Sodium Carbonate——Both were found to contain more
impurities than the results printed on the labels seemed to warrant.
Sodium Carbonate.—Has also been found to run too high in chlorides.
Sodium Hydroxide—Some samples were reported as containing so much carbonate
as to make them objectionable for Kjeldahl work. Other samples of this chemical
were much too high in chlorides and sulfates for satisfactory analytical work.
Sulfuric Acid.—In one case gave too high a blank for nitrogen determinations.
As the recent experience of the Bureau of Chemistry with certain
reagents may be of interest your referee has copied the following items
from ihe Information Sheet on Chemical Reagents, compiled in the
Bureau in July, 1921:
Acetic Acid purchased by the Bureau has as a rule been very good. The limit of
residue is 1 mg. per 100 cc. and the greater part of this residue isiron. Only occasionally
is it possible to obtain an acid running as high as 99.9%, even though this percentage
is claimed by the dealer. The acid strength is usually from 99.5 to 99.7%. The test
for acid strength in this case is determined from the temperature of the congealing
point.
Amyl Alcohol pure enough for use as a reagent in dyestuff or alkaloidal analyses has
been difficult to obtain from American producers. One American firm, however, is at
present offering a grade of the highest purity.
One of the branch laboratories of the Bureau has recently found soluble sulfates in
the Asbestos that has been supplied for Gooch crucibles. Other samples of the asbestos
have been found to contain no sulfates. This point is mentioned as a warning to the
members of the association that asbestos should never be taken on faith but should
be carefully tested before using.
U.S. P. Ether contains up to 3% ethyl alcohol and 1% of water. Particular atten-
tion is paid to the residue and more than 0.001% is never allowed in this or any other
organic solvent.
The absolute Ether is as a rule very good. This will quickly develop peroxide if
exposed to air and sunlight, but this peroxide formation may be entirely prevented by
removing the ether from the can immediately and placing it over sodium.
The Hydrochloric Acid purchased in recent years has varied in acid strength from
33.5 to 36.5% and has contained more or less arsenic. Other impurities have generally
1922} SPENCER: REPORT ON CHEMICAL REAGENTS 3
been absent. The residue, if any, has not exceeded 0.001%. Sulfuric acid is recom-
mended for arsenic work as a substitute for hydrochloric as the good commercial grades
are practically free of arsenic.
Zine Sticks have always been somewhat unsatisfactory for arsenic determinations,
and it is always advisable to run a sufficient number of blanks on all samples.
In conclusion, it is desired to emphasize a more extended use of the
metric system of weights and measures. An effort has been made to
have all chemicals put up in standardized packages of metric weight or
volume. Chemical dealers have expressed a willingness to supply their
products in metric units if the trade demanded it. All colleges, experi-
ment stations and other parties who purchase chemicals have accord-
ingly been requested by the American Chemical Society to state their
future orders for chemicals in metric units and the General Supply Com-
mittee of the Federal Government has already adopted this policy so
far as practicable. A representative list of unit packages of chemicals
in common use has been prepared by W. D. Collins’.
RECOMMENDATIONS.
It is reeommended—
(1) That all members of this association make an effort to specify
metric units when ordering new supplies of chemicals.
(2) That this association again declare itself in favor of urging all
members to report unsatisfactory reagents to manufacturers during the
coming year and to notify the secretary of this association of their action.
REPORT ON NON-ALCOHOLIC BEVERAGES.
By W. W. Skinner (Bureau of Chemistry, Washington, D. C.), Referee.
It was planned by the association last year that the referee should
study a method for the analysis of those fruit products which are largely
sophisticated. This is considered important work owing to the large
trade in emulsified flavors and drinks prepared from them, in imitation
of true fruit products, which has developed in the past two years. The
Bureau of Chemistry found it necessary to issue a warning regarding
the misbranding of such material.
It is necessary to differentiate between artificial flavors, imitations of
true products, and the beverages made from true fruit extract.
Work has progressed, and a method has been formulated which it is
thought will ultimately be of service. No collaborative work has been
accomplished.
1 J. Ind. Eng. Chem., 1920, 12: 1206.
4 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. /
REPORT ON EGGS AND EGG PRODUCTS.
By H. L. Lourte (Food and Drug Inspection Station, New York, N. Y.),
Referee.
At the last meeting your referee reported that there seemed no pos-
sibility of determining whether or not dried egg products were decomposed
unless a study of their composition was made at the point of production
in order to obtain definite data as to the composition and character of
the raw eggs used and the changes that take place during manufacture.
It is well known, generally, that dried eggs are produced almost
exclusively at the present time in China. The methods of production
have been radically changed owing to the action of the Department of
Agriculture in refusing admission to eggs which were contaminated with
large amounts of zinc.
It is to be regretted that no methods which will conclusively show
the use of decomposed material are available at the present time.
The analyst must depend largely on the physical characteristics of the
dried-egg product to determine whether or not it has been made from
decomposed material. The methods for the determination of heavy
metals are satisfactory as are those for the presence of preservatives.
As it was considered that it would be of great value, a tentative
chapter on the methods of analysis generally used in government
laboratories for the determination of the sanitary quality of liquid eggs
has been prepared, including methods of analysis for liquid eggs, dried
eggs and egg products. [t was impossible for your referee to obtain
collaborative action which would decide conclusively whether the
methods proposed are acceptable or not. However, it should be pointed
out that the Bureau of Chemistry has conducted a valuable piece of
research work with respect to the examination of frozen egg products
and interpretation of results under the direction of H. W. Redfield!.
With respect to the analysis of egg products, the work of your referee
has been confined to the analysis of materials such as egg noodles, in
which the important consideration is to determine whether or not the
quantity of eggs present is in compliance with the standards formulated
by the Standards Committee for this commodity. There has been a
great deal of discussion as to the accuracy of the Juckenack method for
the determination of the amount of eggs and work done at the Bureau
of Chemistry and at the New York and San Francisco Food and Drug
Inspection Laboratories shows that this method does not give results
which indicate the true amount of egg present. The difficulty that the
investigator who attempts to devise new methods for the estimation of
eggs in products of this type meets is that it is necessary to work out
1U.S. Dept. Agr. Bull. 846: 1920.
1922] LOURIE: REPORT ON EGGS AND EGG PRODUCTS 5
new ratios with respect to the lecithin P205 content of the various
flours. There is a growing practice among manufacturers of egg noodles
and similar products to use dried yolk or so-called dried whole egg mix-
tures which contain excessive amounts of yolk instead of whole egg
which the standard set forth by the Department of Agriculture requires.
The problem here is to prove that there is a deficiency in albumen
derived from egg. It can readily be seen that a manufacturer using
5 per cent of dried yolk would obtain a product which, on analysis,
would indicate from the lecithin P205 content that it contained much
more than 5 per cent of whole eggs. Yet this product would be in
violation of the standard which calls for 5 per cent of whole eggs.
The New York and San Francisco Stations and the Bureau of Chem-
istry have been working on methods to determine whether egg noodles
are made from whole egg, yolky mixtures or yolk. This work has not
been completed. With respect to the determination of lecithin P205,
Jacobs and Rask have devised a method, based on the saponification of
the fat, which recovers practically all of the lecithin P205 content in
egg noodles. It has been noted that the lecithin P205 of flour and of
egg solids, when determined by this method, is considerably higher
than when determined by the Juckenack method; hence, different
values for these constants must be inserted in the formula which is used
for calculating the equivalent of egg solids from the lecithin P205 con-
tent of noodles. It should be noted that the values for this method,
which are given in the following compilation of methods, are not based
upon a sufficiently large number of determinations to be accepted as
final.
FROZEN AND LIQUID EGG PRODUCTS.
TAKING OF SAMPLES.
Frozen egg samples shall consist, when possible, of original unopened packages.
They shall consist of representative containers of the product in any individual ship-
ment. Enough containers shall be taken to represent a whole shipment fairly. All
samples shall be sent to laboratories in the quickest possible way. When transported
by common carriers, samples shall be so packed as to prevent thawing and every pre-
caution shall be taken to prevent delay in transit. They shall be delivered to the
analyst immediately upon arrival at the laboratory and no sample shall be examined
which does not arrive in a frozen condition. If the material is slightly melted around
the circumference, the subsamples for bacteriological and chemical examination must
be withdrawn from the portion which is still frozen.
When samples are opened, the bacteriologist, chemist, and microscopist shall all be
present and, in case of official samples, shall initial and date seals and cans for identi-
fication in the regular manner.
In order to preclude all possibility of a claim of contamination during sampling, the
bacteriologist shall always withdraw subsamples first when a container is opened.
The chemist shall then withdraw subsamples. The remainder shall be turned over to
the microscopist. Each analyst shall give a receipt to the one from whom the con-
tainer was received, in the case of official samples.
6 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No 1
For withdrawing subsamples, it will be found convenient to use a sterile butter
sampler of sufficient length to enable one to remove a core of frozen material from the
top to the bottom of the container, after first removing with a sterilized instrument
(chisel) the surface layer of the frozen material.
If the sample is frozen very solidly, it may be found necessary to use a brace and
long-shanked bit or ship-builder’s auger and to collect the shavings for the sample.
Cores shall be taken midway between the center and circumference, from at least
three widely separated parts of the container to form a composite sample.
Liquid egg samples shall be thoroughly mixed with a sterilized utensil such as a long-
handled dipper which has been immersed (including the handle) in alcohol and flamed,
and then subsamples withdrawn for examination. The subsamples for bacteriological
examination must be placed in sterilized containers.
The chemical examination shall be started immediately after the taking of sub-
samples and all determinations shall be made in duplicate.
The subsamples are thawed by partially immersing the containers in warm water,
the temperature of which should not be above 50°C. They must then be thoroughly
mixed, preferably with an electric stirrer. In the absence of such an instrument in
the chemical laboratory, the mixing may be quite satisfactorily accomplished by suck-
ing the melted subsample several times through a Gooch crucible containing no asbes-
tos, using very moderate suction. This mixed composite sample is examined by the
methods which follow:
TOTAL SOLIDS.
Weigh approximately 5 grams of the sample into a tared lead dish of 24 inches to
3 inches diameter and dry in a vacuum of not less than 25 inches at 55°C. until there is
no further loss in weight. This drying usually requires about 4 hours. It is recom-
mended that weighings be made at the end of 3} hours’ drying, and thereafter at inter-
vals of about 30 minutes. Weigh to 3 decimal places. There is an appreciable gain
in weight after the minimum has been reached. Express the results as per cent on
the wet basis.
ETHER EXTRACT.
Extract the dry residue from the determination of solids with absolute ether, pref-
erably in a Knorr apparatus, but if this is not available, in a Johnson extractor. Cut
through the sides of the lead dish containing the solids at 4 equidistant points. Place
the dish upon a fat-free filter paper. Flatten down the sides of the dish. Place another
fat-free filter paper on top of the flattened dish and roll the papers and dish into a
cylinder which will fit the extraction tube fairly snugly. In making the cylinder,
turn in the ends in such a way as to prevent solid particles from dropping into the
extraction flask. Place the cylinder in the extraction tube without any asbestos plug
below it. If the extractor is working rapidly, 3 hours is sufficient to insure a proper
extraction.
Distil off the ether from the extraction flask and dry the extract for one hour at 55°C.
in a vacuum of not less than 25 inches. Weigh to 3 decimal places. Express the results
as per cent on the wet basis.
The ether used should not contain any alcohol or water, as a higher result is
obtained when either is present. It is, therefore, understood that ether freshly
distilled from sodium will be used.
ACIDITY OF THE FAT.
Dissolve the fat obtained in the determination of ether extract in 50 cc. of neutral
benzine to which has been added 2 drops of phenolphthalein indicator. Titrate with
0.05N sodium ethylate. Express the results as the number of cc. of 0.05N sodium
ethylate required to neutralize 1 gram of fat.
1922} LOURIE: REPORT ON EGGS AND EGG PRODUCTS 7
AMMONIA NITROGEN,
Titration Method.
This method is an adaptation of Folin’s method for the determination of ammonia
in urine!. It consists essentially in making the sample alkaline, removing the liberated
ammonia by aeration and catching it in a measured quantity of standardized acid.
The excess acid is then titrated.
The apparatus consists of the following:
1. A wash bottle containing dilute sulfuric acid (about 35 per cent) to remove any
ammonia that may be present in the air entering the system.
2. Some form of trap to prevent sulfuric acid being carried over mechanically.
3. An aerating cylinder about 50 mm. in diameter and 350 mm. high, fitted with a
2-hole rubber stopper carrying a right-angle air-inlet tube, open at the bottom and
extending to within } inch of the bottom of the cylinder and a trap containing either
a cotton or glass wool plug to prevent any liquid from being carried over mechanically.
4. An 8-ounce, wide-mouthed bottle fitted with a delivery tube coming from the
trap on the aerating cylinder. It is not essential that the special ammonia absorption
tubes be used. An ordinary glass tube with a small bulb blown on the end, through
which a few holes are punctured, answers very well. The method of making these is
given by Folin and Farmer’.
5. A means of passing air through the system. This is best done by a pump which
will furnish a blast with a pressure of 10 pounds per square inch and which discharges
into a tank of sufficient size to compensate for the pulsations of the pump and to deliver
a steady blast.
Suction may be used but it is not recommended.
Each of the first four parts enumerated is fitted with a 2-hole rubber stopper and
all are connected by glass tubes of suitable shape and length to permit the proper pas-
sage of air through the apparatus. The tube leading into the acid wash bottle should
contain a stop-cock for regulating the air supply.
Weigh approximately 25 grams of sample in a convenient container. Pour as much
as possible of this material into the aeration cylinder and transfer the remainder by
means of four 25 cc. portions of ammonia free water, stirring each time with a rubber-
tipped glass rod to remove any egg adhering to the sides of the weighing vessel. Add
75 cc. of alcohol, mix well, let stand for 15 minutes. Add approximately 1 gram of
sodium fluoride, 2 cc. of 50% potassium carbonate solution and 1 cc. of kerosene. Con-
nect the apparatus and aerate into the receiving bottle which should contain 10 cc. of
0.02N sulfuric acid, 2 drops of methyl red indicator (saturated solution in 95% alcohol)
and about 75 cc. of ammonia free water.
The aerations should be carried on for 4 hours or as long as necessary to remove all
of the ammonia, using as rapid a current of air as possible.
Titrate the excess of acid with 0.02N sodium hydroxide (free from carbon dioxide).
Express the results obtained as milligrams of ammonia nitrogen per 100 grams of
sample on the wet basis.
If there is insufficient time to complete the determination, the sample may be left
overnight in the cylinder with the alcohol and sodium fluoride added. The potassium
carbonate should, of course, not be added until ready to proceed.
If the sample has a bad odor, it may be necessary to use more than 10 cc. of 0.02N
sulfuric acid.
It is essential that a blank experiment be run to determine the percentage recovery
of ammonia using a known amount of pure ammonium sulfate (containing about 3 mgs.
1 Z. physiol. Chem., 1902, 37: 161.
2 J. Biol. Chem., 1912, 11: 499.
8 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
of nitrogen) and 25 cc. of water, instead of the egg. For method of preparing pure
ammonium sulfate see Folin and Farmer!. The recovery should be over 95 per cent.
It is also essential to run blank experiments with the reagents and water used.
REDUCING SUGARS.
Wash 25 grams of sample into a 200 cc. graduated flask with 75 cc. of water. Make
slightly acid by adding 2 cc. of 5% acetic acid for white or whole egg and 1 ce. for yolk.
Mix and immerse the flask in boiling water until the egg material is thoroughly coagu-
lated. This requires about 15 minutes. Cool to room temperature and make up to
the mark with washed alumina cream. Shake vigorously for 1 minute, allow to stand
5 minutes and then shake 1 minute. Filter through a dry folded filter and determine
the reducing sugar in 50 cc. of the filtrate by the Munson and Walker method?. Calcu-
late as dextrose and express the results as per cent on the wet basis.
The washed alumina cream is prepared by washing ordinary alumina cream 5 times
by decantation, using enough water so that at least half of the total volume may be
syphoned off each time.
On account of the volume occupied by the precipitate, the results are a trifle high.
This error amounts to about 1.4 per cent for white, 3.3 per cent for whole egg and
7.0 per cent for yolk. It is not customary to correct for this.
INDOL AND SKATOL.
A 200 cc. portion of sample is diluted with 500 cc. of water, acidified with 40 cc. of
5% acetic acid for white or whole egg and 20 cc. for yolk, coagulated in boiling water
or live steam and filtered. The filtrate is steam distilled as rapidly as possible. Ex-
tract the distillate (approximately 300 cc.) with ether in a separatory funnel. To the
ether extract add about 3 cc. of water and evaporate before an electric fan until the
smell of ether has almost but not entirely disappeared. A trace of ether does not
affect the result. Add 10 cc. of water, filter and apply the following test to the filtrate:
Vanillin Test for Indol and Skatol.
To the solution to be tested add a few drops of a 5% solution of vanillin in 95%
alcohol, and concentrated sulfuric acid. The acid should be added in the proportion
of 2 cc. for each 5 cc. of solution being tested. If indol is present, an orange color will
be formed which is soluble in chloroform, amy] acetate or amyl valerianate. If skatol
is present, a deep red to violet color will be formed which is readily soluble in chloro-
form, amy! acetate or amyl valerianate?.
As confirmatory tests, if needed, the following are suggested:
p-Dimethylaminobenzaldehyde Test.
To the solution to be tested, add 1 cc. of a solution consisting of 4 parts of paradi-
methylaminobenzaldehyde, 380 parts of absolute alcohol and 80 parts of concentrated
hydrochloric acid, in such a way as to form two liquid layers. If indol is present, a
purplish red color will be formed. If skatol is present, a blue violet color will be formed‘.
Herter’s B-Naphtha Quinone Test.
Make test solution slightly alkaline with potassium hydroxide. Add 1 drop of a
2% solution of B-naphtha quinone sodium monosulfonate. If indol is present,a blue or
green blue color will be formed.
J. Biol. Chem., 1912, 11: 496.
2 Assoc. Official ‘Agr. Chemists, Methods, 1920, 78.
3 J. Biol. Chem., 1916, 24:
' Z. physiol. Chem., 1906, 47:
5 J. Biol. Chem., 1906, 1 : on
1922] LOURIE: REPORT ON EGGS AND EGG PRODUCTS 9
Pyruvic Aldehyde Test.
To the solution to be tested add a small crystal of ferric sulfate and a few crystals of
pyruvic aldehyde. Then carefully run sulfuric acid down the inside of the container
in such a way as to form a layer at the bottom. If indol is present, a red violet ring
will form’.
Dimethylaniline Test.
To the test solution add a few drops of dimethylaniline and sulfuric acid. If skatol
is present, a deep red violet coloration is formed!.
Glycolic Acid Test.
To the solution to be tested add a few crystals of glycolic acid and an equal volume
of sulfuric acid. If skatol is present, a red violet color is formed’.
PRESERVATIVES:.
DRIED EGGS.
PHYSICAL CHARACTERISTICS.
Perform organoleptic tests. Note particularly the taste and odor of the product as
it is. Place about 10 grams in a 100 cc. beaker, add 50 cc. of water, stir, cover with
watch glass and let stand one-half hour. Note odor.
ZINC.
Place 25 grams of a well-mixed sample in an 800 cc. Kjeldahl flask; add 5 grams of
zinc-free potassium sulfate, 3 to 4 glass beads to prevent bumping, 30 cc. of concen-
trated sulfuric acid, in the case of yolks or whole eggs (25 cc. of the acid in the case of
albumens) and 30 cc. of concentrated nitric acid. Do not heat. When spontaneous
action subsides, add 10 cc. of concentrated nitric acid. After 2 or 3 additions of con-
centrated nitric acid the action becomes less violent. Heat gently, at first, continuing
the addition of concentrated nitric acid and increasing the temperature as the digestion
proceeds until the contents of the flask are straw colored or colorless, after the nitric
acid fumes have been boiled off. This digestion may be accomplished in the case of
albumen in 40 minutes and in the case of yolks or whole eggs in 1 hour. To warm
digestion add 100 cc. of water; pour into a 400 cc. beaker and rinse flask with two suc-
cessive 50 cc. portions of water. To the combined water solution add concentrated
ammonia to faintly alkaline. Pass hydrogen sulfide gas through solution for 15 min-
utes which should be sufficient to saturate. (At this point the majority of albumens
indicate the presence or absence of zinc. In the case of albumen, if zinc is present,
add 1 cc. of a diluted solution of ferric chloride containing 0.5 gram of solid ferric chlo-
ride per 100 cc. This will assist in retaining zinc sulfide on the paper when filtering.
Pass hydrogen sulfide gas through the solution for 15 minutes.) Heat beaker on steam
bath for one-half hour. Remove. Allow to settle from 5 to 10 minutes. Decant
through 9 cm. filter paper allowing as much of the precipitate as possible to drain
thoroughly. Dissolve the zinc sulfide from this precipitate with 10% hydrochloric
acid, the solution after passing through the filter paper being returned to the original
beaker. Copper and lead sulfide are insoluble at this point, and may be determined
by the A. O. A. C. methods‘. To the hydrochloric acid solution add 5 grams of ammon-
ium chloride and excess of bromine water and a slight excess of concentrated ammonia.
1 J. Biol. Chem., 1916, 24: 527.
2 Biochem. Z., 1919, 19: 523.
3 Assoc. Official Agr. Chemists, Methods, 1920, 117.
4 Tbid., 151, 285.
10 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
Neutralize carefully with 10% hydrochloric acid adding 2 cc. in excess; add 10 cc. of
50% by weight of ammonium acetate and 8 to 10 drops of 10% ferric chloride solution,
or enough to give a good reddish tinge. Dilute to about 300 cc. with water and boil
for 1 minute. Settle; filter hot and wash with hot 5% ammonium acetate. Pass
hydrogen sulfide gas through filtrate for 15 minutes. Heat one-half hour on steam
bath; filter through weighed heavily padded Gooch crucible using gentle suction. Wash
with hot 5% ammonium acetate solution. Dry in oven; then ignite, roasting first.
Increased weight of Gooch is due to oxide of zinc. This multiplied by 0.8034 gives
zine present in 25-gram sample.
PRESERVATIVES}.
EGG PRODUCTS.
EGG NOODLES.
MOISTURE.
Dry a convenient quantity of the sample, 2 to 3 grams, at the temperature of boiling
water, in a current of dry hydrogen or in vacuo, until it ceases to lose weight (approxi-
mately 5 hours). The loss in weight is the moisture content.
ASH.
Char a convenient quantity of the sample, 5 to 10 grams, in a previously ignited and
weighed platinum or silica dish and burn at the lowest possible heat until free from
carbon. If a carbon-free ash can not be obtained in this manner, exhaust the charred
mass with water, collect the insoluble residue on an ashless filter, burn until the ash
is white or nearly so, and then add the filtrate to the ash and evaporate to dryness.
Heat the residue to redness, cautiously at first to avoid decrepitation or spattering,
cool in a desiccator and weigh.
SODIUM CHLORIDE IN ASH.
Determine chlorides by the silver nitrate gravimetric or the Volhard volumetric
method. These methods are described in detail in any of the standard texts on quanti-
tative analyses. Calculate to the equivalent of sodium chloride. Total ash, minus
sodium chloride, is the salt-free ash.
NITROGEW?.
FAT.
Treat 5 grams of the sample in a loosely stoppered 200 cc. Erlenmeyer flask with a
mixture of 10 cc. of alcohol (95%), 2 ce. of concentrated ammonium hydroxide, and
3 ce. of water, keeping the contents of the flask at the boiling point for 2 minutes, pref-
erably on the stéam bath. After cooling, extract the contents of the flask with 3 suc-
cessive 25 cc. portions of ethyl ether, mixing and tamping the material thoroughly
each time with a glass rod flattened at the end and pouring the extracts off by decan-
tation into a 250 cc. beaker. The last 25 cc. portion of ether should be drained out as
completely as possible, after which another 15 cc. portion of the same ammoniacal
alcohol solution is added to the flask and the matted material disintegrated as thor-
oughly as possible by means of the flattened glass rod which may be left in the flask for
this purpose. The flask is then returned to the steam bath and the entire procedure
repeated, the second set of ether extracts being poured into the beaker containing the
first set. The second treatment with the ammoniacal alcohol mixture should be more
gradual and somewhat longer than the first, so that the ether remaining in the flask
1 Assoc. Official Agr. Chemists, Methods, 1920, 117.
2 Thid., 7.
1922| LOURIE: REPORT ON EGGS AND EGG PRODUCTS 11
may be evaporated off and the ammoniacal alcohol brought to the required boiling
point without results disastrous to the determination.
Evaporate the combined extracts to dryness on the steam bath and extract the fat
from the residue left in the beaker with successive portions (5 or 6 treatments, using
about 15 cc. each time) of a mixture of equal volumes of ethyl ether and petroleum
ether. Collect the extracts in a tared platinum dish (do not try to filter), and evap-
orate to dryness on the steam bath. Dry the residue in a water-jacketed oven at
the temperature of boiling water for 30 to 45 minutes, cool in a desiccator and weigh.
LECITHIN P205. METHOD I.
Add 3 cc. of a concentrated alcoholic solution of potassium hydroxide to the fat in
the dish, as obtained in the preceding method. Evaporate to dryness, char, and
determine total P205 by the volumetric method!. Owing to the small quantity of
P205 in the fat from a 5 gram sample of noodles, it may be advisable in some cases to
use the nephelometric method?.
The following formula is used for calculating the percentage of egg solids in noodles
on the moisture-free basis:
(A—0.0548) X 100= x,
(1.38 =0.0548)
in which A =percentage of lecithin P205 in the sample,
0.0548 = percentage of lecithin P205 in flour (dry basis),
and 1.38 =percentage of lecithin P205 in whole egg solids.
GASOLINE COLOR VALUE.
Place 20 grams of the sample in a wide-mouthed, glass-stoppered bottle of about
120 cc. (4 oz.) capacity, and add 100 cc. of colorless gasolime. Stopper tightly and
shake vigorously for 5 minutes. Let stand for 16 hours, shake again for a few seconds
until the flour has been loosened from the bottom of the bottle and thoroughly mixed
with the gasoline, and then filter immediately through a dry 11 cm. paper into an
Erlenmeyer flask, keeping the funnel covered with a watch glass to prevent evaporation.
In order to secure a clear filtrate a certain quantity of the flour should be allowed to
pass over onto the paper and the first portion of the filtrate passed through the filter a
second time. It will be found convenient to fit the filter paper to the funnel by means
of water, after which it should be dried thoroughly, either by letting stand overnight
in a well-ventilated place or by heating.
Determine the color value of the clear gasoline solution in a Schreiner or Campbell-
Hurley colorimeter, using for comparison a solution of potassium chromate containing
0.05 gram of potassium chromate per liter, conveniently prepared by making 10 cc. of
an aqueous solution containing 0.5 gram of potassium chromate per 100 cc. up to 1
liter. The colorimeter tube containing the gasoline solution should be adjusted to
read 50 mm., then the tube containing the standard chromate solution raised or lowered
until the shades of yellow in both tubes match. The reading of the chromate solution
divided by the reading of the gasoline solution gives the gasoline color value, the color
of the standard chromate solution being considered as unity.
NOTES.
Standing for a longer time than that prescribed does not appear to affect the results.
In fact, the filtration may be dispensed with entirely if the solution is allowed to settle
after the second shaking until perfectly clear, which usually requires at least 24 hours.
The color value may be determined also in Nessler tubes, using for comparison
1 Assoc. Official Agr. Chemists, Methods, 1920, 3.
2 J. Biol. Chem., 1918, 36: 335.
12 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
potassium chromate solutions of various dilutions prepared from the stock solution
(containing 0.5 gram per 100 cc.), and filling the tubes in all cases to the height of
50 mm., or (less accurately) in a Lovibond tintometer. In the latter case the color
value is obtained directly, the solution of potassium chromate containing 0.05 gram per
liter corresponding in color to the 1.0 of the yellow slide. In order to avoid confusion
the color value should be referred to the potassium chromate solution containing 0.05
gram per liter in all cases.
If an approximate result is sufficient for the purpose, it may be obtained by carefully
pipeting off the clear, supernatant gasoline solution before the second shaking. The
results thus obtained are about 10% lower than those obtained by the standard method
as just given.
ARTIFICIAL COLOR.
Hertwig’s Method}.
Macerate with a pestle in a 6-inch mortar 75 grams of the finely ground sample with
40 cc. of hydrochloric acid (1 to 1). A fairly stiff mass results but no more acid should
be added. Continue the maceration until all particles are moistened and the entire
mass is homogeneous. Then add 60 to 70 cc. of amyl alcohol and again macerate well,
in the cold, until most of the color is apparently extracted. The time necessary for
this depends upon the kind of color and its amount, but 5 to 10 minutes is usually
sufficient. Filter the mixture on a folded filter paper or on a Biichner funnel using
suction. Much of the excess of alcohol may be forced out by pressing down on the
material on the filter with the pestle. The filter paper and residue may then be enclosed
in a cloth and the greater part of the remaining alcohol pressed out. In order to remove
all color the exhausted sample may be returned to the mortar and re-extracted with
30 to 40 cc. of fresh amyl alcohol and filtered as before. Two such extractions will
remove most of the color and three will leave the material being extracted almost
perfectly white. The amy] alcohol will contain the color in a fairly pure condition.
Wash the amyl alcohol with 20 cc. of hydrochloric acid (1 to 1), then remove the
color fractionally by successive washings with hydrochloric acid of decreasing strengths
such as 4 N, N, 0.25 N, etc. Warming the acid is recommended. The color or colors
so removed may be identified by Mathewson’s method’. Attention is particularly
called to the directions on pages 18 to 20 of this bulletin under the caption of
“Abridged Procedure for Permitted Dyes Only’’.
Many colors will be colorless in acid amyl alcohol and not apparent to the eye until
washed out and the solution neutralized.
NOTES.
This method seems capable of extracting small quantities of color very thoroughly
from pastes. The procedure is very simple and the extraction takes little time. The
extracted color is fairly free from foreign interfering substances and in a condition
suitable for specific tests for its identification.
Jablonski Method®.
Macerate 250 grams of the sample (depending upon the quantity of color present),
with alcohol of a strength of about 80% by volume and made slightly alkaline with
ammonia. Continue the maceration until the color is extracted, if necessary warming
on the steam bath. Filter and evaporate the filtrate until the alcohol is expelled and
then add about one-fourth its volume of 25% salt solution, cool if necessary, and extract
with gasoline or ether. The solvent will extract saffron, annatto, turmeric and all
! Devised by Raymond Hertwig.
2U.S. Dept. Agr. Bull. 448: (1917).
3 Devised by C. F. Jablonski.
1922] LOURIE: REPORT ON EGGS AND EGG PRODUCTS 13
oil-soluble colors, also fats. Draw off the aqueous layer and wash the solvent with
5% salt solution adding the washings to the water solution. If the aqueous layer and
washings are colorless no other colors are present.
Saffron, annatto and turmeric may be removed from the gasoline (or ether) with
70% alcohol and the usual tests applied. Any oil-soluble colors, if suspected, may be
fractionally separated and identified by Mathewson’s method.
If colored, extract the remaining aqueous solution and washings with amy] alcohol.
This will remove the common orange colors, Orange I, Orange II, and Crocein Orange
(S. & J. Nos. 85, 86 and 13, respectively), also Martius Yellow (S. & J. No. 3). Sepa-
rate the aqueous layer and wash the amy] alcohol 2 or 3 times with a 5% salt solution
to remove small amounts of Naphthol Yellow S and add the washings to the aqueous
solution. If the aqueous solution is colored Naphthol Yellow S or Tartrazine may be
suspected. Naphthol Yellow S may be removed by extraction with amyl! alcohol
after acidifying to approximately 1/64N with hydrochloric acid. If, after this treat-
ment, any color remains in the aqueous solution strongly acidify it with hydrochloric
acid and again extract with amyl alcohol. Tartrazine will be extracted.
The advantage of the procedure as outlined above is the easy separation of the various
color groups as well as a partial elimination of the protein material which usually
causes trouble with other alcoholic extraction methods.
Modification of the Jablonski Method’.
Macerate 250 to 500 grams of the sample, depending upon the quantity of color
present, with alcohol of a strength of about 80% by volume made slightly alkaline
with ammonia. Warm on the steam bath in order to insure sufficient extraction of
color. Filter with suction upon a Biichner funnel and evaporate the filtrate until most
of the alcohol has been expelled and the consistency is that of cool molasses. Take
from the steam bath and add about an equal volume of low boiling petrolic ether. Also
add a large pinch of coarse sand. Stir the mixture until homogeneous and again place
upon the steam bath, taking care that the petrolic ether does not evaporate too quickly.
From time to time when it is noticed that practically all of the petrolic ether has evap-
orated add additional quantities, performing this operation until such time as the mass
assumes a spongy, jelly-like consistency and the odor of alcohol is faint. Take from
the steam bath, spread the product es well as possible upon a large watch glass and
place in the hot water oven. Continue the heating until such time as the product is
dry and tough. It may then be scraped from the glass and ground in a mortar. Pour
the ground mass into a separatory funnel and add about half of its volume of 25% salt
solution. At this point it is advisable to pour into the separatory a few cc. of small
lead shot. This helps to disintegrate the mass upon extraction with gasoline. The
method may then proceed in the same manner as stated in the Jablonski method.
The advantage of this modification depends upon the fact that emulsions due to
gluten are avoided. No special care need be observed in the amount of added am-
monia and, provided the alcohol is finally removed, separations proceed easily.
RECOMMENDATIONS.
It is reeommended—
(1) That the following methods given under the examination of
frozen and liquid egg products be adopted as tentative methods:
Total Solids Titration Method for Ammonia Nitrogen
Ether Extract Reducing Sugars
Acidity of Fat Indol and Skatol.
1 By M. G. Wolf.
14 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
(2) That the following methods of analysis under “Egg Products’,
sub-heading ““Egg Noodles’, be adopted as tentative methods:
Fat Lecithin P205, method by Jacobs and Rask.
(3) That during the coming year, the referee conduct collaborative
work with respect to the determination of heavy metals, especially zinc,
in dried eggs, and that collaborative work be conducted with respect to
the determination of fat and lecithin P205 in egg noodles using the
methods of Jacobs and Rask.
(4) That no further work be done on the Juckenack method for
lecithin P205 since investigative work at three widely separated labora-
tories of the Bureau of Chemistry has shown this method to give low
results.
Nore.—Your referee can not see the value of conducting collaborative work with
respect to the methods of analysis employed in the examination of frozen and liquid
eggs since the research work conducted and already published by the Bureau of Chem-
istry! amply covers the field and represents a type of collaborative work that would be
practically impossible for any referee to conduct for the association.
REPORT ON PRESERVATIVES (SACCHARIN),.
By Mitton G. Wor (U. 8. Food and Drug Inspection Station, New
York, N. Y.), Referee.
Your referee regrets that he was unable to conduct any collaborative
work on methods for the determination of saccharin in foods. How-
ever, the details of a new method for the determination of saccharin in
bread, cake and similar products have been worked out. This method
deals largely with improvements with respect to the preparation of the
sample before the final extraction with ether.
An improved method for the detection of small amounts of coal-tar
dye in alimentary products led to the belief that the same ideas might
be used to advantage in the quantitative estimation of saccharin in
baked-food products. The directions are as follows:
A water-alcohol mixture appears to be the only efficacious solvent of the saccharin
which has been incorporated in the bread; the water moistens the bread while the
alcohol dissolves the saccharin. When this mixture, containing the saccharin filtered
from the bread, is evaporated, the gluten, which at first was soluble, forms into a charac-
teristic gelatinous mass from which ether, the final solvent, does not extract the sac-
charin quantitatively. To obyiate this, heat the hydroalcoholic solution on the
steam bath in a beaker until most of the alcohol is evaporated and the product has the
consistency of molasses. Take from the steam bath and add about an equal volume
of low boiling petrolic ether and a few pinches of coarse sand. Stir the mixture until
homogeneous and again place upon the steam bath, taking care that the petrolic ether
~1U_S. Dept. Agr. Bull, 846: (1920).
1922} MATHEWSON: REPORT ON FOOD COLORS 15
does not evaporate too rapidly. When it is noticed that practically all of the petrolic
ether has evaporated, add an additional quantity, repeating this operation until the
mass assumes a spongy, jellylike consistency, and the odor of alcohol is faint. Take
from the steam bath, spread the product upon a large watch glass and place in the hot
water oven. Heat until the product is dry and tough. It may then be scraped from
the glass and ground in a mortar. Extract the resultant product, to which has been
added a few grams of lead shot, with ether by the usual method and determine saccharin
quantitatively by the usual fusion method!.
Although it has not been possible to conduct sufficient determinations
to state positively that this method will obtain all the saccharin present,
it is believed, in view of the difficulty Seeker and the referee? met in
their research on saccharin, with respect to its determination in various
types of so-called diabetic breads to which known amounts of saccharin
had been added, that this method will obviate some of the difficulties
encountered and may yield satisfactory results.
RECOMMENDATIONS.
It is recommended—
(1) That for the coming year the referee prepare a list of the methods
commonly used in the estimation of saccharin.
(2) That the referee conduct collaborative work on those methods
which previous work done by the association has shown to give good
results.
REPORT ON FOOD COLORS.
By W. E. Matuewson?® (Bureau of Chemistry, Washington, D. C.),
Referee.
The association’s investigational work on food colors comprises two
somewhat different lines of study which relate, respectively, to the
examination of colored food products and commercial food coloring
preparations.
Chapter X of the official methods* deals chiefly with the qualitative
examination of foods colored with coal-tar dyes and gives a compara-
tively full discussion of this phase of the subject. Further study of the
coloring matters of the common fruits and vegetables must be made
before a coherent scheme of analysis can be devised that will provide
for the complete identification of all coloring matters in food products.
The researches of Willst&tter and his co-workers are rapidly extending
our knowledge of the so-called natural colors. Willstatter and Schudel’
have discussed the qualitative analyses of mixtures containing such
1 Assoc. Official Agr. Chemists, Methods, 1920, 122.
2 J. Assoc. Official Agr. Chemists, 1917, 3: 38.
3 Present address, Bureau of Standards, Washington, D. C.
4 Assoc. Official Agr. Chemists, Methods, 1920, 131.
5 Ber., 1918, 51: 782. Schudel, Dissertation, Eid. Tech. Hochscule, Zurich, 1918.
16 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 1
coloring matters, and it is to be hoped that some of the substances used
by them as reagents and which are rather difficult to prepare in the
laboratory will soon be placed on the American market.
The methods for the analysis of commercial coal-tar food dyes which
were adopted tentatively last year were in the main edited from publica-
tions that had been in print for several years, and no doubt had come to
the attention of most analysts engaged in this work. Sets of mimeo-
graphed sheets describing these methods were sent out last December to
all chemists known to be engaged in the analysis of coal-tar food colors
with the suggestion that they report any objectionable or incomplete
statements either at this meeting or to the referee directly. No com-
ments by letter were received other than those of R. E. Doolittle as
chairman of Committee C. It is believed that further work on the
analysis of these products may be directed profitably to the develop-
ment of additional methods for the estimation of the commoner im-
purities in commercial dyes. The method for the estimation of small
amounts of aromatic amino compounds, described in connection with
this report, is of this class.
THE USE OF SODIUM-ALPHA-NAPHTHOL-2-SULFONATE FOR
THE SPECTROPHOTOMETRIC ESTIMATION OF
AROMATIC AMINO COMPOUNDS.
By W. E. Maruewson! (Bureau of Chemistry, Washington, D. C.).
The work described in this paper was undertaken in connection with
the analysis of dye products contaminated with small amounts of aro-
matic amino compounds, and it is believed that the data obtained pro-
vide a basis for a fairly satisfactory analytical method for the estimation
of these and other substances that can be smoothly converted into amino
or diazo compounds by known reactions.
Reverdin and de la Harpe? and Hirsch’ have described methods for the
estimation of amines which depend on converting them into the cor-
responding diazo compounds and titrating the latter against standard
solutions of naphthol derivatives, the first-named investigators using
R-salt (sodium salt of 2:3:6 naphtholdisulfonic acid) the last, Schaeffer’s
salt (sodium salt of 2:6 naphtholsulfonic acid). These processes, like
most other well-known methods, are scarcely applicable when the
amount of amine available is below one centigram. A direct adaptation
of the same reactions for a quantitative colorimetric process is open to
some objection or question because both R-salt and Schaeffer’s salt.
1 Present address, Bureau of Standards, Washington, D. C.
2 Chem. Ziq., 1889, 13: 387, 407; Ber., 1889, 22: 1004.
? Ber., 1891, 24: 324.
1922] MATHEWSON: ESTIMATION OF AROMATIC AMINO COMPOUNDS 17
like other naphthol derivatives that couple in the ortho position, are not
particularly reactive toward diazo compounds and hence may combine
so slowly in dilute solutions that an appreciable proportion of the un-
stable diazo compound undergoes other changes; furthermore, with
small amounts of amines the relative excess of nitrous acid present is
much greater, and the possible action of this on the naphthol derivative
with the formation of colored compounds must be considered. An ex-
amination of the larger handbooks on organic analysis indicates that
reactions of this class have not come into favor for application to colori-
metric methods.
However, the reactions leading to the formation of azo compounds
have, undoubtedly, been studied more thoroughly than those involved
in most other color tests or colorimetric methods for amines. Investiga-
tions of special interest are those of Hantzsch and Schiimann! on the
influence of concentration and temperature on the rate of diazotization
of various amines; of Cain and Nicoll? on the rate of decomposition of
diazo compounds; of Orton, Coates and Burdett’ on the effect of light
on diazo compounds; and of Goldschmidt and Merz‘ and Goldschmidt
and Keppeler® on the coupling of diazo compounds with phenols and
naphthols. The tinctorial power of the azo dyes is well known to be
very high and of the same order as that of dyes of most other classes.
It was found in preliminary tests that when 0.0001M solutions of
benzenediazonium chloride were poured into alkaline solutions either of
R-salt or Schaeffer’s salt the formation of the azo derivative was prac-
tically quantitative as determined by spectrophotometric comparison
with a known amount of the pure dye. The sodium salt of 1-2-naphthol-
sulfonic acid® was selected, however, for more exact work as it reacts
with diazo compounds in dilute solution much more readily and com-
pletely than most of the common sulfonated naphthol derivatives and
can give only para azo dyes. It can be made and purified without
special difficulty and does not undergo oxidation very rapidly when
exposed in alkaline solution to the action of the air (an advantage over
resorcinol). No direct comparative data were found relative to the azo
dyes derived from this substance, but it was believed that as para deriva-
ties of a-naphthol they would show greater tendency to vary in hue
with varying hydrogen ion concentrations, a fact that would aid in their
identification; and furthermore, that they would possess such solu-
bilities that they might be conveniently separated from most other
substances by the use of immiscible solvents. The monosodium salt
aa ‘Giemsa 1901; 81: 14 is: 1903, 83: 220.
3 Ibid., 1907, 91: 35.
: Toid., 1900, 38: 803.
5 See Friedlaender and Taussig, Ber., 1897, 30: 1457 for method of preparation. The salt may be pur-
chased from the Eastman Kodak Co., Rochester, N. Y.
18 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 1
of 1-2-naphtholsulfonic acid is designated throughout this paper as
sodium a-naphtholsulfonate.
DETERMINATION OF CONSTANTS.
The disodium salt of benzeneazo-naphthol sulfonic acid was prepared
by mixing solutions of pure benzenediazonium chloride (made by Kno-
evenagel’s method! with a quantity of sodium a-naphtholsulfonate
slightly greater than the equivalent amount, and then adding a slight
excess of sodium carbonate solution. The dye was separated by the
careful addition of strong C. P. sodium chloride solution, the precipi-
tate filtered on a Biichner funnel and the pressed cake washed with
dilute sodium chloride solution and alcohol; dissolved in hot water,
salted out and filtered as before. It was then washed successively
with moderately strong salt solution, dilute salt solution, alcohol and
ether, several rinsings or treatments with the alcohol and ether being
given. This general process, used by the writer for ten years in the
preparation of dyes free from appreciable amounts of inorganic impuri-
ties, possesses the advantage that the thoroughness of the purification
may be judged after estimating the percentage of chlorides in the
product.
The dyes derived from ortho-toluidine, para-toluidine, anthranilic
acid, benzidine, a-naphthylamine and b-naphthylamine were prepared
similarly, except that in the case of benzidine the base was diazotized in
water solution and the diazo salt precipitated with alcohol’; and with the
naphthylamines, the diazotizations were carefully made in water solu-
tion—avoiding excess of nitrite—and the diazo solutions used directly.
The dyes, as thus separated, were the disodium salts or phenolates,
except those made from benzidine and methyl anthranilate which were
the tetrasodium and monosodium derivatives, respectively. Attempts
to prepare the dyes from aniline, the toluidines and the naphthylamines
in the form of either the monosodium salts or free sulfonic acids were
less successful, these substances separating in such form as to render
their filtration extremely difficult. The dye from methyl anthranilate,
however, was prepared as the monosodium salt, using sodium acetate in
the coupling and carefully avoiding any excess of alkali or strong acid
in the operations. Sulfanilic acid and naphthionic acid were diazotized
in the usual way with an excess of nitrite, the diazo compounds washed
and then added to an excess of the naphtholsulfonate. The subsequent
treatment was the same as that given above, except that after the first
washing the phenolate was decomposed by the addition of sufficient
hydrochloric acid to neutralize the liquid, the colors being finally sepa-
rated as the disodium salts. The hues of the solutions of these coloring
1 Ber., 1890, 23: 2994; 1895, 28: 2048.
2 Castellaneta, Ber., 1897, 30: 2800.
1922] MATHEWSON: ESTIMATION OF AROMATIC AMINO COMPOUNDS = 19
matters are shown in Table 1. Some of the dyes are almost insoluble
in dilute acid or saline mixtures and hence are more or less completely
precipitated when hydrochloric acid or the acetate buffer mixture is
added to their aqueous solutions.
TABLE 1.
Hues of azo dyes derived from 1—2-naphtholsulfonic acid.
Hue oF 0.005% SoLutTion
AMINE FROM WHICH SOLVENT
DERIVED
APPEARANCE OF DYE
Sodium Acetate-
0.1N i 0.1N Hydrochloric - =
liydeoskle Reid Acetic Acid
Aniline Red-brown powder | Orange Orange-red Orange-red
o-Toluidine Bran cry Yellow-orange| Red-orange Red-orange
powder
p-Toluidine Red-brown cryst. | Orange Orange-red Orange-red
powder
a-Naphthylamine | Brown cryst. Orange-red Dull green- Dull red-
powder yellow? brown+
b-Naphthylamine | Red-brown powder | Orange-red Yellow-brown; | Violet-red;
Benzidine Black powder Violet-red Dull red-violet} | Dull am
violet
Anthranilic acid | Scarlet powder Orange Orange-red Violet-red .
Methyl
anthranilate Orange powder Orange Orange-red} Orange-red{
Sulfanilic acid Red powder Red Orange Orange
Naphthionic acid | Black cryst. powder} Violet-red Brown-orange | Brown-orange
» *Solution containing in 1 liter 0.1 molecule of sodium acetate and 0.1 molecule of free acetic acid.
tIndefinite as part of the coloring matter was in suspension.
The percentages of moisture, total sodium and chlorine in the prepara-
tions were estimated by the official methods! and the amount of coloring
matter calculated, correction being made for the small quantity of
monosodium compound usually present. The solutions used for the
optical examination were, in most cases, so prepared as to contain in
one liter exactly 0.0500 gram of pure dye as disodium derivative. The
dyes from the unsulfonated amines showed, excepting in the case of
benzidine, values for the proportion of sodium from 0.3 to 0.5 per cent
below that required by theory for the phenolate salt. The phenolic
acidity of these substances is so weak that it is very difficult to wash
them thoroughly on the filter without hydrolizing them to some extent.
The benzidine derivative contained a considerable amount of the hy-
drolized compound formed during washing.
The dye from b-naphthylamine contained 1.53 per cent of sodium
chloride. The other products, however, were free from amounts of this
substance exceeding 0.3 per cent.
Dilute solutions of each of the dyes were tested with phosphate and
1 Assoc. Official Agr. Chemists, Methods, 1920, 131.
20 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
borate buffer or regulator mixtures! to determine the hydrogen ion
concentrations between the limits 10° and 107°, at which the maximum
color change is produced by a given change in the hydrogen ion ex-
ponent. With the dyes from aniline, the toluidines, the naphthyla-
mines, sulfanilic acid and naphthionic acid the maxima were at alkalin-
ities corresponding to hydrogen ion concentrations between 107 and
10°82, and the hue at 10° was almost identical with that in 0.1N sodium
hydroxide. It was assumed, therefore, that in so far as the effect of
the hydrogen ion concentration was concerned, the optical properties
of solutions in 0.1N sodium hydroxide and in normal sodium carbonate
should be practically identical, and that the differences shown with
ordinary mixtures containing equal quantities of carbonate and_ bi-
carbonate should be small’.
The transmittances of solutions of the dyes were determined with the
Koénig-Martens spectrophotometer, quartz mercury lamp and double
cell used for work already described*, values being expressed as “‘extinc-
tion coefficients” or transmissive indices‘.
Table 2 shows the values found with 0.1N sodium hydroxide solutions
containing in one liter an amount of the respective dye corresponding to
0.0500 gram of the pure disodium derivative, except in case of the
methyl anthranilate derivative for which the pure color was calculated
as the monosodium salt. Other solvents employed were 0.1N hydro-
chloric acid and 0.1N acetate mixture, the latter being a solution made
by mixing one volume of normal sodium hydroxide with two volumes of
normal acetic acid and diluting to ten volumes. Determinations were
made also with several of the colors using normal (0.5M) and 0.5N sodium
carbonate solutions as solvents, the values found in each case being
very closely similar to those obtained with 0.1N sodium hydroxide.
Satisfactory neutral and acid solutions of the colors from benzidine and
the naphthylamines could not be prepared because of the low solubility
of these dyes. The values for the derivatives of aniline and the tolui-
dines obtained with hydrochloric acid and with the acetate mixture as
solvents showed no differences so marked as to be well adapted for their
differentiation. The observations were made at room temperature,
which was 28°C. The figures given in Column 4 of Table 2, under the
heading ‘“Transmissive Index A’’, were calculated from those in Column
3 and express the transmissive indices for solutions containing in a liter
1 Sérensen. Biochem. Z., 1909, 21: 175 and Ergebnisse Ehysit, 1912, 12: 437, 438; Palitzsch. Biochem. Z.,
1915, 70: 341; Clank & Labo J. Biol. Chem., 1916, 25:
2 Auerbach and Pick, Arb. Kais. Gesundh., 1911, 38: O86, give the value 10°9-° for the hydrogen ion
concentration at 18° C. of a solution made by mixing equal volumes of 0.05M sodium carbonate and 0.1M
sodium acid carbonate.
3 J. Ind. Eng. Chem., 1920, 12: 883.
‘ Priest, J. Optical Soc. Amer., 1920, 4: 186; Bunsen and Roscoe, Pogg. Ann. Physik, 1857, 101:248,
defined the extinction coefficient of an absorbing medium as the reciprocal of the thickness of the layer
required to reduce the intensity of the incident light to 1/10 its origmal value. They pointed out also
that with a dissolved colored substance this function could be taken as proportional to the concentration.
1922] | MATHEWSON: ESTIMATION OF AROMATIC AMINO COMPOUNDS = _21
the quantity of the dye in question equivalent to 0.0100 gram of the
corresponding amine.
TABLE 2.
Extinction coefficients or transmissive indices of azo derivatives of 1-2-naphtho!-sulfonic
acid in 0.1N sodium hydroride solutions.
ft 7 Wave LenetH Gg cag Tn ee ee
AMIN M W ERIVED NDEX soIS LESS)
MINE FROM WHICH R IN es ee Renee Tvoek A
Aniline 436 1.87 1.50
Aniline 546 0.89 0.71
Aniline 579 0.18 0.08
o-Toluidine 436 2.09 1.37
o-Toluidine 546 0.67 0.44
o-Toluidine 579 0.08 0.06
p-Toluidine 436 1.86 1.22
p-Toluidine 546 0.83 0.55
p-Toluidine 579 0.09 0.06
a-Naphthylamine 436 1.50 0.88
a-Naphthylamine 546 1.83 1.08
a-Naphthylamine 579 0.57 0.34
b-Naphthylamine 436 1.59 0.94
b-Naphthylamine 546 1.78 1.05
b-Naphthylamine 579 0.34 0.20
Benzidine 436 0.48 0.28
Benzidine 546 2.00 1.18
Benzidine 579 1.40 0.82
Anthranilic acid 436 2.15 1.23
Anthranilic acid 546 0.55 0.315
Anthranilic acid 579 0.04 0.025
Methy]! anthranilate 436 1.55 0.84
Methyl anthranilate 546 1.40 0.75
Methy] anthranilate 579 te ee
p-Sulfonilic acid 436 1.35 0.71
p-Sulfonilic acid 546 2.20 1.15
p-Sulfonilic acid 579 0.50 0.26
Naphthionic acid 436 1.04 0.47
Naphthionic acid 546 2.68 1.20
Naphthionic acid 579 1.45 0.65
The transmissive indices of the dye derived from methyl anthranilate
in 0.1N sodium hydroxide solution could not be obtained directly be-
cause of the rapid saponification of the ester. The alkaline solutions
were prepared by mixing such amounts of stronger aqueous solutions of
the coloring matter, 5N sodium hydroxide solution and water as to give
the desired concentration. Readings were then taken at definite inter-
vals from the time of mixing in light of wave lengths 436u, and 546uu
22 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 1
and the values for solutions of the pure ester calculated from these
numbers. Measurements made at 546,, with solutions in 0.1N sodium
hydroxide containing 0.100 gram of pure color per liter gave the values
shown below, the first readings being taken about four minutes after
mixing. The temperature was kept at 20°C. +0.3°C.
TABLE 3.
Transmissive indices of dyes from methyl anthranilate.
Time in Minutes AFTER
First READING ‘TRANSMISSIVE INDEX AT VeLocity Constant (c)
(t-t’) 546 mu (r)
0 2.57 STEIN:
7 2.24 0.0151
14 1.99 0.0148
26 1.69 0.0143
41 1.43 0.0145
62 E22 0.0150
95 1.09 0.0156
1300 1.04 Beaten
The velocity constant (c) as given in Table 3 was calculated by the
formula—
1 2.57 —1.04 i
amie’ ane
Nore.—As the solution contained a large excess of alkali it was assumed that the
amount of dye saponified at any instant was proportional to the amount of ester present
at that time.
A few similar measurements at 40°C. gave the value 0.064 for the
velocity constant at this temperature. The transmissive index at
546, of the anthranilic acid derivative at 40°C. appears to be approxi-
mately 2 per cent higher than at 20°C.
The monosodium salt of 4:1:2 nitroso-naphtholsulfonic acid was pre-
pared by mixing solutions of equivalent amounts of sodium nitrite and
sodium a-naphtholsulfonate and adding a slight excess of acetic acid.
The reaction mixture was allowed to stand for several hours and the
yellow crystalline nitroso compound then filtered off and purified by
recrystallization, the salt being finally obtained in the form of bright
yellow needles containing two molecules of water. Moisture was
determined by drying at 125°C. to constant weight. The analyses
gave the following results:
Moisture found—11.37 per cent (calculated 11.58 per cent).
Sodium found—7.36 per cent (calculated 7.39 per cent).
From these figures the transmissive indices were calculated for so-
lutions in 0.1N sodium hydroxide containing in one liter the amount of
1922| MATHEWSON: ESTIMATION OF AROMATIC AMINO COMPOUNDS = 23
TABLE 4.
Values for the transmissive indices.
Wave LENGTH IN
Souvant Moria, | eee) | Gomera
0.1N sodium hydroxide....... 436 0.0500 1.64
546 0.0500 0.035
0.1N hydrochloric acid....... 436 5.00 0.53
546 5.00 Less than 0.01
Solution containing in 1 liter
0.1 molecule of acetic acid 436 2.50 0.39
and 0.1 molecule of sodium 546 2.50 Less than 0.01
ACCTAUCS cw tchencewests = eeu chet
dye corresponding respectively to one centigram of water-free sodium
nitroso-naphtholsulfonate, one centigram of sodium nitrite and one
centigram of nitrous acid. The values were as follows:
TABLE 5.
Transmissive indices of sodium nitroso-naphtholsulfonate.
TRANSMISSIVE INDEX TRANSMISSIVE INDEX
Wave Lencrx IN py OF | TRansmissivE INDEX CoRRESPONDING TO CoRRESPONDING TO
Licgut EMPLOYED For Dry DYE 0.01 Gram or Soprum 0.01 Gram oF Nitrous
NITRITE AciD
436 0.370 1.47 2.16
546 0.008 0.03 0.05
SPECTROPHOTOMETRIC ESTIMATION OF AMINES.
The data in Table 5 were applied for the estimation of amino com-
pounds, the tests being made as follows: The solution of 0.00050—).00100
gram of the base in 100 cc. of 0.25N hydrochloric acid was treated at
room temperature (25°-30°C.) with 1.0 cc. of 0.5N sodium nitrite solu-
tion, stirred and allowed to stand exactly 2 minutes. It was then poured,
with stirring, into a beaker containing a mixture of 15 cc. of 5N (2.5M)
sodium carbonate solution and 5 cc. of a 5 per cent solution of sodium
a-naphtholsulfonate. The solution was transferred to a graduated flask,
diluted to exactly 150 cc. or 200 cc. and the transmittance determined
at 546uu.
The colored solution obtained by this procedure contained in addition
to the azo dye a small amount of the intensely yellow nitroso derivative
of sodium a-naphtholsulfonate. The effect of this on the light absorp-
tion at 546, was negligible, however, as was shown by taking readings
24 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
at 436, and calculating the correction. For example, 100 cc. of a solu-
tion of 0.00100 gram of carefully prepared crystallized sodium naph-
thionate was treated as described, the dye solution being finally diluted
to 150 ce. The readings for the transmissive indices at 546,, and at
436up were, respectively, 0.552 and 0.325—recovery, 97.5 per cent. A
similar test using 0.00200 gram of naphthionate in 50 cc. of acid and
finally diluting to 100 cc. gave indices at 546y, and 436,, of 1.656 and
0.881, respectively—recovery, 97.5 per cent. When quite accurate
analytical results are desired it would seem necessary in all cases to
carry through parallel determinations with known quantities of the pure
amine to eliminate small errors such as those due to variation in
temperature, alkalinity and salt content of the solutions.
A special case exists with the dye derived from diazotized methyl
anthranilate since this coloring matter gradually saponifies in alkaline
solution forming the anthranilic acid derivative, the absorption at 436y,
increasing, that at 546,, decreasing. The velocity constant for the rate
of saponification in 0.5M sodium carbonate solution at 30°C. was found
to be approximately 0.0027, from which it follows that during the first
minute after mixing the reading at 546, had decreased about 1/300 of
its value. With such solutions the change in the transmission for a time
interval of, say five minutes, will be very small and almost the same as
that taking place during the next equal interval.
The following equation is calculated from the data already given and
shows the amount of the amine corresponding to the total coloring
matter in a solution in 0.1N sodium hydroxide containing both saponi-
fied and unsaponified dye, X representing the quantity of total amine
(in centigrams per liter), a and 6 the respective transmissive indices of
the solution at 436,, and 546,, at any given instant: X=0.773 a+0.465
b. This formula is of interest but is not strictly applicable under con-
ditions easily fixed in analytical practice.
The general procedure for the coupling of the diazo compounds that
has just been discussed is open to two disadvantages. With the simpler
derivatives such as those from aniline and the toluidines the absorptions
at 546y, are rather low. The radiation of wave length 492,, from the
mercury arc would be much more suitable but, like similar monochromatic
light from other sources, is not intense enough for spectrophotometric
work with the Kénig-Martens apparatus. Furthermore, the dyes are
obtained in alkaline mixtures containing sodium nitrite and sodium
a-naphtholsulfonate, and can not be conveniently separated from these
substances with immiscible solvents. To insure complete diazotization
before any appreciable quantity of the diazo compound has suffered
decomposition, an amount of nitrite equal perhaps to 0.0005 molecule
of nitrite has been employed to diazotize 0.00001 molecule of amine. If
the carbonate solution is acidified, the nitrous acid at once reacts with
1922] MATHEWSON: ESTIMATION OF AROMATIC AMINO COMPOUNDS = 25
the sodium a-naphtholsulfonate, producing an amount of new coloring
matter very much greater than the quantity of azo dye present and
forming a mixture from which the latter can scarcely be separated
satisfactorily.
Experiments were made with a number of amines using hydrazine
sulfate to destroy the excess of nitrous acid before coupling. According
to Dennstead and Gohlich' the products formed by the action of hydra-
zine sulfate on nitrous acid are water, nitrogen, oxygen, nitrous oxide,
sulfuric acid and azoimid or triazoic acid. The reaction of diazo compounds
with hydrazine and with azoimid has been investigated by Noelting and
Michel? who showed that in both cases the diazo salts were converted
under the conditions of their experiments into the corresponding organic
azoimides. The common organic azoimides are not strongly colored
and are moderately stable so that their formation in small amount is
without perceptible influence on the colorimetric procedure excepting in
so far as destruction or loss of the diazo compounds is involved.
Tests were made with several different amines according to the follow-
ing procedure:
The solution of 0.00100 gram of the amine in 100 cc. of 0.25N hydrochloric acid was
treated at room temperature (28°C.) with 1.0 cc. of 0.5N sodium nitrite and allowed
to stand exactly 2 minutes. Four cc. of a 3% solution of hydrazine sulfate was added
and the mixture well stirred for 20 seconds. About 5 cc. of the 5% solution of sodium
a-naphtholsulfonate was then poured in, followed quickly by 15 cc. of 5N (2.5M)
sodium carbonate. The portions of a-naphtholsulfonate and sodium carbonate were
previously measured off in graduated cylinders so that they could be added to the
diazo solution and mixed quickly. In case of the carbonate solution special care was
taken to pour it into the solution in such a way that the full addition and mixture
were made almost instantly.
When solutions of b-naphthylamine were treated by this procedure 97% or more
of the amine was converted into the dye. The coloring matter was estimated
directly in the mixture after diluting it to a known volume; it was also estimated in
other tests by acidifying the liquid and extracting the dye with 3 small portions of
amyl alcohol. The Jatter was washed with 0.1N hydrochloric acid, diluted with
petroleum ether, the dye extracted with 0.1N sodium hydroxide and the solution made
to a definite volume in the same solvent. Aniline and methyl anthranilate gave yields
of 93-95% of the corresponding dyes. The yield from naphthionic acid was variable
and lower (70-80%).
Similar experiments with aniline using Schaeffer’s salt and R-salt
instead of the sodium a-naphtholsulfonate showed that with these
b-naphthol derivatives less than one-third of the diazo compound was
converted into dye. This would seem clearly to be due to the lower
velocity of the coupling of the b-naphthol derivatives as the result of
which more of the diazo compound reacted with the hydrazine.
The procedure with hydrazine sulfate is convenient and when check
1 Chem. Zig., 1897, 21: 876. See also Curtius, Ber., 1893, 26: 1263.
2 Ber., 1893, 26: 86.
26 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS |[Vol. VI, No. 1
determinations with known amounts of amine were carried through at
the same time and in exactly the same way gave fairly accurate data in
most cases. In order to limit the side reactions as much as possible it
was found desirable to use but a little more hydrazine sulfate than was
necessary to destroy the nitrous acid completely. A few blank tests
made by treating 100 cc. portions of 0.25N hydrochloric acid with sodium
nitrite, hydrazine sulfate, sodium a-naphtholsulfonate and sodium car-
bonate served to show the quantity of the hydrazine sulfate solution
which under the conditions was just sufficient to prevent the formation
of yellow coloring matter when the liquid was made alkaline. An excess
of 0.5 to 1 ce. of the approximately 3 per cent solution was used in
the test with amines.
The intense coloring power of sodium nitroso-naphtholsulfonate, and
the ease with which it is formed from sodium a-naphtholsulfonate sug-
gested that the latter substance might serve as a useful reagent for the
spectrophotometric estimation of nitrous acid. Ten cc. of a 0.00100M
solution of sodium nitrite were mixed with 2 cc. of 5 per cent sodium
a-naphtholsulfonate solution, cooled to about 8°C. and acidified with
0.10 cc. of 5N hydrochloric acid. After standing for ten minutes the
mixture was made alkaline with 2.1 cc. of 5N sodium hydroxide, diluted
to 100 cc. and the transmissive index at 436,, determined. The value
found was about 96 per cent of that calculated from Table 5. The
standard dilute sodium nitrite solution was prepared from crystallized
silver nitrite and sodium chloride, and it is possible that a slight change
in titre through absorption of oxygen may have taken place during its
preparation. The a-naphtholsulfonate does not react with nitrates in
these dilute solutions.
COLORIMETRIC METHOD FOR THE ESTIMATION OF B-NAPHTHYLAMINE
IN COMMERCIAL OIL-SOLUBLE FOOD DYES.
The colorimetric method outlined below has been used for the estima-
tion of small amounts of b-naphthylamine in samples of commercial
Yellow A B (benzeneazo-b-naphthylamine) and Yellow O B (o-tolueneazo-
b-naphthylamine). Since the proportion of b-naphthylamine in these
products seldom exceeds 0.5 per cent a method giving figures accurate
to about 10 per cent of their value is considered satisfactory.
Separation of b-naphthylamine from Yellow A B and Yellow O B.
The b-naphthylamine is separated by dissolving 1.00 gram of the dye in 50 ce. of ben-
zene and extracting in a separatory funnel with four 25 cc. portions of 0.25N hydro-
chloric acid. A second funnel containing 50 cc. of benzene is provided and the acid
portions separately shaken out with this solvent, being passed through the second
funnel in the same order as through the first. With some commercial dyes the im-
purities form a precipitate that appears at the junction of the two liquid layers in the
first funnel and interferes with their complete separation. The precipitate may usually
1922] MATHEWSON: ESTIMATION OF AROMATIC AMINO COMPOUNDS 27
be caused to collect so as to occupy a volume not greater than 2-4 cc. by gently rotating
the funnel. However, only the clear solution should be drawn into the second funnel
and as the separation of the acid is thus incomplete it is necessary in such a case to pass
an additional washing portion of acid through the funnels and test it to make sure that
all naphthylamine has been extracted.
Conversion of base into azo dye.
The solution of the base in about 100 cc. of 0.25N hydrochloric acid is treated at
room temperature (20°-30°C.) with 1 cc. of 0.5N sodium nitrite solution and allowed
to stand exactly two minutes. 5 cc. of a saturated solution of hydrazine sulfate is
added, the mixture stirred, allowed to stand exactly } minute and treated with 5 cc. of
a 5% solution of sodium a-naphthol-2-sulfonate and finally with 15 ec. of a 25%
solution of sodium carbonate. The sodium carbonate must not be poured in
slowly but should be added in one portion and the solutions quickly mixed by stirring.
The alkaline dye solution is finally diluted to 200 cc. A solution containing a known
amount of b-naphthylamine is carried through in exactly the same way and aliquot
portions of the two dye solutions obtained are diluted further if necessary, and com-
pared colorimetrically. If the results show the standard to be very dissimilar in con-
centration to the solution under examination it is discarded and a more similar standard
prepared. The comparison is best made in monochromatic green, blue or violet light.
If a white light source is used a colored glass or film should be placed in the path of the
light to intercept the red, orange and yellow rays.
Notre.—Care must be taken that no appreciable amount of the mixture adhering to the walls of the
beaker above the surface of the liquid escapes the action of the hydrazine and that the diazo solution is
not exposed to brilliant sunlight.
Procedure with dyes contaminated with a-naphthylamine derivatives.
A sample of Yellow A B contaminated with benzeneazo-a-naphthylamine will give
a reddish acid extract when treated as described above. The amount of this base
removed is usually very small, but its influence on the colorimetric determination of
the naphthylamine may be eliminated when necessary as follows: The pink acid extract
containing the naphthylamine is compared before the diazotization-coupling operation
with a somewhat more strongly colored solution of benzeneazo-a-naphthylamine in
0.25N hydrochloric acid and the latter then diluted with 0.25N acid until the color con-
centration is the same. 100 cc. of this solution is carried through the diazotization and
coupling processes in exactly the same way as the dye extract and the standard naph-
thylamine solutions. 20 cc. of the resulting solution (containing sodium benzeneazo-
naphthaleneazo-naphtholsulfonate) is placed in a graduated 100 cc. colorimetric tube
and 20 cc. of the dye solution obtained from the acid extract is measured into a second
similar cylinder. The dye solution from the standard naphthylamine mixture is then
added to the first cylinder from a buret until the liquids show nearly the same color
on looking down the tubes. They are finally diluted to the equal volumes and a few
drops more of the standard naphthylamine dye solution added to the known mixture
to bring its color intensity exactly to that of the sample. The buret reading divided
by 20 and multiplied by the weight of b-naphthylamine used in making the standard
solution gives the amount of b-naphthylamine in the original unknown solution.
Application of the method with dyes containing aniline or o-toluidine.
Aniline and o-toluidine do not often occur as impurities in Yellow A B and Yellow
O B. When present, they are extracted with the b-naphthylamine in the treatment
with benzene and produce the corresponding azo derivatives in the coupling process.
Dilute alkaline solutions of these derivatives are orange in hue, while a similar solution
28 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
of the b-naphthylamine derivative is red. The amounts of each of the components in
a mixture of two dyes of dissimilar hue, while best determined with the spectrophoto-
meter, may be judged by colorimetric comparisons with known mixtures.
SUMMARY.
1. Values are given for the transmissive indices or extinction co-
efficients of alkaline solutions of the azo dyes formed from aniline,
o-toluidine, p-toluidine, a-naphthylamine, b-naphthylamine, benzidine,
anthranilic acid, methyl anthranilate, sulfanilic acid and naphthionic
acid by diazotizing and coupling with 1-2-naphtholsulfonic acid.
2. Similar values are given for the transmissive indices of solutions
of 4:1:2 nitroso-naphtholsulfonic acid.
3. The application of these values to the estimation of small amounts
of the amines is discussed.
4. Tests are described in which the sodium salt of 1-2-naphtholsulfonic
acid was used as a reagent for the estimation of nitrites.
5. A method is described for the colorimetric estimation of b-naph-
thylamine in commercial oil-soluble food colors.
REPORT ON METALS IN FOODS.
By W. F. Cxiarke (Bureau of Chemistry, Washington, D. C.),
Referee.
The work of the referee for 1920 was limited to the devising of a
modification of the Penniman method! for tin and to a collaborative
study of the modification. The resulting revision carries several features
of the Baker-Sellars method?.
Briefly, the original Penniman method may be outlined as follows:
The tin is separated from the food material by extraction with hydrochloric acid and
filtration of the acid solution; after adjustment of the acid concentration powdered zinc
is added to the hydrochloric acid extract to precipitate the tin; after filtration the
mixed metals are dissolved in hydrochloric acid in an atmosphere of carbon dioxide;
after cooling in the same atmosphere the stannous chloride is titrated with potassium
iodate.
Objections to the original method are based on these points:
(1) Some of the coloring matter extracted by the hydrochloric acid
may be carried along throughout the process and may interfere when
the stannous chloride is being titrated.
(2) It appears that the zinc does not completely precipitate the tin;
possibly it might do so were the proportions of zinc and acid varied con-
siderably from those proposed in the original specifications.
1 J. Assoc. Official Agr. Chemists, 1920, 4: 175.
2 Assoc. Official Agr. Chemists, Methods, 1920, 150.
1922] CLARKE: REPORT ON METALS IN FOODS 29
(3) The titration of stannous chloride with potassium iodate in the ©
presence of strong hydrochloric acid involves at least four reactions.
it was assumed that the stannous chloride is completely oxidized before
the remaining three reactions begin, the end point being marked by the
liberation of free iodine due to one of the later reactions. It has been
found, however, that iodine is liberated prior to the complete oxidation
of the stannous chloride.
After modification of the method based upon these criticisms, your
referee sent out samples and directions for collaborative study. An out-
line of the specifications submitted is as follows:
Destroy the organic matter by wet combustion in a Kjeldahl flask; transfer the
residue, consisting in part of metastannic acid and stannic sulfate, to a large Erlenmeyer
flask, the Kjeldahl flask being washed out with hot sodium hydroxide solution. Make
the liquid in the Erlenmeyer suitably acid with sulfuric acid and precipitate the tin as
metal by means of an initial charge of powdered zinc and a later charge of powdered
iron. After decantation through an asbestos mat, washing to remove sulfates, dissolve
the metals in hydrochloric acid, an atmosphere of carbon dioxide being maintained
during the dissolving and the later cooling. Titrate the resulting stannous chloride
with 0.01N iodine which has been standardized by thiosulfate, the value of which is
determined by running against weighed dry iodine.
The samples sent out consisted of a solution of tin chloride, some tin
foil and a supply of tin-free dried beans.
To 20-gram portions of the beans in a Kjeldahl flask each analyst
added a measured portion of the tin solution or a weighed amount of
tin foil.
The results obtained are shown in the table, page 30.
In explanation of the large amounts of tin apparently found in the
blanks it will be noted that the values are the same for blanks with beans
and for those without beans: in other words, the beans are tin-free.
Furthermore, the work of Hale! has shown that for very dilute iodine a
large blank is found when the volume of solution is large and the con-
centration of potassium iodide is low. This effect is increased under
the conditions reported here with the result that for quantities of tin
of at least 5 milligrams the amount apparently found is excessive; how-
ever, when 10 milligrams or more are present the volume of iodine
required contains enough potassium iodide to eliminate this error.
Some unreported determinations were run, in which an effort was made
to add potassium iodide solution in sufficient amount, but it was found
that free iodine was liberated under the conditions of the method. Fur-
ther work will be done on that point. Finally, it appears that for an
amount of tin of 10 milligrams or more the titration with iodine gives a
reasonably good figure, the blank being disregarded.
1 Am. Chem. J., 1902, 28: 450.
30 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
i eagle SAMPLE TIN TIN
OF BEANS PRESENT FOUND
grams milligrams milligrams
0 0 0.24
0 0 0.21
20 0 0.36
20 0 0.42
A. E. Stevenson, National Canners Asso- 20 5.00 4.04
ciation, Washington, D. C 20 5.00 4.39
20 50.00 48.19
20 50.00 43.38
20 5.63 5.10
20 5.63 5.34
20 22.50 21.54
20 22.50 21.60
20 56.25 52.88
20 56.25 52.17
20 0 1.20
20 5.63 7.08
20 56.25 56.13
R. M. Hann, Bureau of Chemistry, Wash- 20 56.25 55.78
ington, D. C. 50 33.75 34.48
0 11.25 11.14
0 11.25 11.23
0 11.25 11.69
0 0 1.03
0 0 1.36
20 0 1.09
20 0 1.31
20 5.63 5.91
20 5.63 6.49
W. F. Clarke. 20 22.50 22.61
20 22.50 22.66
20 56.25 55.87
20 56.25 56.37
20 4.71 5.40
20 5.50 6.36
20 33.96 33.76
20 25.70 25.44
The only comment received was from Hann, who considers the pro-
posed modification an improvement over the original Penniman method
and also over the Baker-Sellars method. He states that it avoids both
the laborious filtration of the metals in the original method and the
precipitation and subsequent dissolving of sulfide as required in the
Baker-Sellars method. He also reports that results are more consistent
than those found by the other methods.
DISCUSSION.
The analysts’ results are better than those found last year when the
original method was studied. The accuracy is about equivalent to
that of a carefully performed Baker-Sellars procedure. Apparently the
1922] HANN: REPORT ON ARSENIC IN FOODS 31
wet combustion is slower than the hydrochloric acid extraction in the
original method, but in reality it takes much less of the analyst’s time;
besides it avoids the carrying along of interfering coloring matter. The
precipitation of the sulfide in the Baker-Sellars method and its more
disagreeable subsequent dissolving are substituted for the Penniman
zinc precipitation procedure, which is made complete by a later charge
of powdered iron, the effectiveness of which is probably due to a coupling
effect with the other metals. An interesting controversy is now in
progress between Kolthoff and Bouman! regarding the procedure of
Ada Prins? in precipitating tin by powdered iron. The inaccurate
iodate titration of the original method is replaced by the use of iodine.
RECOMMENDATION.
It is recommended that the modification of the Penniman method for
tin be studied further with collaborative work.
REPORT ON ARSENIC IN FOODS.
By R. M. Hann (Bureau of Chemistry, Washington, D. C.), Associate
Referee.
In accordance with the recommendation of the Referee on Metals in
Foods, 1920, the H. V. Farr modification of the Gutzeit method was
subjected to a comparative study with the present tentative Gutzeit
method’.
APPARATUS.
The modified apparatus consists of a generator equipped with a funnel, for the intro-
duction of acid and reagents, and an outlet tube, through which the gases evolved are
passed before contact with the sensitized paper. The generator itself is cylindrical in
shape, of approximately 50 cc. capacity and has a hollowed ground-glass stopper to
allow placement of the other parts of the apparatus without overcrowding and general
instability. The funnel is introduced through the top; its stem is placed as near the
center of the generator as possible and reaches nearly to its base. The outlet is a
small calcium chloride tube in which the gases are purified by contact with lead acetate
cotton and diffused before final passage through the mercuric chloride paper attached
to its extremity. The apparatus is of glass and ground joints are used throughout.
REAGENTS.
The reagents required are arsenic-free zine (No. 30-mesh powder), arsenic-free hydro-
chloric acid, saturated water solution of bromine and a 10% solution of potassium iodide.
The sensitized paper was prepared by soaking soft filter paper in 5% mercuric chloride
solution and spreading it on a clean towel until dry.
1 Rec. trav. chim., 1920, 39: 537-41, 606-8, 711-14. f
2 Prins, Ada. Beknopte leidraad voor gualitatieve chemische analyse, 1919. Chem. Weekblad, 1919,
16: 1592.
3 Assoc. Official Agr. Chemists, Methods, 1920, 147.
29 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
DETERMINATION.
Introduce 5 grams of the sample into the body of the apparatus and add 4 or 5 grams
of No. 30 powder arsenic-free zinc. After inserting the stopper, add 6-8 drops of
saturated bromine solution and then concentrated hydrochloric acid until fairly vigorous
action commences. <A very slight excess of bromine should be present at this time.
Next fill the apparatus about 24 full with diluted hydrochloric acid. In 2-5 minutes
add 10 drops of 10% potassium iodide solution and fill the apparatus to within 4 in.
of the top with diluted hydrochloric acid. The strength of acid should be such that
when a blank is run it will require from 30 to 40 minutes to dissolve the 4 grams of
zinc. When practically all the zinc has dissolved remove the sensitized paper and esti-
mate the arsenic by comparing the intensity of the stain with a set of standards pre-
pared under like conditions with known amounts of arsenic.
A copy of the method, a set of apparatus, paper to be sensitized and
a solution containing 350 milligrams of arsenious oxide per 100 cc.,
with directions for diluting the solution to a strength of 3.5 micro-
milligrams per cc., were sent to each of six collaborators, located at
stations where arsenic work is part of the regular analytical procedure.
The author of the method very kindly consented to assist and give the
benefit of his experience.
The following results (reported in milligrams of arsenious oxide per
kilo) were received from the collaborators:
TENTATIVE
Susee Ginznt H. V. Farr
Mimon MopIFICcCATION
te Berry, Food and Drug Inspection Station, Chicago, 5 4.5
J. O. Clarke, Food and Drug Inspection Station, Sav- Hh 3.0
anna, Gaerne. MRNA ema. Cones
R. Hertwig, Food and Drug Inspection Station, San Fran- 3.0
cisco, (alike 22am. . WME at. bvsyays clabvewiy dels «Je 3.4
W. E. Kirby, Food and Drug Inspection Station, New 3.6 3.4
Works IN YO. ROR Ch ANING NN ey EP AA MRRAR 8M nnn 3.6
UE CB) a shed Eo nee MSL RN AC es A a 3.7 3.6
3a)
COMMENTS BY COLLABORATORS.
FeO! Clarke.—Binding the sensitized Paper over the end of the tube is a very ex-
cellent departure from the usual method of collecting the stain on a strip of paper.
In my opinion this could be combined successfully with the present tentative method
as outlined in the A. O. A. C. methods!. In other words, an ideal procedure appears
to be the use of the reacting mixture as outlined in the present tentative method and
the making of the stain as outlined in your method.
1 Assoc. Official Agr. Chemisls, Methods, 1920, 147.
1922] HANN: REPORT ON ARSENIC IN FOODS 33
W. E. Kirby.—In regard to changes suggested in the present tentative method for
arsenic, I believe that the use of potassium iodide and warming the solution to 90°C.
is unnecessary.
E. H. Berry—Considerable difficulty was experienced with the Farr method. A
large number of determinations were made where few, if any, stains were obtained.
It was impossible to account for this as the details of the method were followed very
closely. A special and delicate piece of apparatus is very objectionable. It is easily
broken and it is believed the use of such an apparatus should be avoided, if possible,
for a determination so frequently encountered as the arsenic determination. Again it
does not seem possible to make as close a comparison of the stain spots on the paper,
as it is of stain strips as obtained in the A. O. A. C. method. The directions for the
A. O. A. C. method call for the use of 15 grams of stick zinc. It is believed that the use
of so large an amount of zinc is unnecessary. The rapidity of the action in the generator
bottle can be much more easily controlled with a much smaller amount of zinc. I
would suggest that a further study of both methods be made.
R. Hertwig.—The tentative Gutzeit method of throwing the stains out into lengths
has the extra advantage of having the length besides the intensity to aid in making
comparisons. The technique of the official Gutzeit method is as simple as that of the
Farr method. From my experience with the former, I should recommend it as having
more in its favor as a practical working method and offering greater chances for reliable
results than the method here under discussion.
DISCUSSION.
The work of the referee has almost entirely consisted of a study of
the Farr modification. Excellent results were obtained in concentrations
below twenty micromilligrams of arsenious oxide. Above this con-
centration perfect stains were consistently obtained but the accurate
comparison of differences in color became difficult. Fading out of
stains was not so noticeable, as observed by Clarke, and this objection
will in ail probability be overcome by the substitution of mercuric
bromide for the chloride. While the preliminary treatment suggested
seems adequate in the case of a simple arsenic solution it would doubtless
be necessary to use a more vigorous method of reduction in the case of
refractory substances. Samples of phosphoric acid were analyzed and
they gave excellent checks with similar samples analyzed by the tenta-
tive method. The Farr method as it stands is admirably suited for
rapid determination of arsenic when the amount of arsenic detected is
below some definite limit, which at present is in the neighborhood of
twenty parts per million. Renewed interest in the arsenic work is
evident in the reports of the various collaborators. The objections to
the Farr method are well founded, but in view of the promising results
obtained by a majority of the collaborators, the method seems worthy
of further study and possible modification. Several helpful suggestions
were received, and an attempt will be made to determine the practi-
cability of incorporating one or more of these ideas into the method as
it now stands. The use of a larger outlet tube and therefore larger
absorption surface, as suggested by Clarke, would tend to give a more
34 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
uniform stain but the difference in intensity of the stain per unit surface
of the absorbing paper would be very slight and for that reason decrease
the sensibility of the method. After working with the Farr modifica-
tion, Clarke devised a simpler form of apparatus which he used with
good results. An effort will be made to try out this apparatus.
Further study of the tentative method especially in regard to the
potassium iodide reduction seems to be necessary. While the work of
H. M. Loomis! and E. L. P. Treuthardt?, former associate referees on
arsenic, seems to prove the reduction with iodide an essential step there
is a feeling among workers in this field that it is an unnecessary detail.
In this connection it may be noted that the function of stannous chloride
in the determination is almost entirely that of an accelerator and that
it is doubtful if it acts as a reducing agent under the conditions. The
work of the coming year will include a study of the value of this re-
duction.
RECOMMENDATIONS.
It is recommended—
(1) That the H. V. Farr modification of the Gutzeit method for the
determination of arsenic be further studied with a view to simplifying
the apparatus as described and ascertaining the conditions necessary
for a more accurate determination in concentrations above 20 micro-
milligrams of arsenious oxide.
(2) That the present tentative Gutzeit method be studied again in
comparison with the H. V. Farr modification.
REPORT ON DETERMINATION OF PECTIN IN FRUIT AND
FRUIT PRODUCTS.
By H. J. Wicumann? (U.S. Food and Drug Inspection Station, Denver,
Colo.), Referee.
Fruits contain more or less natural pectin. The commercial pectin
on the market at the present time is extracted from apple pomace, from
dried apple chops, or from dried skins and cores from which the sugars
and other substances soluble in cold water have been removed. This
pectin can be legitimately used in those jams or jellies which are made
from fruits low in natural pectin or those sensitive to continued boiling,
provided its use does not conceal inferiority; for example, a deficiency of
fruit. It is, therefore, of great importance to devise methods suitable
for the purpose of detecting added commercial pectin and to determine
whether it conceals inferiority due to a deficiency of fruit.
The Denver Station of the Bureau of Chemistry has developed
1 J. Assoc. Official Agr. Chemists, 1915, 1: 244.
2 Tbid., 1916, 1: 580.
‘Presented by W. W. Randall.
1922] WICHMANN: DETERMINATION OF PECTIN IN FRUIT 35
certain methods that appear to be useful for the purpose mentioned.
It was determined to try out certain of these methods cooperatively.
Pectin is a constituent of the cell-wall of fruits and other plants soluble
in water and insoluble in alcohol. The alcohol precipitate should,
therefore, be a measure of the amount of pectin present in a fruit prod-
uct. Accordingly, four methods for its determination were submitted
to the collaborators.
Since gums, dextrine and other alcohol-insoluble substances, naturally
or otherwise present in a jam or jelly, may contaminate the alcohol
precipitate, or the nature of the fruit used or its degree of ripeness may
cause variations in results, it was desired to obtain some derivative of
pectin in a pure condition that would be a stable, definite chemical
compound. ‘‘Pectic acid’, formed by the action of alkali on pectin
and subsequent precipitation with hydrochloric acid, was believed to be
such a product. The method for pectic acid devised by the referee was
therefore included in the list of methods sent to collaborators. It is
not the purpose of this report to go into the chemistry of pectin or pectic
acid, since it would lead too far afield.
One sample of strawberry jam containing added pectin was prepared
by the referee, and portions were submitted to six stations of the Bureau
of Chemistry for analysis. Reports from four of these stations were
received. The formula employed in the preparation of the jam was as
follows:
POUNDS
ROARS © «sacs ovakane. beat iit And 4) decalteds. ae os bowwstle 2.29
Ciemmerctal pectinyiroh24 Je yr, 8) Noo: fs pbk 7S
BEE ee BOE. FO ee). Roles Oiled 11.50
NCR 9 ee eR eg wk eae 4.50
Total open Ba es eset. hey cs eo ee: 20.00
The mixture was boiled until the temperature rose from 94° to 100°C.
The total weight of the finished jam was 15 pounds, 11 ounces. The
percentages of fruit and pectin in the finished jam, therefore, amounted
to 14.3 and 11.1, respectively. In order to preserve the jam, it was well
stirred while hot, transferred to fruit jars and sterilized by placing in
boiling water for 20 minutes. A portion of the pulped strawberries
used in the preparation of the jam was also sterilized in glass jars for
analysis by the referee, for the purpose of comparing the jam and the
fruit used in its preparation. Collaborators were requested to report
results obtained according to the following outline:
METHODS.
PREPARATION OF SAMPLE.
The fruit should be pulped and the sample thoroughly mixed. This may be done by
passing it through a meat chopper. Weigh 300 grams of the mixed sample into a 1.3
36 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
liter beaker, add 800 cc. of water, bring to a boil and boil for one-half hour. Transfer
the jam solution to a 2000 cc. graduated flask, cool and make up to the mark. Filter
through a folded filter. Make the following determimations on the filtrate except when
otherwise directed:
Notre.—Subsequent work by the referee indicates that the one-half hour boiling may not be sufficient
in all cases. It was found that slightly increased amounts of pectin could be extracted from fruits by
boiling from 1 to 2 hours. In the case of jams containing only 10 to 15 per cent of fruit, boiling for one-
half hour is sufficient, but 50 per cent fruit jams may require a longer period. Therefore the referee rec-
ommends that the period of boiling be specified as 1 hour in all cases.
Alcohol Precipitate.
Method I.—Evaporate 100 cc. of the filtrate to 20 cc. and proceed exactly as indicated
in the official and tentative method!.
Method II.—Evaporate 100 cc. of the filtrate to 20 ce. If an insoluble scum forms
during the evaporation, stir the cold solution vigorously and add 1 cc. of 10 per cent
hydrochloric acid. This procedure will usually redissolve the insoluble substance.
Add slowly from a separatory funnel, and with constant stirring, 200 cc. of 95 per cent
alcohol. Allow the mixture to stand 1 hour. Standing overnight does no harm.
Filter on a smooth, qualitative filter paper and wash the precipitate with 80 per cent
alcohol. Wash the precipitate from the filter paper back into the original beaker with
hot water. Wash the paper well. If insoluble substances were present before the
addition of the alcohol, dissolve the precipitete on the paper and filter through the
paper. Evaporate the water sclution of the pectin to 15 cc., add 5 cc. of 10 per cent
hydrochloric acid and again precipitate with alcohol as before. Allow the mixture to
stand 1 hour, filter and wash well with 80 per cent alcohol. Now wash the precipitate
from the filter into a platinum dish, evaporate to dryness, dry in a water oven for 1
hour, weigh and ash. Calculate the loss in weight as alcohol precipitate. The result
of the second precipitation may be almost colorless. Care should be used to avoid
loss in washing from the filter paper.
Method III.—Proceed as in Method II for the first precipitation. Previous to the
second precipitation add 5 cc. of 10 per cent hydrochloric acid and one-half gram of
acid-treated, ignited asbestos. Precipitate with alcohol the second time, allow to
stand 1 hour and collect the alcohol precipitate and asbestos in a Gooch crucible with
a thin asbestos mat. Wash with 80 per cent alcohol, suck dry and dry the crucible
and contents in a water oven. Weigh, ignite and weigh again. The loss in weight is
the alcohol precipitate.
Method IV.—Proceed as in Method II but make three precipitations of the alcohol
precipitate. Omit the acid on the third precipitation.
Pectic Acid.
Evaporate 200 cc. of the jam solution to 25 cc. Precipitate with 200 cc. of 95 per
cent alcohol. Allow to settle, filter and wash with 80 per cent alcohol. Dissolve the
precipitate from the filter with hot water and wash well. Evaporate to 25 cc., cool
and add 2 cc. of 10 per cent sodium hydroxide diluted to 25 ce. Allow to stand 15
minutes; then add 40 cc. of water and 10 cc. of 10 per cent hydrochloric acid and boil
5 minutes. Collect the pectic acid on a qualitative filter and wash with hot water.
Wash the pectic acid back into the beaker with a stream of hot water. Adjust to 25
cc. and repeat the saponification and precipitation just described. Then wash the
pectic acid into a platinum dish, evaporate to dryness, dry 1 hour in a water oven,
weigh and ignite. The difference in weight is the pectic acid.
1 Assoc. Official Agr. Chemists, Methods, 1920, 156.
1922] WICHMANN: DETERMINATION OF PECTIN IN FRUIT 37
Ash.
Evaporate 100 cc. of the jam filtrate to dryness and ash at low redness. Determine
water-insoluble and water-soluble ash, water-insoluble and water-soluble phosphoric
acid, expressed as P» O;, by the official methods’.
Sulfur in Ash.
Ash 100 cc. of the jam filtrate. Dissolve the ash in 5 cc. of 10 per cent hydrochloric
acid and evaporate to dryness. Heat to 110°C. for an hour to dehydrate any possible
silica. Add 5 ce. of 10 per cent hydrochloric acid and filter. Wash the filter paper
with hot water. Precipitate the sulfur as berium sulfate from the boiling solution.
Evaporate to 100 cc. and allow to stand overnight. Since the weight of the barium
sulfate is very small a Monroe crucible would be convenient for collecting the pre-
cipitate.
Total Sulfur.
Into the largest casserole that can be placed in an available electric muffle, put 4
grams of magnesium oxide. Add 50 cc. of concentrated nitric acid and then 100 cc.
of jam solution. Cover the casserole with a glass triangle and cover glass, and evapo-
rate on the steam bath to a pasty consistency. Wash down the cover glass and tri-
angle with water and again evaporate to a paste. Place the casserole in a cold electric
muffle and gradually heat to low redness, until all nitrogen tetroxide fumes have been
driven off. All the organic matter will have been destroyed. Then cool, dissolve in
hydrochloric acid and filter. Adjust the acidity so that the solution contains 0.5 to 1
gram of free hydrochloric acid and precipitate the sulfate as barium sulfate from the
boiling solution. Eyvaporate to approximately 100 cc. and allow to stand overnight.
Do not evaporate to such an extent that salts will crystallize out. Filter, wash,
ignite and weigh as usual. If possible, filter on a Monroe crucible. This determi-
nation should be made in a room free from sulfur fumes of all kinds. A careful blank
should also be run with 2 quantitative filter papers as a source of organic matter. So-
called C. P. magnesium oxide frequently contains considerable amounts of sulfur
compounds.
Water-Insoluble Solids.
Method I.—Dry 15 cm. qualitative filter papers in covered aluminum dishes. Weigh
25 grams of mixed jam into a 400 cc. beaker. Add 200 cc. of water and boil gently
for 30 minutes. Filter on the filter paper. If the paper becomes clogged, so that
the filtering is too slow, it is better to start afresh with a smaller sample. Wash the
insoluble solids well with hot water. When the washings are colorless or contain no
acid, place filter and contents in the aluminum dish, dry and weigh. The difference in
weight is the water-insoluble solids.
Method II.—Weigh into a 250 cc. beaker, 25 grams of the well-mixed product. Add
100 cc. of warm water and heat on the water bath for about an hour with frequent
stirring. Place a fair-sized wad of absorbent cotton, previously dried in an aluminum
dish and weighed, in a funnel, part of the cotton being wedged into the neck with a
wire. Filter the fruit solution through this cotton. Wash with hot water until the
wash water is no longer acid. Washing can be accomplished with approximately 250 cc.
of water. Then replace the cotton wad, together with the insoluble fruit solids, in
the aluminum dish, dry and weigh.
RESULTS.
The data obtained by the collaborators are collected in the following
table and, in addition, the referee’s results of analysis of the strawberry
1 Assoc. Official Agr. Chemists, Methods, 1920, 105, 194.
38 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
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1922] WICHMANN: DETERMINATION OF PECTIN IN FRUIT 39
pulp used in the manufacture of the jam are given for purposes of com-
parison.
A glance at the table shows very gratifying results for alcohol pre-
cipitate. Method I, the tentative A. O. A. C. method, produces high
results and should be discarded. This is believed by the referee to be
entirely due to contamination with sugar and calcium citrates or malates.
Judging from the data obtained by the collaborators, it would appear
that Methods II, II] and IV are equally reliable. However, it has
been the experience of the referee that Method II, in the case of fruits
or high pectin jams, does not give as satisfactory results as do the other
two methods; it shows slightly high results, probably due to incomplete
elimination of impurities. The referee prefers Method III. as it is
the simplest.
The pectic acid results are equally good. The referee believes that
the pectic acid determination is more reliable than the alcohol pre-
cipitate, because it is believed to be a pure compound whereas the alcohol
precipitate may not be.
Nore.—Since the preparation of this report, the referee has had experience in the
determination of alcohol precipitate and pectic acid in fruits where water-insoluble
substances, of a non-pectic nature, are apt to be more troublesome than in the analysis
of jams or jellies. It was found that their precipitation could be generally prevented
by adding from 1 to 4 lumps of Domino sucrose to the solutions of fruit during evap-
oration and about 1 cc. of 10 per cent hydrochloric acid just before the first precipita-
tion with alcohol. If insoluble substances were subsequently encountered, they were
filtered off before the final precipitation of the alcohol precipitate or pectic acid. In
some cases, especially in the determination of pectic acid in immature fruit, it was
found expedient to work with smaller quantities than the directions specify.
The collaborators appear to have found but little difference in the
results for water-insoluble solids by the two methods tried. Either one
appears to give satisfactory results. This determination should, in the
case of jams, give an approximation of the proportion of fruits in the jam.
The collaborators did not agree so well in their sulfur determinations,
which was not wholly unexpected. The quantity of barium sulfate
weighed is very small and the factor is large. The method for total
sulfur is rather tedious and exacting, and it is not surprising that the
results do not check closely when first tried by analysts who are not
familiar with it. It will be observed, however, that some of the sulfur
is lost in the ashing process. The percentage thus lost may vary accord-
ing to the conditions of the ashing. Determining the sulfur in the ash
is by far the simplest method, but not the most accurate.
Nore.—Since submitting the methods, the referee has determined that quantitative
filter papers are not entirely free from sulfur and should, therefore, not be used as a
source of organic matter in the blank. Domino sucrose has been found to be sufficiently
free from sulfur to serve for this purpose.
RECOMMENDATIONS.
It is recommended—
(1) That a comprehensive study of the composition of the fruits used
40 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
in the manufacture of jam and jelly be made to determine the natural
variations and to serve as a basis for interpretations.
(2) That further work be done on methods for determining the total
sulfur in fruits.
(3) That the present tentative method for alcohol precipitate determi-
nation be discarded as unreliable.
REPORT ON THE DETERMINATION OF MOISTURE
IN DRIED FRUITS.
By R. W. Hitts (U. 8. Food and Drug Inspection Station, U. 8.
Appraiser’s Stores, San Francisco, Calif.), Referee.
In 1919 this association approved a recommendation that a definite
method applicable to the determination of water in dried fruits be
formulated and submitted to the association’. The present work was
undertaken in an endeavor to meet this need, which is a very urgent
one among food control officials and manufacturers of dried and de-
hydrated fruits. At present an official standard limits the moisture con-
tent of dried apples and standards for other fruits may be hereafter
adopted.
An examination of the present official methods for this determination
in dried fruits? shows that much latitude both as to method of dry-
ing and manipulation is permitted, and the directions are not definite.
Briefly, a sample yielding 3 to 4 grams of dried material is to be weighed
out, mixed with a few cc. of water, “if necessary to secure a thin layer
of the material’, and dried to constant weight in vacuo at 70°C. It is
not definitely stated whether an absorbent is to be used or not. An
alternative method permits drying on quartz sand in a water oven at
the temperature of boiling water for 8 to 10 hours with stirring and suc-
cessive heatings until the weight loss is not greater than 3 milligrams
per hour. The accurate estimation of water in foods and especially in
those containing much levulose is universally admitted to be a very
difficult problem, and anyone with experience in the analysis of dried
fruits knows that the latitude permitted will give very discordant results.
However, it appears possible that by adopting manipulations especially
suited to the product in question and by describing the method very
definitely comparable and consistent results reasonably close to the
actual truth should be obtained.
Previous work on this subject by the association has resulted in the
general conclusion that no method can be recommended which involves
heating above 70°C., above which temperature levulose suffers de-
1 J. Assoc. Official Agr. Chemists, 1921, 4: 570.
2 Assoc. Official Agr. Chemists, Methods, 1920, 101, 153.
1922] HILTS: DETERMINATION OF MOISTURE IN DRIED FRUITS Al
composition!. Barnard has published results of experiments on dried
apples”, comparing drying at 70°C. in vacuo with that in air and hydro-
gen at 98°C. at atmospheric pressure. He confirmed the usual observa-
tion that the higher temperature caused caramelization and decompo-
sition with continuous loss in weight. The lower temperature in vacuo
gave lower and more concordant results but constant weights were not
obtained.
The work here described was done by W. T. McGeorge in the San
Francisco Station of the Bureau of Chemistry, who also planned it in
large part. Many samples of California dried fruits of different degrees
of dryness, collected in connection with another investigation, were
available. Dried apricots, peaches, pears and apples were used for
experiment. Considerable work had previously been done on the de-
termination of moisture in dried apples and raisins. All samples were
prepared for analysis by mixing and passing twice through a meat
grinder as rapidly as possible and placing in hermetically sealed glass
jars. Theoretical considerations as well as much experience having
convinced McGeorge and the writer that the method of drying
in vacuo at not to exceed 70°C. was the most reliable, the principal
effort was directed to a study of this method. A secondary object was
to devise, if possible, a simple empirical method not requiring the use
of elaborate equipment which would give results close to the vacuum
oven and be available for factory control purposes. Experiments were
also made with other methods. Drying in an atmosphere of hydrogen
at the temperature of boiling water was found to produce as much
caramelization as drying in air.
The official method of drying in vacuo over sulfuric acid without
heat® was also tried, using ether to obtain a high vacuum. After two
months’ time the samples had only lost about three-quarters of the
moisture content indicated by the vacuum oven method and further
weighings were discontinued. The distillation method, with the form
of apparatus devised by Dean and Stark‘, was given a thorough trial on
all four fruits. Xylol, toluol, kerosene, amylacetate and various com-
binations of these were tried. The results on apples were quite promising
but on pears, apricots and peaches results several per cent above the
vacuum oven figures could easily be obtained owing to production of
water from decomposition. This decomposition appeared to commence
long before all the water was expelled, and no point could be selected at
which to discontinue distillation. Dried apples in general yield their
water rather easily, whereas the other fruits are gummy in texture and
dry more slowly.
iy ig Fa ey ea Chemists, 1921, 4: 54.
? Assoc. Official Agr. Chesats, Methods, 1920, 71.
4 J. Ind. Chem., 1920, 12: 486.
42 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS | Vol. VI, No. 1
The vacuum ovens used were of the cylindrical water-jacketed gas-
heated type with shelves of perforated sheet copper. The water jacket
was kept nearly full. The temperature of the drying chamber was
indicated by a thermometer whose bulb was near the shelves. Three
points are worthy of mention: (1) Rarified air is not a good conductor
of heat, hence it is desirable that the samples should be placed in metal
dishes, resting directly on metal shelves which are in contact with the
walls of the oven; (2) a means should be provided for displacing the
water vapor by dry air as by admitting through the air inlet tube a
slow current of air dried by concentrated sulfuric acid in a gas wash
bottle; (3) when a number of moist samples are introduced into a pre-
viously regulated vacuum oven, the temperature of the chamber and of
the metal shelf promptly drops several degrees and rises again after
most of the water is evaporated. If an attempt is made to compensate
this cooling effect by application of more heat, it will certainly result in
overheating during the latter part of the drying.
The vacuum ranged from 26 to 29 inches of mercury, usually 26 to
28 inches (pressure of 2 to 4 inches), which is as high as can be con-
veniently maintained by the usual rotary vacuum pump. A consider-
able number of preliminary experiments were made on the vacuum
method at 70°C., using flat aluminum dishes 83 cm. in diameter with
tight fitting covers. The effect of different methods of distributing the
sample was tried as follows: (1) Several grams of finely divided asbestos
were weighed into the dish with the sample; hot water was added and
the whole thoroughly mixed, evaporated on the steam bath just to
dryness and placed in the vacuum oven; (2) the sample was smeared over
the bottom of the dish with a spatula; (3) the material was simply weighed
into the dish without any treatment except to break up any very large
lumps. Results using 5- and 10-gram samples were also compared.
The differences were negligible or within the limits of experimental
error and so a 10-gram sample, without any absorbent or special attempt
to spread it, was adopted for further work. It is believed that the
larger sample is more likely to be representative simply because dried
fruits can not be ground very fine and the mixing of samples is rather
difficult.
Next, 3 or 4 samples each of apricots, peaches and pears, prepared as
above, were dried in the water oven at the temperature of boiling water
(about 98°C.) and in the vacuum oven at 70°C. and weighed at intervals
up to about 30 hours. The corresponding drying curves were plotted
and studied. Fig. 1 shows these curves for 4 samples of apricots. The
others were similar. These curves show very rapid and continuous loss
of weight in the water oven, as compared to the lower temperature in
vacuo. Experience with numerous samples shows that rate of loss in
the water oven also varies with the amount of moisture originally present
1922] HILTS: DETERMINATION OF MOISTURE IN DRIED FRUITS 43
and with the variety of fruit in question. This work confirms the
general experience that definite results can not be obtained by drying at
the temperature of boiling water. The drying curves in vacuo at
70°C. are quite uniform and similar for all the fruits studied. Most of
the weight loss occurs in the first 6 or 7 hours. The rate of loss is at
first very rapid, then becomes more gradual and after 10 to 12 hours
becomes slight and practically constant. However, the rate never
becomes zero, i. e. the weight never becomes entirely constant even
after long drying.
a)
£
|
|
sul feos coe
FO,
Loss IN WEIGHT (PER CENT)
FIG. 1—FOUR SAMPLES OF APRICOTS DRIED AT 70°C., 26—28 INCHES VACUUM
AND IN WATER OVEN, TEMPERATURE OF BOILING WATER.
Again, one sample each of apricots, peaches and pears was dried
in vacuo at 60°, 70° and 80°C. up to 30 hours. The curves for pears are
shown in Fig. 2. All were similar. The rate of loss gradually decreases
until, after 10 to 12 hours, it becomes small but constant. The final
rate of loss at 80°C. is somewhat greater than at 60 or 70 degrees, indi-
cating the probability of some progressive changes different in kind or in
degree from those at lower temperature. This confirms the advisa-
bility of not exceeding 70°C. in drying such substances. However, it
is quite evident that even at 60 or 70 degrees a slight weight loss will
continue almost indefinitely. It can not be said whether this is due to
some slow decomposition of levulose or to some other changes. Drying
in vacuo at lower temperatures undoubtedly gives results nearer the
actual truth than any other method yet suggested, but it is plainly
44 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
evident that to get strictly comparable results the temperature, length
of drying and degree of vacuum must be more or less arbitrarily fixed.
It is self-evident that the bulk of the free water is expelled in the early
part of the period; it is highly probable that all of the free water has been
removed when the rate of loss becomes constant, and that the subsequent
loss is due to some form of decomposition. Accordingly, drying a
10-gram sample at 70°C. at a pressure not exceeding 4 inches of mercury
for an arbitrary period of 12 hours was adopted as a standard. The
method has been used in practically this form in the San Francisco
station on thousands of samples of dried fruits, including peaches,
apricots, pears, apples and raisins, although the use of 5-gram samples
with an absorbent has been found advisable with raisins.
Loss (IN WEIGHT (PER CENT)
4 8 /2 76 20 ey £8
TIME IN HOURS.
FIG. 2—SAMPLE OF PEARS DRIED IN VACUUM OF 26-28 INCHES AT
DIFFERENT TEMPERATURES.
Past experience with dried apples has shown that drying a 10-gram
sample in a metal dish in the water oven at the temperature of boiling
water, for a period of 4 hours, gives results quite concordant with the
vacuum method above described. An attempt was made to devise a
similar rapid empirical method for peaches, apricots and pears. Thirty-
seven different samples of apricots, 30 of peaches and 26 of pears were
dried by vacuum oven for 12 hours as above, and also in the water oven
for three different arbitrary periods selected from a study of the drying
curves. These samples ranged from very moist to very dry. The
water-oven periods for each fruit giving results which averaged closest
1922] HILTS: DETERMINATION OF MOISTURE IN DRIED FRUITS 45
to the vacuum figures were selected for further trial. The results for
these optimum drying periods are summarized in Table 1.
TABLE 1.
Determination of moisture at 70°C. in vacuo at temperature of boiling water in water oven.
APRICOTS PEACHES PEARS
(37 Samples) (30 Samples) (26 Samples)
Vacuum |Water Oven| Vacuum |WaterOven| Vacuum |Water Oven
12 Hours | 344 Hours | 12 Hours | 4144 Hours | 12 Hours 5 Hours
per cent per cent per cent per cent per cent per cent
ETARE IE See es 15.85 15.41 17.90 17.68 24.69 24.77
Maximum difference above
TETCIEEP ET eS aes 2 a Ee 2.00 a 1.35 A ee 1.21
Maximum difference below
ACTIN: ie iad eden ais Se 2.61 ues ye 1.50 ere os
Number of results agreeing
within 0.5 of vacuum..| ..... 15 OP 12 Le ae | 13
Number of results differ-
ing by 1.0 or more from
WACTIUIN EC Pe. 5 5S a Sh es 12 eae 6 Neer 4
Composite samples of apricots, peaches and pears in condition as
packed were next prepared, allowed to stand in a closed vessel a con-
siderable time to equalize moisture and passed three times through a
meat chopper; they were mixed between grindings. Portions were placed
in wide-mouth glass-stoppered bottles which were paraffined. Sets of
these samples were submitted to every field station and to the Food
Control Laboratory of the Bureau of Chemistry. To prevent evaporation
collaborators were instructed not to remove the samples from the bottles
for mixing, but to mix in the bottle.
The following methods were submitted:
Vacuum Oven Method.
Weigh approximately 10 grams of the thoroughly mixed sample into an aluminum
dish 8.5 cm. in diameter, with cover. Dry in a vacuum oven at 70°C. at as high a
vacuum as possible for 12 hours. The metal dish must be placed in direct contact with
the metal shelf of the vacuum oven without the use of any intervening sheets of paper
which might prevent the conduction of heat to the dish. During the drying a slow
current of air, dried by bubbling through sulfuric acid, must be admitted to the oven.
The rate should be about 2 bubbles per second. At the conclusion of the drying place
tops on dishes, cool in a sulfuric acid desiccator and weigh as scon as cool. Report
loss in weight as moisture, making duplicate determinations.
If oven is provided with a vacuum gage reading in inches of mercury, as is usual,
report the reading of the gage and also the uncorrected barometer reading for the same
day. If the oven is provided with a mercury manometer, giving the actual pressure
46 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
in the oven, this reading should be reported in place of the above. In your report
specify the type of vacuum oven used, whether water-jacketed or electrically heated,
etc.
Water Oven Method.
Weigh approximately 10 grams of the thoroughly mixed sample into an 8.5 cm.
aluminum dish with cover and dry in a water-jacketed oven at the temperature of
boiling water, apricots for a period of 33 hours, peaches for 43 hours and pears for
5 hours. After drying for the above periods cool the dishes in a sulfuric acid desiccator
as above and weigh. Report loss in weight as moisture, making duplicate determina-
tions. Dishes in the water oven should always be placed on the shelves and not on
the bottom of the oven.
If your equipment differed in any manner from the above, describe in detail.
The collaborators’ results are given in Table 2.
DISCUSSION.
With one exception the pressures given for the vacuum ovens were
obtained by deducting the readings of the vacuum gages from the
prevailing uncorrected barometer readings and, on account of the
inaccuracy of such gages, are only approximate. With one exception
the vacuum ovens were of the water-jacketed gas-heated type. The
Seattle station used a Freas electrically heated oven with an inner
vacuum chamber. Considering the difficult nature of this determina-
tion and the rather elaborate equipment required, it is felt that the
results for the vacuum method are quite satisfactory. Very close
agreement can not be expected. Of the 92 results reported 68, or 74
per cent, are within 0.5 per cent of the average. It is recommended
that this method be submitted another year for study with a view to
adoption as official.
The results in the water oven are not satisfactory, due, unquestion-
ably, to differences in size of oven, temperature, ventilation and possibly
other factors. The oven temperatures, given by some analysts, varied
from 95° to 100°C. The low results of Chernoff are easily explained by
the fact that the boiling point of water at the given barometric pressure
at Denver would be 94.6°C. and the oven temperature would be a few
degrees lower. Hertwig suggested a mechanical device for spreading
the sample in a uniform layer, without the use of water, which might
give better results. This method is highly empirical, depending on
close control of conditions and on the compensation of errors of large
magnitude, i. e. the incomplete expulsion of water and decomposition.
It is not clear whether it can ever be made reliable for most fruits, and
further work is not recommended at this time. However, the case of
dried apples is different, since this fruit loses its water with greater ease
and uniformity. Experience in the San Francisco station and other
Bureau of Chemistry laboratories has shown that drying a 2- to 10-gram
minced sample for 4 hours in a water oven gives results quite comparable
to the vacuum method. In 1920, at San Francisco, comparative determi-
1922| HILTS: DETERMINATION OF MOISTURE IN DRIED FRUITS 47
TABLE 2.
Results of collaborators on moisture determination in dried fruit.
|
PEARS PEACHES APRICOTS
ANALYST eee ee | AVERAGE, PRESSURE
; r IN VACUUM OVEN
: ental bie Vacuum we Vacuum yg (Inches of Mercury)
per cent | per cent | per cent | per cent | per cent | per cent
H. R. Smith, 24.5) | 24.0 | 23.4 | 22.0 ) 20.2 | 20.6 | 1.55
Baltimore, Md. 24.6. | 25.0 | 23.5 | 23.6 | 25.2 | 24.0
C. H. Hickey, 24.80 | 24.04 | 23.42 | 21.42 | 24.96 | 22.92 | 0.97
Boston, Mass. 24.83 | 23.39 | 23.42 | 21.03 | 24.85 | 23.30
W. C. Taber, = --+.. | 23.1 | 23.4 | 25.2 | 26.2 | 1.10; occasionally
Buffalo, N. Y. Os ad eee aan eal os ROR A rose to 14.0
L. Jones, t 24.68 | 24.56 | 23.64 | 23.19 | 25.47 | 24.94 | 0.88
Chicago, [il. 24.70 | 24.55 | 23.62 | 22.64 | 25.46 | 25.29
M. L. Hitchcock?, Pesce eee eal Eade | eae | 2er3) leona
Cincinnati, Ohio. SSSR CIs SAO? VOLS AA Oe Dos
L. H. Chernoff, 24.79 | 21.63 | 23.57 | 17.88 | 25.52 | 20.71 | 0.10
Denver, Colo. 24.69 | 19.29 | 23.58 | 20.85 | 25.26 | 21.82
D. B. Scott, 24.34 | 24.07 | 23.21 | 22.66 | 25.30 | 25.07
Washington, D. C. 24.21 | 23.66 | 23.32 | 22.77 | 25.28 | 25.17 | 3.0 to 5.0
J. I. Palmore, 24.42 | 24.81 | 23.21 | 23.72 | 25.29 | 25.01 | 1.50
Washington, D. C. 24.51 | 25.09 | 23.19 | 24.09 | 25.09 | 25.57
L. C. Mitchell, 25.2) | 20-4, | 20-0.9) 23:0 | 24.3) 125.7 | 0:32
Minneapolis, Minn. | 24.9 | 26.4 | 21.9 | 24.2 | 24.9 | 25.8
F. L. Elliott, 23.47 | 24.29 | 22.23 | 21.24 | 23.94 | 24.29 | 6.0
New Orleans, La. 23.43 | 24.50 | 22.15 | 21.35 | 24.05 | 24.88
M. Ruderman, 23.93 | 24.33 | 22.83 | 21.38 | 24.56 | 23.71 | 3.5
New York, N. Y. 24.07 | 23.51 | 22.73 | 22.31 | 24.45 | 23.13
C.S. Brinton, 24.50 | 22.08 | 23.05 | 20.83 | 24.82 | 21.14 | 0.23 to 0.39
Philadelphia, Pa. 24.47 | 21.17 | 22.97 | 19.06 | 24.79 | 22.37 | (manometer)
R. Hertwig, 24.37 | 23.54 | 22.70 | 22.78 | 24.18 | 23.42 | 1.29
San Francisco, Calif. | 24.59 | 24.28 | 22.73 | 23.05 | 24.27 | 24.42
J. Calloway, Jr., 24.73 | 24.49 | 22.87 | 23.05 | 24.96 | 24.61 | 0.92
Savannah, Ga. 24.76 | 24.57 | 22.94 | 23.34 | 24.99 | 24.73
V. B. Bonney, 24.32 | 24.97 | 22.70 | 23.12 | 24.13 | 24.56 | 0.10
D. H. McIntire, 24.25 | 24.88 | 22.68 | 22.90 | 24.41 | 25.46 | 0.10
Seattle, Wash. sastove ahd the cone Reel le secs rant meee eal leer ss och
D. B. Bisbeet 24.85 | 24.70 | 23.74 | 23.95 | 25.65 | 26.23 | 3.41
St. Louis, Mo. 24.68 | 24.98 | 23.65 | 23.54 | 25.64 | 25.49
Maximum... 5.:.'.- 25.2 | 26.4 | 23.74 | 24.2 | 25.65 | 26.4
Minimum§.......... 23.43 | 21.17 | 21.9 | 19.06 | 23.94 | 21.14
*Sample arrived in bad condition.
7Used double-wall steam-heated ovens instead of water ovens.
{Used a ventilated electric oven, temperature 98° to 100° C., instead of water oven.
§Excluding results of Chernoff in water oven. See discussion.
48 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 1
nations were made by both methods on 52 different samples, using 10
grams. The average for the vacuum oven was 23.59 per cent and for
the water oven 23.69 per cent. In only seven of these samples was the
difference between the methods greater than 0.5 per cent, and it was
usually very much less. It is believed that this method should receive
further attention with a view to adoption as a tentative method, on
account of its great practical value.
It is suggested that future work should include an attempt to de-
termine moisture by some method depending on a totally different
principle, as the calcium carbide method described by McNeil’.
RECOMMENDATIONS.
It is recommended—
(1) That the following method for the determination of moisture in
dried fruits by drying in vacuo be studied for another year with a view
to adoption as official:
Weigh about 10 grams of sample into a metal dish about 8.5 cm. in diameter, pro-
vided with a cover, breaking down any large lumps. Dry in vacuo at 70°C. for 12
hours at as low a pressure as possible, not to exceed 4 in. (100 mm.) of mercury. Dur-
ing the drying admit to the oven a slow current of air, about 2 bubbles per second,
dried by bubbling through concentrated sulfuric acid. The metal dish must be placed
in direct contact with the metal shelf of the oven. Replace cover, cool in a desiccator
and weigh. Disregard any temporary drop of oven temperature which may occur
during the early part of the drying period owing to rapid evaporation of water.
(2) That the following method for the determination of moisture in
dried apples be further studied with a view to adoption as tentative:
Weigh 5 to 10 grams of sample into a metal dish about 8.5 cm. in diameter, provided
with a cover, breaking down any large lumps, and dry for 4 hours in a water oven at
the temperature of boiling water. Replace cover, cool in a desiccator and weigh.
Place dishes on shelves and not on oven bottom. Temperature of the oven should not
be below 96°C.
(3) That an attempt be made to determine moisture in dried fruits
by some method depending on a totally different principle, as the calcium
carbide method.
1U. 8S. Bur. Chem. Circ. 97: (1912).
1922] BALCOM: REPORT ON CANNED FOODS 49
REPORT ON CANNED FOODS.
By R. W. Batcom (Bureau of Chemistry, Washington, D. C.), Referee.
The referee regrets that, owing to his appointment by the Executive
Committee to fill the positions of secretary of the association and chair-
man of its Board of Editors, made vacant when Dr. Alsberg severed his
official connection with the United States Department of Agriculture
and therefore with the association, he found little time to give to the
work on canned foods. The association had recommended that the
investigation of methods for the detection of spoilage and for distinguish-
ing conditions which are likely to lead to spoilage be continued.
R. S. Breed and C. A. Darling of the New York Agricultural Experi-
ment Station, Geneva, N. Y., submitted some recommendations for
changes in the wording of the Howard methods! for the micro-analysis
of tomato pulp, catsup, purée, sauce and paste. The suggested changes
are for the purpose of securing greater clearness or accuracy of state-
ment. They are as follows:
It is recommended that under XIII, 28, the third paragraph be
changed to read—
Place the slide under the microscope and examine with a magnification of about
90 diameters and with such adjustment that each field of view covers? 1.5. sq. mm.
This area is of vital importance and may be determined by adjusting the draw-tube in
such a way that the diameter of the field becomes 1.382 mm. as determined by measure-
ment with a stage micrometer. A 16 mm. Zeiss apochromatic objective with a Zeiss
X6 compensating ocular or a Spencer 16mm. apochromatic objective with a Spencer
X10 compensating ocular, or their equivalents, shall be used to obtain this magnifica-
tion. Under these conditions the amount of liquid examined is 0.15 cmm. (0.00015 ce.)
per field.
It is recommended that in XIII, 29, line 4 of the third paragraph
“1/60 cmm.” be changed to read “‘1/60,000 cc.”
It is recommended that XIII, 30, be changed to read—
BACTERIA.—TENTATIVE
Estimate the number of rod-shaped bacteria from the mounted sample used in 29
but, before examination, allow the sample to stand not less than 15 minutes after
mounting®. Employ a magnification of about 500, which may be obtained by the use
of an 8 mm. Zeiss apochromatic objective with an X18 Zeiss compensating ocular
with draw-tube not extended, or an 8 mm. Spencer apochromatic objective with an
X20 Spencer compensating ocular and a tube length of 190, or their equivalents.
Count and record the number of bacteria having a length greater than 1} times their
width in an‘ area consisting of five of the small sized squares. Count five such areas,
preferably one from near each corner of the ruled portion of the slide and one from near
1 Assoc. Official Agr. Chemists, Methods, 1920, 164.
2 Matter deleted.
3 Matter deleted.
4 Matter deleted.
50 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
the center. Determine the total number of the rod-shaped bacteria in the 5 areas and
multiply by 480,000. This gives the number of this type of bacteria per cc. If a
dilution of 1 part of the sample with 8 parts of water, instead of 1 part of the sample
with 2 parts of water is used in making up the sample, then the total count obtained as
above must be multiplied by 1,440,000. Thus far it has proved impracticable to
count the micrococci present as they are likely to be confused with other bodies fre-
quently present in such products.
These recommendations are approved by the referee and the author
of the methods with the exception of that in which it is suggested that
“1/60 cmm.” be changed to read ‘‘1/60,000 cc.”
RECOMMENDATIONS.
It is recommended— ‘
(1) That the changes in wording of Howard’s methods for the micro-
analysis of tomato pulp, catsup, purée, sauce and paste, proposed by
Breed and Darling of the New York Agricultural Experiment Station,
Geneva, N. Y., be adopted, except for the proposed change by which
“1/60 cmm.” in XIII, 29, paragraph 3, line 4 would be made to read
*1/60,000 cc.” It is not believed that this change is advisable. Prac-
tically the same end can be attained without changing the unit 1/60
cmm., heretofore used, by inserting immediately following it, in paren-
theses, the equivalent expression 1/60,000 cc., and it is recommended
that this be done.
(2) That the methods for the micro-analysis of tomato pulp, catsup,
purée, sauce and paste, with the changes in expression specified, be
adopted as official.
A NET MICROMETER FOR USE IN MAKING MOLD
COUNTS.
By B. J. Howarp (Bureau of Chemistry, Washington, D. C.).
In the tentative official methods for the microscopic examination of
tomato products the analyst is directed that “no field should be con-
sidered positive unless the aggregate length of the filaments present
exceeds approximately one-sixth of the diameter of the field’. With the
apparatus as usually employed the determination of this length of
filament becomes merely a question of individual estimate and judgment
since there is no scale in the field of view to use for comparative measure-
ments.
Some time ago C. H. Stephenson and W. K. Makemson of the Micro-
chemical Laboratory of the Bureau of Chemistry suggested having the
mold-counting chamber ruled in squares of 0.23 mm. on a side (1-6 of
1.382 mm. the diameter of the field of view). A chamber of this con-
1922! WILEY: ADDRESS BY THE HONORARY PRESIDENT 51
struction was obtained and tested out, but it was found that some
tomato products were of such consistency as to render invisible part of
the fine rulings, thus limiting its practicability. Later Stephenson sug-
gested a drop-in eyepiece micrometer ruled in squares equal to one-
sixth of the diameter of the opening in the eyepiece diaphragm. Inas-
much as the size of the opening varies in different makes of eyepieces
the disk must be ruled accordingly, after a careful measurement of the
diameter of opening has been made. Such a micrometer was given a
preliminary practical test by two members of the Microchemical Labora-
tory, and they report enthusiastically in its favor. It has two definite
advantages over the ruled chamber as first proposed, namely, (1) that
the rulings are always in plain view and (2) the ocular with the disk can
be instantly rotated to effect parallelism with the mold filaments being
measured.
From the practical tests which have thus far been made with it, it is
believed that the introduction of this device will help eliminate the
personal factor of judging the length of filaments by those using this
mold-counting method. Fortunately its employment does not intro-
duce any change whatever in the method itself.
ADDRESS BY THE HONORARY PRESIDENT.
H. W. Wirtry (Good Housekeeping, Bureau of Foods. Sanitation and
Health, Washington, D. C.).
It is with very great pleasure that I am able to be here today. With-
out ever consulting me you changed the time of your meeting and came
very near depriving me of the great pleasure which you have just been
told you have. If I had not had a good deal of influence with my
surgeon I would not be here today, but when I told him that the interests
of the country were involved and that I must have leave of absence for
this meeting, he very reluctantly allowed me to come. I can hardly
say that I take pleasure in seeing you because my seeing days are tem-
porarily in eclipse, but I hope with the aid of the skilful surgeon’s knife
to be able really to see you at this time next year.
I was much interested in and instructed by the two papers to which
{ was privileged to listen this morning. In the first paper the importance
of expressing all business relations in chemicals in metric units was
stressed. I wonder if you realize how important that question is today.
For 25 years or more, yes, since 1866, efforts have been made to intro-
duce a simple system of measurements into this country. In 1866 the
only system of weights and measures ever legalized by Congress was
adopted, the metric system, so called. Our Constitution authorized
52 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
the Congress of the United States to coin money and to regulate or
establish standard weights and measures. Our fathers understood the
importance of this matter and so incorporated it into the first section
of the Constitution. They also ordained and established a decimal
system of money, and | doubt if the most rabid opponent of the metric
system in business in this country would dare advocate going back to
the old system of pounds, shillings and pence. So Congress, in 1866,
legalized the metric system. I do not suppose Congress would do it
now—there would be such an opposition to it—but in those days nobody
had ever heard of the metric system and therefore there was no oppo-
sition. If you want to get really good legislation, slip it in. That was
the way I got into the appropriation bill the authority to inspect im-
ported food products four years before the National Food and Drugs
Act was inaugurated. Nobody ever noticed it, and it went through for
that reason. They began to notice it thereafter, but not in time.
In 1873, in my first paper read before the American Association for
the advancement of Science, entitled “The Introduction of the Metric
System into Medicine’, I pointed out the advantages which would
accrue to the medical profession and the pharmaceutical profession by
the adoption of that simple system of weights and measures. That
bore fruit earlier than I had anticipated, because in 1894 the Congress of
the United States passed a law requiring the use of the metric system of
weights and measures in all the medical departments of the United
States Government. The Pharmacopoeia of the United States in the
9th revised edition has incorporated the metric system as the sole sys-
tem legalized by the Pharmacopoeia, but it gives in parentheses the
ordinary system for the convenience of those who have not had time to
forget the old. I won’t say have not had time to learn the new one
because it takes no time, but those who are incapable of forgetting have
to have a little sop thrown to them in the Pharmacopoeia, 9th Revised
Edition. There is now before Congress the annual bill to establish the
metric system of weights and measures as the sole system to be used in
this country, and the usual opposition, of course, is manifested. We
are told that it will disarrange business, scrap thousands of dollars’
worth of models, impose untold hardships on the American manu-
facturer, obfuscate the farmer and all such gaff, which we are accustomed
to hear in the case of all really great reforms. When I was before the
committee the other day the chairman of the subcommittee to consider
this matter made this objection. He said: “I would not mind these
objections of the business men but the farmers would be hard hit if
they had this system imposed upon them’. And I promised to bring
facts before him to show him how the farmers will be the parties that
are chiefly benefited by this system of weights and measures; how the
farmer buys a short ton and sells a long ton and is defrauded out of
1922| WILEY: ADDRESS BY THE HONORARY PRESIDENT 53
about 200 pounds by the operation; and how the farmer in one State,
if he sells a barrel of products in another State, runs into a different
form of valuation. The Bureau of Standards has published a list of
laws, State laws—not municipal but just State Jaws—showing the
innumerable systems of weights and measures in use in this country.
The publication is a small volume, in fine print, of 694 pages. If it
attempted to give the laws of the municipalities, another volume equally
as large would be required.
Now, if we want relief from a great and intolerable burden, we want
that suggestion made by the speaker this morning adopted, not only
for drugs and chemicals but for everything that we buy and sell. Why
should we delay any longer lifting this burden from the shoulders of our
children? They begin in the first grade to try to learn weights and
measures; they continue through all the eight grades, the high school,
the college, and all through life, and then never learn anything of value.
I do not suppose there are four persons in this audience who can tell
the value of a fathom or a furlong. I found my older boy had learned
three things in four years, and one of them was wrong. [I said: ““How
many ounces in a pound’? Immediately he responded twelve. That
boy is going to be a pharmacist, | am sure. His pound was the troy
pound. And then I said: ““What is the metric system, my son’? He
said: ““The metric system is something that falls out of the sky”. He
thought it was the meteoric system I was asking about. Now he did
know that there were twelve inches in a foot and three feet in a yard.
Those were the only things he had learned in four years of effort, and
he is still trying every day to learn something more.
Another thing struck me this morning in that wonderful address of
the President. I am almost convinced that chlorophyl is about as im-
portant as the Saccharomyces cerevisiae. You see the sop that was
thrown to the brewers this morning by the ruling of the Secretary of
the Treasury that the homeopathic doctor prescribing for his patient
any homeopathic dose may write a prescription of two gallons and a
half! Now that is going some for a homeopath, isn’t it? So you see
the little bug is not dead yet. But now this chlorophyl is going to run
the race also to become commercialized just as soon as this paper of
the President gets into the public press and people begin to talk about
it. You will have chlorophyl cakes to cure pimples; and you will have
chlorophyl tooth paste to cure pyorrhea; and you will have chlorophyl
beauty soap for the young ladies; and it will run the whole gamut that
yeast has run in the last few years. I do not know but that we ought
to hale Atherton Sidell before this organization and try him for treason
because he with the aid of John Uri Lloyd was able to isolate and sepa-
rate vitamines from yeast. Look at the yeast propaganda that is
going on all over the world! Knowing that I was to make an
54 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
extemporaneous address I brought some of this with me, just to show
you how it is going and what rate of speed it is making. Here it is:
‘“Vitamines extracted from yeast, combined with fat, soluble vitamines
etc. into a proper dose; tablets easy to take; results guaranteed; cure
all the diseases to which the human flesh is heir’. And here again is
“Yeast beauty soap, containing pure yeast, price 25 cents, for skin and
scalp’; ‘“Yeasto tooth paste’; ““Yeasto beauty soap”. So you see what
your friend, chlorophyl, is coming to. This yeast campaign has in fact
broken into the realms of poetry, as one poet has written:
Fresh milk and greens give vitamines
Enough for little Sid,
So he at least will need no yeast,
A real self-rising kid.
I suppose that it would not be out of place if I should just run over a
few of the things in the realm of chemistry and agricultural chemistry
which have occupied the public mind since we last met. I think the
outstanding feature was the visit to this country of Madam Curie.
Never was a scientific man or woman accorded such honors as were
given to her. She was received by the President of the United States
in the historic East Room as the Prince of Wales or Lloyd George would
be received and with equal honors, and she was met there by a company
of people especially invited to meet her, representing the very best of
American scientific and social life. There this modest little woman
who would not attract attention, except perhaps by someone offering
to help her across the street—she seemed so timid and unpretentious—
was the recipient of honors which are paid only to royalty and to rulers.
In addition to that, the heartfelt sympathy and gratitude of the great
American people were expressed by a gift which in pecuniary value
probably is larger than any ever presented to a visiting potentate or
ruler of the world.
This features the progress that chemistry has made in the minds
and hearts of our people. Who could have imagined forty or fifty
years ago that such honors would be paid to a chemist? And the more
we know—or the less our ignorance is perhaps would be better—of
radium, the more wonderful do the achievements of this woman appear.
We sometimes wonder whether she or her husband was the real dis-
coverer. I am certain it was Madam Curie because radium is so like
a woman that I do not believe any man could ever have discovered it.
Its peculiarities, its reactions and inter-reactions, its violation of all
the rules of ethics and of scientific accuracy, its snapping of fingers at
gravity, the rules of combination and the integrity of matter all stamp
it as feminine. All the other elements may be masculine or neuter,
but radium is distinctly feminine, and I propose that we call it radia
Or
1922] WILEY: ADDRESS BY THE HONORARY PRESIDENT 5:
because that is the feminine form that it ought to bear, instead of
radium, which is neuter.
After I found I was to come to this meeting I attempted to sum-
marize the real benefits received and the progress which had been made
in agriculture as the result of the formation of this association. Now
it seems to me that we measure these largely from the scientific and not
from the economic point of view. I mean that the benefit from this
association to agricultural chemistry is largely scientific—bringing
together the workers into a harmonious organization of great solidarity
and persistence and working a great influence on the scientific world,
thus adding to science that unity of purpose, of design and of effort
which is necessary to effect great changes and get great results. But
when I come to look at the crop reports and compare them with those
of thirty or forty years ago, when this association was first formed, [
fail to see that our work has been reflected in any way in increased
production. The yields of our crops are due largely to seasonal in-
fluences. In other words, the variety of yields is not due to any system-
atic application of the principles of scientific agriculture which this
association has inculcated. If you go out among the farmers you will
find that while they use commercial fertilizers much more extensively
than they did in the old days, as a rule the actual yield of crops has not
been very greatly increased. Our wheat still stands around about 13
bushels per acre in a series of ten years, and our yields of Indian corn
about 27 bushels per acre in the same length of time. Now that con-
dition, of course, will not continue. There must soon be a reflection
of the activities of the association in an economic sense because we
need larger yields. Our tillable areas are now largely occupied. When
we recover from swamps or from deserts an additional acre, it is at an
investment which places its initial value very high, so that a cheap
crop can not profitably be grown upon it. In this association we must
all insist, for economic reasons, upon a better yield or a better system
of crop rotation and crop selection. In other words, if it costs a hun-
dred dollars to reclaim an acre of land one can not afford to grow 13
bushels of wheat upon that acre, or 27 bushels of Indian corn. It does
not pay because of the initial investment. Hence, in the reclaimed
areas scientific agriculture is necessary; but in the old areas of broad
and wide agriculture it is not yet a necessity. We see the crops of
wheat diminishing, the yield per acre falling, and we do not have those
wonderful yields that we had a few years ago. It is true that on the
Pacific coast there are still some phenomenal yields. At this time
last year I was on the Pacific coast and attended a fair in the State of
Oregon. I saw wheat placed there on exhibit by the State Board of
Agriculture, with a yield of 115 bushels per acre! It was not very
good wheat; it was soft and would not make high-grade flour, I imagine,
56 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS |[Vol. VI, No. 1
but it was there and showed the capacities and possibilities of agri-
culture in that region. But we have no such yields here. We can get
a yield of 100 bushels of corn to the acre here—it has been repeatedly
done in nearby places—and of thirty or perhaps forty bushels of wheat,
although [ have never seen a field that measured forty.
The relation of yield per acre to population is a great question you
know, and it is not reflected in a corresponding increase in the number
of persons engaged in agriculture. There are more people to be fed
and the agriculturists are hardly able to do it, without being forced
into a systematic, scientific agriculture which will greatly increase the
yields of crops. This I expect to see accomplished in the near future as
one of the results of the organization of this association.
Another feature that I want to speak of is the progress that has been
made in the utilization of foods for dietary purposes. The human
animal has really waked up to the fact that he is quite as important
from the dietary point of view as the pig or the cow or the sheep. For
years we have known all about the scientific feeding of domesticated
animals, and now we are about to learn something about domesticated
babies and how they should be fed. Our systems of diet are just on the
point of change, and they will change very rapidly. I attended, last
week, that wonderful health exhibit at Cincinnati, one of the first of the
kind in this country. Another, similar to the one in Cincinnati and
probably on a larger scale but not on a better scale, will be held in New
York about the middle of November. I saw the University of Cin-
cinnati exhibit of dietary substances, and it was wonderfully informing
and interesting. One of the peculiarities of human nature is that side
by side with that was an exhibit of the Coca Cola Company. There I
found the health exhibits of the Health Office and of the Public Schools
and learned what a child should eat at its noon-day meal and every-
thing of that kind, reflecting all the modern progress that has been
made in the last ten or fifteen years on dietary studies. I saw there in
operation a mill cleaning and grinding whole wheat flour. [ saw ex-
hibits of cereals that contained all the vitamines that little Sid needs
without eating yeast; the featuring of leaf vegetables and undegermi-
nated and undecorticated and undenatured cereal products. The
people of this country are realizing the danger that comes from the
eating of refined foods. Now, I have always been an advocate of pure
foods, as you know, and I find I have always been wrong because pure
foods will not nourish. This has been demonstrated time and time
again. If you feed pure fat, pure protein, pure carbohydrates, pure
minerals, the animals will starve to death. So, after all, the impure
foods are necessary to health and vitality, not the kind of impurities
that have been visited upon us, but natural foods as Nature put them
up. Nature certainly knows her job when she decrees that the diet
1922| WILEY: ADDRESS BY THE HONORARY PRESIDENT 57
shall be colorful. We do not appreciate color as we should. We should
all be artists because the chrome is a great thing not only in vegetation,
but in animal life. The very beginnings of animal life are the colorable
products, chromosomes, just as wonderful as the chlorophyl, the xan-
thophyl and the erythrophyl, which condition heredity. What would
the October days be without the change of chlorophyl into xanthophyl
and erythrophyl? The artist will paint the forest and the woods and
gratify the eye and the aesthetic taste of the people who look at them.
We do not appreciate as we should the value of color, not only in
art and beauty but in vitality and health. I am not surprised to find
that the vital principle of vegetable growth, the vitamine, is a color
lover because vegetable growth is distinguished by color just as
the chromosomes are the vital principles of animal life. The blood of
life of the animal is a color substance. I[t is the colorless substance
that is free of vitamines; they are always associated with color. So
life is indelibly associated in every respect with color, both at its in-
ception and through its whole progress. I think this progress in dietary
chemistry is the outstanding mark in chemistry in this country during
the past three or four years and will continue to be until we find out
more definitely what these vitamines are and how they perform their
function. We do not know their chemical composition; we do know
they resemble in some respects the catalases. They induce reaction
even if they do not take part in it, and hence nutrition without this
element is impossible. And thus the argument for natural foods be-
comes imperative and will make its impression even upon the doctors
of this country in the course of time. I hope to live until I see doc-
tors who will prescribe a food for an infant with some rhyme and reason,
instead of empirically using sweetened condensed milk because it is
easy to prescribe and because the child when it dies looks fat and healthy,
and that is a great comfort to the mother.
If our work as chemists and scientific men reflects itself in this way
in public service, then we will not be unrewarded. I wonder some-
times why it is that while in foreign countries scientific men take a great
part in governmental affairs and have always done so, our scientific men
do not become more active. They do not consider it beneath their
dignity to give public service, and especially when they have made
their career and have acquired a competence. I can understand why
a scientific man in the early part of his career does not like to abandon
it and give himself to politics; it is because there is nothing in politics
to reward him, except service, and he can get plenty of that and get
mightly little reward from a monetary standpoint. But when a scien-
tific man does acquire a competence and does have time to give himself
to public life. why doesn’t he? We have had two chemists at least in
the House of Representatives, and now we have one chemist in the
58 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS |Vol. VI, No. 1
Senate. | understand he is not here today; he is probably detained
for some political reason rather than some scientific reason. But the
fact that he, our own colleague, is in the Senate is a great consolation
to all of us.
It is plain that the scientific man has to serve humanity not only in
his profession, but in every possible way for we are all human beings.
As we all belong to the great commonwealth we should not be selfish
in our activities. So I hope that in the future more scientific men will
be able to enter the halls of legislation and give themselves largely to
the public service. That I would consider one of the great marks of
progress.
We have almost perfected the systems of animal feeding. We know
exactly what foods to use for the kind of service we need, and we find
the same system good for the human animal We should not feed every
human animal alike. If a boy is going to be a prize-fighter, of course
he should largely have punch in his food, but if he is going to be a min-
ister of the gospel he should be fed on angel’s food, although that has
no vitamines in it, I am sorry to say; but still that would be the Jogical
thing to do. In other words, if a man leads an active physical life his
food should be different from that of a man in sedentary employment.
There is no question about that. And the foods in the summer should
be different from those in the winter and less in quantity because less
heat is required in summer. All these things have been neglected up
to the present time, but now through health exhibits as in Cincinnati
and in New York next week, and through the public press the good work
goes on. The newspapers featured this exhibit in Cincinnati as they
would the series for the baseball championship, making it the real
outstanding feature of the week. So, I say, we should devote ourselves
first of all to our scientific studies and to the solution of such problems
as your President has elucidated in such a charming way. ‘That is our
first duty. Then we have another duty—to serve the people of this
country in every possible way and with every possible power and effort
which we can command.
W. F. Hand.—Dr. Wiley has placed us under renewed obligations.
Nothing I can say in your behalf would give him any assurance of our
increased appreciation. We can only indulge a hope that we will meet
here next year and year after year for many years to come and assure
him of our love and esteem.
Dr. Wiley referred to Dr. Ladd’s absence. He expected to be here
and he wants the association to know that it was only through the
direst necessity that he was compelled to be away.
B. B. Ross.—Reference has been made to the fact that one of our
most distinguished members, a former president of this organization,
1922] WILEY: ADDRESS BY THE HONORARY PRESIDENT 59
has now been called into the service of hiscountry. He is a member
of the highest branch of our national legislative body, and I feel sure
that he was called to that position by reason of the service that he
rendered to the people of his State in the cause of pure food and im-
proved methods in agriculture. In recognition of his long service in
the field of agricultural chemistry and in the cause of pure food, I
move that although his active official connection with this organiza-
tion has been severed, he be elected an honorary life member of the
Association of Official Agricultural Chemists. I refer to Senator
E. F. Ladd.
William Frear.—I desire to have the honor of seconding this motion.
The motion was carried unanimously.
SECOND DAY.
TUESDAY—AFTERNOON SESSION.
REPORT ON CEREAL FOODS.
By GC. H. Baitey (Agricultural Experiment Station, St. Paul, Minn.),
Referee.
The Committee on Referees, at the 1920 meeting, recommended
that the work on the determination of moisture, gluten, soluble carbo-
hydrates, cold water extract, chlorine and ash be continued; and that
the referee study methods for the determination of fat in baked cereal
products.
Since it is impossible to carry work on all these methods simultaneously
with the limited number of collaborators interested in cereal foods, the
referee and the associate referee selected what appeared to be the methods
most urgently needing development. These were (1) methods for the
determination of fat in baked cereal products, the results of collaborative
studies being included in this report; and (2) the quantitative determi-
nation of chlorine in bleached and natural flours, which is reported by
the associate referee.
While a number of methods for the determination of fats in baked
cereal products based upon the Polenske method! have been discussed
in the literature, two methods developed in the Bureau of Chemistry
seemed worthy of collaborative study. The first, for the determination
of fat in alimentary pastes, noodles, etc., was suggested by R. Hertwig;
the second, by C. R. Smith, was for essentially the same products.
With the advice and assistance of the associate referee, the following
instructions were prepared and distributed to the several collaborators,
together with two ground samples of bread (A) and ordinary soda
biscuit or “crackers” (B):
The collaborators will determine in duplicate the fat content of Samples A and B by
each of the two following methods:
Method I.
Place 2 grams of the finely divided material in a 50 cc. beaker. Add 10 cc. of hydro-
chloric acid, sp. gr. 1.125. Heat the beaker and contents in a water bath maintained
at 65°C. until particles are broken up, and everything except fibrous material is in
solution. During this heating (10-15 minutes) stir the material in the beaker with a
glass rod in such a way that the rod touches the sides of the beaker from top to bottom.
Cool; then add 10 cc. of 95% alcohol. Finally cool in a bath of melting ice and pour
' Assoc. Official Agr. Chemists, Methods, 1920, 249.
60
1922] BAILEY: REPORT ON CEREAL FOODS 61
the “solution” into a Mojonnier extractor’, washing the beaker with several portions
of ethyl ether, 25 cc. in all being used for this purpose. To the mixture in the Mo-
jonnier extractor, add 25 cc. of petroleum ether (boiling point below 60°C.). After
mixing, allow to settle, and carefully decant off the ether layer into a weighed flask or
“fat bulb”. Add 50 cc. of a mixture of equal parts of ethyl and petroleum ether to the
material remaining in the Mojonnier extractor, and again decant into the same flask.
If the ether layer has been thoroughly drained from the aqueous layer each time the
two treatments with mixed ethers will suffice; if incomplete drainage is effected a third
extraction should be made with the mixed ethers. The ether in the combined extracts
is distilled off over a steam bath; the flask and contents are dried at 100°C. for 30
minutes, cooled, and weighed from a desiccator.
Method II.
Place 5 grams of ground sample in a 200 cc. Erlenmeyer flask and add a mixture of
10 ec. of 95% ethyl alcohol, 2 cc. of concentrated ammonia and 3 cc. of water. Cap
with a short-stemmed funnel, tip downwards. Maintain contents of the flask at the
boiling point over a steam bath for 2 minutes. Cool and extract the mixture with
3 successive portions of ethyl ether of 25 cc. each, kneading and tamping the matted
material thoroughly each time with a glass rod flattened at the end. Combine the
ether extracts in a 200 cc. flask. The last portion of ether must be drained off as com-
pletely as possible or it will later cause trouble?. To the solid residue in the flask, add
another 15 cc. portion of the ammoniacal alcohol mixture and repeat the entire opera-
tion, except that the period of boiling on the steam bath should be extended to 15 or
20 minutes in order to disintegrate the glutinous mat of solid material. Then distil
off the ether in the combined extracts, heat the latter to dryness on the steam bath,
cool, and extract the fatty residue in the flask with several successive portions of a
mixture of equal parts of ethyl and petroleum ether, using about 25 cc. in all for this
purpose. Collect these extracts in a tared beaker or “fat bulb’’, evaporate to dryness
on a steam bath, dry in an oven at 100°C. for 30 minutes, cool and weigh.
The reports of collaborators are summarized in Table 1.
DISCUSSION.
From the comments accompanying the reports, it is evident that the
phraseology of the methods should be changed in one particular, and
that is to dry the fatty residue in the bulb or flask to constant weight,
since 30 minutes was not necessarily sufficient to volatilize all the mixed
ethers used as fat solvent.
With the Smith (II) method the results are quite satisfactory. par-
ticularly with the sample of crackers (B). The variation in results
with the sample of bread (A) may possibly be attributed to the lack of
homogeneity in the sample, consisting as it did of a mixture of dried
crust and crumb fragments. It was suggested that a finer subdivision
of the material might have contributed to greater uniformity in the
analytical findings. Hertwig’s method (I) resulted in much wider
1 Note.—Mojonnier extractors can perhaps be made by constricting a large-bore (114 inch diameter)
test tube about 1 inch from the bottom and a like distance from the top, and bending slightly at the con-
strictions to the angles shown in the cuts of this device.
2 Nore.—Failure to drain out the ether completely at this point necessitates a cautious and gradual
heating with the second portion of ammoniacal alcohol solution, as the ether must be distilled off before
the mixture can be brought to the desired boil. Otherwise disastrous bumping will occur, and part of
the solution may be thrown out of the flask.
62 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
variations in the results, particularly with the ground crackers (B), and
even when employed by the same analyst, as shown by the report of
Rask.
TABLE 1.
Results of collaborative study of two methods for the determination of fat in baked products.
Mernxop I Mernop II
ANALYST econ Sy es ey
Bread Crackers Bread Crackers
(A) (B) (A) (B)
per cent per cent per cent per cent
C.B. Morison, American Institute of Baking, Ne bs 2.25 10.438
Chicago, Ill. ee ale 2.58 10.50
J. L. St. John, Agricultural Experiment Sta- aes his 2.62 10.61
tion, Pullman, Wash. Sop. pas 2.63 10.64
C. M. Fritz, Howard Wheat and Flour Test- PIMs) 4.65 3.57 10.38
ing Laboratory, Minneapolis, Minn.
G.S. Taylor, Agricultural Experiment Station, | 2.78 9.68 2.92 10.67
St. Paul, Minn. 2.12 9.88 2.95 10.50
C. E. Goodrich, Bureau of Chemistry, Wash- 1.83 6.97 2.52 10.70
ington, D. C. 1.87 6.54 3.40 10.76
BA 8 6.51 2.90 10.73
Ruth Buchanan, Bureau of Chemistry, Wash- 3.20 10.72
ington, D. C 3.13 10.78
O. S. Rask*, Bureau of Chemistry, Washing- 1.96 8.94 2.92 10.62
ton, D.C. 2.08 9.96 2.89 10.75
2.19 7.35 te white. ths
*Present address, University of Minnesota, University Farm, St. Paul, Minn.
The referee concluded that the present official ash and moisture
methods are so adequate as hardly to justify further collaborative
study at this time. The principal difficulty now is to insure that cereal
chemists actually employ the official methods, since it is evident that
many of them are following other methods. The referee also believes
that the determination of cold water extract is not of sufficient value to
justify collaborative study until further research develops the changes
occurring during the process of extraction and the character and sig-
nificance of the solids in the extract.
RECOMMENDATIONS.
It is recommended—
(1) That collaborative work on the determination of cold water
extract be discontinued.
(2) That work on the determination of moisture and ash be dis-
continued until further research develops more desirable methods.
1922] BAILEY: STUDIES ON WHEAT FLOUR GRADES 63
(3) That the following method for the determination of fats in baked
cereal products be adopted as a tentative method and be subjected to
further collaborative study:
Place 5 grams of ground sample in a 200 cc. Erlenmeyer flask and add a mixture of
10 ce. of 95% ethyl alcohol, 2 cc. of concentrated ammonia and 3 cc. of water. Main-
tain contents of the flask at the boiling point over a steam bath for 2 minutes. Cool,
and extract the mixture with 3 successive portions of ethyl ether of 25 cc. each, kneading
and tamping the matted material thoroughly each time with a glass rod flattened at
the end. Pour off the ether layer by decantation into a 250 cc. beaker. The last
25 cc. portion of ether should be drained off as completely as possible. Add another
15 ce. portion of the ammoniacal alcohol solution to the extracted residue in the flask
and disintegrate the matted material as thoroughly as possible by means of the flattened
glass rod which should be left in the flask for this purpose. Return the flask to the
steam bath and repeat the entire procedure, prolonging somewhat the treatment with
ammoniacal alcohol. Add the ether extracts to those obtained before. Evaporate
the combined extracts to dryness on the steam bath, and then extract the fatty residue
with 5 or 6 successive portions (about 15 cc. each) of a mixture of equal volumes of
ethyl ether and petroleum ether. Collect the extracts in a tared dish (do not try to
filter) and evaporate to dryness on a steam bath. Dry the residue to constant weight
in an oven at the temperature of boiling water, cool in a desiccator and weigh.
STUDIES ON WHEAT FLOUR GRADES, [I1I—EFFECT OF CHLO-
RINE BLEACHING UPON THE ELECTROLYTIC RESIS-
TANCE AND HYDROGEN ION CONCENTRATION OF
WATER EXTRACTS!
By C. H. Bartey and ArNoLp Jounson (Division of Agricultural Bio-
chemistry, Minnesota Agricultural Experiment Station,
St. Paul, Minn.).
Bleaching of flour with nitrogen peroxide can be detected more readily
than similar treatment with chlorine. Through the use of the Griess-
Tlosvay reagent? the test for nitrogen peroxide can be made either quali-
tatively or quantitatively. A qualitative test for chlorine bleaching
has been suggested by Alway and Gortner’, in which the fat from sus-
pected flour is ignited in a flame on a freshly oxidized copper wire. On
page 1512 they say: “If chlorine or bromine has been used as a bleaching
agent a green or blue coloration is produced’’. Chlorine can be determined
quantitatively in the flour, and Utt* found appreciable differences
in the total chlorine content of bleached and unbleached flours. Jacobs®
devised a procedure which has been adopted as a tentative method by
the association. In this method the determination of chlorine is con-
1 Published with the approval of the Director as Paper No. 277, Journal Series, Minnesota Agricultural
Experiment Station.
2 Assoc. Official Agr. Chemists, vo 1920, 170.
3 J. Am. Chem. Soc., 1907, 29:
4 J. Ind. Eng. Chem., 1914, 6: os
5 Assoc. Official Agr. ‘Chemists, Methods, 1920, 169.
64 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
fined to the extracted fat. O. S. Rask, as Associate Referee on Cereal
Foods, has simplified this method and subjected it to collaborative
study. (See page 68.)
These quantitative methods are somewhat involved and time-con-
suming. It accordingly appeared desirable to develop, if possible, a
more rapid technical method for determining the extent of treatment
with chlorine. In addition, there were at least two other important
phases that should be studied: First, the effect of chlorine treatment
upon the electrolytic resistance of flour extracts, to ascertain whether
such treatment would seriously affect the correlation previously de-
termined by Bailey and Collatz' between the conductivity and flour
grade; second, to determine the effect of chlorine bleaching upon the
hydrogen ion concentration and buffer action of flour extracts, because
of the significance of such values as discussed by Bailey and Peterson’.
In the first series of studies two samples of natural hard-wheat flour
were employed: (1) Patent, containing 0.43 per cent of ash; and (2)
clear, containing 0.84 per cent of ash. These flours had already aged
for several months and hence were somewhat less creamy than fresh
hard-wheat flour. This is evident from the gasoline color values shown
in Table 1. Six portions of each sample were bleached with the equiva-
lent of 10, 20, 30, 40, 50 and 60 cc. of chlorine per 100 grams of flour,
respectively. Ten grams of each portion, as well as the original natural
flour, were then suspended in 100 ce. of water at 25°C. and maintained
at that temperature for exactly 30 minutes. The mixture was shaken
at frequent intervals during the extraction period to keep the flour
particles in suspension, after which it was placed in a suitable glass
vessel and whirled rapidly in a centrifuge for about 5 minutes to throw
the particles out of suspension. A portion of the clear supernatant
extract was then poured into a conductivity cell and its electrolytic
resistance at 30°C. determined in the conventional manner. This
method and the correlation between electrical conductivity and flour
grade have been discussed in the paper by Bailey and Collatz previously
referred to.
Another portion of each sample was mixed with water in the pro-
portion of 1 gram of flour to 5 cc. of water at 25°C. and maintained at
that temperature for exactly 60 minutes. The mixture was clarified
by centrifuging and the hydrogen ion concentration determined electro-
metrically by means of the hydrogen electrode (described by Bailey*)
connected through a calomel half-cell to a potentiometer. Results of
these measurements are reported in terms of PH. In addition, the
gasoline color values were determined, using the method of Winton‘.
Thi oie Chem., 1921, 13: 319.
3 J. Am. Chem. Soc., 1920, 42: 45.
4U.S. Bur. Chem. Bull. 137: (1911).
1922] BAILEY: STUDIES ON WHEAT FLOUR GRADES 65
From the data in Table 1 it appears that the specific conductivity
increases fairly regularly with the quantity of chlorine used in bleaching.
Thus bleaching the patent flour with 20 cc. of chlorine per 100 grams of
flour, which is slightly more chlorine than is recommended for commercial
bleaching, increased the conductivity of the water extracts 0.48 (K 3ox10%).
This is equivalent to about 0.045 per cent of ash, when unbleached
flours of varying ash content are compared. Bleaching the patent with
40 cc. of chlorine per 100 grams of flour increased the conductivity
1.13 units. If the ash content be known, it is probable that the extent
of treatment with chlorine could be estimated by the deviation of the
specific conductivity from the normal for flour of the same ash content.
It is evident also that the ash content of flours treated with chlorine
can not be accurately estimated from the conductivity alone unless the
extent of treatment be known.
Hydrogen ion concentration is also increased appreciably by the
chlorine treatment. Since the patent flour used in these studies was
milled several months previously it followed that its initial PH was
lower, and its hydrogen ion concentration accordingly higher than freshly
milled flours of the same grade, which generally have a PH of about
6.0 to 6.1. Bleaching with 20 cc. per 100 grams of patent flour changed
its hydrogen ion concentration through 0.34 units in terms of pH, while
the clear grade flour, because of its higher buffer action, on similar
TABLE 1.
Effect of varying quantities of chlorine upon the specific conductivity and hydrogen ion
concentration of patent and clear flour bleached in the laboratory.
CuiorninE Usep
Per 100 Grams GasoLinE Coton VALUE Speciric ConpuctTIvITY PH
or FLour or Water Extract
Patent flour.
ec. Kao x 10!
0 0.72 5.51 Dok
10 0.70 5.70 5.33
20 0.58 5.99 Se
30 0.53 6.21 5.00
40 0.53 6.64 4.77
50 0.52 7.06 4.60
60 0.52 7.40 4.43
Clear flour.
0 0.86 8.50 6.00
10 0.86 8.72 5.93
20 0.72 9.23 5.83
30 0.69 9.70 edie
40 0.67 10.05 5.61
50 0.65 10.34 5.49
60 0.64 10.54 5.38
66 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 1
treatment changed pH only 0.17 units. Heavier dosages of chlorine
further increased the hydrogen ion concentration.
To ascertain the effect of varying dosages of chlorine upon the buffer
action of flour extracts, the procedure used by Bailey and Peterson was
employed. To different portions of the 1 to 5 extract were added
0.02 hydrochloric acid and 0.02 sodium hydroxide in the proportions of
10, 20, 30, 40 and 50.cc. per 100 cc. of extract, respectively. The hy-
drogen ion concentration of each of these preparations was then de-
termined and from these results, as given in Table 2, it appears that
chlorine bleaching does effect an increase in the buffer action of water
extracts. Possibly this is due to the increased hydrolysis of phytin in
the presence of the hydrochloric acid resulting from the chlorine treat-
ment. Certain products of such hydrolysis, notably phosphates, may
constitute the buffers which manifest themselves on such treatment.
TABLE 2.
Hydrogen ion concentration (in terms of pH) on addition of 0.02 acid and alkali to water
extracts of patent and clear flour.
CHLORINE
Usep PER 0.02 N HyprocuLoric Acip ADDED 0.02 N Soprum HyproxipE ADDED
100 Grams Per 100 cc. Extract Perr 100 cc. Extract
oF FLounR
50 40 30 20 10 0 10 20 30 40 50
ce. Patent flour.
0 2.54 2.69 2.93 3.36 4.14 5.51 6.96 8.52 9.33 10.06 10.43
10 2.50 2.65 2.93 3.31 4.06 5.838 6.938 8.39 9.47 9.97 10.41
20 2.52...2.67 2.92 3.31 4.04 5.17 6.90 8.33 9.42 9.96 10.35
40 2.62 2.76 3.03 3.40 3.94 AC 5-80" (O.9o Torlt oo) one
60 POR) Pa, SHIBY Neko) | Schl) ARMAS 5:22) 6.22) 1 720Sikw Slo Ol09
Clear flour.
0 2.92 3.16 3.55 4.09 4.90 6.00) 6.78 7.44 8:28 “S!0l*. 9i63
10 3.01) 13:25) 3.6007 4.21 0:00 3-93. 16:61 7.10 97-64 8:57 7 9ise
20 3.01 3.23 3.63 4.16 4.94 5.83 6.39 6.96 7.54 8.18 9.06
2 £839) .S67
40 2.96 3.18 3.52 4.01 4.72 5.61 6.34 6.80
The flours discussed in the foregoing paragraphs were bleached on a
small scale in the laboratory. It then appeared desirable to apply
these tests to flours treated in a flour mill on a commercial scale. The
Pillsbury Flour Mills Company kindly agreed to provide the material,
and on the afternoon of August 4, 1921, a sample of unbleached patent
flour was drawn from their packers. Immediately thereafter the chlo-
rine was introduced into the agitator at the rate of one-half ounce per
barrel of flour, and a sack of flour thus treated was drawn from the
spout immediately below the bleaching agitator. Rask also supplied
samples of the bleached and natural flour used in the determination of
chlorine by his collaborators. The bleached sample of this pair had
1922] BAILEY: STUDIES ON WHEAT FLOUR GRADES 67
been treated with chlorine at the rate of 14 ounces per 26 barrels of
flour, or slightly more than was used in the Pillsbury mill.
Results of tests of these flours, given in Table 3, show that the com-
mercially treated samples responded to chlorine treatment in essentially
the same manner as did those bleached in the laboratory. These studies
will be repeated in the Minnesota State Experimental Flour Mill as
soon as the bleaching equipment is installed and ready to operate.
TABLE 3.
Effect of ordinary commercial bleaching with chlorine upon the specific conductivity and
hydrogen ton concentration of flour.
@ksorine SPECIFIC
Conpbuc-
S is Cc st As
ee Desomenon | Gowen” | umvor |" :
EXTRACT
K 30x10! per cenl
Le) se eee Unbleached....... ee 5.29 6.00 0.48
Bleached......... 0.86 5.53 5.64 Toe.
Pillsbury Mill....| Unbleached....... 2.00 5.50 6.07 0.40
Bleached ......... 15) 5.99 5.65
Winton called attention to the partial or entire disappearance of the
nitrite reaction from flours bleached with nitrogen peroxide when stored for
several months. It was accordingly deemed advisable to determine
whether or not the differences in these physico-chemical constants were
modified on extended storage. The pair of samples from the Pillsbury
Mill was accordingly retained and tested at occasional intervals. A por-
tion of each sample was stored in a tightly covered Mason jar, the
remainder in an ordinary cotton flour sack. After two months of
storage in this manner, as shown in Table 4, no appreciable change in
conductivity had occurred, and the increase in hydrogen ion concentra-
tion was about the same in all cases. The pH of the natural or un-
TABLE 4.
Effect of storage in jars and sacks upon the conductivity and hydrogen ion concentration
of patent flours.
Speciric Conpuctivity
or WATER EXTRACTS PH or Water Extracts
SAMPLE SrorED IN— ee
August 4, | October 3, August 4, October 3,
1921 1921 1921 1921
K30 x 104 Kao x 104
Unbleached...... WIABOR, NAL oo eo 5.48 5.50 6.07 5.92
Cotton sack...... 5.49 5.49 6.07 5.95
Bleached........ WLESOB TAL 5-014: 6.00 6.01 5.65 5.48
Cotton sack...... 5.90 5.87 5.65 5.46
68 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS |[Vol. VI, No. 1
bleached flour had not reached that of the freshly bleached flour as yet,
however. These samples will be retained, and this study extended over
as long a time as possible.
SUMMARY.
Bleaching flour with chlorine increases the specific electrical con duct-
ivity, hydrogen ion concentration, and buffer action of flour extracts in
direct ratio to the quantity of chlorine used.
These differences apparently do not disappear on storing the flour
for several months.
QUANTITATIVE DETERMINATION OF CHLORINE IN
BLEACHED AND NATURAL FLOURS.
By O. S. Rask (University of Minnesota, University Farm, St. Paul,
Minn.), Associate Referee.
At the request of the Referee on Cereal Foods, the writer conducted
a collaborative study of methods for the determination of the chlorine
content of chlorine-bleached flours. Two methods, designated as
Method I and Method II, were studied. Method I was proposed by
the writer and Method II is given in Methods of Analysis! as the present
tentative method. The materials used consisted of unbleached and
chlorine-bleached portions of a hard-wheat patent flour milled in a
commercial mill under the writer’s supervision. The unbleached por-
tion was taken on a Monday morning after the mill had been in opera-
tion about three hours and before the bleacher had been turned on.
The chlorine bleacher was then turned on and the bleached portion
taken about one hour later. Chlorine was applied at the rate of 14
ounces per 26 barrels of flour. So far as the writer is aware, this rate of
application approximates that of average commercial practice in bleach-
ing with chlorine.
Copies of Methods I and II, together with samples of the unbleached
and chlorine-bleached flours, were sent to each collaborator. At the
suggestion of certain cereal chemists, the collaborators were requested to give
special consideration to Method I and to study Method II only if their
time and other facilities permitted. For this reason several collaborators
reported no results on Method II.
The methods are the following:
CHLORINE CONTENT OF CHLORINE-BLEACHED FLOUR.
REAGENTS.
(a) Petroleum ether fractionated at 60-100°C. (1).
(b) Alkali solution—Dissolve 40 grams of sodium or potassium hydroxide in 1
liter of alcohol.
1 Assoc. Official Agr. Chemists, Methods, 1920, 169.
1922] RASK: DETERMINATION OF CHLORINE IN FLOURS 69
(C) Potassium chromate indicators.—Dissolve 5 grams of potassium chromate in
water, add a solution of silver nitrate until a slight red precipitate is produced, filter
and dilute to 100 cc.
(d) Dry C. P. calcium carbonate.
(€) Standard silver nitrate solution.—Dissolve 4.791 grams of silver nitrate in water
and dilute to 1 liter. 1 cc. is equivalent to 1 mg. of chlorine. Check by titration
against standardized solution of sodium chloride.
DETERMINATION,
Method I.
Weigh 75 grams of the flour into a cork-stoppered bottle of suitable size and shape.
Add, by means of a pipet, 150 cc. of the petroleum ether. Stopper tightly and shake
vigorously for about 1 minute. After standing 1 hour, shake again until the flour has
been loosened from the bottom of the flask. Set aside for 16 hours, preferably over-
night. Shake once more until the flour has been loosened from the bottom of the
flask. Allow to settle for a few minutes and then filter on a dry folded filter. The
funnel should be covered with a watch glass during filtration in order to reduce evapora-
tion. Collect the filtrate in a 100 cc. Erlenmeyer flask (2) and pipet 50 cc. into a nickel
or platinum (3) dish of 80-90 cc. capacity. Add 5 cc. of the alkali solution and evap-
orate to dryness on a steam bath. Carefully char the contents of the dish over a Bun-
sen burner or in an electric muffle, preferably the latter. Extract the charred mass
with 15-18 cc. of water, then once with an equal amount of dilute nitric acid (2 parts
water and 1 part acid) and finally 2 or 3 times with water, all extracts being filtered
through a 7 cm. filter paper and collected in a 300 cc. beaker or Erlenmeyer flask.
Transfer the filter paper containing the charred residue to the dish and return same to
the muffle and ignite contents to a white ash. Dissolve the ash in 5% nitric acid and
add the solution to the filtrate previously obtained. Neutralize the acidity of the
filtrate with a slight excess of dry calcium carbonate. Add 5 cc. of potassium chromate
indicator solution and titrate with the standard silver nitrate solution. Prepare a
blank containing the same amounts of all reagents used in the determination. As
calcium carbonate labeled C. P. invariably contains appreciable amounts of chlorine
a certain weighed quantity of this reagent should be used in the determination and the
same amount in the blank. 2 to 24 grams is usually sufficient. Correct for the amount
of silver nitrate necessary to give in the blank, so prepared, the shade obtained at the
end of the titration of the sample. Compute chlorides to parts per million.
Owing to the small amount of chlorides dealt with in this determi-
nation, special precautions must be taken that the air of the laboratory
during the entire operation is not contaminated with chlorine or hydro-
chloric acid fumes and that all reagents employed are as free as possible
from chlorine. The blank determination should be conducted simul-
taneously to ascertain the necessary corrections for conditions in the
laboratory as well as chlorine content of reagents.
NOTES.
(1) A low boiling petroleum ether can not be used because of errors introduced
through rapid evaporation.
(2) Filtrate may be collected directly in a 50 cc. volumetric flask if desired. Attention
is called to the fact that such flasks are usually calibrated to contain and not to deliver
the specified volume. Hence in transferring its contents to the dish it must be rinsed
with additional portions of the solvent.
70 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS | Vol. VJ, No. 7
(8) Nickel dishes are usually prescribed for this kind of work on account of the
corrosive action of chlorides on platinum. However, by following the above pre-
scribed precautions, platinum may be used.
Method IT.
Weigh 25 grams of flour into a flat-bottomed aluminum dish, 8-10 cm. in diameter,
and dry 5 hours in a boiling water or steam oven; transfer, with as little exposure to
the air as possible, to a continuous fat extractor and extract for 16 hours with anhy-
drous alcohol-free ether, which is also free from chlorine. Transfer the ether extract
to a nickel or platinum dish and add 5 cc. of the alkali solution. From this point pro-
ceed as in Method I.
The results of the collaborators are compiled in the following table:
Determination of the chlorine content of chlorine-bleached flours.
(Results reported as parts per million.)
MeEtnHop I Mernop II
ANALYST
Natural Bleached Natural Bleached
Flour Flour Flour Flour
J.A.LeClere, Minor-Hillard Co., Wilkes-
barre, Paws cisetes lh cauisod tiled oe 4 100
T. H. Hopper, North Dakota Agricultural
Experiment Station, Fargo, N. D.....} None 60
C. B. Morison, American Institute of
Baking, Chicago, ELA, BAS ed i og 25 106
E. L. Tague, Kansas Agricultural College,
Manhattan; Kang)§ ijn. i245. See 8 104 6 92
E. E. Smith, F. W. Stock & Sons, Hills-
dale, Mich selves Cait Sh LO soba a Ne bp eupbae 20 76
C. H. Bailey, University of Minnesota,
StvPauls Minneged ohne). wang 27 96 40 102
Emily Grewe, Federal Mill & Elevator
Gok tockport. IN Yiees Saeed 24 106 + Ta
ee RSE. eee LL a pie a Me ee 25 102 50 95
IAVET ARE yawc tthe. ate diye mah gia detente a as 16.6 93.7 32 96.3
D. J. Mayveety*, National Biscuit Co.,
INGWAVGrk INDI: yas Salo) See 74 177 93 215
B. A. Dunbar*, South Dakota nee
cultural College, Brookings, S. D...... 52 86 49 128
*As these collaborators used a slightly different technique in correcting for the chlorine content of
reagents used, their results were not included in computing the average.
DISCUSSION.
The work thus far has shown the necessity of making certain changes
in the directions which apply to both methods. It has been found
necessary to make the first extraction of the charred mass with acid
instead of wat« un order to obtain a clear and colorless filtrate in which
the subsequent colorimetric determination can be made. Apparently
the carbon in this char fails to act as a decolorizing agent in an alkaline
medium. It is recommended therefore that the sentence under Method I,
1922] SILBERBERG: DETERMINATION OF RICE HULLS IN RICE BRAN 71
which reads as follows: “Extract the charred mass with 15-18 cc. of
water then once with an equal amount of dilute nitric acid, etc.”’, be
changed to read as follows: “Extract the charred mass with two suc-
cessive 18-20 cc. portions of dilute nitric acid (one part acid to three
parts water) being careful to avoid mechanical losses due to evolution
of carbon dioxide. Then extract the mass two or three times with water,
all extracts being filtered through a 7 cm. filter paper, etc.”
Collaborators who used nickel dishes in which to char the extracts
report the formation of a green nickel nitrate which interfered with
the end point in the titration. It is further recommended, there-
fore, that directions be changed so as to specify the use of platinum
dishes exclusively for charring the extracts.
A glance at the tabulated results of the collaborators will show the
necessity of a continuation of this work before any definite recommenda-
tions can be made with regard to the value of either method. However,
these results show that Method I is worthy of further consideration. As
a technical method it is preferable to Method II owing to its simpler
technique and the less expensive apparatus which it requires. It is
recommended, therefore, that the above change be made in the direc-
tions and that the study of both methods, so changed, be continued to
ascertain more completely their relative merits.
MICROSCOPIC METHOD FOR THE QUANTITATIVE DETERMI-
NATION OF RICE HULLS IN RICE BRAN.
By B. H. Sr-BerBERG (Bureau of Chemistry, Washington, D. C.).
The Bureau of Chemistry has been using on official samples the micro-
scopic method for the determination of rice hulls in rice bran! which
was presented to the association last year by the Associate Referee on
Stock Food Adulteration. The following table is compiled from results
on record in the Bureau:
Rice hulls in rice bran.
Huis Estmmatep From Huis DETERMINED By
Sampte No. Cruve FIBER Crube FIBER Microscopic METHOD
per cent per cent per cenl
1 ees 21 About 20
2 15.4 21 20-25
3 14.8 19 15-20
4 10.7 9 Not over 10
5 11.6 10 Less than 10
1 J. Assoc. Official Agr. Chemists, 1921, 5: 77.
72 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 7
Since these results bear out the conclusions drawn last year from those
submitted by collaborators, it is again recommended that the method
be adopted by the association as a tentative one.
No report on the limit of accuracy in the determination of small
amounts of alcohol in beers was made by the associate referee.
No report on vinegars was made by the referee.
No report on flavoring extracts was made by the referee.
REPORT ON MEAT AND MEAT PRODUCTS.
By C. Rospert Moutron (Agricultural Experiment Station, Columbia,
Mo.), Referee.
In accordance with the recommendations adopted last year a further
study was made of the ferrous chloride method for nitrates and nitrites
(calculated as sodium nitrate) and the method for sugar in meat.
The referee secured the assistance of nine collaborators, but some of
these were unable to make reports.
The material used—lean, ground, air-dry, fresh beef—was prepared
by Ralph Hoagland, of the Bureau of Animal Industry, Washington,
D. C. The total sample weighed 1390 grams. Thirty-five grams of
C. P. dextrose and 7 grams of C. P. potassium nitrate were dissolved in
water and sprayed over the spread-out sample. After thorough mixing
the material was again spread out thinly on glass trays, stacked one
above the other, and dried by a current of air at room temperature.
When dry, the sample, weighing now 1455 grams, was again well mixed
and placed in glass sample jars provided with rubber gaskets and clamps.
If the chemicals added were dry and pure the sample would have con-
tained 2.40 per cent of dextrose and 0.402 per cent of nitrate calculated
as sodium nitrate. About 150 grams were sent to each collaborator, with
the advice to keep the sample sealed when not in use so as to prevent
the taking up of moisture from the air by this hygroscopic material.
ESTIMATION OF TOTAL SUGAR IN MEATS.
Directions were given that the methods as outlined in the Book of
Methods! be followed. Twenty grams of the dried meat was recom-
mended as equivalent to 100 grams of fresh meat. As an alternate
method of extraction the following was offered:
Weigh out the meat into an 800 cc. beaker, add 400 cc. of water and gently heat
to boiling. Continue boiling for about 30 minutes, transfer the mixture to a 1000 ce.
volumetric flask, cool and fill to the mark with water. Mix, filter and evaporate 800 cc.
of the solution in the usual manner.
! Assoc. Official Agr. Chemists, Methods, 1920, 213.
1922] MOULTON: REPORT ON MEAT AND MEAT PRODUCTS 73
The results shown in Table 1 were obtained in the chemical laboratory
of Swift & Company, Chicago, Il.
TABLE 1.
Estimation of dextrose in dried meat.
Cuprous Ox1pE METHOD ELectro.tytic METHOD THIOSULFATE Metuop
per cent per cent per cent
1.06 1.018 1.018
1.01 0.980 0.980
0.962 0.914 0.903
1.018 1.020 1.006
0.928 0.928 0.906
The following comments were offered with the report:
The three determinations shown in Table 1 were made on the same sample and in
the order given, consequently any errors made on the cuprous oxide and electrolytic
methods are cumulative in the thiosulfate method. We prefer the electrolytic method
because we believe there is less chance of error init. We have the following suggestion
to offer: After evaporating the extract to 25 cc. filter it as it is transferred to the 100 cc.
flask. This would remove an appreciable amount of organic matter that separates
out on evaporation and would diminish the bulky phosphotungstic precipitate.
C. H. Robinson, Central Experimental Farm, Ottawa, Canada,
obtained the results shown in Table 2. He reported a water content
of 8.54 per cent in vacuo at 80°C.
TABLE 2.
Total sugar in meats.
(Calculated as dextrose.)
I. First method of extraction:
Percentage Of GEKEFOSC.. 0.0.0 cre. ke ee ee A-0.51
B-0.50
IJ. Alternate method of extraction:
Pereentage @f Oct rOge . 55%y. cayayiteear-Yensaaenes 0 A—0.48
B-0.46
Comments by Robinson.—Dextrose in every case was determined by the cuprous
chloride-iodine method', checked against a commercially pure dextrose. This method
is in general use in the laboratory for similar determinations such as starch in sausages.
I had intended to check these results by the official Munson and Walker method? but
the sample ran out before this could be done. Better results were obtained by removing
the excess of phosphotungstic acid by powdered potassium chloride before instead of
subsequent to inversion, as outlined in methods of determinations.
Hoagland reported 0.39, 0.37 and 0.38 per cent of sugar as dextrose.
He found that the precipitation of phosphotungstic acid occurred more
readily when the solution was not neutralized. His comments follow:
The sugar was estimated by the method supplied with some modification. After
inversion of the sugar in the clarified extract, the method states that the solution should
be cooled, neutralized to litmus, made to volume, filtered and that potassium chloride
1J. Ind. Eng. Chem., 1919, 11: 747.
2 Assoc. Official Agr. Chemists, Methods, 1920, 78.
74. ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 7
should be added to the filtrate to precipitate any excess of phosphotungstic acid present.
On following this procedure I found that the precipitation took place slowly and in-
completely. However, on adding a little concentrated hydrochloric acid, a heavy
precipitate formed and complete precipitation was obtained. I then adopted the
following procedure: After inversion of the clarified extract, cool, but do not neutralize
the acid, and make to volume. Filter if necessary, add dry potassium chloride to
precipitate excess of phosphotungstic acid, filter and test for complete precipitation.
Take an aliquot portion of the filtrate, neutralize to litmus, make up to a given volume
and take an aliquot portion for the determination of sugar. Good results were ob-
tained by this procedure, the reduction of the Fehling’s solution being normal. The
reduced copper was estimated by Low’s method since we commonly use this method.
Since the meat contained about 2.4 per cent of added dextrose and
the collaborators found only about 1.0, 0.5 and 0.38 per cent it seems
to be inconsequential that neither the original dextrose in the meat nor
the purity of the added dextrose was determined. That the difficulty
was not due to differences in the samples is shown by the reports on
nitrates which follow.
It is to be regretted that more reports were not received. More
work on the method is demanded.
NITRATES AND NITRITES (CALCULATED AS SODIUM NITRATE).
Ferrous Chloride Method.
The material described previously was used for this work. The
collaborators were asked to follow the procedure given in the Book of
Methods!. Sodium hydroxide replaced potassium hydroxide, and the
use of the pinch-cock was not recommended since it leads to difficulties.
Instead of calculating the nitrate from the observed volume of gas
the following standard sodium nitrate solution was recommended:
Dissolve 2 grams of C. P. sodium nitrate in 1 liter of recently boiled distilled water.
Take 50 cc. (equivalent to 0.1 gram sodium nitrate) and determine the amount of
nitric oxide. 0.1 gram of sodium nitrate should give 26.36 cc. of nitric oxide at 0°C.
and 760 mm. pressure. Calculate the percentage of sodium nitrate from the volume
of nitric oxide obtained from the sample with the volume obtained from 0.1 gram C. P.
sodium nitrate, both being measured at room temperature. This is conveniently
done by transferring the measuring tube to a tall jar containing 40% sodium hydroxide
solution (commercial). The temperature of the surrounding caustic solution will soon
(10-15 minutes) be imparted to thecontents of the tube, and the volume of nitricoxide
is read with the tube in such a position that the level of the solution within and without
the tube coincide. The caustic in the jar should be kept at room temperature.
Nore.—A single coil of tin tubing fitted into the trough and carrying a current of cold water during
the determination greatly facilitates the operation. After all the air has apparently been driven out of
the apparatus, always boil a short time longer after the delivery tube has been placed under the eudio-
meter to make certain that no air remains. Next gradually introduce a measured portion of standard
nitrate solution, rinse the funnel tube with 10 per cent of hydrochloric acid and boil until all nitric oxide
has been driven over. After the gas tube has been removed quickly invert another tube over the delivery
tube and boil a short time longer to make sure that all nitric oxide has been driven over. Another portion
of the standard solution is run into the apparatus and the determination is repeated as above. Then run
the samples in the same way in each case making certain that all the nitric oxide has been driven over.
After running 6 or 8 determinations, not counting the standards, finally run another standard. The
three standards should check within 0.5 and about 35 cc.
The following results were reported:
1 Assoc. Official Agr. Chemists, Methods, 1920, 210.
1922] MOULTON: REPORT ON MEAT AND MEAT PRODUCTS 75
TABLE 3.
Nitrates in dried meat.
S
ANALYST Reine AVERAGE
per cent per cent
Chemical Laboratory, Swift & Co., Chicago, Ill......... 0.400
0.421 0.409
0.407
(Coy LIB LEO) OTTO ene mrcHe NE, GEV ECHO ce ENCES ECTS ESTO mate tare ork 0.373
0.382 0.382
0.389
A. L. Mehring, Bureau of Animal Industry, Washington, 0.332
BC NiO SN oe eee atl) uni AC eS set oe Sea 0.319 0.324
0.321
Ralphkigaglan dats s/ii'5 sua verona aS heb a rea 0.39
0.42 0.407
0.41
PSLGICEL TANEEGUE3 552 5) ao vogsns'e Sgaynieaiots ec pel en ae ee eae 0.402
Robinson reported that he calculated the nitrate by comparison with
the gas evolved from 0.1 gram of sodium nitrate. The results from two
other collaborators were probably calculated in the same manner ac-
cording to the directions although no statement was made by them.
Hoagland reported as follows:
The nitrates were determined by the method furnished except for slight modification.
Instead of extracting the meat several times with hot water, it was boiled with about
500 cc. of water, transferred to a liter flask, and when cool the solution was made to
volume. The contents of the flask were filtered and 850 cc. of the filtrate were
evaporated to about 30 cc. and used for the determination.
The results of three of the four analysts show a recovery of 100, 100
and 95 per cent of the added nitrate. This speaks well for the method
and shows the advisability of using a standard sodium nitrate solution
for calculating the nitrates in the sample under investigation.
The report of the associate referee for 1919! showed that 82.6 per
cent of the added sodium nitrate was recovered by comparison with a
standard nitrate solution while only 69.4 per cent was recovered by
calculating from the volume of gas alone.
The modified procedure outlined by Mitchell and given in the 1919
report seems to give more accurate results and to be safer.
RECOMMENDATIONS.
It is recommended—
(1) That the method for sugar in meats receive further study.
1 J. Assoc. Official Agr. Chemists, 1921, 4: 505.
76 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
(2) That the method outlined for the determination of nitrates in
meat products be adopted in place of, or as a modification of, the present
tentative method.
THE SEPARATION OF MEAT PROTEINS.
By C. Ropert Moutron (Agricultural Experiment Station, Columbia,
Mo.), Associate Referee’.
The Official and Tentative Methods of Analysis of the A. O. A. C.
permit the determination of a few protein groups in meat and its prod-
ucts. The soluble nitrogenous matter can be divided into coagulable
protein (globulin and albumin), proteose, peptone and gelatine, and
meat bases. In an attempt to extend these methods to allow a further
subdivision of the soluble nitrogenous matter the methods used by
Grindley? at the University of Illinois and extended by Trowbridge at
’ the University of Missouri have been used and further amplified. These
methods permit the subdivision of the soluble nitrogenous matter into
soluble protein, coagulable protein, proteose, peptone and peptid, and
amino acid and extractive nitrogen. This gives one more group than
permitted by the official methods.
The first attempt at extension was to apply well-known principles to
the separation so as to allow the determination of globulin and albumin
as separate fractions. The water-soluble, heat-coagulable proteins con-
sist of a mixture of globulin and albumin. Pure water will dissolve
albumins but not globulins*. However, when pure water is added to
raw meat a dilute salt solution results owing to the solubility of the
phosphates of potassium and smaller amounts of other salts of potassium
and sodium. This salt solution will dissolve some globulin. Heat will
coagulate both the globulin and albumin. The globulins can be re-
moved by half saturating their solutions with ammonium sulfate. Some
can be salted out by saturating with sodium chloride. Other salts
may also be used.
PREPARATION OF THE EXTRACT.
A cold water extract of the raw meat is prepared according to XX, 244. In the
laboratories of the Department of Agricultural Chemistry of the University of Missouri a
total of 150 or 180 grams of fresh meat is about equally divided among twenty beakers
of 150 cc. capacity, and one washing with 50 cc. of cold water and eight with 25 cc.
are employed. All the washings are collected and made up to some convenient volume
—six liters. This extract is used for analysis.
1C. F. Ahmann and W. S. Ritchie of the Department of Agricultural Chemistry, University of Mis-
souri, collaborated with the associate referee in this work. The data presented were used by Ahmann in
his dissertation for the degree of Master of Arts at the University of Missouri. The interpretation and
emphasis in this report differ in some essentials from those in the thesis.
2 J. Am. Chem. Soc., 1904, 26: 1086; 1905, 27: 658; 1906, 28: 25, 469.
3 There is a water-soluble pseudo-globulin in ox serum and there may be examples in other tissues. See
Haslam, H. C. Biochem. J., 1913, 7: 492.
* Assoc. Official Agr. Chemists, Methods, 1920, 214.
1922] MOULTON: SEPARATION OF MEAT PROTEINS 77
GLOBULIN.
Several 100 cc. aliquots of the extract prepared as directed are placed in 250 cc.
(or 400 cc.) beakers and 100 cc. of cold saturated zinc sulfate (ZnSo, . 7H.O) solution
are added to each. After mixing, the solutions are allowed to stand in a cold room
until separation occurs. Under the conditions outlined a good separation occurs in
48 hours. The solutions are then filtered onto filter papers fitted and wet with half-
saturated zinc sulfate solution. The coagulum is washed with cold half-saturated
zinc sulfate solution. Three washings of 20 to 25 cc. were used on account of the slow
filtration. Coagula fairly free from mother liquor are thus obtained. The nitrogen
was determined by the Kjeldahl-Gunning-Arnold method’.
In Table 1 are shown the results on four samples of lean round steak
of beef and two of pigeon flesh. The results, expressed as per cent
nitrogen in fresh meat, in many cases show uniformity. In others the
agreement is not so good as is desired. Sample 20 was the first one
tried and both the method and the manipulator were new. Two out
of the other 25 results are excluded from their respective averages since
they are much higher than the companion results. The method seems
to give sufficiently good agreement for comparative purposes.
TABLE 1.
Globulin nitrogen in flesh.
(Percentage of total flesh.)
BAMPLE BEEF arg crvi al ak 7a ag B
1 0.168 0.123 0.172* oe 0.208 0.112
2 0.143 0.113 0.131 0.394 0.214 0.112
3 0.134 0.135 0.151 0.395 0.228 0.117
4 nae Boa 0.137 0.400 0.214 0.141*
5 0.134 0.404 0.211 0.129
6 Fy 0.400 0.208 0.102
Average 0.148 0.124 0.138 0.399 0.214 0.114
* Omitted from average.
The effect of saturated sodium chloride on the coagulation of globulin
was next studied. Beef Sample 9 was used. When the calculated
amount of the salt was added but two-thirds of the globulin coagulated
by half-saturated zinc sulfate was thrown down. Table 2 shows the
results. Two samples, marked with asterisk, were treated with quite
an excess of sodium chloride, and the globulin coagulated was increased
about 20 per cent but still remained considerably below the amount
coagulated by half-saturated zinc sulfate.
It was thought that perhaps the ratio of the salt to the amount of
material to be precipitated might affect the results obtained. Conse-
quently aliquots of the extract were taken and diluted with an equal
volume of cold water. Then they were treated with the two salts as
1 Assoc. Official Agr. Chemists, Methods, 1920, 7.
78 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol, VI, No. 1
TABLE 2.
Zine sulfate vs. sodium chloride for globulin nitrogen.
Haur-SaTurRATED ZINC SULFATE SATURATED Sopium CHLORIDE
Concentrated Extract Dilute Extract Concentrated Extract Dilute Extract
0.394 0.409 0.252 0.200
0.395 0.344 0.246 0.199
0.400 0.377 0.252 0.168 t
0.404 Phy se 0.318* 0.187
0.400 DES ie 0.314* 0.200
Average 0.399 0.377 0.260 0.197
*Omitted from above average. Large excess of sodium chloride.
tOmitted from the average.
before. The results are shown in Table 2. In both cases a smaller
quantity of material was coagulated than when the undiluted extract
had been used, although the concentration of salt was the same as in
the undiluted extracts.
Dilution of the extract or the use of sodium chloride to saturation
does not remove as much nitrogen, classed as globulin, as is removed on
half saturating the undiluted extract with zinc sulfate.
This water extract was acid to both litmus and phenolphthalein and
so the pH was probably on the acid side of the iso-electric point of the
proteins in solution. Consequently the anion of the salt used was
prepotent over the cation! in forming combinations with the protein.
The sulfate would therefore be a better coagulant (or precipitant) than
the chloride as has been shown by Lewith, Hofmeister, Pauli and others
and quoted by Robertson?. Chick and Martin? have shown that di-
luting a solution of egg-albumin allowed the same concentration of
ammonium sulfate to precipitate not only a smaller quantity of the
protein but a smaller proportion of the total.
The amounts of globulin are in all cases probably too low. Both
Haslam‘ and Mellanby® have shown that zinc sulfate is not so good a
precipitating agent as ammonium or sodium sulfates. On the other
hand it must be emphasized that not globulin alone is precipitated
(coagulated) under the conditions given. Some albumin will be thrown
down also.
ALBUMIN.
The filtrates from the globulin determination were coagulated by
heat in an attempt to coagulate the albumin remaining in solution. In
"1 For the theory and facts on which it is dependent the reader is referred to the recent work of Loeb.
J. General Physiol., 1918-19, 1: 39, 237, 363, 483, 559.
2 The Physical Chemistry of the Proteins, 1918, 107-134.
> The Precipitation of Egg-albumin by Ammonium Sulfate. A contribution to the theory of the salting
out of proteins. Biochem. J., 1913, 7: 380.
‘J. Physiol., 1907-8, 36: 164.
5 [bid., 288.
1922] MOULTON: SEPARATION OF MEAT PROTEINS 79
all cases the coagulum obtained was very small in amount representing
only from 0.050 to 0.098 per cent of the meat as albumin nitrogen.
From results shown it will be seen that these figures are much too low.
A few of the later filtrates were examined for acidity, since it was thought
that perhaps the albumin failed to coagulate, owing to high acidity of
the liquid which might have developed on standing, and coagulation of
the globulin. Some of these required 54.5 cc. of normal sodium bi-
carbonate solution to neutralize them, using phenolphthalein as an
indicator. Heat coagulation of the neutralized filtrate from the globu-
lin determination gave no better results. The salt solution in some
manner other than aiding in increasing the acidity prevents the heat
coagulation of the albumin.
The albumin nitrogen can be determined indirectly by subtracting
the globulin nitrogen from the nitrogen obtained on coagulating the
water extracts by means of heat. In this work the extracts were neu-
tralized while on the steam bath by adding an excess of moist, freshly
precipitated magnesium carbonate. This method has been used in the
referee’s laboratories for some time and has been considered very satis-
factory. The percentage of the meat obtained as _heat-coagulable
nitrogen is shown in Table 3. Again Sample 20 does not give uniform
results, due, probably, to the lack of experience on the part of the opera-
tor. Two of the six results for Sample 104 are at wide variance with
TABLE 3.
Heat coagulable nitrogen in flesh.
(Percentage of total flesh.)
BEEF 20 BEEF 26 BEEF 104 BEEF 9 PIGEON 78 SQUAB 88
0.321 0.381 0.379* 0.536 0.428 0.229
0.316 0.362 0.493 0.550 0.438 0.232
0.312 0.386 0.523 0.533 0.443 0.225
0.287 0.370 0.496 0.539 0.469 0.219
0.282 0.378 0.333* 0.529 0.433 0.248
0.282 0.378 0.454 0.536 0.441 0.202
0.304 0.375 Sys Be 0.441 0.223
0.299 0.385 Mace BGS, 0.455 0.215
0.303 0.385 Aces =n CS 0.501 0.201
oes aera Bp ie ee A 40 0.410 0.215
0.471 0.221
0.453 0.221
0.414 0.215
0.452 0.217
0.407 0.186*
0.436 0.232
0.448 0.226
0.466 0.216
0.445 0.222
ee “toes sheet Beles 0.424 0.219
Average 0.301 0.377 0.492 0.537 0.442 0.223
*Omitted from average.
80 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 1
the others. In general fairly good agreement is shown between the
aliquots of the same extract.
In Table 4 is shown the calculation of the albumin nitrogen. The
average results shown in Table 1 and Table 3 are used. Comparison
of the different samples is of little value except to show the differences
in composition of commercial samples of beef round. In half of the six
samples the albumin and globulin were about equally divided. In two
cases the albumin was much the larger, while only in one case was the
globulin the larger.
TABLE 4.
Albumin nitrogen in flesh.
SAMPLE BEEF 20 BEEF 26 BEEF 104 | BEEF 9 PIGEON 78 | sQuaB 88
per cent per cent per cent per cent per cent per cent
Globulin and albumin...| 0.301 0.377 0.492 0.537 0.442 0.223
Globulin (20°22. 29 2022 0.148 0.124 0.138 0.399 0.214 0.114
Albumin by difference...| 0.153 0.253 0.354 0.138 0.228 0.109
PROTEOSE.
The filtrates and washings from the heat-coagulable protein were
concentrated to a volume of about 25 cc. They were then saturated
with zinc sulfate (ZnSO, . 7H:O) when cool and acidified with acid.
Different quantities of acid were used with some of the extracts and in
one case acetic acid was used. Table 5 shows the results obtained
expressed as percentage of proteose nitrogen in the meat sample. It is
seen that a larger quantity of acid added increased the proteose nitrogen
precipitated by saturated zinc sulfate.
TABLE 5.
Influence of acidity on the precipitation of proteose by zinc sulfate.
SAMPLE NO ACETIC SULFURIC ACID
ACID ACID
5ce.2N |2.5 ce: 2N'| 5cec.2N | Fec.2N |} 1 ceed tol
20 0.000 0.020
26 0.012 0.019 hee
78 0.030 0.037 es
88 0.019 0.024 Jaen
In Table 6 are shown the results for all samples expressed in the
usual terms. The quantity of proteose nitrogen is exceedingly small
and this determination might well be omitted. I[t serves in this study,
1922] MOULTON: SEPARATION OF MEAT PROTEINS 81
TABLE 6.
Proteose nitrogen in beef and pigeon flesh.
(Percentage of total flesh.)
BEEF BEEF BEEF BEEF PIGEON SQUAB
20 26 104 9 78 88
0.017 0.030 0.017 0.042 0.023
0.015 0.012 0.014 0.023 0.035 0.039
0.028 0.027 0.023 0.023 0.035 0.031
0.023 0.020
0.065* pana
4G ae 0.029 0.017 picts ena
Average 0.020 0.019 0.024 0.020 0.037 0.031
*Omitted from average.
however, as a means of checking other determinations. These results
are probably lower than would have been obtained with ammonium
sulfate!.
GLOBULIN, ALBUMIN AND PROTEOSE.
Several 100 cc. aliquots of the water extract were saturated with zinc
sulfate (ZnSO, . 7H.O) and acidified. This treatment should have
thrown down globulin, albumin and proteose (albumose). Various
amounts of sulfuric acid were tried and in one case acetic acid was used.
The weight of sample varied from 2.25 to 3.00 grams and the percentage
of nitrogen coagulated varied from 0.256 to 0.516. In Table 7 are
shown the detailed results. This study of the effects of acidity was
rather incidental to the work since the samples were used mainly for
another purpose. There are consequently many gaps in the data.
The values of 9, 18, 27 and 45 cc. of 2N sulfuric acid are the equivalents
of 1, 2, 3 and 5 cc. of 1 to 1 sulfuric acid. These small amounts of
more concentrated acid were used for the higher acidities in order not
to dilute the 100 cc. of water extract unduly.
There is apparent a relation between the percentage of nitrogen
precipitated and the acidity of the solution. For example, in Sample
88 an acidity given by 5 cc. of 2N acid coagulated 0.263 per cent of
nitrogen which was complete as shown by the percentage on the bottom
line of the table. This is the sum of the proteose nitrogen and the heat
coagulated nitrogen. For Sample 20 an acidity of 9 cc. of 2N acid
coagulated 0.330 per cent, i. e. it was sufficient for complete coagulation.
For Sample 104 the lower concentrations of acid precipitated too small
an amount of protein. However, 45 cc. of 2N acid gave complete
coagulation, i. e. 0.516 per cent.
With Sample 26 low concentrations of acid gave incomplete coagula-
tion, but sulfuric acid was better than acetic acid. With Sample 78
1 Haslam, H. C., J. Physiol., 1907-8, 36: 164.
82 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
the amount of acid in no case was great enough to give complete coagula-
tion.
TABLE 7.
Protein coagulated with saturated zinc sulfate with varying acidities.
(Per cent nitrogen of fresh sample.)
ACID USED SQUAB BEEF BEEF PIGEON BEEF
88 20 26 78 104
114 cc. of 2N acetic acid. Pete: Sead 0.307
Lehi oa 0.313
0.313
Flee eer} 0.342 Hae 0.169
114 cc. of 2N sulfuric acid. hiker aby 0.336 feta Heh 0.473
0.334 0.485
21% cc. of 2N sulfuric acid. ene fet) yout 0.438 0.485
fear Soe Beas 0.438 0.498
0.438 0.501
0.256 0.445 0.501
5 0.272 0.421 0.452
0.260 0.442 0.449
0.231 0.329 ia Be 0.503
9-10 0.178* 0.329 ee 0.445 0.481
0.272 0.332 0.421 0.487
0.256 0.445 0.478
15-18 0.239 0.424 0.501
0.260 0.428 0.471
0.478
27 0.501
0.501
LAKE Bs 5 LPR iam | 0.514
45 ne ie Poe ei, Mee 0.504*
0.517
Amount present that should
have been coagulated. . 0.254 0.321 0.396 0.479 0.516
*Omit from average.
In Fig. 1 are plotted the milligrams of nitrogen coagulated by zinc
sulfate at saturation with the concentrations of acid added as abscissae.
The three samples that gave complete coagulation lie on a straight line.
For the two cases of incomplete coagulation the weight of protein (nitro-
gen) coagulated by a given concentration of acid was larger than the
curve shows for complete coagulation. The weight that should have
been coagulated is shown above the first point, and the concentration
of acid probably needed for complete coagulation is shown by pro-
jecting this last point until it strikes the line. It should thus have taken
a little over 3 cc. of 1 to 1 sulfuric acid to give complete coagulation in
Sample 26 and about 4.5 cc. for Sample 78.
1922] MOULTON: SEPARATION OF MEAT PROTEINS 83
X= Bseve” volves. EEG
| 08%. of wtrogen that should pave been a coarulnod SERRSRE eee
4.2 Sroboble relation berweern acidity and Hao PCE ee
109. oF ritregen to be coagulated. HH Baga LI]
| ei a a
16 r]
PennnSeereeeeeeneers SO00000 0000000500500 0RR>".
id EOE eeeaoUe ioe iaaguname ae fe ae55--<c008
Siescart eeebasencuee*=-tasactereesnae
Sebel
a =
a
OMAYTEDPOH ZMHOnI-zZ OB
SEE Cease gee | Poo
° 5 CO yg OM. yg eFQ820 af OED ag Jo os 4o 45
a y C.C. 2 Pil FieSOx . ALOED Bs &
FIG. 1—THE RELATION BETWEEN THE CONCENTRATION OF ACID AND THE
QUANTITY OF PROTEIN COAGULATED BY SATURATED ZINC SULFATE.
Haslam has shown that the addition of acid to zinc sulfate is neces-
sary in the separation of albumoses. The results given in this paper
indicate that there is probably also a relation between the protein
(globulin, albumin, and proteose) to be coagulated and the acidity of
the solution. It is known that acid increases the precipitating power
of salts. To what extent this is true in this case is shown by the fol-
lowing results with Sample 20 (Table 8) where the globulin fraction is
increased from 0.148 to 0.269 per cent by the addition of 1 cc. of 1 to 1
sulfuric acid. The total globulin, albumin and proteose was but 0.330
per cent.
TABLE 8.
Effect of acid on the globulin fraction.
(Per cent nitrogen of fresh sample.)
ZINC SULFATE
HALF
HALF SATURATED
SATURATED
SATURATED ACIDIFIED
ACIDIFIED
0.168 0.273 0.329
0.143 0.264 0.329
0.154 0.269 0.332
The concentration of the proteins to be coagulated has an effect on
the total amount coagulated. The filtrates from the globulin determi-
nation for Sample 26 were saved, saturated with zinc sulfate and acidi-
fied with the equivalent of 114 cc. of 2N acid. Albumin and proteose
should have been coagulated. The percentage of nitrogen thrown
down was, however, only 0.169 when the difference between the globulin,
albumin and proteose combined and the globulin fraction is 0.123 per
84 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 7
cent. Similar results occurred in the globulin determination when the
water extract was diluted before adding the salt.
AMINO ACIDS AND EXTRACTIVES.
The fraction known as amino acids and extractives is sometimes
called “rest’’ nitrogen and sometimes “meat bases’. It is the fraction
not precipitated by salt and tannic acid.
In this work an attempt was made to treat original aliquots of the
water extract with salt and tannic acid as well as filtrates from the
heat-coagulable protein. In nearly all cases difficulty was experienced
in getting triplicate determinations to agree. The water extract, or
the concentrated filtrate and washings from the coagulable protein
determination, were placed in volumetric flasks of 100 cc. (or 200 cc.)
capacity and 15 grams (30 grams for 200 cc.) of salt were added. This
did not dissolve readily and the manipulator in many cases added the
30 cc. (60 cc. for the larger flask) of 24 per cent tannic acid before all
the salt had dissolved. Even where solution was practically complete
a difference in color of the mixtures was noticed on settling. The
rapidity of addition and the method of mixing seemed to affect the color.
Another difficulty experienced was to get the manipulator to use enough
alkali during distillation to more than neutralize the larger amount of
sulfuric acid required during the digestion.
It made no difference whether the original extract or the filtrate and
washings from the coagulable protein was used. The detailed figures
will not be given.
TABLE 9.
Distribution of nitrogenous bodies in raw meat.
(Expressed as nitrogen in percentage of meat.)
SAMPLE BEEF BEEF BEEF BEEF PIGEON SQUAB
20 26 104 9 78 88
Total nitrogemas. + 20. .25 3.150 3.579 4.079 3.350 3.466 3.794
Water soluble nitrogen...... 0.699 0.994 0.876 0.777 0.795 0.563
Heat coagulable nitrogen... .| 0.301 0.377 0.492 0.587 0.442 0.223
Proteose nitrogen........... 0.020 0.019 0.024 0.020 0.037 0.031
Sum of above two.......... 0.321 0.396 0.516 0.558 0.479 0.254
Globulin, albumin and _ pro-
TEOSE We NU Ate ates: Na 0.330 ¥ 0.516 tT s 0.256
Globulin nitrogen...........| 0.148 0.124 0.188 0.399 0.214 0.114
Albumin nitrogen..... 0.153 0.253 0.354 0.138 0.228 0.109
Amino acid and extractive N.| 0.315 | 0.233 l\ gs6q | 9.313 } 0.273 | 0.198
Peptone and peptid nitrogen {| 0.062 ONS: ihe ;
~ * Lower than sum of heat coagulable and proteose nitrogen.
t+ Not determined. +t Determined by difference.
SUMMARY OF ANALYTICAL RESULTS.
In Table 9 are collected the summarized data for all the samples.
Some few results are omitted because of obvious error or because the
determination had not been made.
1922] MOULTON: SEPARATION OF MEAT PROTEINS 85
GENERAL SUMMARY.
The nitrogen of meat soluble in cold water is divided according to
the methods of separation here employed approximately into globulin,
albumin, proteose, peptone and peptid, and amino acid and extractive
nitrogen.
Zinc sulfate at half saturation coagulates more nitrogen as globulin
than does sodium chloride at saturation. Diluting the extract reduces
the amount of nitrogen coagulated.
Globulin and albumin nitrogen are readily coagulated by heat in the
presence of an excess of moist freshly precipitated magnesium car-
bonate.
Globulin, albumin and proteose nitrogen are coagulated by saturated
zinc sulfate (ZnSO, . 7H.2O0) when sufficiently acidified with sulfuric
acid. Seven milligrams, or less, of nitrogen to be coagulated require
1 cc. of 1 to 1 sulfuric acid for complete coagulation; 12 milligrams require
at least 314 cc. and 15 milligrams require about 5 cc. The necessary
amount of acid can be estimated from Fig. 1. Dilution of the extract
resulting from a previous removal of globulin gives a smaller recovery
in this fraction by an amount considerably greater than the globulin
removed.
Difficulty was experienced in determining the amino acid and ex-
tractive nitrogen by coagulating the other fractions with tannic acid and
sodium chloride. The method needs further study.
No claim is made that the fractions designated by specific names are
pure. It is recognized that contamination may be great, but the results
should nevertheless be of qualitative value.
Work will be continued along this general line. Zinc sulfate will be
compared with ammonium sulfate.
RECOMMENDATIONS.
It is recommended—
(1) That further work be done concerning the relation of the con-
centration of acid and protein to the coagulation by salts of proteins
of meat soluble in cold water.
(2) That zinc sulfate be compared with ammonium and sodium
sulfates.
(3) That further work be done with the sodium chloride and tannic
acid method to determine all the conditions necessary to give com-
parable results.
86 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 7
THE AMINO ACIDS IN THE GLOBULIN-ALBUMIN FRACTION
OF BEEF FLESH.
By C. Rosert Moutron (Agricultural Experiment Station, Columbia.
Mo.), Associate Referee!.
Three samples of the water-soluble, heat-coagulable proteins from
the lean of the round cut of three beef steers were used in this work.
These samples included the albumins and part of the globulins in the
flesh and did not represent a single pure protein. Nevertheless the
amino acid make-up of this fraction is of value, e. g. in questions affect-
ing the nutrition of the animal.
The methods used were in general those devised by Van Slyke”. They
are given with modifications below:
HYDROLYSIS‘.
Three grams of protein, in duplicate, were placed in 250 cc. Erlenmeyer flasks, to
which 100 cc. of 3N hydrochloric acid were added. The flasks were placed in a water
bath at 100°C. and allowed to remain until the protein was completely dissolved, when
they were placed in an autoclave at 150°C. for 14% hours. At the end of this time the
hydrolysis was considered to be complete.
TOTAL NITROGEN.
The hydrolyzed material was washed into a 250 cc. Claissen distilling flask and con-
centrated in vacuo, driving off all the hydrochloric acid possible. The concentrate
was then taken up with hot water, transferred to a 100 cc. graduated flask, cooled and
made up to the mark. An aliquot of 5 cc. was taken for the total nitrogen determi-
nation, the Kjeldahl-Gunning-Arnold method‘ being used.
ACID-INSOLUBLE HUMIN‘®.
The remaining 95 cc. were filtered and washed till free from chlorides. The nitrogen
content of the black residue was determined by the Kjeldahl-Gunning-Arnold method.
AMMONIA (AMIDE) NITROGEN.
The filtrate from the acid-insoluble nitrogen determination was transferred to a
liter Claissen distilling flask; 100 cc. of alcohol were added to prevent frothing and also
a slight excess of a 10 per cent suspension of calcium hydroxide, as shown by the alka-
line reaction and by the turbidity of the solution. The flask was placed in a water
bath at 40°-50°C. and connected with two trap flasks containing N/14 hydrochloric
acid and a few drops of methyl red and distilled at less than 30 mm. pressure for one-
half hour. The acid from both trap flasks was transferred to a wide-mouth 500 ce.
Florence flask and titrated with N/14 ammonia. The amount of hydrochloric acid
neutralized by the ammonia distillate is found by difference.
1E. G. Sieveking of the Department of Agricultural Chemistry, University of Missouri, collaborated
with the associate referee. This work forms a part of the dissertation presented by him for the degree
of Master of Arts at the University of Missouri.
2 J. Biol. Chem., 1911, 10: 15; 1915, 22: 281.
3 Van Slyke, D. D., J. Biol. Chem., 1912, 12: 295.
* Assoc. Official Agr. Chemists, Methods, 1920, 7 .
5 Gortner, R. A., and Holm, G. E., J. Am. Chem. Soc. 1917, 39: 2477.
1922] MOULTON: AMINO ACIDS IN BEEF FLESH 87
ACID-SOLUBLE HUMIN'.
The solution and precipitate from the ammonia determination were filtered and
washed free from chlorides and the nitrogen content of the precipitate determined by
the K jeldahl-Gunning-Arnold method.
PRECIPITATION AND WASHING OF THE PHOSPHOTUNGSTIC ACID
PRECIPITATE.
The filtrate from the acid-soluble humin determination was returned to the liter
Claissen distilling flask, acidified with hydrochloric acid, concentrated to about 100
ec. and washed into a 250 cc. Erlenmeyer flask. Then 18 cc. of concentrated hydro-
chloric acid and 15 grams of phosphotungstic acid, purified as described by Winter-
stein’, were added. It was then diluted to 200 cc. and heated on a steam bath till
practically all of the precipitate had dissolved. The precipitate was allowed to stand
for 48 hours or more.
The solution and precipitate were poured onto a 2-inch Biichner funnel and washed
until free from calcium with successive portions of from 10-15 cc. of a wash solution
containing 2.5 grams of phosphotungstic acid and 3.5 grams of concentrated hydro-
chloric acid per 100 cc. and cooled to nearly 0°C. The test for calcium was made by
allowing a drop or two of the solution from the Biichner to run down the side of a test
tube containing about 5 cc. of an alkaline oxalate solution. If calcium were present
the solution became turbid after standing a few minutes.
DECOMPOSING THE PHOSPHOTUNGSTATE PRECIPITATE AND THE
DETERMINATION OF PHOSPHOTUNGSTATE HUMIN'.
The precipitate was transferred to a 500 cc. separatory funnel with a spatula and
by washing. It was then shaken with 5-10 cc. of concentrated hydrochloric acid and
enough of a 1 to 1 amyl alcohol-ether mixture so that it floated on top after all the
precipitate had gone into solution. The solution did not become entirely free from
turbidity due to the presence of phosphotungstate humin which was removed by pass-
ing the entire solution through a Biichner funnel. The nitrogen content of the pre-
cipitate was determined by the Kjeldahl-Gunning-Arnold method. The water solu-
tion of the bases was then separated from the amy! alcohol-ether mixture and extracted
with 3 or 4 successive 50 cc. portions of the mixture and finally the combined amyl
alcohol-ether solutions were extracted with about 100 cc. of water to remove any traces
of the bases. The wash water was extracted with a fresh portion of amy! alcohol-
ether mixture before being added to the main solution of the bases. The solution
of the bases was evaporated to dryness in the vacuum distilling apparatus in order to
remove the excess hydrochloric acid and then it was taken up with hot water, trans-
ferred to a 50 cc. graduated flask, cooled and made up to the mark.
ARGININE.
Arginine was determined on a 25 cc. aliquot of the solution of the bases using Plim-
mer’s’ modification and an apparatus as modified by Koehler’. Twenty-five cc. of
40% sodium hydroxide were added to the aliquot in a 200 cc. Kjeldahl flask. The
flask was attached to a reflux condenser the upper end of which was connected by a
glass tube to a bottle containing 15 cc. of N/14 hydrochloric acid. Air was drawn
through the apparatus during the 6 hours’ boiling, after which the water was drawn
1Gortner R. A., and Holm, G. E., J. Am. Chem. Soc., 1917, 39: 2477.
2 Z. physiol. Chem., 1901, 34: 153.
3 Biochem. J., 1916, 10: 115.
4 J. Biol. Chem., 1920, 42: 267.
88 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
from the condenser and the boiling continued for about 20 minutes in order to drive
off all the ammonia. The excess acid was titrated with N/14 ammonia, using methyl
red as an indicator.
TOTAL NITROGEN OF THE BASES.
The solution remaining after the arginine determination was completed was trans-
ferred to a 500 cc. Kjeldahl flask and nitrogen determined by the Kjeldahl-Gunning-
Arnold method. The nitrogen driven off as ammonia during the arginine determi-
nation added to this gave the total nitrogen of the bases.
CYSTINE.
Cystine was determined by Denis’s! modification of Benedict’s? method. An aliquot
of 10 cc. of the solution of the bases was transferred to a 10 cm. evaporating dish and
5 cc. of a solution containing 25 grams of copper nitrate, 25 grams of sodium chloride,
and 10 grams of ammonium nitrate per 100 cc. of water were added. It was then
evaporated to dryness on the water bath and gradually heated to a dull red heat which
was maintained for about 10 minutes. The black residue was dissolved in 10 cc. of
10% hydrochloric acid, diluted to 150 cc., and heated to boiling. To the boiling
solution 10 cc. of 5% barium chloride were added slowly and with stirring. The
precipitate was allowed to digest overnight on a steam bath after which it was filtered
hot through a No. 589 S. & S. blue-ribbon filter paper. It was then washed till free
from chlorides with hot water, ignited at a dull red heat and weighed. A blank was
run on the reagents and the necessary correction made.
AMINO NITROGEN OF THE BASES.
Amino nitrogen was determined by the Van Slyke* method of decomposing the amino
acid with nitrous acid in the micro apparatus’. Two cc. of the solution of the bases
were allowed to react for 30 minutes in the micro apparatus after which the amount of
nitrogen evolved was read, the temperature and pressure being noted.
HISTIDINE (Calculated)*.
Histidine was determined by solving the formula,
Histidine N =3/2 (D—3%% arginine)
=1.5 D—1.125 arginine,
D being the difference between the total nitrogen of the bases and the amino nitrogen
determinations, or the nonamino nitrogen.
LYSINE (Calculated).
Lysine nitrogen was determined by difference.
Lysine N =Total N of the bases — (Arginine N +Cystine N+ Histidine N).
TOTAL NITROGEN OF THE MONOAMINO ACIDS.
The combined filtrate and washings of the phosphotungstate precipitate were
rendered just alkaline by adding 50% sodium hydroxide and then just cleared
of the turbidity formed by adding 50% acetic acid. The acid solution was
concentrated in vacuo until salt began to crystallize out when the solution was trans-
ferred to a 250 cc. graduated flask and made up to the mark. The total nitrogen was
1 J. Biol. Chem., 1910, 8, 401.
2 Ibid., 1908, 6, 363.
3 [bid., 1911, 9, 185; 1912, 12, 275.
‘ J. Biol. Chem., 1913, 16, 121; 1915, 23: 407.
5 Tbid., 411.
1922] MOULTON: AMINO ACIDS IN BEEF FLESH 89
determined on a 50 cc. aliquot by the Kjeldahl-Gunning-Arnold method; the digestion,
however, was continued for 3 hours after the solution had become clear in order that
the phosphotungstic acid present would not interfere with the determination.
AMINO NITROGEN OF THE MONOAMINO ACIDS.
A 4 cc. portion of the solution was allowed to react with the nitrous acid for 6 minutes
in the micro apparatus after which the volume of nitrogen evolved was read and the
temperature and pressure noted.
NONAMINO NITROGEN (Calculated).
The nonamino nitrogen of the monoamino acids was determined by difference.
Nonamino N = Total N—Amino N.
TOTAL SULFUR'.
Inasmuch as sulfur is lost during the hydrolysis of proteins it was decided to determine
the total sulfur content on the original sample in order that a comparison might be
made with the percentage of sulfur found in the cystine determination.
Ten grams of sodium peroxide were placed in a 100 cc. nickel crucible and enough
water added so that it was completely decomposed to sodium hydroxide. The solution
was heated over an alcohol flame until a scum formed on the surface of the liquid on
cooling. One gram of protein was added and thoroughly mixed with the sodium
hydroxide with a nickel stirring rod. The heating was continued until the mass in the
crucible subsided and changed from a brown to a black oily appearing liquid.
After a few minutes of heating small amounts of sodium peroxide were added till
the oxidation was complete. The substance was cooled, dissolved in water, trans-
ferred to a 600 cc. beaker and strongly acidified. It was then boiled to drive off the
excess chlorine, exactly neutralized with ammonium hydroxide, 4 cc. of concentrated
hydrochloric acid added and evaporated to a volume of 400 cc. if necessary. Ten cc.
of hot 10% barium chloride were added slowly and the solutions allowed to stand
overnight on a steam bath. Then they were filtered hot through No. 589 S. & S.
blue-ribbon filters, washed with a little weak hydrochloric acid solution and then with
hot water till free from chlorides. They were ignited, weighed and calculated as per-
centage of sulfur and as percentage of nitrogen as cystine, assuming all the sulfur was
present as cystine.
TOTAL NITROGEN.
One gram of the original sample was weighed out and placed in a Kjeldahl flask and
digested. The solution was made up to volume and a fifth aliquot taken for distil-
lation. All operations were carried out as in the Kjeldahl-Gunning-Arnold method.
It was necessary to know the total nitrogen of the original sample, since the sulfur
was determined directly, in order to make the percentage of nitrogen as cystine com-
parable with the figures of the Van Slyke analysis.
The results of the analyses are shown in the table, where the nitrogen
in each fraction is expressed in percentage of the total nitrogen. The
nitrogen in the air-dry material varied from 12.50 to 13.61 per cent.
The sample was fat free but not moisture and ash free. The moisture
and ash were not determined and consequently it is necessary to present
the results as indicated.
1 Osborne, T. B., J. Am. Chem. Soc., 1902, 24: 140.
90 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
Nitrogen distribution of globulin-albumin fraction of lean beef round.
(Percentage of total nitrogen.)
SAMPLE NO.
CONSTITUENT
504 592 594
Ammonia MItnOPen ry oe cei. AA ae Seer Cee 6.18 6.93 6.98
Acid insoluble humin nitrogen............ ast? Mea! 1.14 0.82 0.55
Acid'soluble bumin nitrogen’... 000 ON 1.98 1.75 1.68
Phosphotungstate humin nitrogen............... 0.69 0.80 0.73
Arginine nitrogen... .jackid «2s SERA ee 14.64 12.98 14.10
Gystinemrtropent sync eres absicraroeree lemeenae 1.40 0.80 1.01
[Sysine mifrorent she eias cite acris ome cee Ee 14.92 11.96 14.96
Histidine mitrogemirrene s/s sess ks ere oe ee ees 2.76 10.32 3.82
‘Total nitrogenof thebasesie (08 sexu. <2. /eemodonk 33.71 36.05 33.88
Amino nitrogen of the monoamino acids.......... 55.34 55.99 58.64
Nonamino nitrogen of the monoamino acids. ..... 2.88 2.61 2.59
Total nitrogen of the monoamino acids........... 58.22 58.60 61.23
TotallrecOver ys ye eye Meee Ne ae ON ea 101.92 104.95 105.05
Total nitrogen in air-dry sample................. 12.50 13.61 13.40
The monoamino acids comprise 58 to 60 per cent of the total nitrogen
and the arginine and lysine nitrogen 14 to 15 per cent in a normal animal.
The histidine nitrogen runs from 3 to 4 per cent and the cystine nitro-
gen 1 to 1.5 per cent. The total humin nitrogen runs 3 to 4 per cent.
Sample 592 was not from a normal animal and differed in some re-
spects from the other samples. This phase of the matter will be dis-
cussed in a future paper.
No report on gelatin was made by the referee.
W. F. Hand.—This morning we congratulated ourselves that we
had a scientist in the Senate. We must not forget that we have a
scientist as the administrative head of one of the largest government
departments. We are very glad that he is a scientist. We believe that
he is a better administrative head because he is. I believe Secretary
Wallace is somewhat of a chemist. We also believe that is a hopeful
sign. We count ourselves distinctly honored that he has consented to
come here and make an address, and we will now be very glad to hear
him.
ADDRESS BY THE SECRETARY OF AGRICULTURE—THE
HONORABLE HENRY C. WALLACE.
As you expect me to be perfectly honest, I must disclaim some of
the honor which your chairman has so generously accorded me. I
cannot claim to be a scientist of very long standing. You notice I
wear your badge, but I did not come by it very honestly. Some very nice
young lady pinned it on me out there. A long time ago I was engaged
for a time in certain lines of scientific work, but I fear the record I made
1922} WALLACE: ADDRESS BY SECRETARY OF AGRICULTURE 91
would not entitle me to admission to a scientific body of real standing,
such as this, and I did not come here with the thought that I could
contribute anything worth while to your deliberations, but rather to
show in a personal way my interest and the interest of the Department
in the work you are doing.
Coming over, I learned from one of the committee for the first time
that this lusty young organization is a child of our own Department.
It gives the Department a feeling of pride, just as every parent has a
feeling of pride when the young man grows up and goes out on his own
hook and is able to take care of himself. So I think everyone in the
Department has a deep sense of satisfaction in noting the growth made
by this association, and the splendid work you have done.
I shall not undertake now to tell the story of the service which the
chemist has rendered to agriculture. It is a most interesting story,
and in it are some of the most briJliant chapters in scientific history.
Permit me to say, however, that the opportunities in the future will
call to you just as strongly as they have in the past. We have been
going through what we might call the period of agricultural exploita-
tion. We had seemingly unlimited areas of fertile land, simply waiting
for our people to go in and possess it. That is what we have been
doing up to the last ten or fifteen years—possessing the land and
harvesting the fertility of the soil. For the past year agriculture has
been in a very severe state of depression; indeed, the most serious we
have ever experienced. We are, as it were, smothered in our own sweet-
ness. We seem to have a great surplus of food, more than we can use
ourselves under present economic conditions. But this will not con-
tinue, and when we wear our way through this period of instability
and economic distress, I think we shall find ourselves at the beginning
of what will prove to be a new era, so far as our agriculture is con-
cerned. Population has been growing steadily. Our easily cultivated
land already has been taken up. We still have arid land which can be
brought into production by the addition of water; swamp land which
needs draining; and cut-over Jand which will produce when cleared of
the stumps. But the chances are that the needs of our increasing
population cannot be met by the addition of new plow lands. ‘These
needs must be met by increasing production on land already under
the plow. If this is true, and I think it is, then the scientist will be
called upon even more urgently than in the past to help the farmer by
showing him how to develop higher yielding strains and varieties, how
to improve his cultural methods, how to combat plant pests and dis-
eases of one sort or another, how to utilize not only products which
heretofore have gone to waste very largely, but how to utilize at a
profit surplus crops in times of plenty.
I do not need to emphasize the importance of the chemist in this
92 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
program of crop improvement, reduced production cost and greater
utilization. Your minds have passed mine already and anticipate what
[ would say if I were to elaborate the suggestion just made. Our debt
to the chemists who have given especial attention to agricultural prob-
lems already is very great, more than we can ever repay, but the very
fact that they have contributed so generously and so splendidly in the
past gives us warrant for expecting more and more of them in the future.
Before I close, permit me to say that during the time I have been in
the Department of Agriculture I have been very much impressed with
the thoroughly conscientious, unselfish, scrupulously honest work of
our chemists who have to do with food control; and not alone those in
the Department, but those with whom we cooperate in the various
States. You who have to do with this work realize that you occupy
a position of very great responsibility, and we who have an opportunity
to observe your work know that you are measuring up to this in a very
fine way. You stand between the producer and consumer and the
unscrupulous manufacturer. You stand also for the utilization of waste
while preventing that utilization of waste masquerading under false
colors to the harm of products which do not come from waste utilization.
Speaking for the Department of Agriculture, I am proud of the fine
record our chemists have made. It is an inspiration to everyone who
gets an understanding of it.
All I can say further is that, speaking for the Department, our heart
interest is with you in the work you are trying to do. We are interested
in every improvement you make in methods. We are interested in
everything you do toward making even better our control of foods and
drugs, in order that the consumer may be assured of wholesome pro-
ducts and the producer’s interest may be properly conserved. So I
bring to you the very best wishes of everyone connected with our De-
partment, and the pledge in their behalf to hold up your hands and
work with you in every possible way in the common cause.
REPORT ON SPICES AND OTHER CONDIMENTS.
By Arruur E. Paut! (U. S. Food and Drug Inspection Station, Cin-
cinnati, Ohio), Associate Referee.
Many features of the official and tentative methods for the examina-
tion of spices and other condiments are not entirely satisfactory. Those
for prepared and powdered mustard? are perhaps more urgently in need
of attention and possibly revision than others. In fact, so necessary
seemed this revision that before the collaborative work reported in this
1 Presented by W. C. Geagley.
* Assoc. Official Agr. Chemists, Methods, 1920, 261, 97.
1922] PAUL: REPORT ON SPICES AND OTHER CONDIMENTS 93
paper was done, R. W. Hilts and R. Hertwig of the U. S. Food and
Drug Inspection Station, San Francisco, Calif., had made a study of this
problem. Their modification of the present method for the determina-
tion of crude fiber in prepared mustard and other available details were
submitted for collaborative study.
Some years ago Carl S. Miner, Chicago, [ll., conducting a similar
investigation, prepared known mixtures of mustard, the ingredients of
which had been previously examined as to fiber content. This investiga-
tion resulted in the formulation of a set of details which was also sub-
mitted.
In accord with the recommendation of last year’s associate referee
the present tentative method for the determination of volatile oil in
mustard seed! was also included in the instructions sent to collaborators,
with a view to its adoption as an official method in the event that the
results obtained proved to be satisfactory.
One sample each of prepared and powdered mustard was submitted
to those association members who volunteered to cooperate on the
subject of spices and condiments. They were requested to make the
indicated determinations by the methods which were submitted and also
to make full comments and suggestions as to additional work or investi-
gations.
DETERMINATION OF CRUDE FIBER IN PREPARED MUSTARD.
Although the tentative method for crude fiber is given a special cap-
tion under Prepared Mustard in the Book of Methods, it is not com-
plete, since there is included a reference to a more general description
of the crude fiber method under Foods and Feeding Stuffs. By this
arrangement there is introduced some uncertainty relative to the details
involved in the handling of the finally separated fiber. Therefore the
method submitted to collaborators as the tentative method was re-
constructed as follows:
Method I.
Transfer 8 grams of the sample (equivalent to about 2 grams of dry matter) to a
porcelain or glass mortar. Treat with a little hot dilute sulfuric acid (1.20 grams per
100 cc.) and rub to a uniform thin paste. It is absolutely essential that this paste be
uniform in consistency and entirely free from lumps. Rinse the thin mixture into a
500 cc. Erlenmeyer flask using a total volume of 200 cc. of the hot dilute sulfuric acid
for the entire operation. Connect the flask with a reflux condenser, the tube of which
passes only a short distance beyond the rubber stopper into the flask, or simply cover
a tall conical flask, which is well suited for this determination, with a watch glass or
short-stemmed funnel; boil at once and continue boiling gently for 30 minutes. A blast
of air conducted into the flask wiil serve to reduce the frothing of the liquid. Filter
through linen and wash with boiling water until the washings are no longer acid; rinse
the substance back into the flask with 200 cc. of the boiling dilute sodium hydroxide
1 [bid., 259.
94 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
solution, boil at once and continue boiling gently for 30 minutes as directed above for
the treatment with acid, filter at once rapidly and wash with boiling water until the
washings are neutral. The last filtration may be performed upon a Gooch crucible, a
linen filter or a tared filter paper. If a linen filter is used, rinse the crude fiber, after
washing is completed, into a flat-bottomed platinum dish by means of a jet of water;
evaporate to dryness on a steam bath, remove all the fat by repeated washings of the
dry fiber with ether, again dry first on a steam bath and then to constant weight at
110°C.; weigh, incinerate completely, and weigh again. The loss in weight is considered
to be crude fiber. If a tared filter paper is used, weigh in a weighing bottle. In any
case the crude fiber after drying to constant weight at 110°C. must be incinerated and
the amount of the ash deducted from the original weight.
Method II.
Same as Method I except that the final washing with water is followed by washing
with alcohol and then ether.
Method III.
(Proposed by Hilts and Hertwig.)
Weigh 10 grams of the sample and transfer to an 8 ounce nursing bottle with 50 cc.
of strong alcohol, stopper and shake vigorously. Add 40 cc. of the ethyl ether, shake
and let stand about 5 minutes with occasional shaking. Centrifuge and decant off the
alcohol-ether mixture. Treat twice more with 40 cc. portions of ether, shaking, cen-
trifuging and decanting as before. Transfer the extracted material to a 500 cc. Erlen-
meyer flask with as small an amount as possible of the 1.25% sulfuric acid, cool, and
expel the ether by heating and shaking. Now add a sufficient amount of the boiling
hot dilute sulfuric acid to complete the 200 cc. Proceed as directed in VII, 661, begin-
ning with the eighth line ‘‘connect the flakk * * *”. If preferred the sample may be
treated with the alcohol and ether in a small beaker, finally transferring to a hardened
11 cm. filter paper and washing two or three times with ether. Permit to drain com-
pletely, but not to dry or cake, and proceed as above.
Method IV.
(Proposed by Carl S. Miner.)
Transfer 8 grams of the sample (equivalent to 2 grams of dry matter) to a small
evaporating dish. Add sufficient acetone to make a thin cream and then, gradually,
a total of 50 cc.of acetone. Boil the perfectly homogeneous mixture for a few minutes,
allow to settle and decant the clear supernatant ecetone through linen end repeat the
operation twice, using 40 ce. and 30 cc. of acetone. Allow the dish to stand until most
of the acetone has disappeared. Add sufficient 1.25% sulfuric acid to make a smooth,
thin cream and transfer completely with a small amount of the acid to a 500 cc. Erlen-
meyer flask. Expel the acetone by heating and shaking. Now add sufficient of the
boiling hot acid to make a total of 200 cc., washing off any mustard that may be on the
linen; connect the flask with a reflux condenser and proceed as directed in VII, 66%.
COMMENTS BY COLLABORATORS.
J. H. Bornmann.—The tentative A. O. A. C. method appears to be unsatisfactory in
that it specifies washing with ether after drying the fiber. It is impossible to wash out
the fat after the fiber has been dried.
1 Assoc. Official Agr. Chemists, Methods, 1920, 98.
1922] PAUL: REPORT ON SPICES AND OTHER CONDIMENTS 95
Results of collaborative determinations.
CrubeE Fiser
ANALYST Tota.
Soups Method Method Method | Method
Iil IV
per cent per cenl per cent per cent per cent
J. H. Bornmann, U.S. Food and Drug |_ 15.82 1.28 0.98 0.91 0.92
Inspection Station, Chicago, Ill.....| 15.80 1.39 0.97 0.90 0.90
arbi se Niimers rset ery et pysige othhh. is esl 1.33 1.35 0.94 1:25
1.39 1.41 0.95 U25
W. D. Richardson, Swift & Co., 16.04 1.43 1.04 0.88 0.88
ancaey DHS Ee Ae is ae Lele fa Leben Wi
W.B. Owen, Agricultural Department, | 16.19 220 1.57 1.07 1.19
Maliahnssee: shia rs a re ASRS! 3 Fn: 16.26 PAST leva! 1.06 1.25
Mercere re Wh ae eI Siig | 15.92 | 1.22 1.01 0.99 1.02
15.95 1.27 1.02 1.01 1.02
Method II differs from Method I in that the fiber is washed with alcohol and ether
before drying. Fairly good results are obtained by this method, though the results are
somewhat higher than those obtained by Methods III and IV. Identical results were
obtained by the latter methods. There is some advantage in centrifuging. The
solvent may be decanted almost completely, and there is no need of decanting on a
filter, since the mustard remains packed in the bottom of the flask.
With regard to cost, the advantage lies with Method III. It is also easier to remove
the last trace of ether. When extracting with acetone the mixture must be heated
cautiously as there is great danger of violent bumping. Centrifuging requires less
time and is more effective than boiling and decanting. The third method appears to
be preferable for the reasons just enumerated, though it requires more time and there
is more danger of loss of material.
The difference between results obtained by Methods II] or IV and Method II is
not very great. If Method III were adopted, the existing standard for crude fiber
ought to be lowered, in which case the end results would probably be the same; that is,
a mustard judged by the present standard for fiber using Method II would appear as
good as it would when judged by a lower standard using Method ITI.
Carl S. Miner.—I prefer to use alundum crucibles instead of Gooch crucibles. About
1% to 34 of an hour was required for filtration through Gooch crucibles.
In Method IV I believe it would be better to use a beaker instead of an evaporating
dish and to boil for longer periods, also to use a larger quantity of solvent, because I
am sure I did not remove all the oil by following Method IV as written.
Method III seems to me to be the best method, and it is the easiest to manipulate.
W. D. Richardson.—Method I apparently gives high results. The fiber, after wash-
ing with ether, appears waxy and gummy before drying, and with Method II a some-
what similar appearance is produced. In both Methods I and II the material adheres
to the linen on the first filtration, perhaps due to the oils and gums present. Methods
III and IV, although perhaps requiring a little more time and manipulation, appear to
give better results. From the work we did we rather favor Method IV as it filters a
little more readily and gives a cleaner appearing fiber.
R. J. Qwen.—Suggest that the method for total solids allow the use of electric oven
as well as water oven. Methods III and IV are simpler and I believe more accurate
96 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS |[Vol. VI, No. 1
than Methods I and II. We prefer Method II on account of its simplicity and because
no special apparatus is required. Why should not carbon tetrachloride be a better
solvent than acetone? If there had been more sample we would have tried carbon
tetrachloride.
R. Hertwig.—In ordinary practice I use hardened filter paper and a Biichner funnel
for the first filtration. For the second filtration I add about 1 gram of asbestos at the
completion of the alkali digestion, shake well and immediately filter on asbestos in a
Hirsch funnel. After the washing with water and finally with alcohol I transfer the
entire mat as a unit to a platinum dish, * * * etc. I should think that a similar
procedure might be commendable for the acid filtration also, making both filtrations
the same. The simplicity of the filtering, washing and transferal surely should be in
its favor.
I had been of the opinion that the efficient crude fiber method for prepared mustard
gave high results only because of the possibility that the fat present protected the
material somewhat from the action of the acid and alkali. At present I am not so
certain that this is the only possible cause. Another possible cause is that some fat
in the official method remains included in the crude fiber material, which after drying
and hardening is not extracted by the ether and thus gets weighed as crude fiber. I
hardly think that the use of paper in Method I and asbestos in Method II would explain
the difference in results although very possibly the asbestos allows more efficient
washing.
Considering this immediate work and also other experience I have had with Methods
I and III, which has been considerable, I should recommend Method III as the most
satisfactory and at the same time the most reliable one of the four methods. The
official method for prepared mustard stands as an exception to the crude fiber determi-
nations of all other materials, in having the fat present. There always is the possibility
that this fat may in certain instances cause high results for the two possible reasons as
given above. The fat makes the digestions, the filtrations and the washings more or
less unsatisfactory. The fat is the cause of lumping. All these objections are elimi-
nated in Method III, which is neat in technique and preferable to the others.
In Method III, I should recommend a slight change in the procedure. Replace the
sentence ‘“‘Transfer the extracted material to a 500 cc. Erlenmeyer * * * etc.’’ and
the two subsequent sentences by the following:
Rest the bottle on its side for a short time, without heat, to allow the ether
largely to evaporate. Transfer the material to a 1000 cc. Erlenmeyer flask,
using 200 cc. of boiling hot dilute sulfuric acid and proceed as directed under
VII, 66.
In this way the procedure is more satisfactory, one is not troubled with frothing and
an extra heating is avoided.
CONCLUSIONS.
A glance at the results reported will show at once that the “personal
equation” enters into the determination of crude fiber to a marked
degree. Of the five collaborators, two reported results which are in
each instance higher than those reported by the others. But it will be
observed, especially, that the disparity in the results is greatest in the
case of Method I. With this method the highest result reported is
2.37 per cent and the lowest 1.28 per cent, a range of 1.09 per cent.
In the case of Method II, a slight modification of the tentative method,
the extreme range is 0.74 per cent. It would seem that these variations
1922| PAUL: REPORT ON SPICES AND OTHER CONDIMENTS 97
are quite extreme. For Methods II and III the ranges are, respectively,
0.19 and 0.37 per cent. It is apparent, therefore, that the “‘personal
equation” is reduced to the minimum in the case of Method III.
Attention should also be directed to the fact that in the case of crude
fiber a procedure which gives the lowest results would be the most
desirable. The lowest results were reported with Method III. All
collaborators reported higher figures by all other methods, with the
exception that one collaborator reported identical results by Methods
III and IV.
DETERMINATION OF VOLATILE OIL IN MUSTARD SEED.
As previously stated, the method submitted to collaborators for study
is that which is now included among the association methods as ‘‘tenta-
tive” and is described in the Book of Methods'.
The following results show the percentage of volatile mustard oil
found in the submitted sample by each collaborator:
PE ESOLNINANTE ee, Tene ete ee ene ane een NEE NE RAD \p 0.67—0.69
WR) By ivichardsom.(%ihin) 3 ee Pea es, 7 ee Bed 0.68
WanleswVUONET Sosa eee ce ea ar Pai cieds oe 0.70—0.70
[Rie LS IGiE FA palais SA Ce 4 ad as RE Ne OU IRR, SNIP URI PRE tony WOO 0.72—0.73
COMMENTS BY COLLABORATORS.
J. H. Bornmann.—The manipulations necessary to this determination are simple
and easy, and the method appears to be satisfactory in its present form.
W. D. Richardson.—It would be advantageous to use 0.05N instead of 0.1N solution
as specified in the method.
CONCLUSIONS.
The exact proportion of volatile oil in the sample submitted is not
known, but in view of the facts that these three skilled analysts obtained
such very satisfactory and concordant results and that their work con-
firms that previously done by this association it would seem that this
method should be made official.
RECOMMENDATIONS.
It is recommended—
(1) That the present tentative method for the determination of
volatile oil in mustard seed be made official.
(2) That the method submitted by Hilts and Hertwig for the determi-
nation of crude fiber in prepared mustard, including the suggestions of
Hertwig, be adopted as tentative and replace the present method, and
that same be studied by next year’s associate referee with a view to its
final adoption as an official method.
(3) That consideration be given to the recommendation of last year’s
associate referee on spices and other condiments, to study methods for
the examination of salad dressings.
1Assoc. Official Agr. Chemists, Methods, 1920, 259.
98 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 1
REPORT ON DETERMINATION OF SHELL IN CACAO
PRODUCTS.
By B. H. Smserserc (Bureau of Chemistry, Washington, D. C.),
Referee.
Various factors have contributed to the enormous growth of the
chocolate industry in this country in the last few years. The familiar
cakes of chocolate, known in the trade as “bar goods’, met ideally the
demand created by the war for a compact, highly nutritive food-con-
fection. The export trade received a decided impetus owing to the
lowered production of chocolate in the warring countries of Europe, as
well as to the increased demand created by the war. The prohibition
of alcoholic beverages is also considered a factor contributing to the
greater demand for confectionery of all descriptions. This demand
naturally led to an increase in production and keener competition which,
in turn, brought about the desire on the part of the trade to produce an
article as cheaply as possible. This kind of competition always leads to
the temptation to adulterate.
The form of adulteration to be considered in this report is the presence
of excessive cocoa shells, due either to inefficient cleaning of the nibs or
the addition of ‘‘fines’’. This method of adulteration makes more
urgent than ever a satisfactory means of determining the amount of
shell in cacao products. W. C. Taber, as Referee on Crude Fiber in
Cacao Products, in his report to this association last year! presented
data which showed clearly that the crude fiber method was not a
satisfactory or conclusive means of determining the presence of excessive
shell. The crude fiber figure will probably not be low if excessive shell
is present, but it may be high when practically no shell is present if the
product is made from certain types of beans, the nibs of which are high
in fiber. Knapp and McClellan? in a paper, ““The Estimation of Cacao
Shell’, conclude that ‘‘the only method employed by itself which is capable
of giving results of any value is the estimation of the crude fiber’, but
add that ‘‘there is no process which will determine so low a percentage as
5 per cent’. Such a process would obviously be of little advantage.
The acknowledged inadequacy of chemical analysis to determine
excessive shell turns the analyst to the next alternative, the microscope,
although the inclination is to regard quantitative microscopy with more
or less suspicion. In the discussion following the paper by Knapp and
McClellan the point is brought out that microscopic examination should
never be omitted, but the paper states that “‘no analytical method by
itself, or in conjunction with others, will enable the analyst to distinguish
between cocoa containing two per cent and cocoa containing five per
~1J. Assoc. Official Agr. Chemists, 1921, 5: 253.
2 Analyst, 1919, 44: 2.
1922] SILBERBERG: DETERMINATION OF SHELL IN CACAO PRODUCTS 99
cent of shell’. This, however, is thought to have been disproved. In
his report for 1920 the referee recommended that further study be made
of the microscopic method for the examination of cacao products for
shells in order that its limit of accuracy might be determined by those
experienced in its use.
The method referred to was developed by analysts in the Bureau of
Chemistry, and may be stated as follows:
Method for the Quantitative Determination of Cocoa Shell in Cocoa and Chocolate Products.
Eliminate the fat with gasoline or ether in a centrifuge or on a suction filter. In the
case of chocolate, shave the sample off so that the defatting agent will penetrate easily.
Wash the sample three or four times. If necessary, remove the sample to a mortar,
grind, and then continue the defatting process to completion. If the sample contains
sugar remove by washing several times with water in the same way and wash finally
with a mixture of ether and alcohol. Dry, powder and mix the sample thoroughly.
Weigh accurately 2 mgs. and mount on a glass slide (a ruled slide is very desirable)
with just sufficient chloral hydrate (1 to 1) to fill in under a square cover glass. Before
applying the cover glass stir and spread the material with the point of a needle in order
to get a uniform mount. Warm slightly (do not boil) and let stand until tissues have
cleared (preferably about 12 hours).
Examine the entire mount, counting all the stone cell groups present. Compare
the result with those previously obtained on standard samples containing a known
percentage of cocoa shells. The standards used for comparison should be prepared
from defatted material, and all results should be reported on the fat-free basis.
Note.—The careful preparation of the standard samples is of immeasurable importance. It is not
advisable to use as a basis for standards a commercial cocoa which may be assumed to be practically free
from shell. The only accurate method is tostart with clean cocoa nibs and shells. Grind and thoroughly
defat both nibs and shells separately until each passes through a 100-mesh sieve. Then weigh and mix
nib powder and shell powder in desired proportions, finally sieving each standard through the 100-mesh
sieve to insure thorough and uniform mixing.
Care should be taken in making mounts not to use too much chloral
hydrate as there should be none protruding around the edges of the
cover glass. The stone cell groups are often difficult to recognize,
especially when partially obscured by other tissues, and some types of
tissues may be easily confused with stone cells if the analyst is not
experienced in noting fine histological differences. The only way to
avoid these difficulties is by careful study of, and constant familiarity
with, the various tissues in cocoa.
It is advisable when counting a sample to make a check by counting
a standard. A good plan is to count one slide of the sample, then count
the standard to which it seems to be nearest in shell content, and then
count at least one more slide of the sample.
Pursuant to the recommendation made in last year’s report, your
referee prepared five standards, according to the instructions outlined
in the method, containing 2, 3, 4, 5 and 8 per cent of shell, respectively.
Samples of each were sent to each collaborator, the 2 per cent, 4 per
cent and 8 per cent being labeled as to their shell content and the 3 per
cent and 5 per cent being used as unknowns and labeled A and B, respec-
100 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
tively. A copy of the method was also sent to each collaborator, with
the following instructions:
It is requested that in making this report each analyst give the counts—at least two
on each sample—obtained on the standards and on the unknowns, as well as his estima-
tion of the amount of shell in each unknown. If the first two counts on a sample do
not check fairly well, more should be made.
Many samples of nibs taken from the hoppers of mills were examined by
analysts in the Bureau of Chemistry to determine the amount of shell
present, and various manufacturers were consulted as to how free from
shell they could reasonably be expected to clean their nibs. The in-
formation obtained from these two sources led to the conclusions that
the better grades of cacao products contain not more than | per cent of
shell on the basis of the nibs, which would be equivalent to 2 per cent on
the fat- and sugar-free basis, and that any product containing more than
2 per cent on the basis of the nibs or 4 per cent on the fat- and sugar-free
basis can justly be regarded as containing excessive shell. Since 4 per
cent on the fat- and sugar-free basis has been recommended as the limit
of tolerance for shell it was considered that by making the two unknowns
3 per cent and 5 per cent, respectively, of shell, the results would indicate
how sharply the line might be drawn in enforcing this limit. Further-
more, it is not especially important that the method be as accurate
beyond 5 per cent as under this percentage, since anything above that
is unquestionably excessive. The results of the collaborators are shown
in the following table. The counts given represent the widest extremes
reported by each analyst. In many cases more than two counts were
made.
Counts obtained by collaborators en shell in cacao products.
STANDARDS UNKNOWNS
ANAxysr 2% 4% | 8% A (3%) | Estimated | B (5%) | Estimated
per cent per cent
1 18-20 39 74-77 30-32 3 48-52
Z 10-13 29 68-92 28-31 4 40-43 5
3 30-35 54-60 93-98 53-59 4 72-74 6
4 9-16 | 25-26 57-60 25-29 4 32-43 Spy)
5 27-41 73-76 110-153 42-62 3 83-89 6.2
6 32 66 122 43-44 3 89-92 6
if 5-9 2-9 11-16 4-10 4.2 9-18 fi
8 17-23 35-42 65 13-16 1:5 24-26 2
9 1 SOL eh Gena 28-29 3.0 42 4.5
Of the nine collaborators reporting, only five (1, 4, 5, 6 and 9) are
known to be more or less familiar with microscopic work and to have
had some experience in the use of the method. Practically nothing is
known with respect to the experience of the other four collaborators, but
the results of two (2 and 3) lead to the belief that they are at least fairly
1922) BAUGHMAN: METHODS FOR EXAMINATION OF CACAO BUTTER 10!
familiar with the use of the microscope. The results of the other
two (7 and 8), indicate that they have had little experience in
micro-analysis or in the use of this method. It would therefore seem
unjust to the method to judge it by their results as the statement has
been made repeatedly that the method is not one which can be used by
a novice in the work. Considering then the results of the other seven,
four reported correctly on A, and the other three reported 4 per cent,
which was only 1 per cent high. Using only the whole numbers—as it
is believed that the accuracy of the method does not warrant reports
being given in decimals—four out of the seven reported correctly on B,
two reported 6 per cent, which was only | per cent high, and, while the
other one reported 4.5 per cent, calculating from his own figures, his
results indicate practically 5 per cent, the amount present.
It is evident from the results obtained by the collaborators that the
personal factor in making the counts is most important; some analysts
seem able to identify stone cell groups where others do not. However,
if the analyst’s counts are consistent on standards, enabling him to
report results as shown in the table, ‘t suffices for practical purposes
even though it does not place the method entirely above criticism.
In order to determine whether differences of 1 per cent in shell content
could be detected the referee placed portions of each of the five samples
used in collaborative work in separate vials, marking each one with the
amount of shell present. A co-worker removed these marks and sub-
stituted letters, for which he kept the key. These samples were then
counted by the referee, and the results were so conclusive that the five
samples were listed in their proper order without any difficulty whatever.
In view of the results reported by the collaborators and this experi-
ment, your referee considers that the method is worthy of adoption by
this association as a tentative method for the quantitative determi-
nation of cacao shell in cacao products and so respectfully recommends.
REPORT ON METHODS FOR EXAMINATION OF CACAO
- BUTTER.
By Watter F. BaucuMaAn (Bureau of Chemistry, Washington, D. C.),
Referee.
At the 1920 meeting of the association the Referee on Methods for
Examination of Cacao Butter! reported the results of a study he had
made on the critical temperature of dissolution determination and the
Bloomberg? acetone-carbon tetrachloride test for hydrogenated oils,
tallow, etc., and recommended that these two methods be submitted to
collaborators. This recommendation was approved.
1 J. Assoc. Official Agr. Chemists, 1921, 5: 263.
2 Tbid., 1920, 3: 493.
102 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 7
The critical temperature of dissolution is the temperature at which a
solution of 5 cc. of a melted neutral fat in 5 cc. of glacial acetic acid
becomes turbid on cooling. Practically all potential! substitutes for
cacao butter with the notable exceptions of hydrogenated oils, tallow
and oleostearine have a considerably lower temperature of dissolution
than cacao butter, and when mixed with pure cacao butter they lower
the temperature of dissolution. [Free fatty acids also lower the tem-
perature, and it is necessary to determine the acid value of the fat and
make a correction. The temperature of dissolution also varies with the
strength of the acetic acid; therefore it is recommended in the descrip-
tion of the method that the acetic acid be standardized against an
authentic sample of cacao butter. The purity or sophistication of the
sample under examination is then indicated by comparing its critical
temperature with that of the authentic cacao butter.
The acetone-carbon tetrachloride test is simply the determination of
the solubility of the sample in a mixture of equal parts of carbon tetra-
chloride and acetone. Five cc. of the melted fat are dissolved in 5 ce.
of the carbon tetrachloride mixture and the solution cooled in ice water
for 20 or 30 minutes. If hydrogenated oil, tallow, oleostearine, lard or
paraffin is present a flocculent precipitate is found which goes into
solution again—but slowly—when the mixture is removed from the ice
water and allowed to come to room temperature. These are qualitative
tests.
The critical temperature of dissolution determination will detect the
presence of coconut, palm nut and cottonseed oils or stearines, corn oil,
peanut oil, etc., but not hydrogenated oils, tallow or oleostearine, while
the acetone-carbon tetrachloride test will detect hydrogenated cotton-
seed oil, tallow, oleostearine and paraffin but not the other possible
adulterants.
The following samples and instructions were sent to ten chemists who
had expressed a willingness to collaborate in this work:
(1) Cacao butter adulterated with 5% hydrogenated cottonseed oil.
(2) Cacao butter adulterated with 5% coconut stearine.
(3) Cacao butter adulterated with 15% cottonseed stearine.
(4) Cacao butter adulterated with 20% peanut oil.
(5) Cacao butter adulterated with 5% oleostearine.
(6) Cacao butter adulterated with 5% palm kernel oil stearine.
(7) Pure cacao butter with a high content of free fatty acids.
(8) Cacao butter adulterated with 10% tallow.
A sample of pure cacao butter to be used as a standard was also sent.
INSTRUCTIONS TO COLLABORATORS.
Critical Temperature of Dissolution in Acetic Acid.
APPARATUS.
Insert a thermometer reading to 0.1°C. into a cork that fits a 6x34" test tube. The
thermometer should extend far enough into the tube that the bulb will be covered by
1922] BAUGHMAN: METHODS FOR EXAMINATION OF CACAO BUTTER 103
10 ce. of liquid. Scratch graduation marks on the test tube at 5 cc. and 10 ec. from the
bottom. Place the test tube in a larger tube (4’’x114”’), containing glycerine, and
hold firmly in place with a cork having a groove cut in the side to equalize the pressure
when heat is applied.
REAGENTS.
(a) Glacial acetic acid.—As free from water as possible.
(b) 0.1N potassium hydrozide solution.
DETERMINATION.
To remove traces of moisture filter a portion of the sample to be examined through
a dry filter paper in an oven where a temperature of about 110°C. is maintained. Allow
the filtered sample to cool until barely warm and run into the test tube up to the 5 cc.
mark. Add the acetic acid, reagent (@) up to the 10 cc. mark. (The portions should
be measured as accurately as possible.) Insert the cork holding the thermometer and
place the test tube in the glycerine bath. Heat and shake the apparatus frequently
until a clear solution of the fat and acetic acid is obtained. Allow the solution to cool
with constant shaking without removing from the glycerine bath. Note the tem-
perature at which the first indication of turbidity appears. Make a similar test with
the same acetic acid on a sample of pure cacao butter. Since fatty acids lower the
turbidity temperature, correction must be made for the acid value of the sample.
CORRECTION FACTOR.
If the strength of the acetic acid, reagent (A) is such that the turbidity temperature
of the pure cacao butter is 90°C., one unit of acid value will cause a reduction of 1.2°
in the critical temperature of dissolution. If the turbidity temperature is 100°C., one
unit of acid value will cause a reduction of 1.0°. For other turbidity temperatures
the correction is proportional.
CORRECTED CRITICAL TEMPERATURE OF DISSOLUTION.
Determine the acid value (mg. of potassium hydroxide required to neutralize the
free fatty acids in 1 gram of the sample) of both the sample and the pure cacao butter
as directed under X XII, 30:. Multiply the acid value by the correction factor and
add the result to the observed turbidity temperature. The figure obtained is the true
critical temperature of dissolution. If this temperature is lower than that of the pure
cacao butter, adulteration with coconut, palm kernel, cottonseed oils or stearines—
corn oil, peanut oil or other vegetable oil—is indicated.
Solubility in Acetone-Carbon Tetrachloride.
REAGENT.
A mixture of equal parts of acetone and carbon tetrachloride.
DETERMINATION.
Dissolve 5 cc. of the warm fat, which has been filtered through dry filter paper in an
oven at about 110°C. to remove traces of moisture, in 5 cc. of the acetone-carbon tetra-
chloride reagent in a test tube. Allow the solution to stand in ice water for 20 or 30
minutes. Run a blank on a sample of pure cacao butter at the same time. If hydro-
genated oil, tallow, oleostearine or paraffin is present a white flocculent precipitate will
soon appear. If the water is cold enough the cacao butter may solidify. If a pre-
cipitate is formed remove the sample from the ice water and allow it to remain at room
temperature for a time. Solidified cacao butter will soon melt and go into solution,
1 Assoc. Official Agr. Chemists, Methods, 1920, 250.
104 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
but if the precipitate is due to any of the above-mentioned possible adulterants a much
longer time will be required for it to go into solution.
Reports were received from four collaborators only, and the results
reported by one of these, who incidentally introduced some modifica-
tions of his own, differed so greatly from those anticipated and also
from those reported by the others that his entire report was discarded.
Results of collaborative work on cacao butter samples.
TEMPERATURE z g
3 Neer ree sti ES a CONCLUSIONS As TO PuRITY ‘ect eee
Z VALUE an : s F rnou, Leseenengae * TETRACHLORIDE TEST
= Found rected > zo
Pure cacao butter used as standard.
id OF IC: vd
1 OR94> 110020 5) 100'9) sate] isd ee SALE: he SAS Ea, ee eee
2 Oot: hei R Oe O Beh i il el Re i aan et eA oll el ec al
3 W954 |292:95)), 94 Olen cece cae seas cbs teeeeteel cetaecetee Sonenetast saat aaa
4 1:05 | “O8!8*|-1OOO) 2) NaN TUES REC eae Pee aaa) eee AR ee
SAMPLE 1
1 0.96 |100.0 | 100.9 0.0} Adulteration not shown.| Adulterated.
2 0.91 | 93.1 | 94.1} +0.4) Adulteration not shown.| Adulterated.
3 1.09 | 90.8 | 92.0} —2.0) Adulterated. Adulterated.
4 1.03 | 93.3 | 94.4) —5.6| Adulterated. Adulterated.
SAMPLE 2
1 2.88 | 92.2 | 94.9] —6.0) Adulterated. Adulteration not shown.
2 4.07 | 82.6 | 87.3] —6.4| Adulterated. Adulteration not shown.
3 4.15 | 84.2 | 88.9} —5.1| Adulterated. Adulteration not shown.
4 4.12 | 87.6 | 92.0; —8.0} Adulterated. Adulteration not shown.
SAMPLE 3
1 4.08 | 92.2 | 96.1} —4.8} Adulterated. Adulteration not shown.
2 4.10 | 75.5 | 80.2}/—13.5| Adulterated. Adulteration not shown.
3 4.21 | 82.0 | 86.8} —7.2| Adulterated. Adulteration not shown.
4 4.28 | 81.9 | 86.4|—13.6} Adulterated. Adulteration not shown.
SAMPLE 4
1 3.00 | 95.0 | 98.0| —2.9| Adulterated. Adulteration not shown.
2 2.90 | 85.0 | 88.2} —5.5| Adulterated. Adulteration not shown.
3 2.89 | 85.8 | 89.1} —4.9} Adulterated. Adulteration not shown.
4 | 3.06 | 87.8 | 91.0} —9.0} Adulterated. | Adulteration not shown.
1922] BAUGHMAN: METHODS FOR EXAMINATION OF CACAO BUTTER = 105
Results of collaborative work on cocao butter samples—Continued.
TEMPERATURE | 7 2
5 D oF iG g 28 | Concrusrons as To Purity
S| Vie P| SSE | rom Demrenarune of = |p AT soare Pest
Z Cor- | <6 S
< Found | rected | > 2
SAMPLE 5
1 0.96 |100:0 | 100.9 0.0} Adulteration not shown.| Adulterated.
2 0.89 | 93.7 | 94.9} +1.2) Adulteration not shown.| Adulterated.
3 1.12 | 88.7 | 90.0} —4.0) Adulterated. Adulteration not shown.
4 0.92 | 83.7 | 84.7|—15.3} Adulterated. Adulteration not shown.
SAMPLE 6
1 2.95 | 92.5 | 95.4| —4.5| Adulterated. Adulteration not shown.
2 4.06 | 82.4 | 87.0] —6.7| Adulterated. Adulteration not shown.
3 4.21 | 84.6 | 89.4) —4.6| Adulterated. Adulteration not shown.
4 4.14 | 83.1 | 87.5|—12.5| Adulterated. Adulteration not shown.
SAMPLE 7
1 4.82 | 96.5 |101.3) +0.4| Adulteration not shown.) Adulteration not shown.
2 4.83 | 89.2 | 94.9} +0.9) Adulteration not shown.| Adulteration not shown.
3 5.02 | 87.0 | 92.7) — 1.3| Adulterated. Adulteration not shown.
4 4.99 | 89.2 | 94.5} —5.5| Adulterated. Adulteration not shown.
SAMPLE 8
1 1.02 | 99.5 |100.5) —0.4| Adulteration not shown.) Adulterated.
2 1.08 | 88.9 | 90.2} —3.5| Adulterated. Adulterated.
3 1.15 | 89.6 | 90.9} —3.1| Adulterated. Adulterated.
4
1.12 | 96.1 | 97.3] —2.7| Adulterated. Egberts
*Analysts referred to are—
(1) Walter F. Baughman.
(2) C.S. Brinton, U. S. Food and Drug Inspection Station, Philadelphia, Pa.
(3) Llewelyn Jones, U. S. Food and Drug Inspection Station, Chicago, Tl.
(4) M. L. Offutt, Bureau of Chemistry, Washington, D. C.
DISCUSSION.
The results obtained with the acetone-carbon tetrachloride test are
quite satisfactory and with one exception are such as were anticipated.
Adulteration was detected in Samples 1, 5 and 8 by all collaborators
except one who reported Sample 5 as not showing adulteration by this
test.
Adulteration of Samples 2, 3, 4 and 6 was detected by the critical
temperature of dissolution determination, but these encouraging results
are offset by those of two collaborators who also found evidences of adul-
teration in Samples 1, 5 and 8, which should have shown no evidences
by this test, as well as in Sample 7, pure cacao butter.
Brinton (Analyst No. 2) sent the following comments with his report:
106 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS | Vol. VI, No. 7
It is unfortunate that the critical temperature of dissolution test is not designated as
the ‘“‘Valenta test’! as it is spoken of in the older books on oils and fats. I used this
test on butter and oleomargarine very satisfactorily about 25 years ago. Pearmain
and Moor? spoke highly of this test. The use of a glycerine bath is advisable and much
better than a water bath. The acetone-carbon tetrachloride test gives good results on
some of the samples, but on others the indications are not as clear cut as desirable,
their behavior in some particulars being almost identical with the sample of known
purity, and yet in others it is very different. Sample 8 is an instance of this. It is
believed to be adulterated because it begins to be flocculent and finally becomes solid
long before the pure sample, but on redissolving it behaves very similar to the pure
sample.
RECOMMENDATION.
It is recommended that further study be given to these two methods.
REPORT ON COFFEE.
By H. A. Lepper (Bureau of Chemistry, Washington, D. C.), Referee.
The Power-Chesnut method’ for the determination of caffeine in
coffee was adopted as an official method (first action) at the 1919 meet-
ing. This method is of wide applicability for the determination of
caffeine in vegetable material in general. Because of its applicability
it is believed desirable to make a minor change in the wording this
year. The authors‘ have found that 20 cc. of 10 per cent sulfuric acid
are necessary to hydrolyze the saponins in some kinds of vegetable
material and that this quantity of acid in the solutions obtained is
without action on caffeine. The latter finding was verified by the
referee last year. It is, therefore, recommended that the wording of
the method be changed to direct the use of 20 cc. instead of 10 cc. of
10 per cent sulfuric acid for the half-hour boiling of the filtrate from the
magnesium treatment and that the method be made official with this
minor change.
The referee believes that no further effort should be spent on the
determination of caffeine in coffee and sees no necessity for the study of
any of the methods for the examination of coffee at present. However,
if the association desires to continue the study of coffee, it is recom-
mended that the acids of coffee receive attention.
1 J. Soc. Chem. Ind., 1884, 3: 643.
2 Aids to the Analysis of Foods and Drugs, 1895.
3 J. Assoc. Official Agr. Chemists, 1921, 5: 271.
4 J. Am. Chem. Soc., 1919, 41: 1298.
1922] ANDREW: REPORT ON TEA 107
REPORT ON TEA.
By R. E. AnpReEw (Agricultural Experiment Station, New Haven,
Conn.), Referee.
As for several years past, the work this year was confined to the
study of methods for the determination of caffeine. Last year the
Power-Chesnut method was recommended for adoption as an official
method for the determination of caffeine in tea, and the second reading
of the recommendation of the Stahlschmidt method was withheld pend-
ing further study of the method proposed by Bailey and Andrew with
a view to the adoption of one or the other of the last-named methods as
an optional official method. The data presented last year were obtained
chiefly in the laboratory of the Experiment Station in New Haven where
the proposed method was devised. The data this year were obtained
chiefly from outside collaboration.
COLLABORATION.
Samples were sent to ten chemists who expressed their willingness to
cooperate. Reports were received from H. A. Lepper, Bureau of Chem-
istry, Washington, D. C.; W. S. Hubbard who reported analyses by
C. A. Herrmann, U. 8. Food and Drug Inspection Station, New York,
N. Y.; I. K. Phelps, Bureau of Chemistry, Washington, D. C., who
reported analyses by Dorothy B. Scott, Lillian Offutt and J. I. Pal-
more, and L. E. Walter, Laramie, Wyo., who reported results obtained
by H. R. Baker, assistant state chemist.
INSTRUCTIONS TO COLLABORATORS.
Three samples were used, viz., (I) green tea, (II) black tea, (III)
mixture of green and black tea. Each sample was finely ground and
well mixed. Sub-samples were sent to each collaborator with the fol-
lowing instructions:
Determine caffeine in each of the samples by the modified Stahlschmidt
method, the Power-Chesnut method and the proposed method (Bailey-
Andrew). The modified Stahlschmidt method follows:
Modified Stahlschmidt Method.
Weigh 3.125 grams of the finely powdered sample into a 500 cc. flask, add 225 ce. of
water (this volume will be reduced to about 200 cc. by boiling) attach a reflux con-
denser and boil for 2 hours. Add 2 grams of dry basic lead acetate and hoil for 10
minutes. Cool, transfer to a 250 cc. graduated flask, fill to the mark, filter through a
dry filter, measure 200 cc. of the filtrate into a 250 cc. graduated flask and pass hydrogen
sulfide through it to remove the excess of lead. Make the solution up to the mark
and filter through a dry filter. Measure 200 cc. of this filtrate into an evaporating
dish and concentrate to about 40 cc. Wash the concentrated solution with as little
water as possible into a small separatory funnel and shake out six times with chloro-
108 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
form, using 25, 20, 15, 10, 10 and 10 cc., respectively, combining the several extracts
in a second separatory funnel. Treat the combined extracts with 5 cc. of 1% potassium
hydroxide, allow the liquids to separate and draw off the chloroform. Wash the aqueous
solution in the separatory with chloroform in two portions of 10 cc. each, adding these
washings to the main extract. Distil off most of the solvent, transfer to a small tared
flask, evaporate, dry at 100°C. and weigh. Test the purity of the residue by determi-
ning nitrogen therein and calculate caffeine by the factor 3.464.
The Power-Chesnut! and the proposed? methods have been published
in the proceedings.
NOTES ON METHODS.
Results for caffeine by weight and from nitrogen are desired.
In the Power-Chesnut method extraction should be continued until the extract is
colorless. The heavy magnesium oxide used should meet the U. S. Pharmacopeeia
requirements.
Evaporation of the last portion of solvent from the caffeine should be done carefully
to prevent loss by spattering.
If the results by all the methods outlined can not be obtained those by the modified
Stahlschmidt and proposed methods are particularly desired.
RESULTS OF COLLABORATIVE WORK.
The results obtained by the various collaborators are given in Table 1.
COMMENTS OF ANALYSTS.
H. A. Lepper.—As far as the analytical results go there seems to be little to say
regarding the methods. The Stahlschmidt method gave me some trouble with emulsion
formation during the chloroform extraction, a condition which was entirely absent in
the other two methods. It seems to me that the Bailey-Andrew method is less time-
consuming than the Stahlschmidt. I do not like the use of the graduated flask for
boiling as it might tend to affect the volumetric contents of the flask after it becomes
cool.
Dorothy B. Scott.—The largest amount of caffeine and the best checks were obtained
from the Bailey-Andrew method.
Lillian Offutt—The apparatus used for the Power-Chesnut method was a modified
Knorr apparatus and extraction was continued for ten hours. I am familiar with the
Power-Chesnut method, but not with the other two. The Power-Chesnut method
appears to me to be the most accurate method but requires more time than is always
convenient for analysis. The Bailey-Andrew method requires less time than the
Power-Chesnut and is less subject to error in manipulation, in my opinion, than either
the Stahlschmidt (modified) or Power-Chesnut methods.
J. I. Palmore.—In point of time and ease of manipulation the Power-Chesnut
method proves superior to the modified Stahlschmidt method. The Bailey-Andrew
method is shorter and easier to manipulate than the Power-Chesnut method. A
very little, if any, difference was observed in the appearance of any of the residues
from the alcohol and chloroform extractions. The average of duplicate results of the
three methods agrees within the limits of experimental error. There is practically
no difference in the results obtained by the Kjeldahl and the Kjeldahl-Gunning-Arnold
method for nitrogen in the extracted matter. In the Power-Chesnut method, the
Rask extractor proved superior to the Soxhlet extractor.
1 J. Assoc. Official Agr. Chemists, 1921, 5: 290.
* Ibid., 292.
109
REPORT ON TEA
ANDREW
1922]
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110 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 1
H. R. Baker.—1 consider the Bailey-Andrew method to be better than the modified
Stahlschmidt owing to the difficulty in the entire removal of lead by the hydrogen
sulfide. Also better checks were obtained from the Bailey-Andrew method.
DISCUSSION OF RESULTS.
The experience with these three methods was summarized by the
referee last year as follows:
The results obtained by the proposed method! are in close agreement with those
obtained by the other two methods and the caffeine residues are of an equal degree of
purity. The time required is very much less than in either of the other procedures.
(The average difference between results for caffeine by weight and from nitrogen was
considerably under 0.10% and practically the same in all methods.)
The results this year show satisfactory agreement as regards results
for caffeine by weight but too wide discrepancies between these figures
and the corresponding results estimated from nitrogen. The trouble
quite evidently lies in the determination of caffeine nitrogen, but why
this should be at all troublesome, or why it should be more so in the
case of the Stahlschmidt method than in the other methods, is difficult
to understand. An allowance of 0.1 per cent for experimental error in
determining nitrogen (equivalent to 0.35 per cent caffeine) is a very
liberal tolerance and about twice as great as is generally necessary;
nevertheless, excluding only those figures for caffeine from nitrogen
which vary from caffeine by weight by more than 0.35 per cent the
averages for the three samples become as follows:
TABLE 2.
Summary of results on determination of caffeine.
Moprr1eEp STAHLSCHMIDT PowEr-CHESNUT BaILeEyY-ANDREW
MeErtTHopD MeErTHOD METHOD
Sampece No.
By From By From By From
Weight Nitrogen Weight Nitrogen Weight Nitrogen
per cent per cent per cent per cent per cent per cent
{ 2.20 2.04 2.18 2.06 218 2.02
{I 2.26 2.10 2.38 2.24 2.34 2.19
iil 2.44 2.39 2.44 2.38 2.54 2.53
In computing this summary all the figures reported by the Power-
Chesnut method were included. Of the results reported by the Bailey-
Andrew procedure only five were excluded. It was necessary to exclude
16 of the 28 results reported by collaborators by the Stahlschmidt
method, as it is manifestly unfair in this case to recognize results which
vary from the results by weight to the extent of from 0.5 to nearly
1 per cent, since it is evident that the results by weight are in satis-
1 Bailey-Andrew Method.
1922] ANDREW: REPORT ON TEA EET
factory accord with the other two methods, and there are ample data to
show that the method will yield caffeine residues of equal purity. The
summary given is reasonably fair to all methods although it will be
noted that the Power-Chesnut method gains by the fact that reports
are less complete by that method than by the other two. If all figures
reported had been included in the averages in the summary the only
conspicuous change would occur in the results for caffeine from nitrogen
in Samples I and II by the Stahlschmidt method.
The accumulated data of the past two years show that the Bailey-
Andrew method compares satisfactorily with the other two methods,
both as regards the gross amount of caffeine obtained and the degree
of purity of the caffeine residues. In the opinion of all collaborators
it is simpler to manipulate and requires less time than the Stahlschmidt
method and, in the opinion of some, it is superior to the Power-Chesnut
method in this respect. Your referee, however, feels justified in re-
peating the recommendation of last year with regard to the Power-
Chesnut method and in offering the Bailey-Andrew method as an
optional official method.
RECOMMENDATIONS.
It is therefore recommended—
(1) That the Power-Chesnut method as described on page 290 of
Volume V of The Journal (except that in line 8, 10 cc. of 10 per cent
sulfuric acid be changed to read 20 cc. of 10 per cent sulfuric acid) be
adopted as an official method for the determination of caffeine in tea.
(Second reading.)
(2) That the Bailey-Andrew method be adopted as an optional
official method for the same determination. (First reading.)
(3) That suggestions for further study of the subject of tea be left
to the next referee.
No report on nitrogen in foods was made by the referee.
The meeting adjourned at 5 p. m. for the day.
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THIRD DAY.
WEDNESDAY—MORNING SESSION.
REPORT OF THE COMMITTEE ON EDITING METHODS
OF ANALYSIS1.
The work of your Committee on Editing Methods of Analysis during
the past year has been practically confined to the compilation of the
additions and changes which were made to the several chapters of the
methods at the 1920 meeting, which compilation is given as a part of
this report.
Your committee expects during the coming year to consider plans
for the next revision of the Book of Methods, and takes this opportunity
of requesting suggestions from the members of the association for ways
and means of improving and making more useful and convenient the
book itself, the arrangement of the chapters, the descriptive matter,
cross references, etc. It is urged that all chemists and others who have
occasion to use these methods submit to any of the members of the
Committee on Editing Methods of Analysis such criticisms as they
may have of the present book, together with suggestions that occur to
them for improvement in the next edition. These will be gratefully
received by your committee and given careful consideration in formu-
lating plans for the next revision.
CHANGES AND ADDITIONS TO THE OFFICIAL AND TENTATIVE METHODS
OF ANALYSIS MADE AT THE 1920 MEETING OF THE ASSOCIATION.
1. FERTILIZERS.
The Ross-Deemer method for the determination of boric acid in
fertilizer materials and mixed fertilizers was adopted as a tentative
method. (First action by the association.) The method has been
published in The Journal?.
II. INORGANIC PLANT CONSTITUENTS.
No additions or changes were made at the 1920 meeting.
Ill. WATERS.
No changes or additions were made to the methods for waters at the
1920 meeting. The association, however, approved a recommendation
1 Presented by R. E. Doolittle.
2 J. Assoc. Official Agr. Chemists, 1922, 5: 327.
113
114 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 2
made by Subcommittee A that the following statement relative to the
determination of bromide in the presence of chloride and iodide be
published in the proceedings for the information of chemists having
occasion to make the determination pending the final adoption of a
method:
A volumetric method for the determination of bromide in the presence of chloride
and iodide will be found in the J. Ind. Eng. Chem., 1920, 4: 358. Cooperative work
indicates that this is probably the best method for bromide which has been published,
but the results obtained show that only about 95% of the bromide present is recovered
when 80 milligrams of bromide are contained in the portion of sample used for analysis.
The method is satisfactory in the absence of iodide as shown by the cooperative work
on water in 1919.
IV. TANNING MATERIALS.
No additions or changes were made at the 1920 meeting.
V. LEATHERS.
No additions or changes were made at the 1920 meeting.
VI. INSECTICIDES AND FUNGICIDES.
The hot bromate method? for the titration of the acid distillate in the
official distillation method for the determination of total arsenic in Paris
green was adopted as an official method. (First action by the asso-
ciation.)
The bromate method? for the determination of arsenious oxide in
Paris green was adopted as an official method. (First action by the
association.)
The bromate method® for the determination of arsenious oxide in
calcium arsenate was adopted as an official method. (First action by
the association.)
The official distillation method! for the determination of total arsenic
in Paris green was adopted as an official method for the determination
of total arsenic in London purple. (First action by the association.)
The zinc oxide-sodium carbonate method® for the determination of
total arsenic in London purple was adopted as an official method. (First
action by the association.)
The bromate method for the determination of arsenious oxide in zinc
arsenite was adopted as an official method. (First action by the asso-
ciation.)
The official method® for the determination of water-soluble arsenic in
lead arsenate was adopted as an official method for the determination of
1 J. Assoc. Official Agr. Chemists, 1921, 4: 381.
2 [bid., 5: 34.
’ I[bid., 36.
4 Assoc. Official Agr. Chemists, Methods, 1920, 54.
5 J. Assoc. Official Agr. Chemists, 1921, 4: 397.
6 Assoc. Official Agr. Chemists, Methods, 1920, 59.
1922] EDITING METHODS OF ANALYSIS 115
water-soluble arsenic in zine arsenite. (First action by the association.)
The tentative method! for the determination of arsenious oxide in
lead arsenate was adopted as a tentative method for the determination
of arsenious oxide in calcium arsenate.
The following method? for the determination of calcium oxide in
calcium arsenate was adopted as a tentative method:
Dissolve 2.0 grams of the sample in 80 cc. of acetic acid (1 to 3), transfer to a 200 cc.
volumetric flask and make to volume. Filter through a dry filter and transfer a 50 cc.
aliquot to a beaker: dilute to 200 cc., heat to boiling and precipitate the calcium with
ammonium oxalate. Allow the beaker to stand 3 hours on the steam bath, filter and
wash with hot water. Dissolve the precipitate in dilute sulfuric acid and titrate with
permanganate.
A modified method’ for the determination of calcium oxide in calcium
arsenate was adopted as a tentative method.
Under the heading ‘‘General procedure for the analysis of a product
containing arsenic, antimony, lead, copper, zinc, iron, calcium, mag-
nesium, etc.”, applicable to such preparations as Bordeaux-lead arsenate,
Bordeaux-zinc arsenite, Bordeaux-Paris green, Bordeaux-calcium arse-
nate, methods! for the determination of lead oxide and copper were
adopted as official methods (first action by the association) and a
method! for the determination of zinc oxide was adopted as a tentative
method.
The mercury-thiocyanate method’ for the determination of zinc oxide
in zinc arsenite was adopted as a tentative method.
The official method‘ for the determination of water-soluble arsenic in
lead arsenate was adopted under suspension of the rules as an official
method for the determination of water-soluble arsenic in zinc arsenate.
(Final action.)
The official distillation method’ for the determination of total arsenic
in Paris green was adopted under suspension of the rules as an official
method for the determination of total arsenic in magnesium arsenate.
(Final action.)
VII. FOODS AND FEEDING STUFFS.
No additions or changes were made at the 1920 meeting.
VIII. SACCHARINE PRODUCTS.
No additions or changes were made at the 1920 meeting.
1 Assoc. Official Agr. Chemists, Methods, 1920, 59.
2 J. Assoc. Official Agr. Chemists, 1921, 5: 37, 50.
3 Tbid., 41.
4 Ibid., 42, 43.
5 J. Assoc. Official Agr. Chemists, 1921, 5: 47.
nee Official Agr. Chemists, Methods, 1920, 59.
id., 54.
116 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 2
IX. FOOD PRESERVATIVES.
No additions or changes were made at the 1920 meeting.
X. COLORING MATTERS IN FOODS.
The methods for the examination of commercial coal-tar food colors
published previously in the proceedings', were adopted as tentative
methods by the association. (First action by the association.)
XI. METALS IN FOODS.
No additions or changes were made at the 1920 meeting.
XII. FRUITS AND FRUIT PRODUCTS.
No additions or changes were made at the 1920 meeting.
XI. CANNED VEGETABLES.
No additions or changes were made at the 1920 meeting.
XIV. CEREAL FOODS.
No additions or changes were made at the 1920 meeting.
XV. WINES.
No additions or changes were made at the 1920 meeting.
XVI. DISTILLED LIQUORS.
No additions or changes were made at the 1920 meeting.
XVII. BEERS.
No additions or changes were made at the 1920 meeting.
XVIII. VINEGARS.
No additions or changes were made at the 1920 meeting.
XIX. FLAVORING EXTRACTS.
No additions or changes were made at the 1920 meeting.
XX. MEAT AND MEAT PRODUCTS.
The methods for the examination of gelatin, as published previously
in The Journal’, were adopted as tentative methods. (First action by
the association. )
XXI. DAIRY PRODUCTS.
No additions or changes were made at the 1920 meeting.
1 J. Assoc. Official Aqr. Chemists, 1922, 5: 198.
2 Thid., 343.
1922| EDITING METHODS OF ANALYSIS 117
XXII. FATS AND OILS.
The Wijs method (XXII, 16') for the determination of iodine absorp-
tion number was made an official method. (First action as official
method by the association.)
XXIII. SPICES AND OTHER CONDIMENTS.
No additions or changes were made at the 1920 meeting.
XXIV. CACAO PRODUCTS.
No additions or changes were made at the 1920 meeting.
XXV. COFFEES.
The modified Stahlschmidt method (XXV, 15?) for the determination
of caffeine in coffees was dropped.
The Power-Chesnut method for the determination of caffeine in
coffees was adopted as an official method. (First action by the associ-
ation.) The method has been published in The Journal’.
The Fendler-Stiiber method‘ for the determination of caffeine in
coffees as modified at the 1919 meeting was adopted as a tentative
method. (Second action by the association.)
XXVI. TEAS.
The Power-Chesnut method*® for the determination of caffeine in
teas was adopted as an official method. (First action by the associa-
tion.) The details of the method are the same as for the determination
of caffeine in coffees.
The modified Stahlschmidt method as further modified at the 1919
meeting to provide for the drying of the caffeine residue at 100°C.
instead of 75°C. was adopted as an official method. (First action by the
association. )
XXVII. BAKING POWDER AND BAKING CHEMICALS.
No additions or changes were made at the 1920 meeting.
EGG AND EGG PRODUCTS.
The following method for the determination of zinc in dried egg
products was adopted as a tentative method (first action by the asso-
ciation) :
Place 25 grams of the well-mixed sample in an 800 cc. Kjeldahl flask. Add 5 grams
of zinc-free potassium sulfate, 3 or 4 glass beads to prevent bumping, 30 cc. of con-
eS Official Agr. Chemists, Methods, 1920, 245.
2 [bi
3 J. randy Official Agr. Chemists, 1922, 5: 271.
4 [bid., 1921, 4: 533.
5 [bid., 1922, 5: 290.
118 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
centrated sulfuric acid in the case of yolks or whole eggs (25 cc. of the acid in the case
of albumens) and 30 ce. of concentrated nitric acid. Do not heat. When spontaneous
action subsides, add 10 cc. of concentrated nitric acid. After 2 or 3 additions of con-
centrated nitric acid the action becomes less violent. Heat gently, at first, continuing
the addition of concentrated nitric acid and increasing the temperature as the digestion
proceeds until the contents of the flask are straw colored or colorless, after nitric acid
fumes have been boiled off. This digestion may be accomplished in the case of albumen
in 40 minutes and in the case of yolks or whole eggs in an hour. To the warm digestion
flask add 100 cc. of water and pour contents into a 400 cc. beaker, rinsing the flask
with two successive 50 cc. portions of water. To the combined water solution add
concentrated ammonium hydroxide until faintly alkaline. Pass hydrogen sulfide gas
through the solution for 15 minutes which should be sufficient to saturate. (At this
point the majority of aibumens indicate the presence or absence of zinc. In the case
of albumen, if zinc is present, add a diluted solution of ferric chloride containing 0.5
gram of solid ferric chloride. This assists in retaining the zinc sulfide on the paper
when filtering. Pass hydrogen sulfide gas through the solution for 15 minutes.) Heat
the beaker on the steam bath for 30 minutes. Remove, allow to settle 5-10 minutes and
decant through a 9 cm. filter paper, allowing as much of the precipitate as possible to
drain thoroughly. Dissolve the zinc sulfide from this precipitate with 10% of hydro-
chloric acid, the solution after passing through the filter paper being returned to the
original beaker. Copper and lead sulfides are insoluble at this point and may be
determined by the usual methods. To the hydrochloric acid solution add 5 grams of
ammonium chloride and an excess of bromine water and a slight excess of concentrated
ammonium hydroxide. Neutralize carefully with 10% bydrochloric acid adding 2 cc.
in excess; add 10 cc. of 50% by weight of ammonium acetate and 8-10 drops of 10%
ferric chloride solution, or enough to give a distinct reddish tinge. Dilute to about
300 cc. with water and boil for 1 minute. Allow to settle, filter hot and wash with hot
5% ammonium acetate. Pass hydrogen sulfide gas through the filtrate for 15 minutes.
Heat for 30 minutes on a steam bath and filter through a weighed heavily padded
Gooch crucible, using gentle suction. Wash with hot 5% ammonium acetate solution.
Dry in oven and ignite, roasting first. Increased weight of Gooch is due to oxide of
zinc. This multiplied by 0.8034 gives the zinc present in 25 grams of sample.
XXVIII. DRUGS.
The followimg method for the evaluation of hexamethylenetetramine
tablets was adopted as a tentative method. (First action by the asso-
ciation.)
REAGENTS.
(a) Modified Nessler’s reagent—(1) Dissolve 10 grams of mercuric chloride, 30
grams of potassium iodide and 5 grams of acacia in a minimum quantity of water and
filter through a pledget of cotton wool. (2) Prepare a solution of 15 grams of sodium
hydroxide in 100 cc. of water.
(b) Standard iodine solution.—Prepare a 0.1N solution by dissolving 12.692 grams
of purified iodine in a solution of 18 grams of potassium iodide in 300 cc. of distilled
water. Dilute the solution to 1000 ce.
(c) Standard sodium thiosulfate solution.—A 0.05N solution.
PRELIMINARY TREATMENT.
Ascertain the weight of 20 or more tablets, triturate in a mortar to a fine powder
and keep in a small capsule tightly closed with a cork or glass stopper. Weigh out
1922] BALCOM: REPORT OF THE BOARD OF EDITORS 119
0.5 gram of the powdered sample on a metal scoop or watch glass, transfer with sufficient
water to a round-bottom flask, and add additional water to a total volume of 100 cc.
and finally 25 cc. of 10% hydrochloric acid. Connect with a reflux condenser (pref-
erably of the worm type) and boil gently 15 minutes; after cooling, wash out the con-
denser tube with a little water and transfer the contents of the flask to a graduated
250 cc. flask, finally diluting to the mark with water.
DETERMINATION.
With a pipet withdraw 10 cc. (containing in the case of the pure product the elements
of 0.02 gram of hexamethylenetetramine) of the solution so prepared to a 200 cc. Erlen-
meyer flask containing a mixture (previously chilled in ice water if available) of 20 cc.
of the modified Nessler’s reagent solution (1) and 10 cc. of the solution (2), wash down
neck of container with a fine jet of water and allow the mixture to stand at least 1
minute after gentle rotation of the flask. Now add 10 cc. of 40% acetic acid in such
manner that the inside of the neck is completely washed by the reagent, mix quickly
and thoroughly by gently rotating and tilting the flask, and immediately run in from a
buret 20 cc. of the standard iodine solution; titrate with the standard sodium thio-
sulfate solution (adding 5-10 drops of starch solution toward the end of the operation)
to the disappearance of the blue coloration. The final color of the solution is a pale
straw-green. If preferred, the end-point may be determined by the reformation of a
faint blue coloration, induced by the addition of a drop of iodine solution.
Since the standard iodine solution employed has twice the titrimetric strength of the
standard thiosulfate and 1 cc. of 0.1N iodine is equivalent to 0.001167 gram of hexa-
methylenetetramine (0 =16), the quantity of this product, as represented by its elements
formaldehyde and ammonia in the aliquot under examination, may be readily calcu-
lated from the expression—
=
—=N 0.001167,
in which H = the number of cc. of 0.05N sodium thiosulfate equivalent to 20 cc. of
0.1N iodine, I = the number of cc. of 0.05N thiosulfate required to offset the unexpended
iodine, and N = the normality of the 0.05N thiosulfate solution.
XXIX. SOILS.
No additions or changes were made at the 1920 meeting.
XXX. REFERENCE TABLES.
No additions or changes were made at the 1920 meeting.
REPORT OF THE BOARD OF EDITORS.
By R. W. Batcom (Bureau of Chemistry, Washington, D. C.), Chairman.
In June, at the time of the taking over of the duties of the secretary-
treasurer of the association as well as those of the chairman of its Board
of Editors from Dr. Alsberg, the financial affairs of the association were
those of a “going concern’, but continued direction was necessary
owing to the many unpaid bills and to the delay in the issuance of the
May and August numbers of The Journal due to a printers’ strike.
The ad interim appointment was made by the Executive Committee
120 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
of the association. At this point it may be stated that the association
owes a great deal to Miss Nellie A. Parkinson for her loyalty to the
association as evidenced by her continued interest in its work in the
face of great difficulties.
With the utmost endeavor it was impossible to get the May number
of The Journal, Number 4 of Volume IV, mailed before the end of August.
The August number, Number 1 of Volume V, which begins the proceed-
ings of last year’s meeting, is now ready. It is hoped that the
November number will issue sometime in December and that the
February 1922 number, in which publication of the proceedings of the
present meeting will begin, will issue practically on time.
All bills received, including all expenses in connection with the first
edition of 3000 copies of the Book of Methods, have been paid with the
exception of the printer’s bill of $1643.85 for Number 4 of Volume IV
of The Journal. 'To do this it was necessary to draw upon subscriptions
to Volumes V, VI, and VII, already paid in, to the extent of $938.75.
There is due the association, and probably in large part collectable,
subscriptions to Volume III of The Journal—$22.61; to Volume IV—
$173.71; and for copies of the Book of Methods—$977.88, or a total of
$1174.20. On October 15, when the books were closed, the deficit
faced by the association—$1643.85 plus $938.75 less $1174.20 and less
available bank balances of $461.78—was $946.62 or, in round numbers,
9950.00. The purpose of preparing this statement is to show exactly
the financial condition of the association. A similar statement next
year will show how much progress, if any, has been made in wiping out
this deficit. The suit brought by the Williams and Wilkins Company,
former publishers of The Journal, has been dismissed, and it is for the
association to decide what further action should be taken in that matter.
The first edition of the Book of Methods, with the exception of a few
copies, has been sold. In spite of the large initial cost, the Book of
Methods has more than paid for itself, and the demand has been most
gratifying from other countries as well as our own. To fill future orders,
1000 additional copies have been run off.
The mailing list for the February issue showed 715 subscriptions to
The Journal; by the end of August, at- which time the May number
issued, this number had been increased to 830. From August to October
15, mainly through circularization of those who had purchased the Book of
Methods and were not at the same time subscribers to The Journal,
the additional subscriptions secured increased the number on our mailing
list to 868. Of these subscriptions 782, including 30 Canadian, are
domestic. The remaining 86, or approximately 10 per cent, are foreign,
distributed as follows: Africa, 14; Australia, 9; Brazil, 3; Chile, 1; China,
4; Denmark, 1; Egypt, 1; England, 20; France, 2; Germany, 2; Hol-
land, 2; India, 12; Ireland, 4; Italy, 2; Japan, 1; Mexico, 1; Norway, 1;
1922] BALCOM: REPORT OF THE BOARD OF EDITORS 121
Scotland, 5; West Indies, 1. This demand from other countries for
The Journal and the Book of Methods shows how highly the work of
the association is regarded outside of those countries to which member-
ship is limited. The evidence of this regard is something of which the
association may justly be proud and it should serve as an additional
incentive to the exercise of its best efforts.
More subscriptions to The Journal are needed. The subscription list
will have to be materially increased to make The Journal self-supporting,
even when every effort has been made to hold the cost of production to
a minimum and to obtain as much revenue as practicable from advertise-
ments. Now that it is possible to publish the proceedings promptly
subscriptions may be more freely solicited than has heretofore been the
case, and every member of the association is urged to do everyting in
his power to increase the subscription list. ‘The members should realize
that The Journal is the enterprise of the Association as a whole and not
merely of its Board of Editors. If the element of personal responsibility
is appreciated and assumed, it is believed to be entirely possible that at
the next year’s meeting a surplus instead of a deficit will be reported.
Those who are now depending upon the libraries, including those who
place the orders for these libraries, might well send in a personal sub-
scription. A telling point is that The Journal gives a complete record
of the work of the association, including any modifications of the official
methods of analysis or additions thereto adopted at its annual meetings.
These changes constitute the basis for the revision, from time to time,
of the association’s Book of Methods and subscription to The Journal
is necessary to keep in close touch with the association’s work.
Every effort should be made by those presenting reports and papers
to make them as concise as may be consistent with clarity. When
submitted they should be in final shape for publication. Illustrations
should be suitably prepared for reproduction and particular attention
should be given to see that appropriate legends accompany each table
and that literature references are complete and accurate. Careful
attention to these matters will expedite the editorial work and help to
cut down the cost of publication. If there is any doubt in the mind of
an author as to the form in which his report should be prepared, reference
to his files of The Journal will probably give the desired information.
It is the feeling of the Board of Editors that addresses, referees’ reports,
and other papers presented before the association should be considered
the property of the association, and now that there will be no great
delay in the publication of these papers in our own journal, it is believed
that it will be sufficient to direct the attention of the members to the
fact that advance publication of any of this material in other journals,
except possibly in abstract form, is not to the best interest of this asso-
ciation.
122 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
Space should soon be available in The Journal for the publication of
contributed articles along the lines of work the association is pursuing
in addition to such papers and reports as are usually included in the
proceedings.
R. N. Brackett.—I move the acceptance of this report of the Board of
Editors with commendation.
The motion was seconded and carried.
R. W. Balcom.—At the 1915 meeting, a Board of Editors of The Journal
to consist of the secretary of the association as chairman and four mem-
bers to serve one, two, three and four years, respectively, each following
appointment to be for four years, was authorized. The duties of the
chairman have been and are likely to continue to be those of a managing
editor. It is my belief, and this belief is shared by the Executive Com-
mittee, that the time has come when these editorial duties should be
borne by someone other than the secretary of the association. There
are several reasons for this, the controlling one of which is that the
work of the Chairman of the Board of Editors as managing editor de-
mands so much time that it should no longer be required of the secre-
tary when he is at the same time one of the superior officers of any of
our organizations; and the second is that eventually editorial policy
and decisions are likely to be the subject of criticism, particularly when
it is necessary to decide whether a contribution offered for publication
in The Journal shall be accepted or rejected. No editorial staff can
escape a certain amount of such criticism. The advantage of having
these two offices separate is that when the association becomes dis-
satisfied with the way its Journal is being conducted, it can change its
managing editor without the secretaryship being at the same time in-
volved. In order to bring the matter before the association, on behalf
of the Executive Committee, I wish to move that the secretary of the
association be no longer required to serve as Chairman of the Board of
Editors, and that a Chairman of the Board of Editors be elected as are
the other members of the Board, for a period of four years.
The motion was seconded and carried.
No report was made by the Committee on Quartz Plate Standardiza-
tion and Normal Weight.
1922] HASKINS: AVAILABILITY OF PHOSPHORIC ACID IN BASIC SLAG 123
REPORT OF COMMITTEE ON VEGETATION TESTS ON THE
AVAILABILITY OF PHOSPHORIC ACID IN BASIC SLAG.
By H. D. Haskins (Agricultural Experiment Station, Amherst, Mass.),
Chairman.
It is regretted that your committee is not able at this time to make a
full report to the association. However, a brief review of the work that
has been done both in pot and field will be given. The form in which
the committee will make its final report for publication is sti!l in doubt
because all the members of the committee have not been consulted. A
meeting of the committee was called at this convention, but W. B.
Ellett of Virginia was the only member, besides the chairman, who was
able to be present. Part of the summaries showing the results of the
vegetation work, particularly of the pot vegetation work, have been
prepared. A lot of extremely good work has been accomplished in these
vegetation experiments, and it is hoped that the final results may be
published in The Journal, and that there may be some discussion with
reference to this point following this report. If there are any instruc-
tions which the association wishes to make to the committee they will
be very acceptable.
Ten different experiment stations have undertaken and completed
work on the availability of phosphoric acid in basic slag. They com-
prise the following: The Hawaiian Station, Illinois, Massachusetts, New
Jersey, New York, North Carolina, North Dakota, Pennsylvania,
Rhode Island and Texas. The total number of pot experiments con-
ducted was 84, comprising 1,731 different pots. In the field work only
three institutions found it possible to do any collaborative work. These
results showed that 12 different experiments were conducted, including
332 tests on plots, making a total of 96 experiments, including pot and
field work, with 2,063 different tests in both forms of experiment. That
is a mass of data. |
The result of the vegetation pot work has been satisfactory because
it was possible for most of the collaborators to select soils that were
known to be deficient in available phosphoric acid.
The vegetation field work did not give as satisfactory results as the
pot work, for the reason, apparently, that the preliminary work was not
conducted for a sufficient length of time properly to deplete the soils of
available phosphoric acid in preparation for the final test. It may be
said, however, that the vegetation field work does not emphasize any
inferiority of the phosphoric acid furnished by the slags.
(A summary of both pot and field tests, showing the average yield
of crop and phosphoric acid recovered by each phosphate, also the
standing of each phosphate on the basis of increase in yield over no
124 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
phosphate pots and plots was then given. These figures were placed
on a blackboard and are not reproduced here as they will form a part of
the final report to the association which will be published in a later
issue of The Journal.)
Your committee reports the following conclusions:
(1) That sufficient experimental work has been done, particularly
along the line of vegetation pot work, to establish the fact that the
phosphoric acid in the four slags under experiment was freely available
to the crops grown; (2) that the results shown compare favorably with
those obtained with acid phosphate, both from the standpoint of yield
of crop as well as in phosphoric acid recovered; (3) that the tentative
Wagner method when used on basic slag phosphates gives about the
same proportion of available phosphoric acid in this class of products
as does the official neutral citrate of ammonia method when used on
acid phosphate or superphosphate, and that both methods give results
which compare favorably with results obtained by the vegetation pot
work.
It is the opinion of your committee that the tentative Wagner method
is a reliable procedure for measuring the available phosphoric acid in
basic slag phosphates and it would, therefore, recommend that it be
adopted by the association as official.
It is also recommended that the detailed report of the Committee on
Vegetation Tests on the Availabiltiy of Phosphoric Acid in Basic Slag
be published in The Journal of the association as soon as it is completed
and space is available.
H. D. Haskins, B. L. HartweE tt,
J. A. BizzE.u, C. B. WILLIAMS.
W. B. ELLetT,
Committee on Vegetation Tests on the Avail-
ability of Phosphoric Acid in Basic Slag.
Adopted.
It was moved, seconded and adopted that the final report be pub-
lished in concise form.
REPORT OF COMMITTEE TO COOPERATE WITH THE AMERI-
CAN SOCIETY FOR TESTING MATERIALS.
The full membership of the committee was present at a meeting pre-
liminary to a subsequent joint meeting with the two proper sub-com-
mittees of Committee C7, of the American Society for Testing Materials.
This meeting was held in Washington in the spring of 1921.
Your committee desires to report as follows:
1922] REPORT OF COMMITTEE FOR TESTING MATERIALS 125
An understanding was reached to the effect that cooperation was
desirable between these two organizations, insofar as agricultural lime
products are involved.
It was agreed that uniformity of chemical analytical methods for use
in production laboratories and official control laboratories would prove
desirable.
It is pointed out that no provision is made in the methods of the A.
O. A. C. for the analyses of lime products which are already under
official regulation in some states.
RECOMMENDATIONS.
It is reeommended—
(1) That further collaboration and cooperation be carried out with
the American Society for Testing Materials.
(2) That the committee be continued and directed to give con-
sideration to the preparation of methods for the analyses of lime pro-
ducts, as a special chapter, or the adaptation of methods now used for
the determined constituents of lime products, as such may be now pro-
vided for in other chapters of the methods of the association.
W. H. MacIntire,
F. P. Verrcu.
WILLIAM FREAR,
Committee to cooperate with the Ameri-
can Society for Testing Materials.
Adopted.
No report was made by the Committee on Revision of Methods of
Soil Analysis.
REPORT OF COMMITTEE ON RECOMMENDATIONS
OF REFEREES.
By R. E. DootitrLe (Food and Drug Inspection Station, Chicago, IIl.),
Chairman.
You have already received the reports of Subcommittees A, B and C
on the recommendations made by the several referees. There is little
to add to these reports. The work of these subcommittees is most
important, not only in the consideration of analytical and other data
submitted in support of the recommendations made by the referees, but
also in the directing and planning of future work. This meeting has
established a record for the number of referee reports received. Out of
a total of 73 referees and associate referees, reports were received from
all except three, and some of these did work but made insufficient prog-
126 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMIsTs [Vol. VI, No. 2
ress to warrant a report. This I believe is a record. It is due, in my
opinion, to the recommendation made by your Committee on Recom-
mendations of Referees last year that insofar as possible specific sub-
jects be assigned associate referees in order that the work of the associa-
tion may be kept under better control and a continuity of work estab-
lished on a problem under consideration until definitely completed.
The chairman of this committee desires to call to the attention of
the referees the following matters which have come to his attention in
connection with this work:
(1) That it is important that the chairman of the subcommittee
submit at least three copies of his report to the chairman to which his
report is to be sent, in order that each member of the subcommittee
may have an opportunity to study the report before the date set for the
meeting.
(2) That the report should be submitted at the earliest possible date
in order that the members of the subcommittees may have time to give
it full consideration.
(3) That it is necessary for referees and associate referees to begin
work upon their subjects immediately on returning to their respective
homes. It appears to be a common practice to postpone starting work
until spring and then vacations come along, collaborators can not be
obtained and everything is rushed through in the last few weeks before
the annual meeting. Many of these difficulties could be avoided if the
main subjects were taken up at once when the details of past actions and
the present status are fresh in mind.
The chairman also wishes, in behalf of the committee, to express its
appreciation and thanks to the referees and associate referees for the
splendid work done during the past year and for the complete and well-
prepared reports submitted.
Adopted.
1922] ROSS: COMMITTEE A ON RECOMMENDATIONS OF REFEREES 127
REPORT OF COMMITTEE A ON RECOMMENDATIONS
OF REFEREES.
By B. B. Ross (Alabama Polytechnic Institute, Auburn, Ala.), Chairman.
[Fertilizers (boric acid in fertilizers, preparation of ammonium citrate, nitrogen, potash,
potash availability, precipitated phosphates, vegetation tests on availability of
phosphoric acid in basic slag), inorganic plant constituents (calcium,
magnesium, iron and aluminium in the ash of seed; sulfur
and phosphate in the seeds of plants), water, tan-
ning materials and leather, insecticides and
fungicides, and soils (sulfur in soils).]
FERTILIZERS.
BORIC ACID IN FERTILIZERS.
It is recommended—
(1) That the Bartlett method be adopted as an official method for
the determination of boric acid in fertilizers and fertilizer materials on
account of its special adaptation to the analysis of samples which are
relatively high in soluble phosphates or organic matter. (First recom-
mendation for adoption as official method.)
Approved.
(2) That the Ross-Deemer method! be adopted as an official method
for the determination of water-soluble boric acid in fertilizers and ferti-
lizer materials on account of its special adaptation to the analysis of
samples which are low in soluble phosphates and organic matter relative
to the boric acid. (First recommendation for adoption as official method.)
Approved.
(3) That further work be done on both the Bartlett and Ross-Deemer
methods, recommended as tentative, to determine the effect of insoluble
boric acid and to study any modifications necessary to make both
methods applicable to the determination of water-soluble, acid-soluble
or total boric acid, as the case may require.
Approved.
PREPARATION OF AMMONIUM CITRATE.
With regard to the recommendation of the associate referee on the
preparation of ammonium citrate solution the committee would state
that objections to the final adoption of the proposed method as the
exclusive official method have been presented to the committee by
several members of the association, it being contended, among other
objections, that the working details of the method are not sufficiently
definite and explicit in certain particulars, and that it is essential that
more definite detailed directions be given before final adoption of the
method as official.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 327.
128 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
The committee desires to commend the excellent work done by the
associate referee in developing the method presented for adoption, but
is of the opinion that it is desirable to embody fuller details in the outline
of the method as presented before final action on the method is taken
by the association.
NITROGEN
It is recommended—‘
(1) That the association continue the study of the Devarda method.
Approved.
(2) That a comparison of results be made with the suggested modified
Kjeldah]-Gunning method, by H. C. Moore’, for the determination of
nitrate nitrogen in nitrates and fertilizers.
Approved.
POTASH.
It is recommended—
(1) That the method by Moore and Caldwell? which calls for the use
of stronger alcohol in connection with the Lindo-Gladding method be
further studied. This was recommended at the last meeting but no
samples were sent out to collaborators.
Approved.
(2) That the ‘Centrifugal Method for Determining Potash’, by
Elmer Sherrill? seems to be applicable when a rapid determination for
factory control is necessary, but can not compare with the Lindo-Glad-
ding method as an official method. However, the method is worthy of
consideration, and it is recommended that it be given a trial by the
association.
Approved.
POTASH AVAILABILITY.
No report or recommendations.
PRECIPITATED PHOSPHATES.
It is reeommended—
(1) That the determination of insoluble phosphoric acid in precip-
itated phosphates be carried out according to the present official method
for the determination of insoluble phosphoric acid in fertilizers, with the
exception that a 1-gram charge be employed. (First reading.)
Approved.
(2) That a perforated crucible and gentle suction be employed in the
filtration of the citrate solution after treatment, and that a filter paper
be employed that will insure a free and rapid filtration without allowing
the finely divided particles to pass through. The following papers have
been found satisfactory (and there may be others): S. & S. No. 597,
1 J. Ind. Eng. Chem., 1920, 12: 669.
2 Thid., 1188.
3 Tbid., 1921, 13: 227.
1922] | ROSS: COMMITTEE A ON RECOMMENDATIONS OF REFEREES 129
Whatman No. 2, Whatman No. 1, Munktell’s No. I-F, Munktell’s
No. 2 and Durieux No. 121. (First reading.)
Approved.
VEGETATION TESTS OF AVAILABILITY OF PHOSPHORIC ACID IN BASIC SLAG.
The committee recommends the adoption of the following recommenda-
tion of the Committee on Vegetation Tests:
It is the opinion of your committee that the tentative Wagner method is a reliable
procedure for measuring the available phosphoric acid in basic slag phosphates and it
would, therefore, recommend that it be adopted by the association as official.
Approved.
INORGANIG PLANT CONSTITUENTS.
CALCIUM, MAGNESIUM, IRON AND ALUMINIUM IN THE ASH OF SEED.
It is recommended—
(1) That further work be done on the determination of calcium and
magnesium in the ash of seeds.
Approved.
(2) That the method for manganese! as given in the report of the
referee be adopted as official.
Approved.
(3) That further study be given to the determination of iron and
aluminium in the ash of seeds.
Approved.
SULFUR AND PHOSPHATES IN THE SEEDS OF PLANTS.
The committee also recommends the adoption of the recommendation
of the associate referee that the method for determining sulfur and
phosphorus in the seeds of plants’, as outlined in his report, be studied
by the coming referee and various collaborators.
WATER.
The committee recommends the approval of the recommendations
of the referee for the adoption of the following as tentative methods
(on first reading) :
(1) Method for the determination of iodine in the presence of chlorine
and bromine’.
Approved.
(2) Method for analysis of salt*—moisture, matters insoluble in water
and matters insoluble in acid.
Approved.
(3) Method of reporting results®.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 467.
2 Tbid., 469.
3 Tbid., 381.
4 Ibid., 384.
5 [bid., 385.
130 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
The committee also favors the adoption of the following recommenda-
tions:
(4) That the tentative method of reporting results! be dropped.
Approved.
(5) That the quantitative methods for the determination of small
quantities of copper and zinc in waters? be studied during the next year.
Approved.
TANNING MATERIALS AND LEATHER.
It is recommended—
(1) That work be continued on the solubility of various soaps in
different solvents and upon a method, probably first breaking up the
soap by heating the leather with an acid, for the extraction of total
soaps in leather.
Approved.
(2) That investigations of a direct method for the determination of
tannin in tanning materials be continued.
Approved.
INSECTICIDES AND FUNGICIDES.
It is recommended—
(1) That the mercury-thiocyanate method for zinc oxide in zinc
arsenite? be adopted as an official method. (First reading. Adopted as
a tentative method in 1920.)
Approved.
(2) That the bromate method, procedures (1) and (2), for the determi-
nation of arsenious oxide in zinc arsenite’ be adopted as an official method.
(Second reading.)
Approved.
(3) That the official method for the determination of water-soluble
arsenic in lead arsenate® be adopted as official for the determination of
water-soluble arsenic in zinc arsenite. (Second reading.)
Approved.
(4) That the bromate method® be adopted as an official method for
the titration of the acid distillate in the official distillation method for
the determination of total arsenic. (Second reading.)
Approved.
(5) That no further study be made of the modified Gooch and Brown-
ing method’ for the determination of total arsenic in calcium arsenate.
Approved.
1 Assoc. Official Agr. Chemists, Methods, 1920, 38.
2 J. Assoc. Official Agr. Chemists, 1922, 5: 382.
3 J. Assoc. Official Agr. Chemists, 1922, 5: 392.
4 [bid., 394.
5 Assoc. Official Agr. Chemists, Methods, 1920, 59.
6 J. Assoc. Official Agr. Chemists, 1922, 5: 394.
7 Thid., 395.
1922] ROSS: COMMITTEE A ON RECOMMENDATIONS OF REFEREES 131
(6) That the bromate method, procedures (1) and (2), for the determi-
nation of arsenious oxide in calcium arsenate! be adopted as an official
method. (Second reading.)
Approved.
(7) That method (1) for the determination of calcium oxide in calcium
arsenate! be adopted as an official method. (First reading. Adopted as
a tentative method in 1920.)
Approved.
(8) That method (2) for the determination of calcium oxide in calcium
arsenate? be adopted as an official method. (First reading. Adopted as a
tentative method in 1920.)
Approved.
(9) That in the “General procedure for the analysis of a product con-
taining arsenic, antimony, lead, copper, zinc, iron, calcium, magnesium,
etc.”’, the methods for lead oxide and copper? be adopted as official
methods. (Second reading.)
Approved.
(10) That in the “General procedure for the analysis of a product con-
taining arsenic, antimony, lead, copper, zinc, iron, calcium, magnesium,
etc.”, the method for zinc oxide? be adopted as an official method.
(First reading. Adopted as a tentative method in 1920.)
Approved.
(11) That further action on the official distillation method for the
determination of total arsenic in London purple be deferred until the
suggested modification! has been studied.
Approved.
(12) That the zinc oxide-sodium carbonate method*® be adopted as an
official method for the determination of total arsenic in London purple.
(Second reading.)
Approved.
(13) That the bromate method, procedures (a) and (b), for the determi-
nation of arsenious oxide in Paris green®, as given in the referee’s report
in 1920, be adopted as an official method. (Second reading.)
Approved.
(14) That no further work be done at this time on magnesium arsenate.
Approved.
(15) That the words “Not applicable in presence of nitrates’ be placed
over the present distillation method for total arsenic wherever it occurs
among the methods of the association.
Approved.
(16) That the distillation method for total arsenic in the presence of
Ae Ae Official Agr. Chemists, 1922, 5: 395.
3 J. Assoc. Official Agr. Chemists, 1922, 5: 398.
‘ Tbid., 402.
5 [bid., peels 4: 397.
6 Ibid.
132 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
nitrates! suggested by Graham and Smith be adopted as a tentative
method, with a view to its adoption as an official method after it has
been further tested by cooperative work.
Approved.
(17) That the work on insecticides and fungicides for 1922 be a study
of the distillation method mentioned in Recommendation 16 for the
determination of arsenic in the presence of nitrates.
Approved.
SOILS.
It is recommended that during the ensuing year a further study be
made of the method of determining sulfur in soils which is described in
detail in the referee’s report?.
J. W. Kellogg: I believe it would be a splendid thing if a committee on
fertilizer definitions and the interpretation of those definitions or of terms
could be appointed. As you perhaps are aware, there is a Feed Control
Officials’ Association which has done a great deal of progressive work
along this line. The 35 or 40 different definitions which have been adopted
are a great help to us in interpretation of what these feeding stuffs
materials are. It has been a great guide in that work. Now, I do not
believe there is any need for a separate fertilizer officials’ association,
but we ought to get a little closer together on fertilizer work, not on
method analysis of course, but on an agreement as to what certain by-
products are and how they shall be listed and named in registration,
and we might also define a fertilizer. It might be well to call it a special
fertilizer committee—a fertilizer section—where the men who are
specially interested could get together. It would expedite the work and
agreement as to what some of these terms mean. Uniform methods of
registration of fertilizer materials might be considered. There are about
as many different kinds of registration blanks as there are States. We
have the same trouble in feeding stuffs work and of course there is great
confusion in meeting the requirements of the different States. There
appears to be no uniformity as to how these blanks shall be submitted
to the different departments. The methods of labelling sacks are different
in the different States, and that is a source of confusion, not only to the
manufacturer, but to the fertilizer control officials.
I would like to hear from others who are interested in this subject,
and I am willing to make a motion that a committee or a section be
appointed. I know that we already have a committee on food definitions;
that does not consider methods of analysis at all, but decides on uniform
terms, uniform interpretations of results.
E. G. Proulx: I heartily agree with what Mr. Kellogg has said on this
subject. Undoubtedly, if you once start in you will find that there will
1 J. Assoc. Official Agr. Chemists, 1922, 5: 402.
2 Ibid., 405.
1922] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 133
be sufficient problems to keep a committee busy. For many reasons I
believe it would be better for this work to be done as a committee of this
association instead of starting a separate association of fertilizer control
officials.
H. A. Huston: You might legislate a lot of good chemists out of a job
that way. At the present time it requires a pretty expert man to keep up
with these laws. If you make it so uniform and so simple that the office
boy can do it, a lot of chemists will be out of a job.
G. S. Fraps: I agree with Mr. Kellogg on some phases of this, but it
seems to me there are some points which we ought to consider. In the
first place, this organization is composed of official chemists, and not of
control officials. Many of the chemists have no control over the marking
of sacks or other things of that kind, and they really might not be in a
position to discuss these things and commit themselves in the absence of
the commissioner of agriculture, or whoever has charge of the fertilizer
law. That is a point we ought to consider in connection with naming a
committee to cover some of those things.
The matter of definitions of fertilizer terms might well be taken up
but I doubt right now if a committee should be appointed as broad as
the one Mr. Kellogg has named. It would hardly be possible for chemists
who do not have authority to undertake to make rules for their respective
departments in the absence of the supervisory officer. If sufficient number
can secure authority then they could go ahead and do it. I do not think
we ought to have a separate fertilizer section yet.
After further discussion a motion was made, seconded and carried
that a Fertilizer Committee on Definitions of Terms and Interpretation
of Results consisting of five members be appointed.
Later the president named the following committee: H. D. Haskins,
J. W. Kellogg, E. G. Proulx, G. S. Fraps and R. N. Brackett.
REPORT OF COMMITTEE B ON RECOMMENDATIONS OF
REFEREES.
By Hermann C. LyTHGor (State Department of Public Health, Boston,
Mass.), Chairman.
[Foods and feeding stuffs (crude fiber, detection of reground bran in shorts, stock feed
adulteration), saccharine products (sugar, honey, maple products, maltose
products, sugar-house products), dairy products (moisture in cheese,
fats and oils), baking powder, chemical reagents, eggs and
egg products, drugs.]
FOODS AND FEEDING STUFFS.
It is recommended—
(1) That a further study be made of sulfur dioxide and chlorine in
bleached grain.
Approved.
134 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
(2) That the method for determining the acidity of corn, as specified
by Black and Alsberg!, be considered by the referee next year with a
view to its adoption as an official method, and that the method be studied
to see if changes are necessary to make it applicable to grains other than
corn.
Approved.
(3) That the referee study the existing official general methods? for
water in foods and feeding stuffs with a view to rewording and fixing
rigidly the conditions of temperature, pressure and other factors.
Approved.
(4) That a definite method applicable to the determination of water
in dried food be designed and submitted to the association
Approved.
(5) That the referee study methods of determining ether extract in
various foods and feeding stuffs the coming year, with a view to ascer-
taining whether or not the official method for the determination of ether
extract is applicable to all the products for which it is now being used.
Approved.
CRUDE FIBER.
It is recommended—
That the present official method’ be deleted and the one proposed by
the referee be substituted. (First reading.)
Approved
REGROUND BRAN IN SHORTS.
It is recommended—
That the work on this subject be discontinued.
Approved
STOCK FEED ADULTERATION.
It is reeommended—
(1) That the microscopic method for the determination of rice hulls
in rice bran® be adopted as tentative.
Approved.
(2) That further study of methods for the estimation of grit in poultry
and similar foods be continued.
Approved.
(3) That further study be employed for the estimation of bone in
meat scraps.
Approved.
(4) That further study of microscopic methods for the examination
of mixed foods be employed.
Approved.
1U.S. Bur. Plant Ind. Bull., 199: (1920).
renee Official Agr. Chemists, Methods, 1920, 71.
3
4 J. Awe neces Agr. Chemists, 1922, 5: 421.
5 [bid.,
1922] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 135
SACCHARINE PRODUCTS.
: SUGAR.
It is recommended—
(1) That the modifications proposed in 1916 for determining sucrose
by acid and invertase inversions be further studied.
Approved.
(2) That the work upon determining small amounts of reducing sugars
in the presence of sucrose be continued.
Approved.
HONEY.
It is recommended—
That the work on resorcin and aniline chloride tests for the detection
of invert sugar sirup in honey! be further studied in connection with
honey heated to a comparatively high temperature. It is suggested that
directions to collaborators be more specific as to details of technique and
color.
Approved.
MAPLE PRODUCTS.
It is recommended—
That further study be made of the Canadian lead number and the
conductivity value.
Approved.
MALTOSE PRODUCTS.
It is reeommended—
That the work begun by the referee be continued.
Approved.
SUGAR-HOUSE PRODUCTS.
It is recommended that the following recommendations which were
made in 1919 be continued—
(1) That a study be made of the influence of different and known
temperatures of incineration on the results of ash determinations in
cane sirups and molasses, carrying out the incineration in both platinum
and silica dishes for comparison.
Approved.
(2) That as large a number as possible of samples of different grades
of cane sirups and molasses be used for preparing ash determinations
by the sulfate and direct methods, to determine, if possible, the proper
correction factor to be applied to the sulfate ash.
Approved.
(3) That a comparative study of methods for the determination of
specific gravity and of total solids of molasses be undertaken.
Approved.
1 Assoc. Official Agr. Chemists, Methods, 1920, 112; J. Assoc. Official Agr. Chemists, 1922, 5: 429.
136 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
DAIRY PRODUCTS.
It is recommended—
(1) That the cryoscopic method for the examination of milk! be
adopted as official. (First reading.)
Approved.
(2) That the neutral method for fat in malted milk as outlined by the
referee be further studied during the coming year. (This takes the place
of recommendations 1, 2 and 3 of 1920.)
Approved.
(3) That the Schmidt-Bondzynski method? for fat in cheese be adopted
as Official. (Second reading; first reading in 1917.)
Approved.
(4) That the referee study the proposed change in the official method
for the determination of fat in unsweetened condensed milk’, suggested
by J. T. Kiester, and report at the next meeting.
Approved.
= MOISTURE IN CHEESE.
It is recommended—
(1) That the present tentative method for moisture in cheese’ be
rewritten to include:
(a) That either 10 to 15 grams of sea-sand or 2 to 3 grams of asbestos
be used; and
(b) that the sample be dried in a vacuum, or at atmospheric pressure
at the temperature of boiling water; and
that this method be further studied with the view of making it official
Approved.
FATS AND OILS.
It is recommended—
(1) That the Wijs method’ for the determination of iodine absorption
number be made official. (Final action.)
Approved.
(2) That the alternative method for the preparation of Wijs solution
be adopted.
Approved.
(3) That further study on the Hanus method® be made as to length
of time of absorption.
Approved.
(4) That the referee confer with the Society on Testing Materials
in order that the methods may be uniform with those of the society.
Approved.
1 J. Assoc. Opie! Agr. Chemists, 1922, 5: 173.
2 Assoc. Official Agr. Chemists, Methods, 1920, 235.
3 J. Assoc. Official Agr. Chemists, 1922, 5: 509.
Tenn oe Oi cial Agr. Chemists, Methods, 1920, 234.
i
6 [bid., oa.
1922] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 137
(5) That further study on the determination of sesame oil be made
along the lines suggested by the referee.
Approved.
BAKING POWDER.
It is reeommended—
(1) That the Chittick method! as modified for the determination of
lead in baking powder be adopted as tentative.
Approved.
(2) That further study of the electrolytic method? for the determination
of lead in baking powder be made.
Approved.
(3) That the use of different indicators or a combination of indicators
be studied in connection with the determination of the neutralizing
strength of phosphates used in the manufacture of baking powder.
Approved.
(4) That collaborative study be made on the determination of fluorine
in baking powder.
Approved.
(5) That further study of volumetric methods for the determination
of carbon dioxide in baking powder be made.
Approved.
CHEMICAL REAGENTS.
It is reecommended—
(1) That the recommendation of the referee regarding specifications
of metric units be referred to the Committee on Resolutions.
Approved.
(2) That the following recommendations of 1920 be reported:
(1) That this association declare itself in favor of cooperating with the Committee
on Guaranteed Reagents and Standard Apparatus of the American Chemical Society
in the collection of data in regard to the quality of reagents on the market.
(2) That the secretary of this association be instructed to transmit a statement of
this action to the proper official of each institution represented in the membership
of the association and request that the purchasing agent or some other official of the
institution send him a carbon copy of each letter written to a manufacturer or dealer
calling attention to a specific instance of delivery of an unsatisfactory reagent.
Approved.
EGGS AND EGG PRODUCTS.
It is recommended—
That the report of the referee be accepted and published in the pro-
ceedings, and that the methods proposed be studied collaboratively
before adoption as tentative or official.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 514,
2 Ibid., 1920, 4: 221.
138 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 2
The referee on eggs and egg products moved that the recommendation
of the committee be amended to provide that the methods submitted in
the referee’s report be adopted as tentative methods.
The amendment was lost.
DRUGS.
ACETYLSALICYLIC Acip1.
It is recommended—
(1) That the method suggested for the determination of the melting
point be compared with the method adopted -by the association and
reported upon next year.
Approved.
(2) That the qualitative test for free salicylic acid, as described by
the referee, be adopted as a tentative method.
Approved.
(3) That the quantitative method for salicylic acid, substantially as
described by the referee but including the details suggested by H. O-
Moraw, be made a tentative method, and that same be resubmitted to
collaborators by next year’s associate referee with a view to its adoption
as an official A. O. A. CG. procedure.
Approved.
(4) That the iodine method for total salicylates, as described in
the recommendation, be made a tentative method, and that same be
further tried out by next year’s associate referee with a view to its final
adoption as an official method.
Approved.
(5) That the bromine method for total salicylates, as described in
the recommendation, be made a tentative method, and that same be
further tried out by next year’s associate referee with a view to its final
adoption as an official method.
Approved.
(6) That the double titration method for acetylsalicylic acid, as
described in the recommendation, be made a tentative method, and that
same be further tried out by next year’s associate referee with a view to
its final adoption as an official method.
Approved.
(7) That A. Nutter Smith’s method for free acetic acid and any other
available methods for this determination be submitted to collaborative
study by next year’s associate referee.
Approved.
(8) That consideration be given to methods for the quantitative
determination of combined acetic acid in acetylsalicylic acid.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 581.
1922] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 139
(9) That the problem of determining aspirin in the presence of pos-
sible interfering substances be given consideration by next year’s asso-
ciate referee. .
Approved.
PHENOLPHTHALEIN.
It is reeommended—
That an associate referee be appointed to continue the study of methods
for the examination of phenolphthalein.
Approved.
CAMPHOR.
It is recommended—
That the methods! suggested for the determination of camphor in
pills and tablets be further studied during the coming year.
Approved.
MONOBROMATED CAMPHOR.
It is recommended—
That the methods? submitted be adopted as tentative and that further
study be made of these methods during the coming year.
Approved.
MERCURY.
It is recommended—
That an associate referee be appointed to study the methods for the
examination of mercurous chloride, mercuric chloride and mercuric
iodine already reported to the association, or such methods as may be
available elsewhere for the purpose of developing a satisfactory method.
Approved.
TURPENTINE OIL’.
It is reeommended—
(1) That the fuming sulfuric acid method be further studied with
special attention to the preparation of the reagent and to the details of
the process.
Approved.
(2) That the sulfuric-nitric acid method be further studied.
Approved.
(3) That additional methods be studied in comparison with the
methods already studied.
Approved.
PAPAIN.
It is reeommended—
That for the present studies on papain be discontinued.
Approved.
lJ. fase, Olpetal Agr. Chemists, 1922, 5: 544.
2 Tbid., 58
3 Tbid., 547.
140 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
ALKALOIDS}.
SEPARATION OF QUININE AND STRYCHNINE.
It is recommended—
That the method submitted for the separation of quinine and strych-
nine be made tentative. (First reading.)
Approved.
t PHYSOSTIGMA.
It is reeommended—
That the method for the assay of physostigma and its preparations
be made a tentative method. (First reading.) It was recommended by
the associate referee that this method be adopted as official, but it
differs from the U. S. P. method.
Approved.
EXTRACT OF HYOSCYAMUS.
It is recommended—
That the method for the assay of extract of hyoscyamus and its
preparations be made a tentative method. (First reading.) It was
recommended by the associate referee that this method be adopted
as Official, but it differs from the U.S. P. method.
Approved.
IPECAC.
It is recommended—
That the comparative study of the volumetric and gravimetric methods
for the assay of ipecac be continued.
Approved.
BELLADONNA LINIMENT.
It is recommended—
That the methods submitted for the assay of the liniment of belladonna
be further studied.
Approved.
STRAMONIUM.
It is reeommended—
That a study be made on methods for assaying the ointment of stra-
monium.
Approved.
ATROPINE.
It is reeommended—
That further studies be made on methods for the assay of atropine
in tablets.
Approved.
STRYCHNINE.
It is recommended—
(1) That the method for the assay of strychnine in tablets, including
the volumetric method, be adopted as an official method. (First reading.)
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 564.
1922] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 141
(2) That the method for the assay of strychnine in liquids, including
the volumetric method, be adopted as an official method. (First reading.)
Approved.
MORPHINE, CODEINE AND DIACETYLMORPHINE!.
It is reeommended—
(1) That the methods for the qualitative and quantitative determi-
nation of morphine, codeine and diacetylmorphine be adopted as tenta-
tive methods. (First reading.)
Approved.
(2) That these methods be further studied with a view to making them
official.
Approved.
SYNTHETIC PRODUCTS.
It is reeommended—
(1) That Recommendations 1, 2 and 3 under synthetic products for
1920? be dropped, since Recommendations 2 and 3 have been taken care
of under other subjects and there are satisfactory methods available
under No. 1.
Approved.
PROCAINE®,
(1) That the methods submitted be further studied during the coming
year with a view to making them provisional.
Approved.
MEDICINAL PLANTS‘.
The methods for the macroscopic and microscopic identification of
certain drugs have been reported, with the results of collaborative study
thereon. Inasmuch as such methods represent a radical departure from
the practice of this association, it is reeommended—
(1) That these be referred to the Committee on Revision of Methods
for consideration before any action is taken. The committee, however,
recommends that these methods should be published in The Journai.
Approved.
(2) That the study of volume weight of medicinal plants be continued
with the assistance of collaborators.
Approved.
(3) That the study of the sublimation of plant products be continued
with the assistance of collaborators.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 573.
2 Tbid., 1921, 4: 573.
3 Ibid , 1922, 5: 589.
4 Ibid., 560.
142 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
SANTONINE.
(4) That the tentative method for the detection of santonine in worm-
seed be studied by collaborators with the view of making it official.
Approved.
POLLEN GRAINS.
(5) That the method for the use of pollen grains asa means of identifi-
cation of plants and plant products be further studied.
Approved.
BITTER TONIC AND LAXATIVE DRUGS!.
It is recommended—
(1) That the gravimetric method evolved for assaying the anthra-
quinone drugs be given a more exhaustive study during the coming year.
Approved.
(2) That conjointly with the study of gravimetric assay, the collabora-
tive work be extended to the colorimetric determinations.
Approved.
(3) That the method for estimating aloin be submitted to the associa-
tion for study and criticism.
Approved.
ARSENICALS?.
It is recommended—
(1) That the qualitative and quantitative methods submitted be
adopted by the association as tentative methods, and that they be
further studied during the next year with a view to their official adoption.
Approved.
(2) That the modification suggested by H. Engelhardt, which provides
for digestion with potassium permanganate, addition of potassium iodide,
discharge of liberated iodine by use of sodium sulfite solution, and final
titration with 0.1N iodine solution, be studied during the next year.
Approved.
(3) That during the next year the associate referee should study and
devise methods to determine the arsenic to nitrogen ratio in arsphen-
amine and neoarsphenamine.
Approved.
(4) That methods for the detection of organic sulfur in arsenicals be
further studied.
Approved.
(5) That methods be outlined for the detection of toxicity tolerance
of arsphenamine and neoarsphenamine.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 575.
2 Ibid., 527.
1922| LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 143
SANDALWOOD OIL.
It is reeommended—
That the methods submitted and studied by C. W. Harrison for the
determination of the acetyl value of sandalwood oil be further studied.
Approved.
GUMS AND BALSAMS.
It is reeommended—
That work on gums and balsams carried forward since 1919 be dis-
continued on account of difficulty of obtaining workers.
Approved.
SILVER PROTEINATES.
It is reecommended—
That further work be carried out on Method 32.
Approved.
ALCOHOL IN DRUGS.
It is recommended—
That the method for the determination of alcohol in drugs be further
studied.
Approved.
SPECIFIC GRAVITY TABLES.
The referee recommended that those portions of the report dealing
with the specific gravity tables be referred to the Committee on Revision
of Methods. Your committee, after further consideration, recommends
that this question be referred to a special committee to be appointed
by the incoming executive committee.
Approved.
CHLOROFORM AND CHLORAL HYDRATE.
It is recommended—
(1) That the method for the determination of chloroform be further
studied.
Approved.
(2) That no further work be done on chloral hydrate.
Approved.
CINCHONA ALKALOIDS,
It is recommended—
That further study be made on the separation of the principal cinchona
alkaloids.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 545.
2 Thid., 543.
144 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
REPORT OF COMMITTEE CG ON RECOMMENDATIONS
OF REFEREES.
By R. E. DoouitrrLe (1625 Transportation Building, Chicago, IIl.),
Chairman.
[Food preservatives (saccharin), coloring matters in foods, metals in foods (arsenic),
fruit and fruit products (pectin in fruits and fruit products, moisture in dried
fruit), canned foods,‘cereal foods, limits of accuracy in the determination
of small amounts of alcohol in beers, vinegars, flavoring extracts,
meat and meat products (separation of meat proteins, de-
composition of meat products, gelatin), spices, cacao
products (determination of shells, methods for
the examination of cacao butter),
coffee, tea, and nitrogen in foods. |}
FOOD PRESERVATIVES.
SACCHARIN.
It is recommended—
(1) That the referee prepare a list of the methods now commonly
used for the determination of saccharin in food products.
Approved.
(2) That the referee conduct collaborative work on those methods
which yield good results as indicated by previous studies.
Approved.
COLORING MATTERS IN FOODS.
It is recommended—
(1) That the methods adopted tentatively at the 1920 meeting for
the examination of coal-tar food colors! be submitted to collaborative
study during the coming year with a view to their perfection for final
adoption as official methods.
Approved.
(2) That the investigative work on the coloring matters of the common
fruits and vegetables be continued.
Approved.
METALS IN FOODS.
It is recommended—
(1) That the modified Penniman method for the determination of
tin?, be submitted to further collaborative study during the com-
ing year.
Approved.
ARSENIC.
It is recommended—
(1) That the H. V. Farr modification of the Gutzeit method for the
determination of arsenic?, be further studied with a view to
1 J. Assoc. Official Agr. Chemists, 1922, 5: 198.
2 Tbid., 6: 29.
§ Thid., 31.
1922] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 145
simplifying the apparatus and ascertaining the conditions necessary
for a more accurate determination in concentrations above 20 micromilli-
grams of arsenious oxide (As2Q3).
Approved.
(2) That the present tentative Gutzeit method! for the determination
of arsenic be studied in comparison with the H. V. Farr modification.
Approved.
FRUITS AND FRUIT PRODUCTS.
PECTIN IN FRUITS AND FRUIT PRODUCTS.
It is reeommended—
(1) That the referee begin a comprehensive study of the composition
of fruits used in the manufacture of jam and jelly to determine the
natural variations and to serve as a basis for interpretation of analytical
results.
Approved.
(2) That further work be done on methods for the determination of
total sulfur in fruits.
Approved.
{3) That the methods submitted by the referee this year be modified
with respect to the period of boiling in the preparation of sample and
the elimination of filter paper in the determination of total sulfur, and
that the methods as modified be subjected to further collaborative
study during the coming year.
Approved.
The referee further reeommends—
(4) That the present method for the determination of alcohol precipi-
tate be disregarded as it is unreliable.
Your committee recommends—
That inasmuch as modifications have been recommended for the
methods as submitted by the referee this year action on the elimina-
tion of the method for the determination of alcohol precipitate be post-
poned until the substitute methods are in form for consideration for
adoption by the association.
Report of committee adopted.
MOISTURE IN DRIED FRUIT.
It is recommended—,
(1) That the method submitted by the referee for the determination
of moisture in dried fruits? (for dried fruits in general), be adopted
as an official method (first action) and submitted to further collaborative
study during the coming year.
Approved.
1 Assoc. Official Agr. Chemisis, Methods, oe 147.
2 J. Assoc. Official Agr. Chemists, 1922, 6:48.
146 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 2
(2) That the method submitted by the referee for the determination
of moisture in dried apples only be adopted as a tentative method and
submitted to further collaborative study during the coming year.
Approved.
(3) That an attempt be made to determine the moisture in dried
fruits by some method depending upon a totally different principle as
the calcium carbide method'.
Approved.
CANNED FOODS
It is recommended—
(1) That the wording of the methods for the micro-analysis of tomato
pulp, catsup, purée, sauce and paste? be changed to read as follows:
MOLDS.—TENTATIVE.
(a) 28, Paragraph 2.
Place the slide under the microscope and examine with a magnification of about 90
diameters and with such adjustment that each field of view covers 1.5 sq. mm. This
area is of vital importance and may be determined by adjusting the draw-tube in such
a way that the diameter of the field becomes 1.382 mm. as determined by measurement
with a stage micrometer. A 16 mm. Zeiss apochromatic objective with a Zeiss X6
compensating ocular or a Spencer 16 mm. apochromatic objective with a Spencer X10
compensating ocular, or their equivalents, shall be used to obtain this magnification.
Under these conditions the amount of liquid examined is 0.15 cmm. (0.00015 cc.) per
field.
YEASTS AND SPORES.—TENTATIVE.
(b) 29, Paragraph 3, line 4.
After the expression ‘1/60 cmm.”’ insert ‘‘(1/60,000 cc.)”’.
BACTERIA.—TENTATIVE.
(c) 30, Paragraphs 1 and 2.
Estimate the number of rod-shaped bacteria from the mounted sample used in 29
but, before examination, allow the sample to stand not less than 15 minutes after
mounting. Employ a magnification of about 500 which may be obtained by the use
of an 8 mm. Zeiss apochromatic objective with an X18 Zeiss compensating ocular with
draw-tube not extended, or an 8 mm. Spencer aprochromatic objective with an X20
Spencer compensating ocular and a tube length of 190, or their equivalents.
Count and record the number of bacteria having a length greater than 114 times
their width in an area consisting of five of the small sized squares. Count five such
areas, preferably one from near each corner of the ruled portion of the slide and one
from near the center. Determine the total number of rod-shaped bacteria in the 5
areas and multiply by 480,000. This gives the number of this type of bacteria per cc.
If a dilution of 1 part of the sample with 8 parts of water, instead of 1 part of the sample
with 2 parts of the water is used in making up the sample, then the total count obtained
as above must be multiplied by 1,440,000. Thus far it has proved impracticable to
count the micrococci present as they are likely to be confused with other bodies fre-
quently present in such products.
Approved.
e U.S. Bur. Chem. Circ. 97: (1912).
2 Assoc. Official Agr. Chemists, Methods, 1920, 164.
1922] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 147
(2) That the methods for the micro-analysis of tomato pulp, catsup,
purée, sauce and paste as corrected in wording be adopted as official
methods. (First action.)
Approved.
CEREAL FOODS.
It is recommended—
(1) That collaborative work on the determination of cold water
extract be discontinued.
Approved.
(2) That work on the determination of moisture and ash be discon-
tinued until further research develops more desirable methods.
Approved.
(3) That the method submitted by the referee for the determination
of fat in baked cereal products!, be adopted as a tentative method
and subjected to further collaborative study.
Approved.
(4) That the methods submitted by the associate referee for the
determination of chlorine in chlorine bleached flours?, be modified
as suggested in his report and the modified methods subjected to collabora-
tive study during the coming year.
Approved.
LIMITS OF ACCURACY IN THE DETERMINATION OF SMALL
AMOUNTS OF ALCOHOL IN BEER.
No report was submitted by the referee.
It is recommended—
That these studies be continued.
Approved.
VINEGARS.
No report was submitted by the referee.
It is recommended—
That the methods for the determination of glycerol, solids and fixed
acids be studied by the referee during the coming year.
Approved.
FLAVORING EXTRACTS.
No report was submitted by the referee.
It is recommended—
(1) That a study of methods for the analysis of imitation vanilla
preparations containing large quantities of coumarin and vanillin be
undertaken.
Approved.
1J. Assoc. Official Agr. Chemists, 1922, 6: 63.
2 Ibid., 68.
148 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
(2) That the method suggested by Penniman and Randall' for the
determination of oil in lemon and orange extracts be studied in connection
with the official method.
Approved.
(3) That a study of methods for the examination of non-alcoholic
extracts be undertaken.
Approved.
(4) That the method adopted at the 1919 meeting of the association
as an official method (first action) for the determination of alcohol in
orange and lemon extracts consisting only of alcohol, oil and water?
be subjected to collaborative study with a view to recommendation for
final action.
Approved.
(5) That the official methods for the determination of citral in orange
and lemon extracts and in orange and Jemon oils* be investigated.
Approved.
MEAT AND MEAT PRODUCTS.
It is recommended—
(1) That the method for the determination of sugar in meats’,
receive further study.
Approved.
(2) That the modified method reported by the referee for the determi-
nation of nitrates and nitrites calculated as sodium nitrate’, be
substituted for the present ferrous chloride method for the determination
of nitrates®.
Approved.
(3) That the phenoldisulfonic acid method for the determination of
nitrites and nitrates calculated as sodium nitrate, XX, 12 and 13’ be
changed in the following particulars:
(a) 12 (b) lines 1, 5 and 7, substitute the word “sodium” for the word
“potassium”, making these lines read “sodium nitrate” in the place of
‘potassium nitrate”’.
(b) 13, line 13, substitute the word “sodium” for the word “‘potassium’’,
making the line read, “Determine the amount of sodium nitrate present
in the sample by comparison”’.
Approved.
1 J. Ind. Eng. Chem., 1914, 11: 926
2 J. Assoc. Official Agr. Chemists, 1922, 5: 308.
3 Assoc. Official Agr. Chemists, Methods, 1920, 201.
‘J. Assoc. Official Agr. Chemists, 1922, 6: 72.
5 [bid., 74.
* Aseac. 0 Official Agr. Chemists, Methods, 1920, 210.
Ibid., 21
1922] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 149
SEPARATION OF MEAT PROTEINS.
It is reeommended—
(1) That further work be done concerning the relation of the con-
centration of acid and protein to the coagulation by salt of protein of
meat soluble in cold water.
Approved.
(2) That zinc sulfate be compared with ammonium and sodium
sulfates for the separation of meat proteins.
Approved.
(3) That further work be done with the sodium chloride and tannic
‘acid method to determine all the conditions necessary to give com-
parable results.
Approved.
DECOMPOSITION OF MEAT PRODUCTS.
No report or recommendations.
GELATIN.
No report was submitted by the referee.
It is recommended—
That the tentative methods! adopted at the 1920 meeting be submitted
to collaborative study during the coming year with a view to their
perfection for final action by the association.
Approved.
SPICES.
It is recommended—-
(1) That the present tentative method for the determination of
volatile oil in mustard seed? be made official (final action).
Approved.
(2) That consideration be given to the recommendation of the referee
for 1920 on spices and other condiments to study methods for the examina-
tion of salad dressings.
Approved.
(3) The referee further recommends a modified method for the determi-
nation of crude fiber in prepared mustard.
Your committee, in view of the action taken by the association drop-
ping the official method under Foods and Feeding Stuffs for the determi-
1 J. Assoc. Official Agr. Chemists, 1922, 5: 343.
2 Assoc. Official Agr. Chemists, Methods, 1920, 259.
150 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
nation of crude fiber and the substitution therefor of a tentative method,
recommends that action on the referee’s recommendation be postponed
and that the referee during the coming year study the newly adopted
tentative method for the determination of crude fiber in prepared mustard
and other spices.
Report of committee approved.
CACAO PRODUCTS.
DETERMINATION OF SHELLS.
It is recommended—
That the method given in the referee’s report for 1920! be adopted as
a tentative method for the quantitative determination of shells
in cacao and chocolate products and that same be submitted to further
collaborative study during the coming year with a view to its final
adoption as an official method.
Approved.
METHODS FOR THE EXAMINATION OF CACAO BUTTER.
It is recommended—
That further study be given to the methods outlined in the report of
the referee for 1920? for determining the critical temperature of dissolu-
tion and to the acetone-carbon tetrachloride test for hydrogenated oils,
tallows, etc.
Approved.
COFFEE.
It is recommended—
(1) That the Power-Chesnut method for the determination of caffeine
in coffee? be modified to require the addition of 20 cc. of 10 per cent
sulfuric acid instead of 10 cc. (line 10) for the half-hour boiling of the
filtrate from the magnesium treatment and the method as thus modified
be adopted as official. (Final action.)
Approved.
(2) That during the coming year the incoming referee study the acids
in coffee.
Approved.
TEA.
It is recommended—
(1) That the Power-Chesnut method for the determination of caffeine
in teat be adopted as an official method. (Final action.)
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 253.
2 Thid., 266.
3 [hid., 271.
4 Thid., 290.
1922] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 151
(2) That the Bailey-Andrew method! for the determination of caffeine
in tea be adopted as an official method. (First action.)
Approved.
(3) That the Stahlschmidt method? for the determination of caffeine
in tea be dropped.
Approved.
(4) That suggestions for further study of the subject of tea be left
to the incoming referee.
Approved.
NITROGEN IN FOODS.
No report was submitted.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 292.
2 Assoc. Official Agr. Chemists, Methods, 1920, ‘274.
THIRD DAY.
WEDNESDAY—AFTERNOON SESSION
REPORT OF REPRESENTATIVE TO COOPERATE WITH
THE UNITED STATES PHARMACOPGIAL
REVISION COMMITTEE.
By L. F. Keser (Bureau of Chemistry, Washington, D. C.), Chairman.
A resolution was passed last year by the drug section authorizing the
appointment of a representative to cooperate with the Committee of
Revision of the United States Pharmacopceia. The idea in mind then was
the appointment of some State official to undertake the work so as to
identify State bodies with the revision, but the writer was delegated to
act in the matter and has kept in fairly close touch with the work and
the progress made so far.
Since the appointment of the Committee of Revision in 1920 much
progress has been made by way of outlining general policies to be followed,
although many of these were formulated at the convention in that year.
The first important step is the selection of the drugs to be recognized
by the Pharmacopceia. This task is the work of the Committee on Scope.
A large number of drugs have been approved for inclusion in the next
revision; some are under active consideration and discussion and some
included in the 9th revision will be deleted.
Monographs have been written up for some of the drugs to be included;
others are in course of preparation. The methods of analysis have been
given in a number of cases. This work, which primarily interests this
association, is about to assume definite form and the organization should
take an active hand.
In the former edition of the Pharmacopeeia efforts were made to adopt
the best methods of analysis available. Such methods as had been worked
out and adopted by this association received some attention, but it is
believed that they would have received more consideration if this organi-
zation had been actively identified with the work of revision in some way.
It is recognized that the alcohol tables contained in the present Pharma-
copeeia differ in a number of material respects from the alcohol tables
contained in the Association’s official methods. The method for estimat-
ing alcohol prescribed for drug products in the Pharmacopoeia differs
somewhat from the methods outlined for food products. The same is
true of the method for detecting adulterations in oil of turpentine. The
152
1922] KEBLER: COOPERATING WITH PHARMACOPQIAL COMMITTEE 153
list could be multiplied but the instances of differences cited are sufficient
to show the need of cooperation and coordination in order to bring about
a more satisfactory condition for the chemist. It is inadvisable to have
two official methods of analysis. The methods in the Pharmacopceia
are legal under the Food and Drugs Act, and those contained in the
Methods of Analysis of the A. O. A. C. are made official by regulation.
It is sometimes contended that the methods in the Pharmacopceia
are unworkable; that they are intended for certain classes of people and
that they do not give the best results or conclusions. It is the duty of
every analyst to bring to the attention of the Committee of Revision
of the United States Pharmacopeia the inaccuracies or shortcomings
of any methods of analysis or procedure so that they may be adjusted
or eliminated in the next revision.
In order to place this work on a more satisfactory basis and to give
representation to those who most frequently use the methods of analysis,
both United States Pharmacopeeia and those of the Association of
Official Agricultural Chemists, it is recommended that a committee of
five be appointed to represent this association in the matter of cooperat-
ing with the Committee of Revision of the Pharmacopceia. By means
of such a committee a definite working relation can be established between
this association and the Committee of Revision through its chairman.
It is believed that such a committee would be able to bring much useful
information to the attention of the Committee of Revision and be in-
strumental in having it incorporated into the book which will become the
legal standard, not only under the Federal law but under State laws.
Adopted.
H. C. Lythgoe: Relative to Dr. Kebler’s report, I have had handed to
me a copy of a motion made and carried in the drug section, which reads
as follows:
In view of the fact that the standards for drugs recognized in the United States
Pharmacopeeia are legalized by Federal and State laws, it seems advisable that the
Association of Official Agricultural Chemists should cooperate with the proper com-
mittees on the United States Pharmacopceia revision. I therefore move that a com-
mittee of three members of this association be appointed whose duty it shall be to
cooperate with the officials of the Committee of the Revision of the Pharmacopeceia
with regard to the methods of analysis of drugs, and that the committee be directed to
report at the next meeting of the association.
The motion was seconded and carried.
Later this motion was amended changing the number to serve on the
committee from three to five, and the chair accordingly appointed the
following members: L. F. Kebler, chairman; H. C. Lythgoe; H. C.
Fuller; A. R. Bliss and W. S. Hubbard.
The amendment was accepted and carried.
154 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
REPORT OF REPRESENTATIVES ON THE BOARD OF GOV-
ERNORS OF THE CROP PROTECTION INSTITUTE OF
THE NATIONAL RESEARCH COUNCIL.
H. J. Patterson: The following report was prepared by B. L. Hart-
well, chairman, but the work of the committee has been so limited that
we invited H. E. Howe of the National Research Council! to come and
tell in greater detail of the aims of the institute.
Since this association has been represented on the Board of Governors
of the Institute only since June, it is desirable to state that the institute,
as its name indicates, is concerned with the protection of crops from
their afflictions, by agencies not interfering with other organized efforts.
It is managed for the public good, by a Board of Governors of nine or
more representatives of appropriate scientific societies, together with
a Board of Trustees from the industries naturally concerned.
Projects receive consideration, approval and direction by the Board
of Governors after consultation with the Board of Trustees.
At present the secretary and the treasurer are the same persons who
hold these offices in the National Research Council.
The annual dues for scientific members are $1, for industrial members
$100, and for associate industrial members $10.
Any funds required for the pursuit of specific projects are secured
by the trustees of the industrial divisions concerned.
Some of the work of this association and of the institute will have
to do with the same projects; the institute with investigations concerning
the adaptation of materials—such as insecticides and fungicides, for
example—for special purposes, as a basis for claims made by the manu-
facturers; and the association in connection with the inspection of the
materials and concerning the validity of the claims which accompany
the commercial products.
It seems obvious that one important function of the institute will be
to act as a clearing house for the transmission of ideas from any interest
concerned in the economics of vegetable food from the beginning of its
production to the time of its consumption.
Until after an opportunity to attend meetings of the institute, your
committee can not undertake to acquaint you with specific projects,
but will welcome suggestions needing consideration by the Board of
Governors.
H. FE. Howe: I am to give you a brief progress report on the Crop Pro-
tection Institute in which you have representation. This Crop Protection
Institute came about through a desire of the entomologists and phyto-
SF eg aa Journal of Industrial & Engineering Chemistry, 810 Eighteenth St., N. W., Wash-
ington, D. C.
1922] REPORT OF CROP PROTECTION INSTITUTE 155
pathologists for some way in which they could cooperate in certain
classes of research work with industry. A great many of the men
concerned were engaged on such work that they could not travel outside
the confines of their own states, except at their own expense, and it was
obviously desirable to bring together these gentlemen for various types
of conferences, particularly with regard to regional research work. The
manufacturers of insecticides, fungicides and similar materials seemed to
be quite willing to support progressive work of this kind, but had no
direct way in which to do it to their own satisfaction. We found upon
investigation that many of these groups really had never worked
together, and there seemed to be a little suspicious atmosphere which
we were anxious to dispel. We endeavored to bring together this group
first here in Washington, and later in New York City, to decide what
might be done. At the conference here in Washington Dr. Alsberg, Dr
Haywood and others, who were interested in the chemical side of the
problem, were present. We were very glad to bring into this work this
association and any others who might be interested in the general pur-
poses that were under consideration. I think the constitution and by-
laws as well as the report of work to date may have reached many of you
through the first bulletin prepared by the institute. I will just read one
or two paragraphs.
The purposes of the Institute are:
(4) To further cooperation between scientific workers and the manufacturers of
insecticides, fungicides and other similar materials, the manufacturers of appliances
required for their use, and the manufacturers, packers and shippers of plant, animal
and other products.
(5) To assist in the dissemination of scientifically correct information regarding the
control of injurious insects and plant diseases.
These paragraphs are preceded by the more important one which is:
(1) To promote the general welfare through the efficient control of injurious insects
and plant diseases affecting all economic and ornamental plants and their products.
The Crop Protection Institute, therefore, is planned to in no way take
the place of existing work, but to offer a common forum in which the
manufacturers—that is the commercial interests—and the purely scien-
tific interests may come together and discuss types of work, state of the
work now in progress, and to plan research to fit into some particular
niche.
In our organization, the affairs are in the hands of a board of nine
scientific men; there may be more added if necessary. Three of these
come from the Association of Economic Entomologists, three from the
American Phytopathological Society, two from the Association of
Official Agricultural Chemists and one from the National Research
156 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
Council. There have been no meetings of this board since your rep-
resentatives were appointed. That is why I am making a brief report
to you, supplementing theirs. I hope another year you can call upon
them for a report of their activities, and that you will learn more of real
progress than [ am able to give you because we are going through the
organization stage.
However, during this: period of organization the institute has been
useful. In the field of agriculture it offered its facilities for the presenta-
tion to the manufacturers of calcium arsenate advice by B. R. Coad, as
to what is necessary if the program to control the boll weevil through the
application of calcium arsenate is to be a success. That meeting, held
in New York, was attended by manufacturers and chemists, and the
subject was discussed from the standpoint of the entomologist, the
chemist and the mechanical engineer. Questions of application in-
cluding machinery, the things that were wrong and the things that were
most efficient for the application of the dust, and the physical properties
of calcium arsenate were fully discussed. Manufacturers, in the first
instance, sent into the South much material that could not be used for
the purpose; also there was not sufficient information as to the methods
of application.
In this instance the Department of Agriculture did not wish to bring
together officially the manufacturers of these poisons and the manu-
facturers of the dusting machinery. The institute was very glad to
ask these people to come together under its auspices, which made it
quite unofficial, and the entire program was given over to representatives
of the Department of Agriculture who presented these various matters
as well as the first showing of the film depicting the control of the
boll weevil.
The Board of Governors of the institute hoped very much to have at
this time rather interesting data on a cooperative experiment on dusting
which it was planned to carry forward in Virginia, West Virginia, Penn-
sylvania, New York and New Jersey this year. We wished to get some
real information on the efficiency of dusting, especially on apples, as
compared with spraying, but in the spring the frosts, as you know,
killed most of the fruit, so very little if anything could be done. Under
the circumstances, there was no use dusting or spraying in these locali-
ties, so the time has been lost in that particular experiment. The
Board has also been interested in trying to lay out certain lines of re-
search which might be carried on in some of the existing laboratories
and have, at this time, two things particularly in mind. One has been
the study from the chemical standpoint of sulfur and sulfur com-
pounds to try to throw light on the use of sulfur as an insecticide.
The other is the effect of climate on the efficiency of sulfur so used.
1922] REPORT OF CROP PROTECTION INSTITUTE 157
I think there is little more I can tell you concerning the present status
of the institute. There is to be another meeting of the Board of Gover-
nors in New York to discuss the work for the coming year and to try to
lay out a new program. I want to emphasize, in closing, that the Crop
Protection Institute is purely a cooperative effort in which you have a
real interest and that it seeks to avoid duplication. Getting together
for conferences, working out résearch programs, presenting the result-
ing data in readable form to those who ought to have it and assisting in
any way possible in the suppression of injurious insects and plant dis-
eases are some of our worthy aims.
W. F. Hand: Dr. Howe has certainly made us a very interesting
address, and we are glad he could find time to come.
158 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
REPORT OF SECRETARY-TREASURER FROM
By C. L. Atspera (Bureau of
RECEIPTS.
1920
NOV Lo aK DAIANCOT eo se ee alee Sree oe eee eee eee ,:-B 921.48
Nove15 oDenositeds:420). .. cusses tenes otecy, wari liees .peemeess 13
Dues from 14* Canadian and State institutions received too late for
inclusion 1920'reportssh, vo koe eetree tones arcane Catade mice eee net 65.00
Dues for year 1921 from 38{ State, Municipal and Canadian
OTGANIZALIOMS): occ ces cc ence) seve ols euaun a eerie tg nae eee 170.00
2 subscriptions to Journal deposited in Treasurer's account in error. . 9.00
Totaliceceipisy:- 0: tens of. thee eee nade $ $1,165.61
*Dues from one State deposited in Journal account.
tDues from four organizations deposited in Journal account.
1922]
ALSBERG: REPORT OF SECRETARY-TREASURER
NOVEMBER 15, 1920 to JUNE 21, 1921.
Chemistry, Washington, D. C.).
1920
Nov. 20
Noy. 20
DISBURSEMENTS.
Amount
Telephone calls, car fare, New Willard Hotel.............. $ 1.95
ips New: Willard,.1920) meeting® 7.2 21S Re ooo eee ae 32.00
Bastian Bros. Co., badges 1920 meeting
PEGE 155 PIR OO Nilo ig Sos ees $ 52.94
POSTAGE LM = 52 Sah nw hose: 51
PHISPIPANEE Ceo ee eer Ne wo eee eas 25
53.70
Meas AOA ISCOUN Eh tstrhes shack oh RRs .b4
53.16
The postmaster, Washington, D. C., box rent, quarter ending
bi SEE Gl US 1 71 Reha Cone ee Ce On a 2.00
Chas. G. Stott & Co., printing 5000 letter heads, 2 boxes thin
BECOME RECCEN pe hoe Mai sors Gt Ae So See orth aes 34.96
eat pes eerie nie hn ier mn a een eras bho Si 5.00
The postmaster, Washington, D. C., box rent, quarter end-
MANE ANIC SP MN Bae TN a ns ek nk I AN oo hg, ol BEE, « 2.00
A. F. Humphreys, stenographic services reporting 1919 meet-
BUNGE re Se es ecg PEE oe, Tees PEN SN RINE ee Ss 9.20
SEG At CisbeReIE MESS £075.50 Si cere arc Riootes aoe ahs $ 140.27
Banke Balanee. 2.5 ois ons hn bo nao kon SPL Shae ah Metta 1,025.34
$1,165.61
159
Check
No.
4
5
oon &
10
11
160 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
REPORT OF SECRETARY-TREASURER FROM
By R. W. Batcom (Bureau of
RECEIPTS.
1921
Re Sy Hari Balance... 50.08 0, Gea ee $1,025.34
Dues from 14 Federal, State, Canadian and Municipal Organiza-
(1371 ee ae Gey: alive + epeas Antaliarn = Geueaiade rae, Scans inna ee ee ee ae 95.00
_—
LC) ay eerimenre Laue bade Pa bec $1,120.34
1922]
BALCOM: REPORT OF SECRETARY-TREASURER
JUNE 21, 1921, TO OCTOBER 15, 1921.
Chemistry, Washington, D. C.).
1921
Aug. 29
Sept. 22
Sept. 26
Oct'13
Oct. 15
Oct. 15
DISBURSEMENTS.
Amount
Cash for postage for mailing programs....................$ 11.66
Byron S. Adams for printing 1000 programs, 1921 meeting. . 37.50
Industrial Printing Co., on account (Journal).............. 500.00
Industrial Printing Co., on account (Journal).............. 200.00
Bastian Bros. Co., 410 badges, 1921 meeting.............. 72.03
Bank*balancey) 0 cease ke eee yeaah edit $ 371.18
Eess''Check No-.17 otitstanding.... . 2. os... oe ee 72.03
299.15
161
Check
No.
13
14
15
16
17
162 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 2
FINANCIAL REPORT ON PUBLICATIONS FROM
By C. L. AtsBerc* (Bureau of Chemistry,
RECEIPTS.
1920
Nov. [Saisbank: balances... 0.\s.2)0) tinal aedegee a ceam cl We pat acai ca Rep ane tee ee $ 1,890.44
otal deposits! 66) 4 sso eed ae Gee eaewe aae ame $ 10,262.82
oss on! exchange) scissile eee tae erence $ (2.13
Less redeposifed checks................... 100.00
Less check returned because of insufficient
LNT 610 Wey de a at, EAT AER ERE I Coe patM SBC LE Yt a Ray AY 5.00
——_—_—_—_— 107.13
— 10,155.69
$12,046.13
DETAILED STATEMENTS RELATIVE TO RECEIPTS.
Journal Subscriptions.
No. Price Total
ordered each cost
14 $5.50 $ 77.00
335 5.00 1,675.00
13 . 4.40 57.20
109 4.00 436.00
55 3.75 206.25
10 1.50 15.00
10 1.40 14.00
6 1.25 7.50
NOI) PO Angee RES LO Seger a Sern § 2,487.95
Less loss through ‘exchange fi... (65 <)5.6\.eheiele Hie ee 0 .93
1 BPC Es Ratee i oad) A NERD IT a AI ee ay tie PRU ARN iE ...9 2,487.02
Methods Subscriptions.
No. Price Total
ordered each cost
49 $5.50 $ 269.50
1394 5.00 6,970.00
25 4.40 110.00
70 4.00 280.00
DPD) 2) DR PRL at SM Gia PES EN a $ 7,629.50
Less loss through exchange}... 325 .25.00¢.-200 408 1.83
Woy 2) RADU eee pen ADI mu nC UUM ESHELF Oho kes SMUD AELON A as ot $ 7,627.67
‘Total: Journals and: Methods)) 2052" ais wens. separ eee Ree ee eee Sena ore $ 10,114.69
Plus $16.00 returned because of excess payment... . .$ 16.00
Plas banks balances: eee. orion eatinioscens cockine mee 1,890.44
Plus) dues.75 nstituvionss.. 64). eae ete Cer 25.00
——_—_—_———. 1,931.44
$12,046.13
*Present address, Food Research Institute, Stanford University, Calif.
tIncludes loss on exchange plus difference through over and under subscription.
1922]
ALSBERG: FINANCIAL REPORT ON PUBLICATIONS
NOVEMBER 18, 1920 TO JUNE 18, 1921.
Washington, D. C.), Chairman, Board of Editors.
DISBURSEMENTS.
Amount
Postage, sending out Methods........................0.. $ 50.00
Industrial Printing Co., on account....................... 1,500.00
N. A. Parkinson, freight and drayage on Methods.......... 1.18
Calif. Dept. of Agriculture, refund on excess payment on
Journals) ce te LO, SELON EMATt re, ewe 1.00
POSLARE..,. co Mette re tre od © oe ee TEEPE Ons ay 25.00
Frederick E. Everett, State House, Concord, N. H., refund
for excess payment made on Book of Methods.......... 5.00
Industrial Printmg Co. ,an account...) ke 1,000.00
Western Union Telegraph Co., reimbursement telegram to
Doolittle. 627.05 setae teeta oe ee EEL .70
Industrial Printing Co., on account....................... 1,000.00
Farran’s Transfer and Storage, hauling Journals........... 1.00
Postage, sending out Methods, etc........................ 50.00
Industrial Printing Co., on account..........:............. 1,000.00
| TSE SAMI: hy hg Oa, A hh A art a a ee 5.00
U. S. Post Office, 5,000 S. R. 2c. envelopes................ 125.00
Industrial. Printing Co., on account... 22 se. 1,000.00
Postage sendimgiout Methodsi.4- fe oo oa eae ee 50.00
Industrial Printme Co., on' account: 0 2. ee eee, 1,000.00
Atlas Powder Co., Philadelphia, Pa., reimbursement for ex-
press charge on Book of Methods..................... 7
Industrial Printing Cos on accounts. 50+ aon) / eo os el 1,000.00
SEADOO ARs Ac re te ee re ee ee ee 25.00
Cleveland Provision Co., reimbursement excess payment
[Age OHV peg OF Wiethoda. 2s te Nee RAE Rey 15.00
Herman Goldberger, overpayment on Journal............. 1.00
Postage, sending out Journal circular letters............... 123.00
Emenuel Baumgarten, rubber stamps..................... 1.25
Rastage. sen@mgont Methods . 1000... 2.6 pata ds secs cals 6 10.00
Postage, sendmep-aut Methods . 23.0) 0S. cheat es oes ee 10.00
Postage, sendingiout Methods... 00) 2 gece cee see oe es 10.00
N. A. Parkinson, expenses trip to Baltimore............... 6.10
Postage, sending out Methods and Manuscripts............ 10.00
R. P. Andrews Paper Co., 500 clasp envelopes............. 7.08
N. A. Parkinson, reimbursement for drayage charges on Vol.
BV Gr a, an oes Le ASCE Ue es ete Te ees cs 1.00
Postage, sending out Vol. IV, No. 3 to foreign subscribers.
SRICE HOSCAPE 2 Win 0). 2 cae oe eRe eet ae 10.00
Industrial Printing Co., on account....................... 1,000.00
Postage, sending out Journal & Methods circular letters.... 250.00
Postage, sending out Methods and Journals............... 10.00
N. A. Parkinson, reimbursement expressage charges on 100
Copier Ola ts INO be Jo. sc ser oh Lem Tet ty itt! 3 1.06
Postage, sending out Methods and foreign Journals......... 10.00
ark alanis icc 5 io ieee re et ed oy $2,732.53
Less check No. 29 outstanding............ eae M 1.16
28 5 7a ay
$12,046.13
163
164 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS |[Vol. VI, No. 2
FINANCIAL REPORT ON PUBLICATIONS FROM
By R. W. Batcom (Bureau of Chemistry,
RECEIPTS.
1921
June 19)) (Banks balance’. << <2 505-5, <;+ 5. + s;<o0.e.5, o) panne tae ob oie accel eee ede S 2731.37
Titel deposits. .....).,..-,-;-.s,-:+.-,5 « -SeEre wep «sie NEE $ 2,861.83
Less check returned for discount........... $ 4.00
Less redeposited checks................... 20.00
Less checks returned because of insufficient
funds and improperly drawn ........... 10.10
34.
2,827.73
$ 5,559.10
DETAILED STATEMENTS RELATIVE TO RECEIPTS.
Journal Subscriptions.
No. Price Total
ordered each cost
19 $5.50 $ 104.50
134 5.00 670.00
10 4 40 44.00
5 4.20 21.00
42 4.00 168.00
28 So 105.00
4 1.50 6.00
4 ieZzo 5.00
WMotal azeeer ck ee te ws oe pee ovale oe Sea ete Slee sge eS $ 1,123.50
Less'loss through exchanges) 2 i..s epee ees ees a 67
PGs Gaal apace Se a caress ata oe boonies or eAeremmte eeerk rete fer eee ae vee Wes aber renct one $ 1,122.83
Methods Subscriptions.
No. Price Total
ordered each cost
$5.50 $ 38.50
270 5.00 1,350.00
11 4.40 48.40
54 4.00 216.00
Gyn) RRNA NPR encr a S) PMIIORRN ARASH esi edi at card aad $ 1,652.90
Less loss through exchange: . 2.00. 0.025 ke sce ss 39
Totals scarcer coe ee eers Se inthe Peeters eae ieee emer ne $ 1,652.51
Total Journals‘and Methods::'2'5)20.s ses ss cas eter imei eee aereeieae $ 2,775.34
Plus checks returned because of excess payment... .$ 52.39
Plus*banksbalance’ =: 26. hen 2s celeaeens ote atten cere 2 folcon
a 2,783.76
$ 5,559.1
1922]
BALCOM: FINANCIAL REPORT ON PUBLICATIONS
JUNE 19, 1921 TO OCTOBER 15, 1921.
Washington, D. C.), Chairman, Board of Editors.
1921
June 29
June 29
June 29
July 8
July 8
July 11
July 12
July §18
July 19
ia 2
Aug. 5
Aug. 5
DISBURSEMENTS.
Postmaster, box rent and key deposit.....................
Industrial Printing Co., on account.......................
IN; A> Parkerisons OInee CXVGnSeR . 9/004 5 9ecc oe. el ew oe
Industrial Printing Co., 2,880 wrappers for Journal; parcel
Host ork Y OOUase ra ei ree ees oe ahs Satie 5) oie i os
Industrial Printing Co., 1,000 cartons for Methods.........
F. W. Faxon Co., refund on subscription, Lewis Institute
Marae yh eee a AE Be le a tel Ra BEE a ota Sah
American Railway Express, return of Book of Methods ad-
dressed: touleon}Hisherx:. Hasche Ker acide Ses needs. 5%
Postmaster, deposit for mailing Journals at second-class mail
EAC rel cteret rr ters cer etera ater Tele er eee demetertetetereLere reise ssere eter hare che
Dept. of Beverage Inspection, Jefferson City, Mo., refund on
SHURCTIDUOR a0 ches oo ne ee ai a ea:
N. A. Parkinson, expenses trip to Baltimore...............
Industrial Printing:Cosion accounticse +5 (4244 «ds #4 ved
Ne A... Parkinson, QMie@expenses oo. ces gh . 5 kis ce = kas 340 on
G. E. Stechert & Co., refund on 3 subscriptions Vol. III, Nos.
2—4 included in 1920 report; refund on 3 subscriptions Vol.
is for University of Illinois Library included in July
Puget S geal News Co., refund on subscription for Washing-
ton University Library OE OSS NER Te NE IN eA
Underwood & Underwood, glossy print of Dr. Wiley........
D. Van Nostrand Co., reimbursement excess payment
Postmaster, 5,000 special request envelopes................
Chas. G. Stott & Co., Inc., Printing 5,000 letter heads......
Postage, mailing Journals and Methods...................
R. W. Balcom, reimbursement W. B. & A. Ry. billofSept.3...
Williams & Wilkins, sent in accordance with letter of Chivers
& Sons, Ltd., England, dated Aug. 25,....:.......:..--
N. A. Parkinson, expenses to Baltimore...................
Colgate & Co., refund on Book of Methods and Vols. IV & V.
St. aah Biscuit Works, reimbursement excess payment
OL sR) 2 Sceeqeeek ce cc ene Sete SOREL: ee Se ees es
G. S. Fraps, reimbursement excess payment Vol. V.........
Postmaster, box rent to, Det akes as oe ee ones Sis eee ass
Maryland State Dept. of Health, refund excess payment on
Journals «cvs 5455, sth SE Er ARO reve wis oles
Industrial Printing Co., 5,200 wrappers..................-.
Industral’Printing)/ Cos, on accounts.) .6)s6 eee
IN. A. Parkmison, olice expenses) «oof 25. ted: adand 4-26
Industrial: Printing, Cos onsaccount: 42 -eeeeee. we. ie le oe
R. E. Rose, reimbursement for excess payment on Journal...
industrial! Printing) Co:, on account. 2Ae554o4-... cia- serckhs
Emery, payment on back numbers of Journal purchased
from: Bim 508) SOOM (FUT Wea. SAVE EE POS
Ream Galaga) Se oy. 43 54 nl pe oe eee ies: © $ 593.65
162.63
$5,559.10
166 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 2
R. W. Balcom: In connection with the matter of the suit against the
Williams and Wilkins Company there is a question whether the asso-
ciation wishes to take any further action in the matter. Briefly, the
status of the case is as follows: Number 1 of Volume 3 of The Journal
was the last number published by that company. Owing to some dis-
agreement the publication was then suspended and was not resumed
until November, 1919, when arrangements were made with another
company to do the printing, merely as job work; that is, there was no
contract except that they agreed to do such work as was given to them.
They, of course, gave us an estimate as to how much it would cost.
The former publishers had been handling the subscription list and
receiving all the subscriptions to The Journal. Subscriptions are paid
in advance, and therefore they received practically all the subscriptions
to Volume 3 of The Journal. They published one number and we pub-
lished the other three numbers of Volume 3. We felt it was our duty
to supply the subscribers with the other numbers of Volume 3 as it was
no fault of theirs that this trouble with the publishers occurred. Dr.
Alsberg has felt that the Williams and Wilkins Company has about
$4,000 of the association’s money. The exact amount can not be ascer-
tained unless we should sue for an auditing. They brought suit for
damages to the extent of $50,000, that amount being based very largely
upon future profits which they hoped, or at least pretended to hope, to
get out of the contract. The question now for the association to decide
is whether it wants to take any further action—that is, legal action—
in this matter. [ have tried to get a little legal advice in the last few
days. Mr. Frank of the Baltimore office of the law firm representing
the association advised by phone that although he was not quite sure
that we were debarred by the statute of limitations from doing any-
thing, he thought possibly that might stand in the way, but he would
prepare a written statement.
That is about the status of the case. It is very problematical as to
whether we should take any legal action. In the first place, we do not
know how much money we are entitled to, and in the second place it
would be costly to attempt to recover it. The association should take
some action; if it feels that it has not enough information at present to
decide whether it is advisable to bring a counter-suit or to dismiss the
matter altogether it is suggested that the matter might be referred to
the incoming executive committee with power to act in the matter
because it would not be well to wait until next year. I am sure the
chair will be glad to entertain any motion in the matter.
W. W. Skinner: What do you say the amount involved is?
R. W. Balcom: We do not know, but it is estimated between $4,000
and $6,000. Whether or not that estimate is anywhere near the truth
1922] BALCOM: FINANCIAL REPORT ON PUBLICATIONS 167
we can not find out unless we sue for an accounting and ascertain just
how much we are entitled to. We would have to pay an expert ac-
countant and his work would be difficult, without doubt, owing to the
opposition of the company.
W. W. Skinner: What is the present status of the finances of the
association?
R. W. Balcom: On October 15, considering all our resources, we had a
deficit of about $950.
W. W. Skinner: Is there a prospect of liquidating that?
R. W. Balcom: A prospect of liquidating that if we do not get any
money from the Williams and Wilkins Company? We hope to do that,
but it remains to be seen.
L. F. Kebler: 1 do not know the exact relations and feelings that exist
between this publishing company and this association. It just ran
through my mind whether or not it would be possible with a new set of
representatives of this association for one of these representatives to go
to the company and talk the matter over in a general way, to see if a
gentlemen’s agreement can not be reached. You can frequently do more
in that way than you can by litigation.
H. C. Lythgoe: I may say that my experience with that company has
not been satisfactory. I had serious difficulty with them myself and our
State Department did, too, in regard to our subscriptions. It would,
no doubt, cost considerable to bring any suit against them and I would
not care to have this association vote right out and out to bring suit,
but I think the best thing to do would be to leave this matter with the
executive committee with power to act.
W. W. Skinner: 1! do not believe it is good practice to send good
money after bad money. I would move, therefore, that the matter be
left with the new executive committee with the suggestion from the
association that it probably would be inadvisable to bring suit.
L. F. Kebler: 1 second the motion. I do not think Mr. Lythgoe’s
experience with the company would preclude having a talk with the
representatives of the company.
R. W. Balcom: I may say for the information of the members of the
association that before I learned that the case had been dismissed |
had already taken steps to see if it were possible to have an interview
with the company to see how they felt about a compromise. Negotia-
tions had been started toward that end when I learned that the case
had been dismissed, but it would seem to me to be entirely practicable
for some officer of the association to go to them if the association decides
not to take any further legal action. It would not do to go while that
question is still pending, but if our representative could tell them posi-
168 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
tively that the association considered the matter closed so far as any
further legal action was concerned, then it might be possible to make
them see that it would be to their interest to refund part of the money.
They might not see it that way, but it would do no harm to have such a
conference.
W. F. Hand: I hope that if a representative of the association has a
conference with this ‘company he will be successful in his negotiations.
H. A. Huston: I think that firm is also engaged in publishing a num-
ber of other associations’ journals, and many of the men who support
those journals are also members of this association. A little pressure
might be brought to bear in that way.
W. F. Hand: Dr. Huston’s suggestion is a good one. I think the
present executive committee has already considered that point; we will
refer it to the new committee.
The motion that the matter be left with the Executive Committee
with the suggestion from the association that it probably would be
inadvisable to bring suit was carried.
REPORT OF AUDITING COMMITTEE.
The auditing committee has made as thorough an examination of the
reports of the secretary-treasurer and of the chairman of the Board of
Editors as the limited time and their inexperience would permit and
report that they are correct to the best of their knowledge and belief.
The committee believes that in view of the fact that the association
does not have among its members persons with training along the lines
of accountancy, in the future it would be a better procedure to have
the treasurer’s accounts audited by a public accountant, provided that
this can be done without too great expense.
The committee, therefore, suggests that the treasurer be instructed to
have his accounts audited by a public accountant prior to the 1922
meeting and submit the auditor’s certificate with his report to the
association.
Respectfully submitted,
J. J. T. Granam,
J. W. KELLOGG.
Auditing Committee.
Adopted.
It was moved, seconded and carried that the suggestion of the Auditing
Committee be referred to the Executive Committee with power to act.
1922] REPORT OF COMMITTEE ON FOOD DEFINITIONS 169
REPORT OF COMMITTEE TO COOPERATE WITH OTHER
COMMITTEES ON FOOD DEFINITIONS.
Your committee respectfully submits the following report of the pro-
ceedings of the Joint Committee on Food Definitions and Standards for
the period since the 1920 meeting of this association.
The membership of the committee has been changed by the resigna-
tion of Carl L. Alsberg and the appointment by the Secretary of Agri-
culture of W. W. Skinner and R. E. Doolittle as the successors of Messrs.
Alsberg and Abbott.
At its meeting Jast week, the Joint Committee elected William Frear
to be chairman and A. 8. Mitchell to be secretary.
During the past year the Secretary of Agriculture authorized and
issued Food Inspection Decisions No. 181 (April, 1921) on cheese stand-
ards, and No. 182 (September, 1921) on citrus fruits, embodying the
schedules of definitions and standards for these groups of commodities
which had earlier been adopted by this association upon the recom-
mendation of the Joint Committee.
The committee’s activities for the period just closed have included
meetings held in Washington, D. C., in November last and in March
and October of the current year.’ Hearings were given in January on
the subject of fruit pies; in March on the subject of potato flour; and in
October on the subjects of bread and ginger ale.
At the March meeting, the Executive Committee of the Joint Com-
mittee made assignments for study of the following subjects:
feaereains iss 288 2G eens. od.eerstacaod oth sect. tus Julius Hortvet
Dried and dehydrated fruits and vegetables.............. William Frear
1 LRT iy E215 Raa ore einen in 2 aa tas ns Ap A een W. W. Randall
PEON - RICO NONS SAVORS 6-01. 35 Os Seats Geta AAO acetate W. W. Skinner
Soy Weamtlourae & Adee a ee FLED Nh eens oe C. D. Howard
IGN PASCE 24-5 ave 0 3 SES, PSI (tt) are ei C. D. Howard
IE APERU ESIC 8 ei 2h cae te bitte WR iy ws aE tak) 8 a R. E. Rose
PEXECa=pPMATM ACO Ocal GLURS poss aes elena ates eae L. E. Sayre.
The Joint Committee has finally adopted, after full publication to the
food control officials of the nation and to the trade interests concerned—
through the medium of the appropriate trade journals—and after careful
weighing of all representations received as the result of such publication,
the following schedule of definitions and standards, which it hereby
submits with the recommendation that you approve the same:
CANNED CORN.
Definitions and standards adopted by the Joint Committee on Defi-
nitions and Standards, October 17, 1921:
Canned sweet corn, canned corn, is the canned vegetable properly prepared from the
grain of sweet corn (Zea mays L.) of the proper degree of maturity, with or without the
1 Presented by William Frear.
170 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS | Vol. VI, No. 2
addition of sugar and salt, and with the addition of potable water sufficient to secure
the consistency proper for the product.
CANNED SWEET CORN STYLES.
Cream canned corn is canned sweet corn prepared from corn removed from the cob
by cutting through the grain and subsequent scraping. It has a creamy consistency.
Whole grain canned corn is canned sweet corn prepared from corn removed from the
cob by cutting in such a manner as to leave the grain substantially entire.
CANNED SWEET CORN GRADES.
Fancy canned sweel corn is the product characterized by superior flavor and prepared
from young, tender corn, the kernels of which are milky or creamy.
Extra standard canned sweet corn is the product characterized by good flavor and
prepared from corn intermediate in tenderness between that used for the fancy and
that for the standard grade.
Standard canned sweet corn is the product characterized by acceptable flavor and
prepared from reasonably tender corn, the kernels of which have reached but not passed
the dough state.
Substandard canned sweet corn is canned sweet corn which fails in some respect to
meet the qualifications of standard grade.
CANNED TOMATOES.
Definitions and standards adopted by the Joint Committee on Defi-
nitions and Standards, October 18, 1921:
Canned tomatoes are the canned vegetables prepared from sound, ripe, fresh tomatoes
(the fruits of Lycopersicum esculentum Mill.) of any red variety or varieties, by thorough
washing and scalding and by proper peeling, coring and trimming, with or without
grading, with or without the addition of sugar and salt, and properly sterilized by
heat. The liquor used for filling the spaces between the fruits prior to sterilization,
is the pure juice’ derived from the tomatoes so prepared or from others of the same
quality and preparation, and does not exceed in quantity that necessary properly to
process and protect the fruit.
CANNED TOMATO GRADES.
Fancy tomatoes are canned select tomatoes of uniform red color, free from pieces of
skin or core, and are, at least for the most part, whole tomatoes, with or without a
few almost whole tomatoes, and with or without a few large pieces.
Extra standard tomatoes are canned tomatoes practically free from under-colored
parts and from pieces of skin or core. Most of the fruits are whole or in large pieces.
Standard tomatoes are canned tomatoes reasonably free from under-colored parts
and from pieces of skin or core.
Substandard tomatoes conform to the definition for canned tomatoes but lack in some
respect the qualifications of the higher grades.
FINAL DEFINITIONS AND STANDARDS FOR STRAINED TOMATOES
AND TOMATO PASTE.
Definitions and standards adopted by the Joint Committee on Defi-
nitions and Standards, March 25, 1921:
Strained tomatoes is the product obtained by straining sound, ripe tomatoes, raw or
cooked, through a screen that removes skins and seeds.
1922 REPORT OF NOMINATING COMMITTEE 171
Tomato paste is strained tomatoes concentrated by evaporation, with or without the
addition of salt, with or without the addition of basil leaf (Ocimum basilicum L.), with
or without the addition of pure sodium carbonate or of sodium bicarbonate to neutralize
a portion of the acidity, and contains not less than twenty per cent (20%) of tomato
solids determined by drying in vacuo at 70°C.
Concentrated tomato pasie is strained tomatoes concentrated by evaporation, with or
without the addition of salt, with or without the addition of basil leaf, with or without
the addition of pure sodium carbonate or of sodium bicarbonate to neutralize a portion
of the acidity, and contains not less than thirty per cent (80%) of tomato solids determ-
ined by drying in vacuo at 70°C.
Strained tomatoes from trimming stock is the product obtained by straining sound
peelings, trimmings and pieces from ripe tomatoes through a screen that removes
skins and seeds.
Tomato paste from trimming stock is strained tomatoes from trimming stock concen-
trated by evaporation, with or without the addition of salt, with or without the addition
of basil leaf, with or without the addition of pure sodium carbonate or of sodium bi-
carbonate to neutralize a portion of the acidity, and contains not less than twenty per
cent (20%) of tomato solids determined by drying in vacuo at 70°C.
Concentrated tomato paste from trimmina stock is strained tomatoes from trimming
stock concentrated by evaporation, with or without the addition of salt, with or without
the addition of basil leaf, with or without the addition of pure sodium carbonate or of
sodium bicarbonate to neutralize a portion of the acidity, and contains not less than
thirty per cent (30%) of tomato solids determined by drying in vacuo at 70°C.
Respectfully submitted,
WILuiAM FREaR,
JuLius Hortvet,
Committee to Cooperate with other Com-
mittees on Food Definitions.
Adopted.
REPORT OF NOMINATING COMMITTEE'.
The following names are respectfully submitted:
President, F. P. Veitch; Vice-President, A. J. Patten.
Executive committee: H. D. Haskins and R. E. Doolittle.
Board of Editors: R. B. Deemer.
Secretary-Treasurer, W. W. Skinner.
R. W. Batcom,
H. C. LytHcoe,
R. N. BrackeEtv.
Nominating Committee.
William Frear: | move that the secretary of the association be directed
to cast the ballot for the officers nominated.
The motion was seconded and carried.
1 Presented by R. N. Brackett.
172 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
W. F. Hand: The secretary will cast the vote of the association for
the officers named.
R. N. Brackett: The committee did not understand that this would
remove Dr. Balcom from the Board of Editors.
R. W. Balcom: The action of the association has left the chairmanship
of the Board of Editors to be filled by election.
R. N. Brackett: The Nominating Committee did not understand that
that removed Dr. Balcom from the position. If it is the sense of the
association, I am sure that every member of the committee was favorable
to Dr. Balcom being retained as chairman of that committee. If you
want to make it official I will cast the vote over again.
W. F. Hand: We will make it by unanimous consent.
R. N. Brackett: While I am on my feet I want to make a resolution.
In view of the long service rendered to this association by one of its
members who is no longer with us, a service characterized by faithful-
ness and exceptional efficiency, during which time he served as secre-
tary of the association, and in view of his efforts in the successful organ-
ization and establishment of our Journal, a task beset with many diffi-
culties and requiring more than ordinary ability and tact—and I might
even add that this gentleman shouldered personally the financial re-
sponsibility for the project at one stage of procedure—and in view also
of the active part which he took in the restoration of cooperation between
the States and the Federal Department in the matter of food definitions
and standards,
Therefore be tt resolved, That Dr. Carl L. Alsberg be elected an honorary
life member of this association. By so doing we shall not only recognize
ability and efficiency, but honor ourseives in honoring him.
The resolution was seconded and carried by a rising vote.
REPORT OF COMMITTEE ON RESOLUTIONS!
The association has, since its last meeting, lost one member by death,
Professor Bert Holmes Hite. Your committee recommends the adoption
of the following resolution:
Resolved, That by the death of Professor Bert Holmes Hite, Chief
Chemist of the West Virginia Agricultural Experiment Station, this
association has lost a distinguished member, one who has rendered
long and valuable service to his commonwealth, and whose researches
have produced valuable contributions to chemical knowledge.
Resolved, That the secretary of the association transmit copies of this
resolution to the West Virginia Agricultural Experiment Station and to
Professor Hite’s family.
1 Presented by William Frear.
1922 REPORT OF COMMITTEE ON RESOLUTIONS 173
Resolved, That the Association of Official Agricultural Chemists
hereby expresses to the Secretary of Agriculture its appreciation of his
high estimate of the service which is being rendered to the country by
its members and their fellow chemists, and of his tender of cooperation.
Resolved, That this association hereby expresses to its president,
W. F. Hand, its thanks for the courteous, efficient manner in which he
has conducted the proceedings of the present convention.
Resolved, 'That this association hereby expresses to Miss Nellie A.
Parkinson its sincere appreciation of her efficient work relating to The
Journal of the association and of the services she has rendered in making
this convention a success.
Resolved, That the thanks of this association be tendered to the
management of the Hotel Washington for the facilities provided and the
courtesies extended to the association and its members.
Resolved, That this association endorses the proposal now under con-
sideration by Congress that, after due notice, the metric system of
weights and measures be made the legal system of the United States:
and also, to further the introduction of this system, recommends that
its members, in the purchase of supplies, designate and describe the same
in terms of the metric system so far as possible.
Whereas, The agricultural and other industrial interests of the country
realize the necessity of a trained chemical personnel and the advantages
arising from the application of chemical research to all industrial prob-
lems; and
Whereas, The research necessary for the solution of agricultural and
other industrial problems can only be carried on with the aid of a firmly
established chemical industry; and
Whereas, The development of chemical industry is one of the great
factors tending toward the future welfare of our country, whether in
times of peace or in times of war, it is therefore
Resolved, That the Congress of the United States is hereby urged to
continue adequate, beneficial legislation until the various chemical
industries in the United States have become firmly established; and
Whereas, The members of this association are engaged in the study
and development of investigational methods as applied to agricultural
and other industrial sciences, all looking toward the ultimate welfare
of our country; and
Whereas, Our association earnestly advocates the promotion of peaceful
industries and cordial relationships among scientific men throughout
the world; be it therefore
Resolved, That this association expresses its hearty endorsement of
the aims and purposes of the Conference on the Limitation of Arma-
ments to be held in this city beginning November 11; and be it further
174 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 2
Resolved, That it is the hope of the Association of Official Agricultural
Chemists in convention assembled, that the highest aims and purposes
of the Conference on the Limitation of Armaments may be attained,
thereby realizing the hopes of the American people and of humanity
at large.
Resolved, That the secretary of this association do and is hereby
instructed to send copies of these resolutions to the chairmen of the
Congressional Committees convened and to the proper Executive
officers.
Adopted.
LE A EE OSD
BERT HOLMES HITE
On October 6, 1921, occurred the death of Professor Bert Holmes
Hite, chemist and vice-director of the West Virginia Experiment Sta-
tion. Professor Hite was born in 1866, received the degree of Master of
Science from the University of West Virginia in 1890 and attended
Johns Hopkins University from 1891 to 1895, being a fellow from 1893
to 1895. He was appointed Chief Chemist in the Experiment Station
in 1895, Professor of Organic Chemistry in the University of West
Virginia in 1896, and was made Agricultural Chemist of the State in
1898 and Vice-Director in the Experiment Station in 1902. He was
also made chief chemist of the West Virginia Geological Survey in 1898
and served as consulting chemist of the Baltimore and Ohio Railroad,
1916 to 1918. During 1918 he did research work for the Ordnance
Department of the Army. He was a member of the American Chemical
Society, the Electrochemical Society and the Franklin Institute.
Professor Hite was an untiring worker, and it was seldom that he
could not be found late at night in his laboratory. Because of his dis-
like for public attention but few, even of his own townsmen, knew of
his achievements, but he was an expert on molecular weights, com-
bustion, soils, and high-pressure researches and in bacteriology. For
notable achievement in his high-pressure work the Franklin Institute
recently conferred upon him a medal for research.
Professor Hite was unusually thoughtful and courteous in his dealings
with his associates, and his fine qualities of character endeared him to
all who knew him well.
His death occurred at Johns Hopkins Hospital, Baltimore, from a
cancerous condition of the spine.
H. H. Hanson.
The Convention adjourned.
Or
1922| DENNY: ESTIMATION OF STARCH IN PLANT TISSUES 1
CONTRIBUTED PAPERS.
METHODS FOR THE ESTIMATION OF SMALL AMOUNTS OF
STARCH IN PLANT TISSUES.
By F. E. Denny! (Bureau of Chemistry, Laboratory of Fruit and
Vegetable Chemistry, Los Angeles, Calif.).
While studying the changes in the composition of cantaloupes during
the ripening period in this laboratory, in following out a suggestion
made by C. L. Alsberg, it was noted that the development of maturity in
melons was accompanied by a decided reduction in the starch content
of the seeds.
Thus, while seed extracts from immature melons always gave a strong
positive test for starch by the iodine method, similar extracts from the
seeds of ripe melons generally gave either a weak test, or one which
indicated the complete absence of starch. It was desired to measure
this progressive change quantitatively, in order to determine what
correlation existed between the stage of maturity of a melon and the
starch content of its seeds.
Cantaloupe seed powders, however, were found to contain only small
amounts of starch. Preliminary tests with ordinary starch methods
indicated that the starch contents were low, but a dependable estimate
could not be obtained by their use. It is now known that even very
immature melons have less than 2 per cent of starch in the seeds, that
most of the seed samples used in this investigation contained less than
1 per cent of starch, and that ripe samples contained less than 0.2
per cent.
A method was needed that would cover the range from 0 to about
1 per cent of starch by steps of about 0.1 per cent. The methods here
described, applied to cantaloupe seed powders, fulfilled this condition
in a satisfactory manner. Since they seem to be open to further im-
provement and to offer the possibility of application to other kinds of
material, they will be described in detail.
APPLICABILITY OF DIFFERENT STARCH METHODS TO CANTALOUPE
SEEDS.
The official acid hydrolysis method? proved to be entirely unsuitable,
as a certain seed sample showing only a trace of starch by qualitative
test indicated a starch content of 2.30 per cent by this method, while
the result with another lot giving a strong starch test was 2.26 per cent.
1 The advice and helpful suggestions given by E. M. Chace, under whose direction this work was done,
are acknowledged, as well as the cooperation of C. G. Church in working out the details of the methods.
2 Assoc. Official Agr. Chemists, Methods, 1920, 95.
176 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
Thus the method not only failed to distinguish between the two lots,
but also gave for both starch values that are known to be too high.
A modification of the official diastase method!, using taka-diastase
instead of malt diastase, was also undependable. The results did not —
agree with the qualitative starch-iodide tests. Samples known to
contain starch required no more permangarate for titrating! than did
the blank, and samples containing traces of starch gave starch values
known to be too high.
Attention was then directed to the starch method proposed by Von
Fellenberg?. By this method the starch is dissolved in concentrated
calcium chloride solution, precipitated as starch-iodide, the iodine dis-
solved and the starch precipitated by alcohol. The starch precipitate
is then filtered, dried, weighed, ignited, reweighed and the difference
taken as starch. The amounts of starch obtainable for weighing by this
method were too small in the case of cantaloupe seed powders to give
sufficiently accurate results. As that portion of Von Fellenberg’s
method which involved dissolving the starch in calcium chloride solu-
tion, however, was well suited to this material, it was adopted in apply-
ing the following methods.
Further progress was made by employing modifications of the method
described by Long*. According to this method, a measured amount of
the starch solution of unknown concentration is pipetted into a volu-
metric flask, together with some potassium iodide solution. A measured
amount of standardized iodine solution is then added, the starch pre-
cipitated as starch-iodide, which is filtered off, and washed with potassium-
iodide solution, and the iodine in the filtrate titrated with standard
sodium thiosulfate. The values so obtained are compared with similar
values by using starch solutions of known concentration.
In attempting to apply this method to cantaloupe seed extracts,
serious difficulties were encountered. In the first place, even after
extraction with fat solvents, substances other than starch, that in some
manner remove iodine from solution, are present in these seed extracts.
Furthermore, the calcium chloride itself contained substances that
absorbed iodine.
These difficulties were overcome by two modifications of Long’s
method: First, by reversing the procedure and titrating the iodine in
the starch-iodide precipitate, using the absorbed iodine rather than the
residual iodine as a measure of the starch; second, by successively re-
precipitating the starch-iodide, thus obtaining a partially purified starch
solution to which the Long method could be applied.
Attempts were made, after separating the starch as starch-iodide, to
hydrolyze the starch by acid and obtain a measure of the starch by the
1 Assoc. Official Agr. Chemists, Methods, 1920, 80.
4 Mill. Lebensm. Hyg., 1916, 7: 369.
8 Trans. Kan. Acad. Sci., 1916-1917, 28: 172.
1922] DENNY: ESTIMATION OF STARCH IN PLANT TISSUES 177
reducing power of the dextrose formed. A small amount of starch was
obtainable in this way from seeds of low starch content, so that the
reduction produced in Fehling’s solution required little permanganate
for titration’. This difficulty, however, was overcome by a modifi-
cation of Scales’ method? which required relatively large amounts
of thiosulfate for the titration of small quantities of dextrose.
PREPARATION OF SEED POWDER AND EXTRACTION OF STARCH WITH
CALCIUM CHLORIDE.
The seeds were first ground coarsely, extracted with petroleum ether
at room temperature and dried in an oven at 100°C. The residue was
then in condition to be reduced to a fine powder by being ground in a
mill until all the particles would pass through a 30-mesh sieve. The
mill used was not capable of producing a finer powder with this material.
From this oven-dry powder, samples (usually 10 grams) were weighed
out and put in 400 cc. beakers, 15 cc. of water were added and the mix-
ture was stirred until the particles were wet. One hundred cc. of a
saturated solution of calcium chloride were added; the mixture was
slowly raised to the boiling point with occasional stirring, and gentle
boiling continued for 15 minutes. Then 100 cc. of boiling water were
added, and after thorough stirring the hot liquid was filtered through
paper into a volumetric flask (usually 250 cc.). Most of the residue was
retained in the beaker and was extracted successively with small por-
tions of half-saturated calcium chloride. On cooling, the final volume
was made up to the mark. The seed extract so obtained is clear, forms
no precipitate on standing and is comparatively stable.
GENERAL DESCRIPTION OF STARCH METHODS USED.
After the starch was obtained in calcium chloride solution, the follow-
ing methods were used for its quantitative estimation:
(1) By removing an aliquot, precipitating the starch as starch iodide under a standard-
ized set of conditions and titrating the iodine in the starch icdide with standard sodium
thiosulfate. Values so obtained were then compared with those given by known
amounts of starch under the same conditions. The method will hereafter be referred
to as the absorbed-iodine method.
(2) By removing an aliquot, precipitating the starch with iodine, purifying the
starch-iodide by successive reprecipitations, regenerating a starch solution by the
removal of the iodine with thiosulfate, again precipitating the starch as starch-iodide
under standardized conditions and titrating the residual iodine. This will hereafter
he referred to as the residual-iodine method.
(3) By removing an aliquot, precipitating the starch with iodine, hydrolyzing the
starch with acid and estimating the dextrose formed by the official method! and that of
F. M. Scales?. This method will be referred to hereafter as the reduction method.
} Assoc. Official Agr. Chemists, ei re 1920, 80.
2J. Ind. Eng. Chem., 1919, 11:
178 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
Most of the experimental work here reported was done in connection
with the first method, only limited observations being made upon the
other two.
DETAILS OF THE ABSORBED-IODINE METHOD.
Inasmuch as the ability to obtain consistent results with this method
was Closely connected with the technique of obtaining the starch-iodide
precipitate and estimating its iodine content, the procedure used will
be described in detail, as follows:
An aliquot was first pipetted into a centrifuge bottle, the amount taken varying
from 100 to 400 cc., depending upon the starch content. A preliminary qualitative
test by iodine in comparison with standard solutions of known starch concentration
was sufficient to indicate approximately the amount to be used.
To the liquid in the centrifuge bottle, strong iodine solution (about 0.1N) was added
drop by drop, until a blue color remained on standing several minutes, the object being
to satisfy approximately the non-starch iodine-absorbing substances present. Then
for each 100 cc. aliquot, exactly 20 cc. of 0.02N iodine solution were added, the bottle
was shaken and the mixture allowed to stand (usually overnight). The iodine added
must be in a sufficient excess (otherwise precipitation will not be produced) and it must
be exactly the same amount and of the same concentration as that added to the standard
starch solutions used for comparison. If the iodine added is insufficient to bring about
precipitation, a smaller aliquot must be taken and made up to 100 cc. with half-saturated
calcium chloride solution before the addition of iodine.
The starch-iodide precipitate is thrown to the bottom of the bottle by centrifuging
and the liquor above drawn off. A glass tube drawn to a coarse capillary and con-
nected with a suction flask is convenient for this purpose and allows the removal of
the liquor without disturbing the precipitate.
Two difficulties were encountered at this point. In a few samples precipitation did
not take place under these conditions. Such samples were rejected. Usually pre-
cipitation could be brought about by diluting with water and adding more iodine, but
this operation causes a deviation from the standardized procedure. If data from such
samples are required, it can be obtained by separating the precipitate obtained in this
way, removing the iodine by the addition of exactly enough thiosulfate, again dis-
solving in calcium chloride solution, and following the standardized procedure. The
cantaloupe seed extracts, however, almost always gave sufficiently good precipitation.
A second difficulty results from the fact that in practically no case is the precipitation
absolutely complete. Very fine particles remain suspended in the liquid. These con-
stitute only a small percentage of the total precipitate, however, and it is believed that
the error involved in neglecting them is small. To remove them by filtration and
return them to the main precipitate was not found to be feasible.
The starch-iodide precipitate was transferred to a hardened filter (123 cm.) by means
of 25 cc. of potassium iodide solution, containing 10 grams per 100 cc., and this pre-
cipitate washed with 75 cc. of potassium iodide solution, containing 5 grams per 100 ce.
These solutions serve the double purpose of removing the excess iodine and at the
same time holding the starch-iodide in precipitation. (The excess iodine is not com-
pletely removed by the process, and it was impracticable to bring about complete
removal. Since the procedure is a standardized one, however, it permits a comparison
of the seed extract precipitate with that of a known starch solution treated in the same
way.) After filtration was complete, the bottom of the filter paper was punctured
and most of the starch-iodide washed into a 400 cc. beaker with a jet of water, after
which the filter paper with the remaining starch-iodide was added.
1922] DENNY: ESTIMATION OF STARCH IN PLANT TISSUES 179
The problem now is to determine the amount of iodine present. This cannot be
done by direct addition of thiosulfate, as the starch-iodide flakes do not break up readily
and the end-point is not distinct. But if a measured excess of sodium thiosulfate is
added and the mixture heated, the starch-iodide precipitate is broken up and the
liberated iodine at once unites with the thiosulfate. The back titration with iodine is
then a measure of the iodine content of the starch iodide, the starch acting as its own
indicator. For these titrations, iodine and sodium thiosulfate of 0.005N strength
were found to be most suitable, one or two drops giving a good end-point. Five to
15 cc. of thiosulfate were sufficient to give an excess, and the back titrations varied
from none to about 10 cc. of iodine for the aliquots taken.
A list of titration values obtained by measuring the iodine absorbed by the starch in
the seed extracts may be secured by this procedure. Such values are then compared
with values obtained by treating starch solutions of known concentrations in a similar
manner.
TABLE 1.
Iodine values of standard starch solutions.
STARCH TAKEN IODINE FOUND
Ratio:
STANDARD AEIQUOT Og | ett rina Carn | ter Geet ae ee ae | LST eta cir Tarr ae | [kG OTT.
NO. TAKEN Solution. Gram 0.005N Gram ~ Grams Starch |
Concentration
ce. gram per 100 ce. ce.
Al 100 0.05 0.05 9.0 0.0057 0.11
2 100 0.05 0.05 9.0 0.0057 0.11
3 100 0.05 0.05 9.2 0.0058 0.12
4 100 0.05 0.05 8.8 0.0056 0.11
5 100 0.05 0.05 8.7 0.0055 0.11
6 100 0.05 0.05 9.1 0.0058 0.12
7 100 0.05 0.05 8.9 0.0057 0.11
Bl 100 0.04 0.04 7.3 0.0046 0.12
2 100 0.04 0.04 en 0.0045 0.11
3 100 0.04 0.04 7.2 0.0046 0.12
4 100 0.04 0.04 7.2 0.0046 0.12
C1 100 0.03 0.03 5.3 0.0034 0.11
2 100 0.03 0.03 5.3 0.0034 0.11
3 100 0.03 0.03 Hy) 0.0033 0.11
4 150 0.03 0.045 8.2 0.0052 0.12
D1 100 0.02 0.02 3.0 0.0019 0.10
2 100 0.02 0.02 3.0 0.0015 0.10
3 100 0.02 0.02 oo 0.0020 0.10
4 150 0.02 0.03 5.4 0.0035 0.12
5 200 0.02 0.04 7.0 0.0044 0.11
6 200 0.02 0.04 6.5 0.0041 0.10
El 200 0.01 0.02 3.6 0.0023 0.12
2 200 0.01 0.02 3.6 0.0023 0.12
3 150 0.01 0.015 2.5 0.0016 0.11
4 400 0.01 0.04 Thee? 0.0046 0.12
Fl 400 0.0075 0.03 4.6 0.0029 0.10
2 400 0.0075 0.03 4.7 0.0030 0.10
G1 200 0.0050 0.01 1:3 0.0008 0.08
2 200 0.0050 0.01 1.4 0.0009 0.09
3 200 0.0050 0.01 1.4 0.0009 0.09
4 200 0.0050 0.01 Ls 0.0008 0.08
5 400 0.0050 0.02 2.8 0.0018 0.09
6 400 0.0050 0.02 2.9 0.0018 0.09
H1 400 0.0025 0.01 ifsit 0.0007 0.07
2 400 0.0025 0.01 1-2 0.0008 0.08
180 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
IODINE VALUES OF STANDARD STARCH SOLUTIONS.
Pure cantaloupe starch would have been preferable for standards of
comparison. This tissue, however, contains such small amounts of
starch and the grains are so minute that it would be impossible to obtain
a sufficient quantity in the required state of purity. Since it was neces-
sary to use another form of starch, potato starch was selected. A
quantity of purified potato starch, whose purity was found by test to
be 96.83 per cent, was obtained.
Starch was weighed out to make a solution containing 0.05 gram per
100 cc. when dissolved in calcium chloride in a manner similar to the pro-
cedure previously described. From this solution as a base, dilutions
were made to produce the concentrations shown in Table 1, Column 3,
the starch in each case being in half-saturated calcium chloride solution.
The solutions so obtained were slightly opalescent but transparent.
They stood for weeks without the formation of a precipitate, although
small particles which did not completely dissolve were noted. The
question of the completeness of the solubility of the starch in calcium
chloride is not important here, however, inasmuch as the aliquot taken
in each represented a certain proportion of the original starch, and
therefore could be directly compared with an unknown sample under
the same conditions.
TABLE 2.
Average value of starch-iodine ratio.
ALIQUOT TAKEN STARCH IN SOLUTION IODINE REQUIRED STARCH-IODINE RATIO
gram per 100 cc.
g
100 0.05 9.0 0.11
100 0.04 7.2 0.12
100 0.03 5.25 0.11
150 0.03 8.2 0.12
100 0.02 3.0 0.10
150 0.02 5.4 0.12
200 0.02 6.8 0.11
200 0.01 3.6 0.12
150 0.01 2.5 0.11
400 0.01 7.2 0.12
400 0.0075 4.65 0.10
Average. .0.11
From such standard solutions aliquots were taken and treated by the
procedure already described for the seed extracts. The titration values,
expressed in cubic centimeters of iodine corresponding to different ali-
quots of different starch standards, are shown in Table 1, Column 5,
and the ratios of the iodine absorbed to the starch used are shown in
SOLUTION
IODINE
1922] DENNY: ESTIMATION OF STARCH {N PLANT TISSUES 181
the last column. Table 2 is a summary of the data in Table 1 for the
standards A to F, inclusive. Standards G and H had starch iodide pre-
cipitates too small in volume and deviated too far from the condition of
proportionality between the starch taken and the iodine absorbed.
Attention is further directed to Fig. 1 in which the results are shown
graphically. The black lines are lines of proportionality between the
iodine and starch and correspond to the ratio 0.11, i. e., “= 2" = 0.11,
Backward extension of all the black lines will be found to pass through
the origin. The crosses represent the average values obtained from
Table 1 and show to what extent the values found correspond with the
_ average ratio found in Table 2.
PER CENT STARCH IN SEED POWDER
0.4 0.5 0.6 0.7 - s 7 Pac
10
02 ei Osh. jo atone
PER CENT STARCH IN SGLUTION
FIG. 1-VARIATION IN RELATION OF STARCH TAKEN AND IODINE ABSORBED.
Examination of the data in Table 1 and of the graph in Fig. 1 shows
that strict proportionality between the iodine absorbed and _ starch
taken was not found. Generally the ratio is high for the higher con-
centrations and low for the lower concentrations. This fact is no doubt
connected with the volume of the starch iodide produced. Thus when
the quantity of starch iodide is too low, too much iodine is removed by
the washing process; and for the large amounts of starch-iodide, rela-
tively too much iodine is retained.
It will be noted, however, that within narrow ranges the ratio is
approximately constant, e. g., from 0.03 to 0.05 per cent for the 100 cc.
aliquot, and from 0.01 to 0.03 per cent for the 150 cc. aliquot, etc. It is
182 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
interesting further to note that while the 100 cc. aliquot of 0.02 per
cent starch solution falls below the line of proportionality, it is probably
not caused by experimental error as may be seen from the agreement
of duplicates for it in Table 1.
In applying the data from results on cantaloupe seed extracts, titra-
tion values that fell upon the black lines were converted into weights of
starch by substitution in the equation £2, = 0.11. For titration
values falling upon the dotted lines, however, calculations were made
by interpolation on the graph, the percentage of starch in solution
being read from the bottom scale and the percentage of starch in the
seed powder from the top scale. The percentage of starch in the
seed powder was calculated on the following basis: 100 cc. of the seed
extract correspond to 4.0 grams of seed powder.
VALUE OF THE STARCEH-IODINE RATIO.
The value of this starch-iodine ratio, 0.11, may now be compared with
that found by others. Taking a typical case from the results reported
by Andrews and Goettsch', 8.08 grams of starch united with 0.518 gram
of iodine, a ratio of 0.064%. Mellanby* carefully determined the point
at which iodine and starch could be added in such proportions that
neither starch nor iodine would appear in the filtrate. In a typical
case, 0.087 gram of starch took up 0.0068 gram of iodine, giving a ratio
of 0.0784. Long found that 0.00125 gram of starch removed 0.000254
gram of iodine, a ratio of 0.2034. It is pointed out by Mellanby, how-
ever, that two reactions are involved here: First, a quantitative one in
which starch reacts chemically with iodine, forming a definite chemical
compound; and second, “that the starch-icdide thus formed is a lyo-
phobic suspensoid colloid, which adsorbs iodine from solution according
to the recognized laws of adsorption’.
Therefore the quantity of iodine taken up by a given amount of starch
depends upon the concentration of the iodine with which it is in contact.
When an excess of iodine is present, an additional amount will be
adsorbed by the starch iodide precipitate. In all the experiments here
reported, an excess of iodine was present (in fact, necessarily so, in
order to produce precipitation), and an excess of iodine was always
present in the starch-iodide precipitate. Hence values higher than
Mellanby’s for the ratios would be expected. The conditions in these
experiments differed from those of Mellanby, in two other respects,
namely, (1) much more dilute starch solutions were used, and (2) the
starch was in solucion, not in water but in half-saturated calcium chloride.
1 J. Amer. Chem. Soc., 1902, 24: 865.
2 Calculations were made by the author.
3 Biochem. J., 1919, 13: 28.
4 Calculations were made by the author.
1922] DENNY: ESTIMATION OF STARCH IN PLANT TISSUES 183
DUPLICATE DETERMINATIONS ON SEED POWDERS BY THE
ABSORBED-IODINE METHOD.
Duplicate samples of 10 grams were weighed out from cantaloupe
seed powders. They were selected to exhibit the range of starch con-
centration found in this material. Thus, Lot No. 442 shows starch
percentages at the upper limits; Lot No. 413B was a seed powder of
low starch content and Lot No. 453 was intermediate in its starch content.
Each sample was carried through the procedure described, and the
results show the sum of all of the errors of the process. (See Table 3.)
Thus the titration values for 413B varied from 4.7 to 6.1, and the per-
centage of starch in seed powder calculated from the iodine titrations
varied from 0.33 to 0.43. For Lot No. 453 these values varied from
5.5 to 6.6 and from 0.52 to 0.62, respectively.
TABLE 3.
Duplicate determinations on seed powders by the absorbed-iodine method.
STARCH FOUND
LOT ALIQUOT IODINE
NO. TAKEN TITRATION
In Solution In Seed Powder
cc. ce. gram per 100 cc. per cent
442 100 8.3 0.047 1.18
442 100 7.8 0.044 1.10
442 100 7.9 0.045 1.20
442 100 sill 0.043 1.08
Average... 7.9 0.045 1.14
413A 200 8.4 0.048 0.60
413A 200 7.8 0.044 0.55
Average... 8.1 0.046 0.58
413B 200 4.9 0.014 0.35
413B 200 4.7 0.013 0.33
413B 200 5.0 0.014 0.35
413B 200 6.1 0.017 0.43
413B 200 5.5 0.016 0.39
413B 200 5.0 0.014 0.35
Average... 5.2 0.015 0.37
453 150 6.4 0.024 0.60
453 150 5.5 0.021 0.52
453 150 6.1 0.023 0.58
453 150 6.6 0.025 0.62
453 150 6.5 0.025 0.61
453 150 6.3 0.024 0.59
453 150 6.4 0.024 0.60
453 150 6.2 0.024 0.58
453 150 6.1 0.023 0.58
453 150 6.0 0.023 0.57
Average... 6.2 0.024 0.58
vv +4 -
184 ASSOCIATION, OF OFFICIAL’ AGRICULTURAL CHEMISTS [Vol. V/, No. 2
A consideration of the data in Table 3 permits a rough approximation,
at least, of the errors involved. Since the calculations are based on the
iodine titration ¥alues, the variations in these values are the ones to be
considered. ‘The average iodine value for Lot No. 453 is 6.2; the prob-
able error of a single observation is 0.2; the probable error of the mean of
10 observations is 0.06 and the probable error of the mean of two ob-
servations is 0.14. Hence the percentage error in using a single sample
is 100*92 or about 3.3 per cent, and if duplicate samples were taken
62
the error would be ~““=?*, or 2.3 per cent. If the average starch con-
tent of the sample is 0.58 per cent, the error of a single sample, expressed
in percentage of starch in seed powder, is 3.3 per cent of 0.58 per cent,
or (0.02 per cent, giving an error of 2 in the second decimal place.
In considering the results from Lot No. 413B, if the objection is made
that the number of samples is too small to justify the calculation of the
probable error, at least the average deviation of a single sample—which
in this case is 0.4—may be determined. The percentage error of a
single observation is thus found to be a or 7.7 per cent. Seven
and seven-tenths per cent of 0.37 is 0.03, giving an error of 3 in the second
place when the results are expressed in the percentage of starch in the
seed powder. Considering the results of Lot No. 442 in the same man-
ner, the percentage error of a single sample is 2.5 per cent, giving an
error of 3 in the second place on the basis of the percentage of starch in
the seed powder'.
Many more such duplicate determinations would be necessary to
obtain an accurate idea of the amount of the error involved in the
method. In the work with cantaloupe seed powders, the results were
thought to be sufficiently accurate to permit the expression of the starch
content to the nearest 0.1 per cent.
ESTIMATION OF ADDED STARCH.
To weighed amounts of seed powder, weighed amounts of starch
were added. The two samples (seed powder plus starch, and seed
powder only) were carried through the process, and the iodine value of
the check subtracted from that of the lot containing added starch.
The amount of starch corresponding to the excess iodine was then
calculated and compared with the weight of starch added. The results
are shown in Table 4. Favorable results were found in Lots I, II and
V, and unfavorable results in II] and [V. But it may be pointed out
that the quantity of starch used was small (particularly in Lot IV), in
which case an error of a small amount of starch gives a large percentage
error. The results in Table 4 seem to justify the belief that about
85-95 per cent of the added starch is recoverable in this way.
1A further error not taken into account here results from uncertainty as to the accuracy of the starch-
iodine factor, 0.11.
1922] DENNY: ESTIMATION OF STARCH IN PLANT TISSUES 185
TABLE 4.
Estimation of added starch.
EXPERIMENT NUMBER
Starch added to seed powder, grams. ..| 0.1225 | 0.0770 | 0.0640 | 0.0174 | 0.0986
Volume of solution and aliquot taken . .| 500-150 | 250-100 | 250-150 | 250-100 | 250-100
{odine titration (excess of total above
. seed powder alone) cc. 0.005N..... 6.1 5.0 5.6 1.5 6.6
Starchequivalent inaliquottaken,grams| 0.035 0.029 0.032 0.009 0.038
Total starch found, grams. .......... 0.117 0.072 0.053 0.023 0.095
Percentage of added starch found... .. 95 94 83 132 97
COMPARISON OF DIASTASE AND ABSORBED-IODINE METHODS ON
CANTALOUPE SEED POWDERS.
Three seed powder lots containing percentages of starch among the
highest found for cantaloupe seeds and one seed powder containing
only a trace of starch were treated by both the diastase method! and
the absorbed-iodine method. The following procedure was used for
the diastase method:
Two duplicate lots of seed powder were taken; the first was gelatinized in boiling
water and taka-diastase added. After the enzyme action had proceeded for 36 hours
at 35°C., the liquid was filtered off, an aliquot hydrolyzed and the reducing power of
an aliquot of this determined. The value so obtained is given under the heading
“total reduction of aliquot” in Table 5. The duplicate lot of seed powder was treated
exactly in the same way except that no taka-diastase was added, and the seed powder
was not gelatinized but merely allowed to remain in water at 35°C., when it was filtered
and an aliquot hydrolyzed as before. The value thus obtained is given under the
heading “‘reduction due to non-starch substances” in Table 5. In addition, a sample
of diastase solution equal in amount to that used with the seed powder was carried
through the process in order to make the proper correction. Thus, in Table 5 the item
“reduction due to starch only”’ is obtained by subtracting the reduction due to dias-
tase alone and reduction due to non-starch substances from the total reduction. The
dextrose value of the permanganate solution was obtained by titration against known
concentrations of pure dextrose, and starch calculated from dextrose by the factor 0.9.
The percentages of starch found by the diastase method are shown in
Table 5, and with them for comparison the results given by the absorbed-
iodine method on the same powders. Although the agreement is not
very satisfactory, more confidence is placed in the values given by the
absorbed-iodine method than in those by the diastase method.
Thus, in Lot IV, the result with the diastase method seems too high,
inasmuch as a qualitative test indicated only a trace of starch, while an
iodine test on a starch standard of the indicated concentration gave a
much stronger color. Additional evidence is found by comparing the
diastase results of Lots III] and IV. The starch content of the tissue in
1 Assoc. Official Agr. Chemists, Methods, 1920, 95; 80, par. 29.
186 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
TABLE 5.
Comparison of diastase and absorbed-iodine methods.
LOT NUMBER
TREATMENT OF POWDER BY DIASTASE METHOD
I II Ill IV
Seed powder ‘faken, Grams... 4.0.): os: ise chai 5.0 6.2 5.0 7.0
Total reduction of aliquot, ec. KMnQ,......... 6.8 7.8 6.4 4.8
Reduction due to non-starch substances, ce.
IVA Te ee a re conc ee ghee ee 3.0 1.9 0.2 0.1
Reduction due to diastase alone, cc. KMnQ,....| 1.7 3.4 3.4 3.6
Reduction due to starch only, cc. KMnQ,...... 1.6 2.5 2.8 1.1
Dextroseun/aliquot.grams. 3.2)... see 0.0082 | 0.01285} 0.0144 | 0.00565
Starchyimaliquot, .2calise ace Sree 0.0074 | 0.0115 | 0.0129 | 0.00500
Starch in entire sample, grams................ 0.0555 | 0.0867 | 0.0981 | 0.0375
Percentage of starch by diastase method....... leila 1.40 1.96 0.54
Percentage of starch by absorbed-iodine method.}| 1.88 1.45 1.40 0.15
Lot III ranked among the highest of the samples analyzed, while that of
the tissues in Lot IV was among the lowest. Yet the difference between
them is represented by only 1.7 cc. of potassium permanganate. The
difference between two such extremes could not be accurately separated
into graded sleps by the diastase method.
COMPARISON OF DIASTASE AND ABSORBED-IODINE METHODS ON OCA
TISSUE (Oxalis tuberosa).
At the time of these experiments, the amount of starch in oca tissue
was being estimated in this laboratory by a modified official diastase
method, using taka-diastase instead of malt diastase, and some samples
of this tissue were taken for comparison by the absorbed-iodine method.
The results are given in Table 6.
TABLE 6.
Comparison of diastase and absorbed-iodine methods on oca tissue.
EXPERIMENT NUMBER
I II
Sample of plant powder taken, grams.......... 1.0 0.1900
Extract make up to volume, cc................ 250 250
Aliquot taken’ CGs 2 eros ok toe uc cae Cheat rack haa one 12.5 25 50 75
Iodine titration in aliquot, cc... .............. 6.0 13.3 5.4 8.4
Iodine found in aliquot, grams................ 0.0038 | 0.00844} 0.00343] 0.00533
Starch equivalent in aliquot, grams............ 0.035 0.077 0.031 0.049
Total starch found in sample, grams........... 0.70 0.70 0.155 0.163
Percentage of starch, dry powder basis......... 70 77 81.6 85.8
Percentage of starch, fresh tissue basis......... 10.8 12.0 12.6 13.2
Percentage of starch found by official diastase
Method jaaiscecneoosueasy aha eee tne 11.62
1922} DENNY: ESTIMATION OF STARCH IN PLANT TISSUES 187
The average of the results from the absorbed-iodine method is close
to that found by the official method', but the variation with the differ-
ent samples and different aliquots of the same sample is large. The
average deviation of a single sample is about 8 per cent of the value
obtained by the diastase method, and when the true value is, say, 11.62
per cent, an error of 8 per cent, which amounts to about 1 per cent,
would be too large for accurate results.
Since the dry powder contained relatively many times as much starch as
the cantaloupe seed powder, small portions only could be taken for starch
extractions, and small aliquots for precipitation of starch-iodide. Hence
the errors of the method were multiplied many times. Thus, the error
in Experiment I is 40-80 times, and that in Experiment II 60-100
times that involved in the cantaloupe seed powder procedure.
Apparently the method is not well suited to tissue containing large
amounts of starch for which material the results are only approximate.
One feature of the method, however, recommends it for use in such
cases, namely, the necessity of drying the tissue and making a pre-
liminary extraction to remove the sugars is avoided, thus shortening
the time required to estimate the starch in a sample. It is possible
that the procedure could be modified to increase its accuracy and make
it applicable to such tissues.
RESULTS WITH THE RESIDUAL-IODINE METHOD.
Starch was precipitated from six samples of 100 cc. each from a seed
extract by adding iodine. (In this case, the exact amount of iodine added
is of no importance, provided it is sufficient to produce precipitation.)
The starch iodide precipitate was thrown to the bottom of the bottle by
centrifuging. In order to apply the principle involved in Long’s resi-
dual iodine method, it was necessary to partially purify the starch-
iodide and remove from it the non-starch iodine absorbing substances
in the seed extract, and also to remove most of the excess calcium chlo-
ride which absorbs iodine.
For this purpose the liquid above the precipitate was removed by
suction, 100 cc. of distilled water added, the bottle shaken, and strong
iodine solution added until an excess of iodine was present (indicated
by the brown color of the foam in the bottle). When this precipitate
settled, it was centrifuged again and the liquid removed by suction.
This process was repeated once more and the precipitate washed into
a 100 cc. volumetric flask.
To remove the iodine present in order that a measured amount of
standard iodine could be added later, small quantities of thiosulfate
were added and the liquid heated. By adjustment with iodine and
1 Determinations were made by C. G. Church.
188 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
thiosulfate, a point was reached when the solution of starch was found
to have an excess of neither.
To the starch solution, 10 cc. of 10 per cent potassium iodide and
20 cc. of 0.02N iodine were added, and the volume made up to 100 cc.
After standing, the precipitate settled and the entire contents of the
flask were poured upon a filter paper. The precipitate was not washed
but the iodine in an aliquot of the filtrate was titrated with thiosulfate.
The titration values obtained were as follows: 12.5, 13.1, 13.6, 14.4,
13.8, 138.8; average 13.5.
It is impossible to calculate the starch percentages from these data,
because no determinations of the values obtained by known amounts of
starch under similar conditions were made. The values in Table 1
can not be used because the precipitation was produced and the pre-
cipitate handled under a widely different procedure. Time to obtain
values for another set of starch standards was lacking.
At present the results of duplicates upon the same seed extracts are of
most interest, and the figures here reported indicate that this modifica-
tion gives promise of affording the basis for a satisfactory method. The
average deviation of the titration values from the mean is 0.5 cc., which
is less than 4 per cent of the mean.
{t was not realized until late in the course of the work that this modi-
fication could be made, and sufficient work upon it was not done. The
procedure here described could be improved and made more accurate
in the following way: The final addition of iodine and precipitation of
the starch should be carried out in a centrifuge bottle with a volumetric
graduation. After being made up to the mark and thoroughly shaken
occasionally after precipitation begins, the bottle should be centrifuged
and an aliquot drawn off the top for titration, the errors of filtration thus
being avoided. Known amounts of starch standards may be treated in
the same way and comparisons made.
The residual-iodine method is less convenient than the absorbed-
iodine method because of the extra work involved in re-precipitating
and centrifuging.
RESULTS OF DETERMINATIONS BY REDUCTION METHODS.
The results of the estimation of the starch in the starch-iodide pre-
cipitate by copper-reduction methods are shown in Table 7. Lot
No. M. S. represents a seed extract containing relatively large amounts
of starch, while Lot L. S. contained only small amounts of starch. Four
aliquots of 100 cc. each were taken from Lot M. S. and 6 aliyuots of
200 cc. each from Lot L. S. The starch in each was precipitated by
adding an excess of iodine and the precipitate obtained at the bottom of
the bottle by centrifuging. This precipitate was purified by repre-
1922] DENNY: ESTIMATION OF STARCH IN PLANT TISSUES 189
cipitation after the addition of water and iodine in order to remove
non-starch reducing substances.
TABLE 7.
Duplicate determinations by reduction methods.
TITRATION STARCH IN TITRATION STARCH IN
VALUES SEED POWDER VALUES SEED POWDER
ECON | | A NUR RTA MEDD ARN) |S aU NEO RO os
NO. NO.
Perman- Thio- ee Scales Perman- Thio- P velar Scales
ganate sulfate Method Method ganate sulfate Motho " Method
ce. cc. per cent per cent ce. ce. percent | per cent
M.S 5.0 14.9 1.16 PATO CRESS 1.2 3.3 0.14 0.13
M.S 4.4 15.6 1.02 1 fesidial | Fito 1.1 4.7 0.13 0.19
M.S 3.5 14.2 0.81 5S: 1.2 Ur 0.14 0.23
M.S 3.5 14.0 0.81 PTS HAWS: 1.2 5.4 0.14 0.22
LS. 15 eal 0.17 0.23
LaywS: Vid 4.5 0.13 0.18
Avge 4.1 14.7 0.95 1.19 1.2 4.9 0.12 0.20
Found by absorbed-iodine method 1.20 Found by absorbed-iodine method 0.28
The precipitate was collected in a 100 cc. volumetric flask and thio-
sulfate added to break up the starch-iodide and react with iodine. By
adjustment with iodine and thiosulfate, a point was reached at which
the liquid had an excess of neither. Concentrated hydrochloric acid
was added to make 2 per cent by weight and hydrolysis carried out for
3 hours on a boiling water bath. The acid was neutralized with sodium
hydroxide and a slight excess of sodium carbonate was added to pre-
cipitate the small amount of calcium present. The volume was adjusted
at 100 cc. and filtered. Aliquots of the filtrate were taken for copper
reduction.
From Table 7 it will be noted that two methods were employed: (1)
The ordinary Fehling’s solution was used for reduction, and the cuprous
oxide formed was titrated with standard potassium permanganate;
(2) Scales’ method modified by using 0.02N iodine and thiosulfate for
titration, 20 cc. of the sugar solution and 25 cc. of the reagent for re-
duction. The flame was adjusted to produce boiling in 44 minutes.
and the boiling continued for 3 minutes. This procedure was standard-
ized with pure dextrose.
Table 7 gives the results of the duplicate determinations upon the
same seed extract and the results of the absorbed-iodine method. The
expectation that this method would give less variable results than the
absorbed-iodine method was not supported by the data. The average
deviations are from 4 to 8 per cent of the mean, which is not an improve-
ment over the results by the absorbed-iodine method.
The estimations by the Scales method gave higher values than were
obtained by the permanganate method. The reason for this is not
190 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
known, but it is apparent that the Scales method is more sensitive than
the permanganate method. Thus the titration ranges between the two
lots of seed extracts were from 4.9 to 14.7 cc. with the Scales method,
and from 1.2 to 4.1 cc. by the other; furthermore, the end-point of the
titration with the Scales method is more distinct.
The percentage of starch in seed powder, calculated from the data
by reduction methods, is lower than that found by the absorbed-iodine
method. This may be explained as follows: (1) Not all the starch was
dissolved in calcium chloride and hence not enough dextrose was repre-
sented to account for the original starch; (2) some of the starch was
lost because part of the starch-iodine was carried away from the pre-
cipitate by suction; (8) some of the dextrose was destroyed by the
process of hydrolysis.
To obtain an estimate of the amount of starch which can be recovered
in this way, the following experiment was conducted: 0.2411 gram of
pure starch was dissolved in calcium chloride in the usual way and
carried through the procedure already described. The dextrose was then
estimated and from it the starch represented by that amount calcu-
lated'. This was 0.2161 gram, which is 89.6 per cent of the original
starch taken. If the percentage values in Table 7 are corrected on the
basis that the amount found is equivalent to 89.6 per cent of that origi-
nally present, the values for the permanganate method become respect-
ively, 1.06 and 0.14 per cent and the values by the Scales method
become 1.33 and 0.22 per cent.
In this connection it should be stated, however, that whether or not
all the starch was dissolved in calcium chloride is not a factor in the
absorbed-iodine method, inasmuch as the aliquots taken in the standard
determinations represented a certain proportion of the total starch
originally taken.
COMPARISONS OF THE THREE METHODS.
From the experience so far gained, it is believed that the absorbed-
iodine method is the most convenient as results are obtained by it in the
shortest time. The reduction method (using the Scales modification),
although tedious, gave promise of being improved to give greater sensi-
tivity, since the range from 0 to 1.0 per cent can be split up into more
distinct steps by means of it than by the others. The residual-iodine
method exhibits the possibility of being intermediate in both respects.
SUMMARY.
A starch method that would cover the range from 0 to about 1.0 per
cent starch by steps of about 0.1 per cent was needed. The methods
here described, applied to cantaloupe seed powders, fulfilled this con-
dition in a satisfactory manner.
1 Assoc. Official Agr. Chemists, Methods, 1920, 80.
1922] HOUSEMAN: ANALYSIS OF LICORICE ROOT AND LICORICE EXTRACT 191
The principal method used consisted essentially in dissolving the
starch in concentrated calcium chloride solution, precipitating the starch
under a standard set of conditions, titrating the iodine taken up by the
starch, and comparing the values thus obtained with those given by
known amounts of starch under the same conditions.
In other methods tried in a limited way, the starch was measured
not by the iodine absorbed, but by the residual iodine left after absorp-
tion, and the starch present in the starch iodide was estimated by copper
reduction methods after hydrolysis with acid.
Detailed descriptions of the methods are given, together with the
results obtained by their use under different conditions, and suggestions
as to their improvement and applicability to other kinds of tissue. For
the present it is recommended only for tissues containing small amounts
of starch.
ANALYSIS OF LICORICE ROOT AND LICORICE EXTRACT.
By Percy A. Houseman (Mac Andrews & Forbes Co., Camden, N. J.).
The analytical methods proposed for licorice root and extract have
the defects which frequently apply to the analysis of plants and plant
products—their incompleteness often prevents a correct judgment of
the quality of the material under examination.
Fairly satisfactory methods have been developed for glycyrrhizin,
sugars, starch and gummy matters, etc., but little has been done toward
developing quantitative determinations of the less desirable constitu-
ents of licorice root and extract. viz., the resins and bitter substances.
A licorice extract made from Oriental licorice root may easily contain
twice as much glycyrrhizin as one from Spanish root, and yet the for-
mer is of less desirable taste owing to the larger amount of bitter sub-
stances which it contains.
Interest has naturally centered around the sweet principle of licorice
root (glycyrrhizin), since this substance has not yet been found in com-
mercial quantity in any other plant, and it is chiefly responsible for the
characteristic taste of licorice.
In a very exhaustive article, Linz' has considered all the noteworthy
contributions to licorice analysis since the earliest ones of Pfaff and
others, which dated from about 1800. He subjected twenty-seven
methods for the determination of glycyrrhizin to experimental investiga-
tion and accepted only the method which was originally published by
the author of this paper.
Linz particularly condemns the method proposed by Tschirch and
Erikson, and in this the writer entirely agrees with him. Linz then
1 Arch. Pharm., 1916, 254: 65, 204.
192 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
passes on to the examination of licorice root and again accepts the
writer's method as the only satisfactory one for the determination of
glycyrrhizin in the root. He states: ‘““Houseman’s method seems to
give quantitative yields of the glycyrrhizic acid, with a ma degree of
purity of the latter’.
The writer, therefore, feels justified in publishing this paper as a
summary of his investigations on licorice root and extract, which have
been reported in a series of papers!, and in bringing them up to date
with the results of later experience. This is done in the hope of in-
ducing other workers to carry on analytical work on licorice, and es-
pecially to contribute methods for the assay of bitter principles in the
root and in the extract, for the separation of starch from gummy mat-
ters, ete:
ANALYSIS OF LICORICE ROOT.
The methods for moisture, total ash, ash insoluble in hydrochloric
acid (sand and dirt), crude fiber and sugars require no special comment,
being carried out according to the accepted methods of the A. O. A. C.*
Resins are determined by extraction with ether. Bitter substances are
extracted by cold absolute alcohol.
GLYCYRRHIZIN.
The licorice root is ground to pass a 20 or 30 mesh sieve, dried at low temperature
to moisture content of not more than 2% and the resins extracted from 3 grams of
powdered and dried root with ether. This may be done in the extraction apparatus
of the Joint Rubber Insulation Committee’ or in a 100 cc. centrifuge tube by stirring
three times for 15 minutes each with 75 cc. portions of ether. The two procedures
give identical results and the latter avoids the necessity of drying and washing a thimble.
The root from which the resins have been extracted is dried to remove ether and is
stirred in the 100 cc. centrifuge tube with 75 cc. of 75% (by volume) alcohol. The
75% alcohol remains on the root not less than three hours, preferably overnight. The
tube is then centrifuged for 5 minutes at 1500 R. P. M. The clear solution is poured
off into a flask, the sediment stirred up with a second portion of 75 cc. 75% alcohol,
centrifuged again, the liquor poured off and a third similar treatment given with 75%
alcohol. The combined three liquors are evaporated just to dryness from a steam
bath and the alcohol recovered. A vacuum is preferred towards the end. The resi-
due in the flask is dissolved in 10 cc. of hot water and the solution filtered through a
small filter paper into a centrifuge tube with a mark at 20 cc. The flask and filter
paper are washed and the volume made to the 20 cc. mark.
The filtrate is cooled to 15°C., and the glycyrrhizin is precipitated with 3 cc. of 10%
(by weight) sulfuric acid. The tube is allowed to stand in the ice-box overnight and
is then packed in cracked ice for half an hour. The tube is centrifuged for half a min-
ute, and the clear liquid is poured off. The precipitate is stirred up with 5 cc. of ice-
water saturated with ether, centrifuged again for half a minute, and the clear liquid
poured off. The sediment is again stirred up with 5 cc. of iced ether-water, centri-
fuged, and the clear liquid poured off as completely as possible. The tube is kept
1 Am. J. Pharm., 1912, 84: 531; 1916, 88: 97; 1921, 93: 481.
2 Assoc. Official Agr. Chemists, Methods, 1920.
aJ. Ind. Eng. Chem., 1914, 6: 75.
1922] HOUSEMAN: ANALYSIS OF LICORICE ROOT AND LICORICE EXTRACT 193
cold throughout the operation and all the glycyrrhizin is retained in the tube. Thirty
ec. of warm 95% alcohol are added to the washed glycyrrhizin in the tube. This solu-
tion is retained to be united later to the second precipitate of glycyrrhizin. To get
this, the liquor and two washings, obtained as above, are combined and neutralized
with ammonia, evaporated to about 5 cc., transferred to a centrifuge tube, made to
10 cc., cooled and precipitated with 2 cc. of 10% sulfuric acid. After standing in the
ice-box overnight, the tube is packed in ice for half an hour, centrifuged, and the clear
liquor poured off. The glycyrrhizin is stirred up with 5 cc. of iced ether-water, centri-
fuged half a minute, and the liquor poured off. A second washing with ice-cold ether-
water is given, using 3 cc. The precipitated glycyrrhizin is dissolved in 10 cc. of warm
95% alcohol. Both portions of dissolved glycyrrhizin are then filtered through a
70 mm. No. 40 Whatman paper into a weighed glass dish. A small amount of gummy
matter not soluble in 95% alcohol remains on the paper. The tubes and paper are
washed with warm 95% alcohol and the washings added to the dish. Two drops of
5% ammonia are added to neutralize any traces of sulfuric acid. The solution in the
dish is then evaporated to dryness and the glycyrrhizin weighed, after drying at 100°C.
overnight. When a more rapid method of analysis is desired, each portion of precipi-
tated glycyrrhizin may.be allowed to stand for 3 hours instead of overnight. The
difference in the result is hardly appreciable.
The glycyrrhizin weighed is fairly pure and there seems no practicable
method of purifying it further, at any rate for technical-analytical pur-
poses. The process of redissolving the glycyrrhizin in dilute ammonia
and reprecipitating with sulfuric acid does not achieve a very notable
increase in purity and is coupled with unavoidable losses. In the
method described above, it is considered that the losses due to solubility
of glycyrrhizin in ice-cold ether-water are about balanced by the im-
purities in the glycyrrhizin weighed.
TREATMENT OF LICORICE ROOT WITH SOLVENTS.
(t) Petroleum Ether extracts less than 1 per cent of a semisolid grease
of bitter taste and unpleasant odor. On long standing, needle-shaped
crystals, which are insoluble in ether and may be crystallized from warm
benzene or chloroform, are deposited. The crystals have not been
further examined.
(2) Chloroform. When a chloroform extract of licorice root is evap-
orated, a mixture of colorless crystals with a yellow fatty substance is
obtained. The latter is removed with ether, and the crystals are puri-
fied by crystallizing from chloroform. The yield of pure crystals was
0.1 per cent.
(3) Ether, used after petroleum-ether, removes from licorice root
from 1.5 to 5.0 per cent of resins; roots from Spain, Italy, Greece, Ana-
tolia and Mesopotamia yield the lower figures and those from Russia,
Syria and China the higher. No glycyrrhizin is removed by ether.
It is of interest to note that the resins are confined to the bark of the
root.
194 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
(4) Alcohol. Cold 95 per cent alcohol removes no glycyrrhizin from
licorice root, the glycyrrhizic acid being present as calcium and potas-
sium salts. After the resins are removed by ether, cold 95 per cent
alcohol yields about 8 to 11 per cent of extracts, consisting chiefly of
bitter principles, together with a small amount of sugars. The gly-
cyrrhizin may then be quantitatively removed by cold 75 per cent
by volume alcohol, but it is found advisable in practice to omit a pre-
liminary extraction with 95 per cent alcohol, because it does not seem
to lead to a purer glycyrrhizin, and has the disadvantage of leaving the
latter, when finally precipitated, in a granular form in which serious
losses during the subsequent washing with ice-cold ether-water can
hardly be avoided. The same objection applies to preliminary extrac-
tion with absolute alcohol (hot or cold), and to alcohol to which a small
quantity of ammonia has been added. The preliminary removal of
resins with ether does not have this objectionable feature and is de-
sirable. For these reasons the quantitative procedure already outlined
has been adopted.
The glycyrrhizin so prepared is of a light brown color, has an intensely
sweet taste and is evidently nearly pure. The amount usually varies
from 6 to 10 per cent of the root, Spanish and Italian roots giving the
lower figure and Oriental roots the higher. One sample of Anatolian
root examined showed no less than 13 per cent of glycyrrhizin. Most
of the figures published in the literature for glycyrrhizin in licorice root
are decidedly too low. The glycyrrhizin extracted by dilute alcohol,
after resins and bitter principles have been removed by ether and %5
per cent alcohol, forms a very satisfactory material from which to pre-
pare the pure, white glycyrrhizin described by Tschirch and Cederberg!
and Tschirch and Gauchmann?. It may be noted that no glycyrrhizin
is found in that part of the licorice plant which grows above the ground.
Saponin. A haemolytically active saponin occurs in the inner bark
of the root, but not in the outer bark, nor in the central part of the root.
The presence of a saponin may be shown by evaporating to dryness a
75 per cent alcohol extract of the root, treating the dry extract with
cold water, and testing in the regular way with sheep- or ox-blood.
Asparagin has also been found in licorice root in small quantity, as
well as a number of sugars.
Tannins. Tests with hide powder show that only a very small amount
of tannin is present in licorice root.
A yellow dye is present in the root which dyes silk a pale, but fast,
yellow. The root is percolated with hot water, the solution evaporated
to Hebe and the residue extracted with absolute alcohol. The alco-
1 Arch. Pharm., 1907., 245: 97.
2 Thid., 1908, 246: 545; 1909, 247: 121.
1922] HOUSEMAN: ANALYSIS OF LICORICE ROOT AND LICORICE EXTRACT 195
hol is evaporated and the dry extract treated with hot water. This
aqueous solution dyes silk yellow.
ANALYSIS OF LICORICE EXTRACT.
This analysis comprises moisture, ash, matters insoluble in cold water
and in hot water, starch and gums, glycyrrhizin and sugars.
Matters insoluble in cold water.
Two grams of the licorice mass are weighed into a small copper-gauze basket, which
is suspended in a 100 cc. centrifuge tube. The tube is nearly filled with cold water,
and when the paste is completely disintegrated (after about 18 hours) the basket is
agitated, washed and removed. The contents of the tube are whirled in an electrical
centrifuge for 10 minutes at about 1500 R.P.M. The clear liquor is poured off, and
the sediment stirred up with fresh water and whirled in the centrifuge for a further
10 minutes. The liquor is again discarded, and the sediment is washed into a weighed
glass dish and evaporated. The residue, dried in an oven at 100-105°C. for 24 hours,
is weighed.
The proportion of water-insoluble material increases markedly with the
age of a licorice paste containing 25 percent moisture. Asampleshowing,
say, 5 per cent when freshly made, is likely to give double that figure
when a month or two old, due to deposition of insoluble starch. This
increase is much smaller on a licorice mass containing less than 20 per
cent moisture.
Matters insoluble in hot water.
Two grams of licorice mass are placed in a 150 cc. beaker, boiled for 5 minutes with
80 cc. of water and the solution transferred to a 100 cc. centrifuge tube. The tube
and contents are centrifuged for 10 minutes at 1500 R.P.M., the liquor poured away,
and the sediment washed into the beaker and boiled 5 minutes with 80 cc. of water.
The centrifuging is repeated, the liquor discarded again and the sediment washed into
a weighed glass dish, evaporated, dried and weighed.
STARCH, GUMS AND GLYCYRRHIZIN.
The procedure for glycyrrhizin follows closely that given for root, but
since most of the resins are left in the spent root in the process of manu-
facture, it is not necessary to extract with ether, as is done in the determi-
nation of glycyrrhizin in licorice root.
Two grams of licorice extract in a 100 cc. centrifuge tube are allowed to stand over-
night with 15 cc. of water at room temperature. The mass is then stirred until com-
pletely disintegrated; 15 cc. of 75% (by volume) alcohol and 53 cc. of 95% alcohol are
added from a buret with stirring, to precipitate the starch and gums. This gives a
mixture containing 75% (by volume) alcohol when the licorice extract contains 25%
moisture. After standing not less than 3 hours, the tube is centrifuged for 5 minutes
at a speed of about 1500 R.P.M. The clear solution is poured off into a flask, the
sediment is stirred up with 75 cc. of 75% (by volume) alcohol, centrifuged again and
the clear solution is poured off. The sediment is stirred up a second time with 75 cc.
of 75% alcohol, centrifuged, and the solution is again poured off. The precipitated
starch and gums are washed into a tared dish, dried and weighed. The combined
196 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 2
three liquors are then treated in the same manner as those from licorice root, except
that in precipitating the first (main) fraction of glycyrrhizin, the aqueous solution is
made up to 30 cc. instead of 20 cc.
A weaker alcohol than 75 per cent should not be used, as some starch
and gums then escape precipitation. A stronger alcohol should also
not be used, as it has been found that 80 per cent alcohol actually pre-
cipitates a little glycyrrhizin with the starch and gums in some cases.
It is more important to obtain all the glycyrrhizin even at the expense
of a slightly low figure for starch and gums, than to obtain all the starch
and gums at the expense of a slightly low figure for glycyrrhizin.
A comparison of the glycyrrhizin content of root with that of the
commercial extract made therefrom shows clearly that considerable
decomposition of glycyrrhizin occurs in the treatment of licorice root
with boiling water.
P. Bertold! claims that the glycyrrhizin in licorice extract was reduced
from 19.22 per cent to 12.03 per cent when “ordinary” water was used
to extract the root instead of distilled water. This claim for the harmful
effect of hard water seemed so extravagant that his results were checked,
using distilled water, Camden (N. J.) city water, and artificially har-
dened water, the latter being saturated with calcium and magnesium
carbonates and with calcium sulfate, while carbonic acid gas was bub-
bled in.
All the results were calculated to the basis of 25 per cent moisture in
the licorice extract and were as follows:
Per Cent
Glycyrrhizin in Extract
Root extracted with distilled water.................00 ese eye ecee 20.4
“a *s “ie Gamden' city water ser >. 2%. Sess pene e . tees 19.8
ss s ‘“* artificially hardened water.................-. 19.5
These results show that within experimental error there is practically
no loss of glycyrrhizin when “ordinary” water, instead of distilled water,
is used to extract licorice root.
SUGARS.
Sugars are determined in a portion of the original licorice mass, using
normal lead acetate and following the official method of the A.O.A.C.?
SUMMARY.
Analytical methods are given for licorice root and extract, with fur-
ther remarks on various constituents extracted by solvents and not
determined quantitatively.
1 Giorn. chim. ind. applicata, 1921, 3: 490; Chem. Absir., 1922, 16: 2573.
2 Assoc. Official Agr. Chemists, Methods, 1920, 73.
1922] NOYES: VARIATIONS IN CONCORD GRAPE DURING RIPENING 197
VARIATIONS IN THE CONCORD GRAPE DURING
RIPENING.
By H. A. Noyes, H. T. Kine and J. H. Marrtsotr! (Mellon Institute of
Industrial Research, Pittsburgh, Pa.).
A leading grape juice concern makes routine determinations of sugar
in the Concord grape as it ripens. These analyses, previous to 1920,
were stopped as soon as factory pressing of grapes commenced. In
only a few instances were samples taken from the same vineyard; there-
fore no predictions could be made from the incomplete data as to how
grapes would ripen in an off year or what their composition would be
the latter part of the pressing season.
The work reported in this paper is a part of that undertaken to find
out how to manufacture a more uniform Concord grape juice. The
literature on the changes in composition of the Concord grape shows that
the analytical results obtained in the laboratory are more uniform than
those obtained in factory practice. The figures given are practically
a complete record of analyses where daily changes were made in factory
operation to give the best juice. As the analyses during 1919 showed
no regularity additional data were procured in the two following years
under different conditions of growth and maturity. Since temperature
changes in the factory process are necessary as the pressing season
advances, the relative differences in the same sample of grapes when
analyzed entire, pressed out cold or pressed out hot give data on the
changes in composition during ripening as well as a basis for adjusting
factory operations with fruit in different degrees of maturity.
The season of 1920 was wet and cool, and many growers in the Chau-
tauqua and Erie grape belt were of the opinion that grapes would not
reach a satisfactory sugar content for the manufacture of grape juice.
A study of the factory records for previous years showed that grapes
had not appreciably increased in sugar content after the first of Octo-
ber. Results of analyses of the Concord grape at different stages of
ripening have been reported by W. B. Alwood! and the following col-
laborators of the United States Department of Agriculture: B. G. Hart-
mann, L. M. Tolman, J. R. Eoff, M. J. Ingle, S. F. Sherwood, J. O.
Carrero and T. S. Harding. The figures obtained by these workers
were more uniform than those obtained by analyzing daily samples of
grape juice during a factory pressing season but were from scattered
vineyards and covered irregular intervals of time.
To get detailed information as a basis for future work, two vineyards
were selected in the town of Westfield, New York, for the taking of
1 Based on a paper parca iiefore the Division of Agricultural and Food Chemistry at the meeting
held in wisbey ie N. Y., April,
Lars Lae Chem. Balle Piao: , Gail); 145: (1911). U.S. Dept. Agr. Bulls. 335: (1916); 452: (1916);
91
198 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
special sets of grape samples from the time the grapes began to show
color until the harvest was completed. Both vineyards were mature;
one had received good care during the seasons of 1919 and 1920, had a
high yield and was in good balance of fertility, while the other had had
average care and bore a representative (average) crop for 1920.
A certain part of each vineyard was set apart for sampling, and no
grapes were harvested, from these sections until after all the season’s
samples were taken. Three times a week—Monday, Wednesday and
Friday mornings—samples were obtained. A series of vines where the
fruit appeared to be in an average state of ripeness for that date was
chosen. From eight to ten pounds of grapes were picked and brought
to the laboratory. Analyses were started immediately and the results
reported are averages for both vineyards.
EXPERIMENTAL WORK.
In 1919 grapes were of uniformly high quality throughout the grape
belt and a large number of factory experiments were started with the
idea of improving commercial grape juice by employing new methods of
processing. As checks on this work several five-gallon samples of each
TABLE 1.
Analyses of factory-run grape juice, 1919.
DATE SDOABa ACIDS AS TANNING AND
TARTARIC COLORING MATTER
1919 per cent per cent per cent
1 a pete ies ie 16.09 0.975 0.303
GAZR IAG. ek5 15.99 1.045 0.352
9-27 16.56 1.062 0.332
Qe ao icin hme 16.74 0.984 0.418
9230. 2:45 70h: 16.45 1.002 0.311
1 {1 Me ae 16.70 0.946 0.364
1d) Seconded erent 16.75 0.937 0.344
LOSSES. HE 16.81 0.951 0.315
LO 4 es. 5 eee 17.14 1.011 0.325
1 oe rae 16.69 0.892 0.299
1QSR Ft. SE 17.00 0.886 0.344
(Uo eee may eee 16.49 0.901 0.303
RUS J si Sortitty 17.38 0.886 0.323
TOFIOF GER 17.02 0.892 0.303
1QSL ese 16.62 0.920 0.354
LOST Aa ee 17.21 0.886 0.336
TOE14.. ae 15.77 0.897 0.342
ROB ict) eudua ot: 16.82 0.879 0.375
HOSTOR ease ie 16.94 0.883 0.321
10-PA ES VAG 0.849 0.317
TORS ee es 17.60 0.812 0.313
1100 Basie i 16.24 0.821 0.297
Average..... 16.73 0.923 0.331
[itd rehab ra aes 17.60 1.062 0.418
Lowes. 15:77 0.812 0.299
Variation. ... 1.83 0.250 0.119
1922] NOYES: VARIATIONS IN CONCORD GRAPE DURING RIPENING 199
day’s regular factory production of grape juice were set aside for observa-
tion. The results of tests made on these samples are shown in Table 1.
Table 1 shows that there is no regular systematic change in the com-
position of grape juice pressed at different times during a regular factory
pressing season of approximately twenty days. This may be surprising
to some since it might be expected that the grapes would get uniformly
sweeter or uniformly less acid each day as the season progressed.
The general tendency is for sugars to increase and for acids to de-
crease when the grapes are left on the vines. Tannin and coloring matter
are problems for future study, but it is certain that the substances
affecting these determinations are not uniform throughout the season.
For example, if tannin formation and liberation is proceeding one way,
if a certain class of coloring matter is proceeding another way, and if
these two are associated in any way with sugar and bitartrate formation,
irregular results will follow.
In 1920 investigations were undertaken from three different angles,
as follows: 1, That of the whole fruit; 2, the cold-press juice; 3, the hot-
press juice. The determinations made on the whole fruit were average
weight of the individual berry, moisture content and sugar content.
Both the hot and cold juices were analyzed for total acids, tannin and
coloring matter, and sugar. Records were made of Brix readings and
those other regular determinations which are usually either made or
calculated.
METHODS OF PROCEDURE.
Whole grapes—The average weight per berry was determined by
weighing 100 berries immediately after picking from the stems. Mois-
ture was determined by weighing 10 average berries on an analytical
balance, crushing them in a tared container and drying at 100°C. to
constant weight. Sugar was determined by the reduction method'.
Preparation of juice-—Two lots of stemmed grapes were macerated.
One lot was pressed at room temperature and the juice was known as
cold-press; the other lot was heated for five minutes at 145°F. before
pressing. This was known as the hot-press juice. In 1920 all pressing
was done by hand?, and the results secured by previous workers’ led to
the belief that a representative juice was obtained. In 1921 a small
hand press was used. After being brought to room temperature the
juice samples were analyzed for sugar, total acids, and tannin and
coloring matter, using the regular official methods’.
Table 2 shows that—
(1) There was no great variation in the weight of the berry as ripen-
ing advanced.
+ Assoc. Official Agr. Chemists, Methods, 1920, 155.
2U.S. Bur. Chem. Bull. 145 hg 1h)
3 Univ. Calif. Pub., 1918, 3:
4 Assoc. Official Agr. Chek, Ficthods, 1920, 153.
200 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
TABLE 2.
Analyses of grapes and cold- and hot-press juice on different dates, 1920.
GRAPES COLD-PRESS JUICE HOT-PRESS JUICE
Tannin Tannin
isture| Sugar | Sugar | Acid and Acid and
Moen use 2 Coloring Coloring
Matter Matter
per cent | per cent | per cent | per cent | per cent | per cent | per cent | per cent
85.82 7.89 9.22 1.89 | 0.043
84.32 7.72 9.52 1.66 | 0.027
84.03 9.10 | 10.51 1.43 | 0.066
83.86 | 10.61 | 11.99 | 1.30 | 0.041 | 12.09 | 1.53 | 0.208
84.70 9.57 | 11.77 | 1.40 | 0.039 | 11.70 | 1.81 | 0.164
82.04 | 1334 | 13.44 | 1.35 | 0.063 | 13.12 | 1.61 | 0.176
82.42 | 12.90 | 13.20 | 1.37 | 0.062 | 13.25 | 1.55 | 0.144
83.05 | 11.10 | 12.99 | 1.18 | 0.038 | 13.14 | 1.44 | 0.158
84.44 | 10.69 | 12.94 | 1.00 | 0.039 | 12.97 | 1.29 | 0.141
83.37 | 10.97 | 13.44 | 1.09 | 0.053 | 13.49 1.33 | 0.149
82.03 | 13.25 | 13.40 | 1.10 | 0.033 | 15.21 1.37 | 0.116
81.70 | 12.59 | 14.02 | 0.95 | 0.044 | 14.25 1.31 | 0.169
82.53 | 12.81 | 13.15 | 1.03 | 0.047 | 13.94 | 1.30 | 0.150
81.51 | 12.94 | 14.82 | 1.02 | 0.061 | 14.47 | 1.22 | 0.141
81.53 | 13.40 | 15.06 | 0.98 | 0.064 | 15.09 | 1.21 | 0.207
81.30 | 12.82 | 16.00 | 0.92 | 0.043 | 16.52 | 1.17 | 0.190
82.24 | 12.41 | 15.62 | 0.88 | 0.062 | 16.48 | 1.00 | 0.103
(2) The moisture content of the grapes decreased somewhat as the
season advanced but was not directly proportional to the increase in
the sugar content.
(3) The sugar content of the grapes increased, in general, as the
ripening period advanced. After ripening had reached a certain point
the changes in sugar content were irregular.
(4) The juices pressed out from grapes by both the cold and hot
processes showed increases in sugar and decreases in acid as ripening
continued.
(5) Tannin and coloring matter were irregular in both the cold- and
hot-press juice but ran much higher in the hot-press.
The effects of season are readily apparent as we compare Tables 2
and 3. The ripening commenced almost a month earlier in 1921 than
it did in 1920.
The following outstanding points are brought out in Table 3:
(1) As in 1920 no large variation in the weight of berry was found
but a tendency towards increase in weight as the season advanced was
noted. The individual grape berry for 1921 was lighter than in 1920.
(2) Moisture content of the grapes decreased as ripening progressed
but, as in 1920, increases in sugar content were larger than the moisture
decrease.
1922] NOYES: VARIATIONS IN CONCORD GRAPE DURING RIPENING 201
(3) Cold- and hot-press juices gave increased sugar content and
decreased acid content as ripening proceeded. This is similar to the
results of 1920 but the changes in acid in 1921 were greater.
(4) Tannin and coloring matter determinations were irregular. The
differences in the tannin and coloring matter content of the cold-press
juice for the two years do not appear significant. The tannin and color-
ing matter of the hot-press juice of 1921 was higher than that of 1920.
TABLE 3.
Analyses of grapes and cold- and hot-press juice on different dates, 1921.
GRAPES COLD-PRESS JUICE HOT-PRESS JUICE
TR Weight Tannin Tannin
of Moisture| Sugar Sugar Acid Gelerine Sugar Acid Gain
Berry Matter Matter
1924 grams per cent | percent | percent | percent | percent | perceni | percent | per cent
as Y Aaa 2.33 | 86.69 5.59 6.77 2.58 | 0.055 6.81 2.87 | 0.142
8-19..... 2.44 | 86.45 5.80 7.94 2.23 | 0.062 7.91 2.50 | 0.164
8-22.....| 2.38 | 85.89 5.58 9.16 2.00 | 0.073 9.34 2.24 | 0.254
8-24..... 2.35 | 85.81 6.25 9.45 1.88 | 0.081 9.09 2.36 | 0.263
8-26..... 2.34 | 83.22 8.03 lost 1.66 | 0.049 lost 1.94 | 0.251
8-29.....| 2.47 |~82.43 9.81 | 12.34 1.33 | 0.103 | 11.94 1.77 |} 0.303
8-31..... 2.42 81.12 8.39 | 12.68 121 0.042 | 12.24 1.69 0.214
G28 . ek 201 82.22 8.12 | 13.96 0.95 | 0.045 | 13.23 1.438 | 0.207
9-5....... 2.62 | 83.46 6.04 | 15.00 0.91 0.045 | 14.14 SZ aim 259
lS dace eee 2.80 | 83.80 | 10.58 | 13.96 0.77 | 0.031 | 13.16 1.23 | 0.279
SOs. 2.66 | 82.15 | 12.19 | 16.25 0.68 | 0.039 | 15.50 1.18 | 0.267
US Oe 2.80 |. 81.20 | .12.21,| 16.38 0.75 0.054 | 16.87 1.19 | 0.370
Q9-14..... 2.81 81.08 | 13.26 | 16.10 0.71 0.044 | 15.64 1.15 | 0.236
BIG), 65:3 2.87 | 82.40 | 12.36 | 16.82 0.62 | 0.032 | 14.78 1.02 | 0.250
DISCUSSION.
The object of the work reported in this paper was to get some funda-
mental information that might be applied to the commercial manu-
facture of grape juice. It is well known that the manufacturer of a
synthetic beverage can make a more uniform product than the pure
fruit manufacturer. The great differences in size of crop, quality of
fruit and character of fruit juice that may be directly attributed to
seasonal conditions are worthy of study. As it was thought that certain
cultural practices and fertilizer treatments might possibly overcome
the seasonal variations in part, an effort was made to ascertain what the
differences are under supposedly good vineyard conditions. The work
will be continued and the results compared with those obtained with
grapes that have been grown under special vineyard conditions.
The laboratory records of the largest grape juice manufacturer in
America show that the average number of harvesting days for a year’s
grape crop is between twenty and twenty-five. From 1904 to 1920, the
recorded dates on which grapes were first considered ready for com-
202 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
mercial pressing of juice show that the earliest date was September 22
and the latest October 15. Records obtained by investigators of the
United States Department of Agriculture and from the company’s
control laboratory show that grapes from different sections of the country
vary in the proportions of acid to sugar present as well as in the total
amounts of these two constituents so important in commercial grape
juice.
The authors’ observations are that the weight of the individual berry
is not of great significance. In a good season certain vineyards will be
found with smaller berries that are equally as sweet as the larger grapes.
The generalization seems to be that the vineyard with a “high product-
ivity balance”’ yields berries of larger unit weight.
Gore! reports the presence of small amounts of sucrose in the Concord
grape. These determinations were made by the polarization method and
no sucrose was obtained in the same samples by the reduction method.
Work by the authors of this article and the results reported by Alwood?
failed to show the presence of sucrose in the Concord grape. The
work of Martinand’ shows that an inverting enzyme, sucrase, occurs
in all parts of the vine, fruit, leaves, stalks and roots. He concludes
that this enzyme occurs in grape must in sufficient quantity to invert
sucrose. The authors do not know the exact temperature at which
this enzyme is killed but take the work of Martinand to show that fresh
grape juice should not contain any sucrose. Hartmann and Tolman‘
make the following statement: ‘““A pure Concord grape juice has not
been found to contain sucrose’.
A number of United States Department of Agriculture investigators
say that “with certain reservations, sugar should increase and acid
diminish as long as the leaves function properly. This, however, is not
always the case, for as soon as the pedicels—the small stems which
carry the berries—begin to wither, the fruit is gradually cut off from
further influence of the growth processes taking place in the plant, and
its sugar content may remain fairly constant for some time. It may
appear to increase by reason of evaporation of water from the berries,
or in certain cases may seem to be reduced by changes induced by the
respiratory processes of the fruit’®. It was observed by the authors
during 1920-21 that the sugar content increased as the ripening period
advanced but when considered from date to date the changes in sugar
composition were not regular. Observations on the weather during the
period of ripening led to the conclusion that cold cloudy days retarded
sugar formation, while warm sunny days accompanied by cool nights
1 J. Ind. Eng. Chem., 1909, 7: 436.
2U.S. Bur. Chem. Bull., 145: (1911).
3 Compt. rend., 1907, 144: 1376.
4U.S. Dept. ‘Agr. Bull., 656: (1918).
5 U.S. Bur. Chem. Bull. 140: (1911); U. S. Dept. Agr. Bull. 335: (1916).
1922] NOYES: VARIATIONS IN CONCORD GRAPE DURING RIPENING 203
seemed to be most favorable to the development of sugar. The con-
clusion of the Department of Agriculture workers quoted is confirmatory
evidence both of the results obtained in this work and of the statement
that sugar formation is associated with weather conditions that have
an influence on the photosynthesis of the plant.
The work of Alwood and his collaborators, of Brunet! and that re-
ported in this paper all agree that sugars increase as ripening progresses
and that acids decrease during the same period. From a study of the
work of different investigators it may be concluded that the decrease
in acid is inversely proportional to the increase in sugar. This is cor-
roborated by the data reported in Tables 2 and 3 and shown in Graphs
1 and 2, although less intervals of time were covered between samplings
than other investigators used. Processes which have not been investi-
gated may accompany the changes in acid and sugar content of ripening
grapes.
Hot Press —
/é Goviprecs) === =
| vA 4
3 pf ms
b
f :
a= 1921 Paes r st.
/ as
/ wt 19z0
;
Flua a Sept “
TEE Ed Se ai AEE I |
GRAPE JUICE.
No attempt will be made to explain the ups and downs in tannin and
coloring matter determinations, Graph 3. Rosenstiehl? reports that the
coloring matter of unfermented must is soluble but that air renders it
insoluble. The extent to which air penetrates the ripe grape and ren-
ders coloring matter insoluble has not been studied by the authors of
1 Rev. Vit., 1912, 37: 15.
2 Boll. chim.-farm., 1914, 53: 740; Chem. Absir., 1916, 10: 2023.
204 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
this paper. Hot-press juice in 1921 gave a much higher tannin and
coloring matter determination than cold-press juice, which might be
interpreted as showing that heat has something to do with making
Hot Press
Cold’ Press --==--
1920
22 Avg. 4 Ss Sept iB 16. 20 ar i oer aee
FIG. 2—VARIATIONS IN ACID CONTENT OF HOT- AND COLD-PRESS
GRAPE JUICE.
eee
t |
Hot Fress
ColdPress ----—
FIG. 3—VARIATIONS IN TANNIN AND COLORING MATTER OF HOT-
AND COLD-PRESS GRAPE JUICE.
1922] CLEMENS: DETERMINATION OF CRUDE FIBER IN MUSTARD 205
coloring matter soluble even after it has been thrown out of solution
by the action of air.
SUMMARY.
(1) Ripening Concord grapes vary greatly in composition. This
variation can not be correlated with season and date of harvesting.
(2) The weight of the individual berry remains fairly constant during
ripening although it tends to increase slightly.
(3) The sugar content of the Concord grape and grape juice increases
as ripening advances.
(4) The acid content of Concord grape juice decreases as ripening
advances.
(5) Changes in the acid and sugar content of the Concord grape and
grape juice are not regular from harvesting date to harvesting date.
(6) The tannin and coloring matter content of Concord grape juice
is very irregular.
(7) Hot pressing increases the tannin and coloring matter content of
Concord grape juice.
THE DETERMINATION OF CRUDE FIBER IN PREPARED
MUSTARD}.
By C. A. CLtemens (South Dakota Food and Drug Department Labora-
tories, Vermilion, S. D.).
In food regulatory work the advantage of any doubt is always given
to the manufacturer of an article. Consequently, while examining
several samples of prepared mustard, it seemed advisable to take into
consideration the statement made by M. C. Albrech? in regard to crude
fiber determination, that “samples of prepared mustard which contained
little oil gave better results than samples which contained a larger amount,
showing clearly that the oil interferes with the method, and gives results
much too high”; and further that, “it has been shown that the official
method for the determination of crude fiber in prepared mustard is
fundamentally defective, giving high results because the oil is not ex-
tracted before treatment with acid, as in the usual method’. The
evidence submitted in support of these statements is meager and
apparently all the examples given are on samples of the same, or nearly
the same, composition. In view of this fact, the official method could
not be discarded without further investigation and therefore the work
presented in this paper was undertaken.
1 This report is an abstract of a — --Biritoniete in partial fulfilment of the requirments for the degree
of Master of Arts, University of South D
2 J. Ind. Eng. Chem., 1920; 12: 1175.
206 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
A summary of the analytical data on the thirty-two commercial
samples of prepared mustard which were used in this investigation is
given in Table 1. The methods used were those of the Association of
Official Agricultural Chemists!.
TABLE 1.
Analytical data on 32 samples of prepared mustard.
ON SAMPLES AS RECEIVED
Maximum Minimum | Average
per cent per cent per cent
SOUGS@ +... coke eee 25.95 11.63 17.02
Age} So seca te Eo cece woe 5.40 2.54 3.72
Salty, scan oot eben 4.35 1.40 2.90
Acidity. aie: Sth nOx Ee 4.51 2.36 3.19
Hitheriextract 3 20.5: ess 1.35 4.27
Provence tho eee 5.83 1.25 3.50
Carbohydrates........ 3.51 1.74 2.25
GCrudesiberssee eee ee 1.75 0.60 1.23
Moisture-salt-fat-free-basis.
RSE ric Mcrae ena 8.1 4.4 6.1
Profan oo eos 44.9 18.3 33.5
Carbohydrates........ 35.7 16.6 22.7
Grude-tibér me occ 21.2 5.0 12.6
Moisture-salt-free-basis.
Ether extract......... | 37.5 | 14.0 | 28.1
Moisture-fat-free-basis.
PN as irae Lear is | 42.7 | 11.6 | 28.4
Difficulties were immediately encountered when the Albrech method
was tried. When treated with hot water the mustard formed a col-
loidal-like solution which was slow in filtering, and when filtered, packed
on the filter paper in such a manner that it could seldom be removed
without considerable loss of mustard or the removal of a portion of the
filter paper along with the mustard.
The object of the treatment suggested by Albrech is the removal of
the oil from the prepared mustard before the determination of crude
fiber. His procedure can be modified in such a manner as to avoid the
difficulties just mentioned and at the same time accomplish the removal
of the oil from the mustard. The procedure found most satisfactory is
as follows:
1 Assoc. Official Agr. Chemists, Methods, 1920, 261.
1922] CLEMENS: DETERMINATION OF CRUDE FIBER IN MUSTARD 207
Weigh out 10 grams of prepared mustard into a small beaker and macerate thoroughly
with 95% alcohol. Wash the mustard by means of a stream of 95% alcohol onto a
12.5 cm. filter paper of firm texture but not hardened, to which suction is applied, the
tip of the filter paper being protected by a platinum cone. Wash the mustard two or
three times with ether and transfer the filter paper containing the mustard to a John-
son or similar fat extractor and extract with ether for not less than 1 hour. Remove
and transfer the main bulk of the mustard to the digestion beaker, break up somewhat
and drive off the ether by gentle heating. A steam radiator was found convenient for
this purpose. The papers containing the remainder of the mustard are also allowed
to dry, after which the mustard is easily washed off into the beaker by means of a
stream of 1.25% sulfuric acid. The mustard is now treated as in the off.cial method.
This method was tried out on thirty-two different samples of prepared
mustard. In nearly every case a lower result than that given by the
A. O. A. C. method was obtained. However, there was no correlation
between the fat content of the samples and the differences between the
crude fiber determinations by the two methods. This is readily shown
by Table 2.
TABLE 2.
Comparison of the resulis by the A. O. A. C. method and the proposed method.
CRUDE FIBER
NUMBER Me eae S|) DIFFERENCE FAT SALT SOLIDS
A.O. A.C. Proposed
Method Method
per ceni per cent per cent per cent per cent per cent
21-143 1.62 1.38 —0.24 3.82 1.82 14.69
21-144 1.03 0.91 —0.12 ifweB: 2.83 23.05
21-145 1.67 0.93 —0.74 4.18 2.94 16.34
21-148 1.46 1.54 +0.08 3.50 3.37 17.25
21-149 1.03 0.92 —0.11 6.05 2.35 18.75
21-159 1.16 1.12 —0.04 5.61 2.20 19.35
21-167 1.75 1.12 —0.63 2.41 3.56 14.90
21-168 1.58 1.25 —0.33 1.37 2.38 12.17
21-169 1.48 1.15 —0.33 6.56 1.40 21.88
21-170 1.27 1.05 —0.22 3.90 2.90 18.09
21-172 1.50 1.42 —0.08 4.16 4.35 20.24
21-173 1.38 1.23 —0.15 4.43 3.15 17.23
21-174 1.44 1.26 —0.18 1.35 4.00 12.14
21-175 1.51 0.95 —0.56 4.12 3.47 17.31
21-181 1.06 0.91 —0.15 3.78 3.34 16.45
21-183 ayy 1.14 —0.43 ThPAS 1.76 21.38
21-185 1.29 0.79 —0.50 4.47 3.20 17.59
21-186 1.63 1.08 —0.55 3.38 2.96 14.76
21-224 1.10 0.86 —0.24 6.78 4.08 22.16
21-225 0.98 1.00 +0.02 1.37 3.42 11.26
21-230 1.58 1.00 —0.58 4.91 2.49 17.42
21-231 1.06 0.94 —0.12 1.67 3.39 11.63
21-232 1.27 1.02 —0.25 3.12 213 14.63
21-235 1.48 1.21 —0.27 7.04 4.20 25.95
21-239 1.19 0.74 —0.45 3.03 3.07 14.72
21-246 0.97 0.69 —0.28 3.04 2.91 14.29
21-249 0.60 0.55 +0.25 7.04 2.98 21.92
21-250 0.87 0.82 —0.05 5.93 2-51 20.10
21-251 0.90 0.84 —0.06 6.22 3.47 20.61
21-252 0.88 0.65 —0.23 5.64 2.88 19.74
21-253 1.16 1.18 +0.02 3.36 Pp 16.48
208 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 2
Inasmuch as materials other than fat are removed by both the Albrech
method and the method proposed in this paper, it is not obvious that
fat is the interfering agent but rather, it would seem, that several other
factors enter in, such as acetic acid, salt and water.
Known amounts of mustard oil were added to several samples and
the effect on the crude fiber determined. The results showed that the
crude fiber generally increased with the increase in fat content in any
one sample, but that the rate of increase was different in different samples.
SUMMARY.
A preliminary treatment for prepared mustard to be used in the crude
fiber determination has been proposed.
A comparison has been made of the results obtained when the A. O.
A. C. method for crude fiber has been used with and without the pro-
posed preliminary treatment.
It has been shown that there is no correlation between the fat content
of the samples and the differences between the crude fiber determinations
obtained by the two procedures, and it is probable that fat is not the
sole interfering agent in the A. O. A. C. method as applied to untreated
prepared mustard.
PROCEEDINGS OF THE THIRTY-EIGHTH ANNUAL
CONVENTION OF THE ASSOCIATION OF
OFFICIAL AGRICULTURAL
CHEMISTS, 1922.
The thirty-eighth annual convention of the Association of Official
Agricultural Chemists was held at the Raleigh Hotel, Washington,
D. C., November 15-17, 1922.
The meeting was called to order by the President, F. P. Veitch of
Washington, D. C., on the morning of November 15, 1922, at 10 o’clock.
OFFICERS, COMMITTEES, REFEREES, AND ASSOCIATE REF-
EREES OF THE ASSOCIATION OF OFFICIAL AGRI-
CULTURAL CHEMISTS, FOR THE YEAR
ENDING NOVEMBER, 1923.
Honorary President.
H. W. Wirtey, Woodward Building, Washington, D. C.
President.
A. J. Parren, Agricultural Experiment Station, E. Lansing, Mich.
Vice-President.
R. E. Dooxrrrie, Transportation Building, Chicago, IIl.
Secrelary-Treasurer.
W. W. Skinner, Bureau of Chemistry, Washington, D. C.
Additional Members of the Executive Committee.
E. M. Baitey, New Haven, Conn.
P. B. DunBar, Washington, D. C.
209
210 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 3
PERMANENT COMMITTEES.
Committee to Cooperate with Other Committees on Food Definitions.
Jutrus Hortvet (State Dairy and Food Commission, St. Paul, Minn.), Chairman.
C. D. Howarp, Concord, N. H.
E. M. Bartey, New Haven, Conn.
Committee to Cooperate in Revision of the U. S. Pharmacopeia.
L. F. Keser (Bureau of Chemistry, Washington, D. C.), Chairman.
H. C. Lythgoe, Boston, Mass. A. R. Bliss, Emory University, Ga.
H. C. Fuller, Washington, D. C. W.S. Hubbard, New York, N. Y.
Recommendations of Referees.
(Figures in parenthesis refer to year in which appointment expires.)
R. E. DoourrrLe (Transportation Building, Chicago, Lll.), Chairman.
SuBCOMMITTEE A: W. H. MaclIntire (1924), (University of Tennessee, Knoxville,
Tenn.), Chairman; B. B. Ross (1926); J. W. Kellogg (1928). [Water, tanning
materials and leather, insecticides and fungicides, soils (sulfur in soils), determi-
nation of active acidity in agricultural products, foods and feeding stuffs (crude
fiber, stock feed adulteration, determination of starch in linseed meal and other
products), saccharine products (honey, maple products, maltose products, sugar-
house products), fertilizers (borax in fertilizers, preparation of ammonium citrate,
nitrogen, potash), inorganic plant constituents (sulfur and phosphorus in seeds
of plants, calcium, magnesium, iron and aluminium in ash of plants).]
SuBcomMITTEE B: E. M. Bailey (1924), (Agricultural Experiment Station, New Haven,
Conn.), Chairman; H. C. Lythgoe (1926); A. G. Murray (1928). [Spices, limit
of accuracy in the determination of alcohol, testing of chemical reagents, drugs
(examination of arsphenamine and neoarsphenamine, turpentine, crude drugs,
alkaloids, methods for the separation of cinchona alkaloids, laxative and bitter
tonic drugs, the analysis of acetylsalicylic acid, methods for the examination of
phenolphthalein, methods for the examination of procaine, methods for the exami-
nation of methylene blue, methods for the examination of pyramidon, atophan,
chloramine products, determination of camphor in pills and tablets by the alcohol
distillation method, determination of alcohol in drug preparations, determination
of chloroform in drug preparations, analytical methods for the determination of
silver in silver proteinates, determination of mercurous chloride, mercuric chloride
and mercuric iodide in tablets, methods for the determination of monobromated
camphor, methods for the examination of barnitaln (Veronal), methods for the
determination of moisture in crude drugs, methods for the examination of benzyl
benzoate, and methods for the examination of chaulmoogra oil).]
SuspcomMitrEE C: W. C. Geagley (1924), (State Food and Drug Department, Lan-
sing, Mich.), Chairman; R. E. Doolittle (1926); C. F. Whitney (1928). [Dairy
products (moisture in cheese, methods for fat in malted, dried, and condensed
milk), fats and oils, baking powder (fluorides in baking powder), eggs and egg
products, food preservatives (saccharin), coloring matters, metals in food (arsenic),
pectin in fruits and fruit products, moisture in dried fruits, canned foods, vinegars,
flavors and non-alcoholic beverages, meat and meat products (separation of meat
proteins, chemical examination of meat after decomposition), gelatin, cereal foods,
microscopical examination of cacao products, chemical examination of cacao
products, methods for the examination of cacao butter, and tea.]
1923] REFEREES AND ASSOCIATE REFEREES 211
Board of Editors.
R. W. Batcom (Box 290, Pennsylvania Avenue Station, Washington, D. C .), Chairman
(1926).
R. E. Doolittle (1923). R. B. Deemer (1925).
W. W. Randall (1924). W. F. Hand (1927).
Marian E. Lapp, Associate Editor.
Committee on Editing Methods of Analysis.
R. E. DoouirtLe (Transportation Building, Chicago, U.), Chairman.
B. B. Ross. J. W. Sale.
A. J. Patten. G. W. Hoover.
W. 1. Macintire.
SpecrAL COMMITTEES.
Committee on Definitions of Terms and Interpretation of Results on Fertilizers.
H. D. Haskins (Agricultural Experiment Station, Amherst, Mass.), Chairman.
J. W. Kellogg. G.S. Fraps.
E. G. Proulx. R. N. Brackett.
Committee to Cooperate with the American Socieiy for Testing Materials on the Subject of
Agricultural Lime.
W. H. MacIntire (Agricultural Experiment Station, Knoxville, Tenn.), Chairman.
J. B. Weems. F. P. Veitch.
Committee on Revision of Methods of Soil Analysis.
C. B. Lipman (Agricultural Experiment Station, Berkeley, Calif.), Chairman.
W. H. MacIntire. R. Stewart.
A. W. Blair. J. A. Bizzell.
Committee on Quariz-Plate Siandardization and Normal Weight.
Freperick Bates (Bureau of Standards, Washington, D. C.), Chairman.
C. A. Browne. F. W. Zerban.
Representatives on the Board of Governors of the Crop Protection Institute of the National
Research Council.
B. L. Hartwell, Kingston, R. I.
H. J. Patterson, College Park, Md.
REFEREES AND ASSOCIATE REFEREES.
Waler:
Referee: J. W. Sale, Bureau of Chemistry, Washington, D. C.
Tanning materials and leather:
Referee: F. P. Veitch, Bureau of Chemistry, Washington, D. C.
212 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
Insecticides and fungicides:
Referee: J. J. T. Graham, Bureau of Chemistry, Washington, D. C.
Soils:
Referee: W. H. MacIntire, Agricultural Experiment Station, Knoxville, Tenn.
Sulfur in soils:
Associate Referee: W. H. MacIntire, Agricultural Experiment Station, Knox-
ville, Tenn.
Determination of active acidity or hydrogen ion concentration for agricultural products:
Referee: E. T. Wherry, Bureau of Chemistry, Washington, D. C.
Foods and feeding stuffs:
Referee: L. E. Bopst, Bureau of Chemistry, Washington, D. C.
Crude fiber:
Associate referee: H. H. Hanson, State Board of Health, Dover, Del.
Starch:
Associate referee: M. R. Coe, Bureau of Chemistry, Washington, D. C.
Stock feed adulteration:
Associate referee: H. E. Gensler, Department of Agriculture, Harrisburg, Pa.
Saccharine products:
Referee: H. S. Paine, Bureau of Chemistry, Washington, D. C.
Honey:
Associate Referee: S. F. Sherwood, Bureau of Plant Industry, Washington, D.C.
Maple products:
Associate referee: To be appointed.
Maltose products:
Associate referee: H. C. Gore, Bureau of Chemistry, Washington, D. C.
Sugar-house products:
Associate referee: J. F. Brewster, Sugar Station, New Orleans, La.
Fertilizers:
Referee: R. N. Brackett, Clemson Agricultural College, Clemson College, S. C.
Boraz in fertilizers:
Associate referee: J. M. Bartlett, Agricultural Experiment Station, Orono, Me.
Preparation of ammonium citrate:
Associate referee: C. S. Robinson, Agricultural Experiment Station, E. Lan-
sing, Mich.
Nitrogen:
Associate referee: 1. K. Phelps, Bureau of Chemistry, Washington, D. C.
Potash:
Associate referee: A. P. Kerr, Agricultural Experiment Station, Baton Rouge,
La.
1923] REFEREES AND ASSOCIATE REFEREES 213
Inorganic plant constituents:
Referee: A. J. Patten, Agricultural Experiment Station, E. Lansing, Mich.
Sulfur and phosphorus in the seeds of plants:
Associate referee: W. L. Latshaw, Agricultural Experiment Station, Man-
hattan, Kans.
Calcium, magnesium, tron, and aluminium in the ash of seed:
Associale referee: A. J. Patten, Agricultural Experiment Station, E. Lansing,
Mich.
Dairy products:
Referee: J. Hortvet, State Dairy and Food Commission, St. Paul, Minn.
Moisture in cheese:
Associate referee: L. C. Mitchell, 310 Federal Office Building, Minneapolis,
. Minn.
Methods for fat in malted milk, dried milk, and condensed milk:
Associate referee: J. T. Keister, Bureau of Chemistry, Washington, D. C.
Fats and oils:
Referee: G. S. Jamieson, Bureau of Chemistry, Washington, D. C.
Baking powder:
Referee: L. H. Bailey, Bureau of Chemistry, Washington, D. C.
Fluorides in baking powder:
Associate referee: J. K. Morton, Bureau of Chemistry, Washington, D. C.
Testing chemical reagents:
Referee: G. C. Spencer, Bureau of Chemistry, Washington, D. C.
Eggs and egg products:
Referee: R. Hertwig, Food and Drug Inspection Station, San Francisco, Calif.
Food preservatives (saccharin):
Referee: M. G. Wolf, U. S. Food and Drug Inspection Station, New York, N. Y.
Coloring matters:
Referee: A. L. Burns, Bureau of Chemistry, St. Louis, Mo.
Metals in focds:
Referee: W. F. Clarke, Bureau of Chemistry, Washington, D. C.
Arsenic:
Associate referee: R. M. Hann, Bureau of Chemistry, Washington, D. C.
Peclin in fruits and fruit products:
Referee: H. J. Wichmann, U. 8. Food and Drug Inspection Station, Denver, Colo.
Moisture in dried fruit:
Referee: R. W. Hilts, U.S. Food and Drug Inspection Station, San Francisco, Calif.
Canned foods: ;
Referee: F. C. Blanck, Bureau of Chemistry, Washington, D. C.
214 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
Cereal foods:
Referee: C. E. Mangels, Agricultural Experiment Station, Agricultural College,
WD:
Limit of accuracy in the determination of small amounts of alcohol:
Referee: H. C. Lythgoe, State Department of Public Health, Boston, Mass.
Vinegars:
Referee: H. A. Lepper, Bureau of Chemistry, Washington, D. C.
Flavors and non-alcoholic beverages:
Referee: W. W. Skinner, Bureau of Chemistry, Washington, D. C.
Meat and meat products:
Referee: C. R. Moulton, Institute of American Meat Packers, Chicago, Ill.
Separation of meat proteins:
Associate referee: C. R. Moulton,
Decomposition of meat products:
Associate referee: K.C. Falk.
Gelatin:
Referee: E. H. Berry, 5456 Ferdinand St., Chicago, Ill.
Spices:
Referee: A. E. Paul, 411 Post Office Building, Cincinnati, O.
Chemical examination of cacao products:
Referee: E. R. Miller, Room 1012 U.S. Appraiser’s Stores, New York, N. Y.
Microscopical examination of cacao producis:
Referee: V. A. Pease, Bureau of Chemistry, Washington, D. C.
Methods for the examination of cacao butler:
Referee: W. F. Baughman, Bureau of Chemistry, Washington, D. C.
Tea:
Referee: R. E. Andrew, Agricultural Experiment Station, New Haven, Conn.
Drugs:
Referee: G. W. Hoover, Transportation Building, Chicago, II.
Examination of arsphenamine and neoarsphenamine:
Associale referee: C. K. Glycart, Transportation Building, Chicago, Ill.
Turpentine:
Associate referee: V. E. Grotlisch, Bureau of Chemistry, Washington, D. C.
Crude drugs:
Associale referee: A. Viehoever, Bureau of Chemistry, Washington, D. C.
Alkaloids: ,
Associate referee: A. R. Bliss, Emory University, Emory University, Ga.
1923] REFEREES AND ASSOCIATE REFEREES 215
Methods for the separation of cinchona alkaloids:
Associate referee: &.O. Eaton, Food andDrug Inspection, San Francisco, Calif.
Laxative and bitter tonic drugs:
Associate referee: H. C. Fuller, Research Institute, Washington, D. C.
The analysis of acetylsalicylic acid:
Associale referee: A. E. Paul, 411 Post Office Building, Cincinnati, Ohio.
Methods for the examination of phenolphthalein:
Associate referee: Samuel Palkin, Bureau of Chemistry, Washington, D. C.
Methods for the ecamination of procaine:
Associate referee: A. W. Hanson, Transportation Building, Chicago, Ii.
Methods for the eramination of methylene blue:
Associate referee: H. O. Moraw, Food and Drug Inspection Station, Chicago, Il.
Methods for the examination of pyramidon:
Associate referee: A. W. Hanson, Transportation Building, Chicago, II.
Alophan:
Associate referee: W. Rabak, 311 Federal Office Building, Minneapolis, Minn.
Chloramine products:
Associate referee: W. H. Heath, Federal Building, Buffalo, N. Y.
Determination of camphor in pills and tablets by the alcohol distillation method:
Associate referee: G. H. Arner, Food and Drug Inspection Station, New York.
Ne ¥:
Determination of chloroform in drug products:
Associate referee: C. K. Glycart, Transportation Building, Chicago, II.
Methods for the examination of mercurial tablets:
Associate referee: G. C. Spencer, Bureau of Chemistry, Washington, D. C.
Other associate referees for special work in drugs will be appointed by the referee.
216 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
LIST OF MEMBERS AND VISITORS PRESENT, 1922 MEETING.
Abbott, J. S., Munsey Building, Washington, D. C.
Aldrich, Elizabeth, Bureau of Chemistry, Washington, D. C.
Allen, Charles D., H. Kohnstamm Co., New York, N. Y.
Allen, R. M., Research Products Department, New York, N. Y.
Almy, L. H., Bureau of Chemistry, Washington, D. C.
Ambler, J. A., Bureau of Chemistry, Washington, D. C.
Anderson, M. S., Bureau of Soils, Washington, D. C.
Appleman, C. O., University of Maryland, College Park, Md.
Arner, G. H., Philadelphia, Pa.
Atwater, C. G., The Barrett Co., New York, N. Y.
Badger, C. H., Bureau of Chemistry, Washington, D. C.
Bailey, C. H., University Farm, St. Paul, Minn.
Bailey, E. M., Connecticut Experiment Station, New Haven, Conn.
Bailey, H. S., Southern Cotton Oil Co., Savannah, Ga.
Bailey, L. H., Bureau of Chemistry, Washington, D. C.
Bainbridge, W. C., H. Kohnstamm Co., New York, N. Y.
Balcom, R. W., Bureau of Chemistry, Washington, D. C.
Baldwin, H. B., Department of Health, Newark, N. J.
Barnes, Jesse W., Bureau of Chemistry, Washington, D. C.
Bartlett, J. M., Agricultural Experiment Station, Orono, Me.
Bates, Carleton, U. 8. Gelatine Co., Milwaukee, Wis.
Bates, Frederick, Bureau of Standards, Washington, D. C.
Baughman, W. F., Bureau of Chemistry, Washington, D. C.
Beal, W. H., States Relations Service, Washington, D. C.
Benedict, L. C., Bureau of Chemistry, Washington, D. C.
Beyer, G. F., Bureau of Internal Revenue, Washington, D. C.
Bidwell, G. L., Bureau of Chemistry, Washington, D. C.
Bigelow, W. D., National Canners Association, Washington, D. C.
Birckner, V., Bureau of Chemistry, Washington, D. C.
Blaisdell, A. C., Bureau of Internal Revenue, Washington, D. C.
Boone, Paul, Department of Agriculture, Jacksonville, Fla.
Bopst, L. E., Bureau of Chemistry, Washington, D. C.
Bost, W. D., Orange Crush Company, Chicago, Ill.
Bower, J. H., 1320 Delafield St., N. W., Washington, D. C.
Boyle, Martin, Bureau of Chemistry, Washington, D. C.
Brackett, R. N., Clemson Agricultural College, Clemson College, 5. C.
Bradbury, C. M., State Department of Agriculture and Immigration, Richmond, Va.
Bradshaw, M. A., Takoma Park, Md.
Brown, B. E., Bureau of Plant Industry, Washington, D. C.
Bubb, John C., 719 Ninth St., N. E., Washington, D. C.
Buchanan, Miss Ruth, Bureau of Chemistry, Washington, D. C.
Burritt, Loren, U. S. Internal Revenue, Washington, D. C.
Burroughs, Lillian C., State Department of Health, Baltimore, Md.
Capen, Miss R. G., Bureau of Chemistry, Washington, D. C.
Carpenter, F. B., Virginia-Carolina Chemical Co., Richmond, Va.
Carroll, John 8., Potash Syndicate, New York, N. Y.
Casey, F. W., Bureau of Internal Revenue, Washington, D. C.
Cathcart, P. H., Ballston, Va.
Charlton, R. C., American Agricultural Chemical Co., Baltimore, Md.
1923] MEMBERS AND VISITORS 217
Chesnut, V. K., Bureau of Chemistry, Washington, D. C.
Clark, A. W., Agricultural Experiment Station, Geneva, N. Y.
Clarke, W. F., Bureau of Chemistry, Washington, D. C.
Clevenger, J. F., Bureau of Chemistry, Washington, D. C.
Coe, M. R., Bureau of Chemistry, Washington, D. C.
Collins, Miss E. W., Federal Relations Bureau, Inc., Washington, D. C.
Conrad, C. M., University of Maryland, College Park, Md.
Cook, F. C., Bureau of Chemistry, Washington, D. C.
Craig, R. S., City Health Department, Baltimore, Md.
Crawford, C. W., Bureau of Chemistry, Washington, D. C.
Crooke, H. L., Box 1064, Raleigh, N. C.
Cummings, J. A., U.S. Food and Drug Inspection Station, New York, N. Y.
Custis, H. H., Bureau of Animal Industry, Washington, D. C.
Dachnowski, A. P., Bureau of Plant Industry, Washington, D. C.
Dallas, Miss M. A., Bureau of Chemistry, Washington, D. C.
Davidson, Mrs. E. W., 2345 Ashmead Place, Washington, D. C.
Davidson, J., Bureau of Chemistry, Washington, D. C.
Davis, Miss C. M., Bureau of Chemistry, Washington, D. C.
Davis, R. O. E., Bureau of Soils, Washington, D. C.
Davis, Watson, 1115 Connecticut Avenue, N. W., Washington, D. C.
Dawson, P. R., Bureau of Plant Industry, Washington, D. C.
Deemer, R. B., Bureau of Plant Industry, Washington, D. C.
DeLawder, J. L., Bureau of Internal Revenue, Washington, D. C.
Dewar, E. S., Department of Agriculture, Raleigh, N. C.
Doolittle, R. E., Transportation Building, Chicago, Il.
Doran, J. M., Bureau of Internal Revenue, Washington, D. C.
Dunbar, P. B., Bureau of Chemistry, Washington, D. C.
Dunlap, F. L., 1457 Monadnock Block, Chicago, IIl.
Easterwood, H. W., Bureau of Soils, Washington, D. C.
Edmonds, H. G., Bureau of Internal Revenue, Washington, D. C.
Edmonds, M. J., 1858 Shepherd St., Washington, D. C.
Ellett, W. B., Blacksburg, Va.
Ellis, J. F., Bureau of Chemistry, Washington, D. C.
Ellis, N. R., Bureau of Animal Industry, Washington, D. C.
Emery, W. O., Bureau of Chemistry, Washington, D. C.
Esty, J. R., 623 Varnum St., N. W., Washington, D. C.
Ethier, L. S., Bureau of Chemistry, Washington, D. C.
Evenson, O. L., Bureau of Chemistry, Washington, D. C.
Fellows, H. C., Bureau of Agricultural Economics, Washington, D. C.
Ferguson, J. J., Swift and Company, Chicago, III.
Fippin, E. O., 407 Star Building, Washington, D. C.
Fiske, A. H., Rumford Chemical Works, Providence, R. I.
Fitz, L. A., Fleischmann Co., New Rochelle, N. Y.
Fleming, R. S., Merrell-Soule Co., Syracuse, N. Y.
Flenner, A. L., University of Maryland, College Park, Md.
Fletcher, C. C., Bureau of Soils, Washington, D. C.
Forbes, D. R., National Preservers Association, Washington, D. C.
Fox, Edward J., Bureau of Soils, Washington, D. C.
Fraps, G. S., Agricultural Experiment Station, College Station, Tex.
French, D. M., American Agricultural Chemical Co., Alexandria, Va.
Frey, R. W., Bureau of Chemistry, Washington, D. C.
218 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
Frere, F. J., 1817 Kalorama Road, Washington, D. C.
Frisbie, W. S., Bureau of Chemistry, Washington, D. C.
Fuller, F. D., Agricultural Experiment Station, College Station, Tex.
Gardiner, R. F., Bureau of Soils, Washington, D. C.
Gascoyne, W. J., 27 South Gay Street, Baltimore, Md.
Gensler, H. E., Bureau of Chemistry, Harrisburg, Pa.
Gephart, F. C., 23 E. 31st St., New York, N. Y.
Gersdorff, C. E. F., Bureau of Chemistry, Washington, D. C.
Gersdorff, W. A., Department of Agriculture, Washington, D. C.
Gibson, A. L., Ontario Agricultural College, Guelph, Canada.
Glycart, C. K., Transportation Building, Chicago, Il.
Goodrich, C. E., Bureau of Chemistry, Washington, D. C.
Gordon, N. E., Agricultural Experiment Station, College Park, Md.
Gowen, P. L., Bureau of Chemistry, Washington, D. C.
Graham, J. J. T., Bureau of Chemistry, Washington, D. C.
Grayson, Miss M. C., Bureau of Chemistry, Washington, D. C.
Griffin, E. L., Bureau of Chemistry, Washington, D. C.
Grotlisch, V. E., Bureau of Chemistry, Washington, D. C.
Guthrie, C. P., Fargo, N. D.
Haigh, L. D., Missouri Experiment Station, Columbia, Mo.
Haller, H. L. J., Bureau of Chemistry, Washington, D. C.
Hallam, H. C., Hibbs Building, Washington, D. C.
Halvorson, H. A., Old Capitol Building, St. Paul, Minn.
Hand, W. F., Agricultural and Mechanical College, Agricultural College, Miss.
Hanks, A. K., Spencer Lens Company, New York, N. Y.
Hann, R. M., Bureau of Chemistry, Washington, D. C.
Hanson, Alfred W., Transportation Building, Chicago, Ul.
Hanson, H. H., State Board of Health, Dover, Del.
Hart, B. R., Department of Commerce, Washington, D. C.
Hart, F. L., Bureau of Chemistry, Washington, D. C.
Hartwell, B. L., Agricultural Experiment Station, Kingston, R. I.
Haskins, H. D., Agricultural Experiment Station, Amherst, Mass.
Hasselbring, H., Department of Agriculture, Washington, D. C.
Hayes, J. F., Department of Agriculture, Washington, D. C.
Haywood, J. K., Bureau of Chemistry, Washington, D. C.
Hazen, William, Bureau of Soils, Washington, D. C.
Heath, W. H., Bureau of Chemistry, Washington, D. C.
Himmler, L. W., Bureau of Animal Industry, Washington, D. C.
Hoffman, C., 132 Bella Vista Ave., Tuckahoe, N. Y.
Holman, H. P., Bureau of Chemistry, Washington, D. C.
Holmes, A. A., 233 Broadway, New York, N. Y.
Holmes, M. G., Northwood, N. H.
Holmes, R. S., Bureau of Soils, Washington, D. C.
Hoover, G. W., Transportation Building, Chicago, Ill.
Horne, W. D., Yonkers, N. Y.
Hortvet, Julius, State Dairy and Food Commission, St. Paul, Minn.
Houghton, H. W., Hygienic Laboratory, Washington, D. C.
Howard, B. J., Bureau of Chemistry, Washington, D. C.
Howe, Harold, University of Maryland, College Park, Md.
Howe, H. E., 810 18th St., N. W., Washington, D. C.
Huffard, C. L., College Park, Md.
Huffington, Jesse M., University of Maryland, College Park, Md.
1923] MEMBERS AND VISITORS 219
Hunter, A. C., Bureau of Chemistry, Washington, D. C.
Hurd, W. D., 819 Southern Building, Washington, D. C.
Huston, H. A., 42 Broadway, New York, N. Y.
Jackson, R. F., Bureau of Standards, Washington, D. C.
Jacob, K. D., Bureau of Soils, Washington, D. C.
Jacobs, B. R., 2026 Pennsylvania Avenue, N. W., Washington, D. C.
Jamieson, G. S., Bureau of Chemistry, Washington, D. C.
Jarrell, T. D., Bureau of Chemistry, Washington, D. C.
Jenkins, L. J., Bureau of Chemistry, Washington, D. C.
Jensen, O. F., 819 Southern Building, Washington, D. C.
Jinkins, R., Bureau of Chemistry, Washington, D. C.
Johnson, J. M., Hygienic Laboratory, Washington, D. C.
Jones, D. B., Bureau of Chemistry, Washington, D. C.
Jones, R. M., Bureau of Soils, Washington, D. C.
Jongeward, M., 504 Tulip Ave., Takoma, D. C.
Kebler, L. F., Bureau of Chemistry, Washington, D. C.
Keenan, G. L., Bureau of Chemistry, Washington, D. C,
Keister, J. T., Bureau of Chemistry, Washington, D. C.
Kellogg, J. W., Department of Agriculture, Harrisburg, Pa.
Kerr, A. P., Agricultural Experiment Station, Baton Rouge, La.
Kerr, R. B., Bureau of Animal Industry, Washington, D. C.
King, J. F., State Capitol, Atlanta, Ga.
Kirby, W. E., New York, N. Y.
Koser, S. A., Bureau of Chemistry, Washington, D. C.
Kraybill, H. R., Agricultural Experiment Station, Durham, N. H.
Kunst, F. B., Agricultural Experiment Station, Morgantown, W. Va.
Ladd, E. F., Fargo, N. D.
Lapp, Miss M. E., Bureau of Chemistry, Washington, D. C.
Law, T. C., Law and Company, Atlanta, Ga.
LeClerc, J. A., Department of Commerce, Washington, D. C.
LeFevre, Edwin, Bureau of Chemistry, Washington, D. C.
Leighty, W. R., Bureau of Plant Industry, Washington, D. C.
Leith, T. B., Department of Agriculture, Morgantown, W. Va.
Leonard, C. 8., Hygienic Laboratory, Washington, D. C.
Lepper, H. A., Bureau of Chemistry, Washington, D. C.
Lichtenwalner, D. C., University of Maryland, College Park, Md.
Linder, W. V., Bureau of Internal Revenue, Weshingion, D. C.
Linton, F. B., Bureau of Chemistry, Washington, D. C.
Lodge, F. S., Armour Fertilizer Works, Chicago, IIl.
Loomis, H. M., National Canners Association, Washington, D. C.
Lynch, W. D., Bureau of Chemistry, Washington, D. C.
Lythgoe, H. C., Department of Public Health, Boston, Mass.
MacIntire, W. H., University of Tennessee, Knoxville, Tenn.
Magruder, E. W., F. S. Royster Guano Company, Norfolk, Va.
Manress, Miss L. M., Hygienic Laboratory, Washington, D. C.
Markovitz, L. N., Bureau of Chemistry, Washington, D. C.
Marshall, W. K., Bureau of Agricultural Economics, Washington, D. C.
Martin, J. B., 1408 Shepherd Street, N. W., Washington, D. C.
Mayer, O. F., H. T. Heinz Co., Pittsburgh, Pa.
McCall, A. G., Agricultural Experiment Station, College Park, Md.
McDonnell, C. C., Bureau of Chemistry, Washington, D. C.
220 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
McDonnell, H. B., Agricultural Experiment Station, College Park, Md.
McHargue, J. S., Agricultural Experiment Station, Lexington, Ky.
McMillin, H. R., Bureau of Animal Industry, Washington, D. C.
Mebhring, A. L., Bureau of Soils, Washington, D. C.
Mehurin, R. M., Bureau of Animal Industry, Washington, D. C.
Miller, G. E., Bureau of Chemistry, Washington, D. C.
Milne, Miss E. L., Bureau of Chemistry, Washington, D. C.
Miner, C. S., The Miner Laboratories, Chicago, Il.
Mitchell, A. S., Bureau of Chemistry, Washington, D. C.
Mix, Miss A. E., Bureau of Chemistry, Washington, D. C.
Moore, Miss M. D., Bureau of Chemistry, Washington, D. C.
Morawski, A. L., Bureau of Internal Revenue, Washington, D. C.
Morison, C. B., 1133 Fullerton Ave., Chicago, Il.
Morton, J. K., Bureau of Chemistry, Washington, D. C.
Moulton, S. C., Health Department, Washington, D. C.
Mount, J. M., Williams & Wilkins Company, Baltimore, Md.
Munch, J. C., Bureau of Chemistry, Washington, D. C.
Murray, A. G., Buceau of Chemistry, Washington, D. C.
Nelson, E. K., Bureau of Chemistry, Washington, D. C.
Nordeman, Miss A. M., Department of Agriculture, Washington, D. C.
Nothstine, A. C., 946 Shepherd St., N. W., Washington, D. C.
O’Brien, Miss A. B., Bureau of Chemistry, Washington, D. C.
Oswald, Carl L., 1004 Eye St., N. W., Washington, D. C.
Palkin, S., 1217 N St., N. W., Washington, D. C.
Pappe, T. F., Bureau of Chemistry, Washington, D. C.
Parkins, J. H., F. S. Royster Guano Company, Norfolk, Va.
Parkinson, Miss N. A., 1216 Delafield Place, N. W., Washington, D. C.
Patten, A. J., Agricultural Experiment Station, E. Lansing, Mich.
Patterson, H. J., Agricultural Experiment Station, College Park, Md.
Paul, A. E., 411 Post Office Building, Cincinnati, Ohio.
Pease, Miss V. A., Bureau of Chemistry, Washington, D. C.
Peeples, W. M., Baugh Chemical Company, Baltimore, Md.
Phelps, I. K., Bureau of Chemistry, Washington, D. C.
Phillips, M., Bureau of Chemistry, Washington, D. C.
Phillips, S., Bureau of Chemistry, Washington, D. C.
Pingree, M. H., American Agricultural Chemical Company, Baltimore, Md.
Pope, W. B., 3171 18th St., N. W., Washington, D. C.
Power, F. B., Bureau of Chemistry, Washington, D. C.
Powick, W. C., Bureau of Animal Industry, Washington, D. C.
Probey, T. F., Hygienic Laboratory, Washington, D. C.
Proulx, E. G., Agricultural Experiment Station, Lafayette, Ind.
Randall, W. W., Department of Health, Baltimore, Md.
Read, Miss E. A., Bureau of Chemistry, Washington, D. C.
Redfield, H. W., Bureau of Chemistry, New York City, N. Y.
Reed, J. B., Bureau of Chemistry, Washington, D. C.
Reid, F. R., Bureau of Soils, Washington, D. C.
Reid, W. D., Swift and Company, Baltimore, Md.
Reindollar, W. F., Department of Health, Baltimore, Md.
Remsburg, C. G., Hygienic Laboratory, Washington, D. C.
Rice, E. L., 316 Machinist Building, Washington, D. C.
Richardson, W. D., Swift and Company, Chicago, Ill.
1923] MEMBERS AND VISITORS
Rider, Miss A. B., 307 C Street, N. W., Washington, D. C.
Riffenburg, H. B., U. S. Geological Survey, Washington, D. C.
Riley, A. A., U. S. Internal Revenue, Washington, D. C.
Riley, H. N., H. J. Heinz Co., Pittsburgh, Pa.
Riley, J. G., Bureau of Internal Revenue, Washington, D. C.
Roark, R. C., General Chemical Company, Baltimore, Md.
Roberts, O. S., Lafayette, Ind.
Robey, V. C. K., Bureau of Internal Revenue, Washington, D. C.
Robinson, C. S., Agricultural Experiment Station, E. Lansing, Mich.
Robinson, W. V., Bureau of Soils, Washington, D. C.
Ross, B. B., Polytechnic Institute, Auburn, Ala.
Ross, W. H., Bureau of Soils, Washington, D. C.
Ruprecht, R. W., Experiment Station, Gainsville, Fla.
Russ, R. F., 32 Franklin St., N. E., Washington, D. C.
Rutledge, Miss R. L., Bureau of Chemistry, Washington, D. C.
Ryan, R. L., Bureau of Internal Revenue, Washington, D. C.
Sample, J. W., Nashville, Tenn.
Schertz, F. M., Bureau of Soils, Washington, D. C.
Schlupp, W. F., Experiment Station, Potchefstroom, S. Africa.
Schneller, M. A., 821 Virginia Ave., Washington, D. C.
Schulze, W. H., Department of Health, Baltimore, Md.
Schwartze, E. W., Bureau of Chemistry, Washington, D. C.
Schwarz, R., 113 Hudson Street, New York City, N. Y.
Scott, R. D., Department of Health, Columbus, O.
Sebring, B. W., Department of Agriculture, Columbus, O.
Seidenberg, Armin, Department of Health, New York, N. Y.
Shaver, A., 919 L Street, N. W., Washington, D. C.
Shovey, E. C., Bureau of Plant Industry, Washington, D. C.
Shrader, J. H., Department of Health, Baltimore, Md.
Shulenberger, F. W., Eimer and Amend, New York City, N. Y.
Sigler, P. S., 2721 Connecticut Avenue, N. W., Washington, D. C.
Skinner, J. J., Bureau of Plant Industry, Washington, D. C.
Skinner, Miss L. A., Bureau of Chemistry, Washington, D. C.
Skinner, W. W., Bureau of Chemistry, Washington, D. C.
Slipher, J. A., 2803 13th Street, N. E., Washington, D. C.
Smith, A. M., University of Maryland, College Park, Md.
Smith, C. M., Bureau of Chemistry, Washington D. C.
Smith, C. R., Bureau of Chemistry, Washington, D. C.
Smith, J. G., Bureau of Soils, Washington, D. C.
Smith, Miss J. K., Bureau of Chemistry, Washington, D. C.
Smith, Miss K. A., Bureau of Chemistry, Washington, D. C.
Smith, Miss S. L., States Relations Service, Washington, D. C.
Smith, W. C., Bureau of Chemistry, Washington, D. C.
Smither, F. W., Bureau of Standards, Washington, D. C.
Snyder, E. F., 1827 Monroe St., N. W., Washington, D. C.
Snyder, H., 1800 Summit Ave., Minneapolis, Minn.
Sorber, D. G., Bureau of Animal Industry, Washington, D. C.
Spencer, G. C., Bureau of Chemistry, Washington, D. C.
Stengel, A., Bureau of Chemistry, Washington, D. C.
Stephenson, C. H., Bureau of Chemistry, Washington, D. C.
Sterling, W. F., Bureau of Chemistry, Washington, D. C.
Stevenson, A. E., National Canners Association, Washington, D. C.
222 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
Stokes, W. E., Royal Baking Powder Co., New York, N. Y.
Strowd, W. H., Department of Agriculture, Madison, Wis.
Swicker, V. C., 713 Princeton Place, Washington, D. C.
Taylor, A. E., Bureau of Chemistry, Washington, D. C.
Thatcher, A. S., Loose-Wiles Biscuit Company, Long Island City, N. Y.
Thomas, Mrs. A., 1838 Vermont Ave., N. W., Washington, D. C.
Thomas, Walter, State College, Pa.
Thompson, E. C., The Borden Company, New York City, N. Y.
Thompson, H. L., Empire Laboratory Supply Company, New York, N. Y.
Thompson, J. W., Hygienic Laboratory, Washington, D. C.
Thornton, E. W., R. B. Davis Co., Hoboken, N. J.
Toll, J. D., 1010 Arch Street, Philadelphia, Pa.
Tonkin, W. H., Bureau of Chemistry, Washington, D. C.
Tracewell, C. E., Evening Star, Washington, D. C.
Trowbridge, P. F., Agricultural Experiment Station, Agricultural College, N. D.
Turner, W. A., Riverdale, Md.
Turrentine, J. W., Bureau of Soils, Washington, D. C.
Ullrich, Miss J. R., 25 Beaver Street, New York, N. Y.
Valaer, Peter, Jr., Bureau of Internal Revenue, Washington, D. C.
Van Horn, R. C., Western Maryland Dairy, Baltimore, Md.
Van Norman, H. E., 426 Star Building, Washington, D. C.
Van Wormer, L. H., College Park, Md.
Veitch, F. P., Bureau of Chemistry, Washington, D. C.
Vollertsen, J. J., Morris and Company, Chicago, Il.
Waggaman, W. H., Bureau of Soils, Washington, D. C.-
Walker, P. H., Bureau of Standards, Washington, D. C.
Walls, H. R., University of Maryland, College Park, Md.
Walton, G. P., Bureau of Soils, Washington, D. C.
Weber, F. C., Bureau of Chemistry, Washington, D. C.
Weems, J. B., Department of Agriculture, Richmond, Va.
Wherry, E. T., Bureau of Chemistry, Washington, D. C.
White, W. R., Department of Agriculture, Ottawa, Canada.
Whitney, C. F., Burlington, Vt.
Wilcox, E. L., 10- 10th St., N. E., Washington, D. C.
Wiley, H. W., 1120 Woodward Building, Washington, D. C.
Wiley, S. W., Wiley and Company, Inc., Baltimore, Md.
Williams, C. C., National Canners Association, Washington, D. C.
Wilson, Miss A., Bureau of Chemistry, Washington, D C.
Wilson, J. B., Bureau of Chemistry, Washington, D. C.
Wilson, S. H., Department of Agriculture, Atlanta, Ga.
Wilson, S. M., Baugh Chemical Company, Baltimore, Md.
Winant, H. B., Agricultural Experiment Station, College Park, Md.
Wolf, M. G., 600 W. 187th St., New York City, N. Y.
Wrenn, J. E., Department of Commerce, Washington, D. C.
Wright, C. D., Bureau of Chemistry, Washington, D. C.
Wright, L. E., Experimental Farm, Ottawa, Canada.
Wright, P. A., Department of Agriculture, Washington, D. C.
Young, J. L., 2517 Wisconsin Ave., Washington, D. C.
Zerban, F. W., Penick and Ford, Ltd., Inc., New Orleans, La.
1923] VEITCH: PRESIDENT ’S ADDRESS 223
PRESIDENT’S ADDRESS".
THE OPPORTUNITIES AND RESPONSIBILITIES OF THE
ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS.
By F. P. Verrcn (Bureau of Chemistry, Washington, D. C.).
It has been my privilege to listen to the addresses before this asso-
ciation for the past thirty years, and some of these have dealt with the
subject matter of my brief talk on “The Opportunities and Responsi-
bilities of the Association of Official Agricultural Chemists’. I can not
hope to say anything that is new nor can I hope to present the matter
as well as it has been done by others. Nevertheless, convinced that the
subject is a live one at this time, I trust that I may be able to redirect
attention to it to some purpose.
The objects of the association, as stated by the constitution, are two:
“To secure uniformity and accuracy in the methods, results and modes
of statement of analysis of fertilizers, soils, cattle foods, dairy products,
and other materials connected with agricultural industry”; and, ‘‘to
afford opportunity for the discussion of matters of interest to agricultural
chemists’. Proceeding with these broad subjects, this association was,
so far as I know, the first to introduce and to develop effectively the
collaborative study of methods and of men. It has done well in these
particulars. Other organizations, growing out of it or organized more
recently, have followed more or less in the footsteps of this association,
but it is fair to say, I think, that none of them has given that thorough,
careful and judicial study to analytical methods that has characterized
the Association of Official Agricultural Chemists, and which has won for
it the respect and confidence not only of the farmer but of those industries
that cater to his needs. Unquestionably this association has developed
the most accurate, reliable and simple methods for the analysis of those
materials with which it deals. As important as this is to all agricultural
work, it is, to my mind, far less important than what has been developed
therefrom—incidentally probably—and that is the training of a body of
real analytical chemists, men trained in methods of investigation, who
can do a reasonable volume of reliable work. These results have fol-
lowed not merely from the routine participation in the collaborative
work of the association, but, I am persuaded, primarily from the full
and vigorous discussions thereon, which took place particularly in the
earlier years of the association.
These things being true, why has it been deemed necessary or even
desirable for other organizations to repeat and duplicate much of the
1 Presented Thursday morning, November 16, as special order of business for 11 o’clock.
224 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
work done by this association? Why must three, or perhaps more,
other organizations investigate the determination of the iodine numbers
of oils? Are our methods for the determination of nitrogen, or phos-
phoric acid, or sucrose, or carbon dioxide, or magnesium oxide, or fats
and oils, or for the preparation of reagents, for example, so inadequate
or so faultily stated that these methods, developed from collaborative
work of from ten to thirty chemists over a period of twenty years or
more, can be made more accurate and rapid and can be more clearly
stated as the result of the work of a year or two by others? Why is it
necessary for these organizations to do more than adopt these methods,
which are the outcome of many years of careful, thorough and impartial
cooperative effort? What can be done to stop this waste of time and
effort and the doubt and conflict that result from the use of different
methods?
We can not escape the larger share of the responsibility for these con-
ditions. We have not been active enough either individually or as an
organization in keeping informed as to the activities of others, or in
cooperating in, and—may I say—shaping, the activities of these organi-
zations and in saving them needless work. Having in mind my own
shortcomings during the year it has been my honor to serve as the head
of this organization, I am constrained to think that the officers of the
association have given little thought to this phase of the association’s
duties.
As the pioneer organization, this association should properly extend
its efforts to eliminate this waste of time and effort and to further ac-
curacy and uniformity in methods of examination. I believe that each
of us should bring to the attention of the secretary of the association
any proposed outside activity within the field of this association of which
he learns and, if through personal acquaintance it is possible, to endeavor
to coordinate such work with the work of this association. The secre-
tary should bring such matters before the Executive Committee, call
the attention of the other organizations to our work and methods, and
offer the assistance of our association. The Executive Committee, if
requested to do so, should have the authority to designate a small com-
mittee to cooperate with the other organizations to promote uniformity
and eliminate useless efforts. Thus, in a larger way, it seems to me, we
would be carrying out the objects of the association and extend its
influence and. usefulness.
Discussion is the life blood of organizations; it denotes interest in
and knowledge of the subject; it promotes work, expands knowledge
and helps to make capable, efficient men. Those of us who recall the dis-
cussions of the earlier meetings realize fully how stimulating, informing
and helpful they were. We went back to our desks with increased
interest and refreshed minds, and took up the burdens of the day with
1923] VEITCH: PRESIDENT’S ADDRESS 225
renewed vigor, derived almost wholly, I venture to assert, from the dis-
cussions—formal and informal—that took place, rather than directly
from the reports and papers that were presented. To my mind it is an
indefensible waste of time and effort for any body of men to gather
simply to listen to the reading of papers, to pass a few resolutions and
elect officers. The papers can be read when published, while the reso-
lutions and elections are useless if they are not the outgrowth of the
meeting of men’s minds.
I have watched with much concern the flaring up and the dying
down of interest and discussions in a half-dozen associations and so-
cieties. We are not alone in this condition, but it behooves us to correct
it now. You will think of many ways in which this can be done and I
may mention a few.
Here, too, the officers of the association should be active, more es-
pecially in preparing to insure full cooperation and attendance and to
present a well-thought-out, attractive program. Success can not be
expected to attend efforts limited to a week or two before the annual
meetings. The work should be clear cut and comprehensive, but not
burdensome. ‘The institutions participating should have the collabora-
tive work done promptly and well and reported to the referee in ample
time for him to prepare a clear, informing and brief report. Moreover,
at least one representative from each organization should attend the
annual meetings. We are not developing methods only but we are
training our force for better things if there can be better things than
doing well the duty before us.
Reports and papers should not be longer than necessary and should
be prepared to bring out clearly the points presented. Tables of results
passed around develop and hold interest. Details should be left to the
discussion. The program should be arranged to give unlimited time for
discussion, even though it require an additional day. We should give
this work our close attention; we are here for a purpose. Each of us,
and especially if an older member, should be prepared to open the dis-
cussion on any subject that is within our knowledge, either to contribute
to or to receive some benefit from the work.
Finally, I believe we should return to the old practice of printing a
full report of the proceedings, including the useful discussions. If we
can do these things, we will have taken a long step toward the revival
of that productive interest of earlier days, the passing of which has
concerned us all.
While we may confidently believe that our methods are the best in
existence, sight must not be lost of the fact that they can be improved
or that their usefulness can be increased and extended. The arbitrary
method for the determination of available phosphoric acid in fertilizers
has not been modified fundamentally in thirty years, although it is
226 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
known that it is not based on unimpeachable evidence. The avail-
ability of phosphoric acid in basic slag has long been a problem to which
the association apparently is now finding a satisfactory solution. Should
agriculture recognize potash in fertilizers other than in its water-soluble
forms? Nitrogen is the most expensive and possibly in general the
most important plant food which the farmer buys. It exists in many
forms of widely differing availability. Through the increasing and
to-be-encouraged utilization of waste, nitrogenous fertilizer materials
are being added to almost daily. Are we keeping the farmer informed
as fully as we can and should concerning the presence and value of these
various forms in the fertilizers which he buys?
It has been 21 years since Dr. C. G. Hopkins and his associates, and
also the speaker, proposed before this association quantitative methods
for determining the “acidity” or “lime requirement” of soils, while even
earlier Wheeler and Hartwell had been investigating the subject. Other
methods have long since been suggested and some of these are in use.
For the past 10 years the literature has been flooded with undergraduate
and graduate efforts on this vital economic problem but to date this
association has no method for determining the “lime requirement”’ of
soil.
Is any man here confident that he can get agreeing results on moist-
ure in a complex organic material, on two successive days? The methods
for determining tannin have always been known to give results that are
too high—how much too high we can not even guess. Recently we have
found in my own laboratory that the quantity of samples employed,
though within the limits stated in the method, is responsible for marked
differences in the iodine number of resin. If this is found to be true of
other fats, oils and resins, we have a partial explanation of differences
in results on iodine number and must needs revise our method accord-
ingly. Numerous other instances of pressing need for better methods
will occur to you, and these should be met by greater individual and
collaborative activity on the part of our members.
Most of the matters I have mentioned are of long standing. The
efforts that have been given to them have not led to material advances.
We need to go at these and similar problems more earnestly and bring
to bear upon them the more recent as well as the older knowledge.
Nothing is of greater fundamental importance than the maintenance
of the fertility of the land, involved in which is definite knowledge of
the availability of plant foods and of the factors which determine it.
I venture to suggest that the longest step that this association can take
now toward the solution of these and other dormant problems is to
appoint committees of one to study thoroughly a number of them,
summarize the work heretofore done and make definite recommenda-
tions for further work. These reports should be printed in The Journal
1923] VEITCH: PRESIDENTS ADDRESS 227
and should be in the hands of the members before the next annual
meeting in order that those interested might familiarize themselves
with and be prepared to discuss them at that time.
What could be more helpful now, for example, than an extended
review of the availability of the different forms of phosphoric acid and
different phosphates by Dr. Hartwell, discussed by Dr. Thorne, Dr.
Haskins, Dr. Patterson, Dr. Wheeler, Mr. Williams, and others, or a
review, by Dr. Lipman of New Jersey, of the different forms of nitrogen,
with discussion by Dr. Hartwell, Dr. Blair and Dr. Thorne? And so
with these other big fundamental problems that have held the advance
of the association for many years. I invite your earnest consideration
of the suggestion that we mark time for a year in at least some of our
collaborative work that we may take stock and survey the field through
these expert summaries and discussions in order that our attack may be
. intelligently concentrated on the crucial points in some of these baffling
problems. Personally | am fully convinced that much more is to be
gained in this way just now than by any other procedure.
One other thought and I am through. Years ago a distinguished
member of this association remarked that no line of agricultural work
progresses far before it is necessary to call in the chemist. This should
be a more generally recognized fact. Take chemistry out of biology or
nutrition and little but a name is left. Forget and abandon today’s
chemical knowledge in agriculture, and industry and civilization drop
back 2000 years, because even in those days they were recognizing the
rudiments of applied chemistry. In peace and in war it plays its major
part.
This being true, have we individually and as an association lived up
to our opportunities—have we met our responsibilities? Have we
placed assertively and confidently at the service of the people, especially
at the service of agriculture, that training, experience and knowledge
that is ours? Have we assumed the commanding, directing position
in public affairs, in research organizations and in scientific police work
that the fundamental importance of chemistry imposes upon us? Do
we insist that the burden of proof shall be assumed by the new and
untried rather than by the old and proved? Do we employ unceasingly
__that infallible weapon “‘publicity”’ in the service of the people?
There exists in each state an agricultural college—a capable, impartial,
experienced scientific organization—which can conduct research or func-
tion to protect the people. It is, I believe, our duty as an association
and as individuals to see that these facts are fully known whenever it
is proposed to conduct research or enact laws against frauds in material,
because such work can be most effectively and economically done by
these organizations. So many concrete things are worth doing that the
tendency to needless expansion and duplication is difficult to foresee or
228 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
to check. Both are so wasteful of the people’s funds, of time and effort
that they should be guarded against at all times.
It seems to me, then, that in addition to the well established work on
methods and their application upon which we have long been engaged
the association can and should take a larger directing part in all scien-
tific service relating to agriculture. When service, private or public,
involving chemistry is, to be performed, let us get from the chemist all
that he has to give.
CHANGE IN ORDER OF PUBLICATION.
The order of publishing the committee reports will be reversed this
year; that is, they will be published at the beginning of the proceedings
rather than in their chronological order at the end, as has formerly
been done. In this way the referees and associate referees will have
readily available the matter for beginning the year’s work.
THIRD DAY.
FRIDAY—MORNING SESSION.
REPORT OF THE COMMITTEE ON EDITING METHODS OF
ANALYSIS.
The work of your Committee on Editing Methods of Analysis has not
been very extensive during the past year. You will recall that the
committee in its report at the 1921 meeting called attention to the
necessity for a revision of the methods in the near future and invited
suggestions for ways and means of improving the present Book of Methods
when such a revision was made. No suggestions of this character have
been received. As the result of a recent conference with the Board of
Editors of The Journal and another with the Board of Directors of the
association, it has been decided to begin at once a revision of the official
and tentative methods of analysis in order that the work may be com-
pleted soon after the next meeting, which will be the fifth since the
present book was issued. It is planned to carry out the greater part
of the work during the present year so that immediately after the close
of the 1923 meeting the additions and changes made at that meeting
can be incorporated and the new Book of Methods made ready for dis-
tribution by July 1, 1924. This will make the revision occur at the
five-year interval which the association appeared to favor at the time
the last revision was made. Your committee plans to retain the present
form of the Book of Methods, the revision to consist principally in the
deletion of methods which have been dropped and the incorporation
of new methods and of additions and changes which have been made
to the methods. We wish, therefore, to renew our request of last year
for suggestions for improving the form or arrangement of the methods
whereby they may be made more useful or convenient, and for reports
of any errors that have been noted in the present edition. The co-
operation of all referees and associate referees and of the sub-committees
229
230 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
on recommendations of referees is most urgently requested, particularly
for the purpose of bringing before the association at the meeting next
year all methods, changes in methods and deletions on which final
action can be taken so that they may be incorporated in the revised
edition of the Book of Methods. Every referee and associate referee is
urged to study carefully the chapter of the methods or the portion of
the chapter of methods with which he is directly concerned for the
purpose of recommending the deletions and changes which should be
made to make the chapters as complete and up-to-date as it is possible
to make them. Your committee will undoubtedly call upon the referees
and associate referees for assistance in editing the methods.
There was referred to your committee, at the last meeting of the
association, the following resolution from Sub-committee C on Recom-
mendations of Referees:
Methods for the macroscopical and microscopical identification of certain drugs
have been reported with the results of collaborative study thereon. Inasmuch as
such methods represent a radical departure from the policy of this association, it is
recommended that these be referred to the Committee on Editing Methods of Analysis
for consideration before any action is taken.
A consideration of the methods referred to showed that they con-
sisted of statements of the macroscopical and microscopical characteristics
of the various parts of the plant as compared with those of the substi-
tutes found. These differentiations are based entirely upon the botanical
structure of the plant, and it is believed that these methods belong more
properly in the United States Pharmacopoeia, or a text book dealing
with the botanical structure of medicinal plants. It is therefore the
opinion of your committee that these botanical descriptions of distinc-
tion should not be included in the official and tentative methods of
analysis of the association.
During the past year the chairman of your committee was requested
by the Chairman of the Board of Editors of The Journal to prepare, in
a form suitable for separate publication, the official and tentative meth-
ods of the association for the analysis of milk, in order that these methods
might be considered by the Board of Editors, the Executive Committee
and the association itself in connection with a request received from the
Secretary of the American Public Health Association for a jot pub-
lication of the methods of the two associations for the examination of
milk. As is generally known, the American Public Health Association
has published for a number of years a pamphlet containing the bac-
teriological methods adopted by the Laboratory Section of that asso-
ciation for the examination of milk. There have been three editions of
this pamphlet. A fourth edition is now being prepared in which the
Public Health Association desires to incorporate the necessary chemical
methods for the examination of milk. Consequently this request for
1923] REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 231
a joint publication of the two sets of methods has been made. The
proposition appealed to the members of your Committee on Editing
Methods of Analysis, provided the identity of the chemical methods as
the methods of the Association of Official Agricultural Chemists was
maintained. The methods for the analysis of milk as printed in Chap-
ter X XI of the Book of Methods, together with the additions and changes
made subsequent to November 1, 1919, were accordingly prepared for
publication in separate form by incorporating the text of other chap-
ters where cross references appear. This set of methods has been sub-
mitted to the Laboratory Section of the American Public Health Asso-
ciation, which section has agreed to accept same. The methods have
also been submitted to the Board of Editors of The Journal, and the
advisability of joing the American Public Health Association in the
joint publication of the milk methods has been discussed with the Board
of Editors and the Executive Committee of the association, both of
which have approved the plan.
Your committee therefore recommends that the association approve
the plan presented by the Secretary of the American Public Health
Association for a joint publication of the bacteriological and chemical
methods of the two associations for the examination of milk on con-
dition that the identity of the chemical methods as the A. O. A. C.
methods be retained in such a publication, and that the Board of Editors
be authorized to attend to the details of such a publication.
The attention of your committee has been called to an error in the
method for the determination of starch by the diastase method!, by
C. P. Walton of the Bureau of Chemistry. Lines 11 and 12, page 96,
direct the analyst to correct the weight of reduced copper by that ob-
tained on a blank of the same volume. This correction should be made
upon the equivalent weight of dextrose obtained by that determined
upon an equal volume of the malt blank as the weight of dextrose is not
in direct proportion to the weight of reduced copper obtained. This is
clearly indicated under “Reagent”, page 95, but as the two sections
now read there is an apparent contradiction in the procedure to be
followed. Proper correction will be made in the next revision of the
methods.
Your committee has prepared a compilation of the changes and
additions which were made to the official and tentative methods at the
1921 meeting of the association. This has been done as in former years
in order that the members of the association may have grouped together
for convenience of reference the additions and changes made from year
to year. A brief summary of these additions and changes for the 1921
meeting, attached as a part of this report, shows that of the thirty chap-
1 Assoc. Official Agr. Chemists, Methods, 1920, 95, par. 61.
232 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
ters of the book fifteen, or one-half, received some additions or changes.
No changes or additions were made to the following:
Chapter Title
Il—Inorganic Plant Constituents.
IV—Tanning Materials.
V—Leathers.
VIII—Saccharine Products.
IX—Food Preservatives.
X—Coloring Matters in Foods.
XI—Metals in Foods.
XV—Wines.
XVI—Distilled Liquors.
XVII—Beers.
XVIII—Vinegars.
XIX—Flavoring Extracts.
XX VII—Baking Powders and Baking Chemicals.
XXIX—Soils.
XXX—Reference Tables.
The additions and changes which were made are as follows:
CHANGES AND ADDITIONS TO THE METHODS OF ANALYSIS see AT
THE 1921 MEETING.
I. FERTILIZERS.
(1) The Bartlett method! for the determination of boric acid in ferti-
' zers and fertilizing materials was adopted as a tentative method for
reason of the special adaptation of the method to the analysis of samples
relatively high in soluble phosphates or organic matter.
(2) The Ross-Deemer method? was adopted as a tentative method for
the determination of water-soluble boric acid in fertilizers and ferti-
lizing materials for reason of its special adaptation to the analysis of
samples low in soluble phosphates and organic matter relative to the
boric acid content.
(3) The present official method* for the determination of insoluble
phosphoric acid in fertilizers was made an official method for the deter-
mination of the insoluble phosphoric acid in precipitated phosphates
with the exception that a one-gram charge shall be employed instead of
a two-gram charge. (First action as an official method.)
(4) It was further provided in the method for the determination of
phosphoric acid in precipitated phosphates that a perforated platinum
crucible and suction be employed in the filtration of the citrate solution
shit ony. Official Agr. Chemists, 1922, 5: 90.
2 Thi
3 Assoc. Official Agr. Chemists, Methods, 1920, 4.
1923] REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 233
after treatment and that a filter paper be employed that will insure a
free and rapid filtration without allowing the finely divided particles to
pass through. The following papers have been found satisfactory (and
there may be others): C. S. & S. No. 597; Whatman No. 2; Whatman
No. 1; Munktell’s No. 1-F; Munktell’s No. 2; and Durieux No. 121.
(First action as an official method.)
(5) The tentative Wagner method! for the determination of available
phosphoric acid in basic slag was made official. (First action as an
official method.)
II. INORGANIC PLANT CONSTITUENTS.
A method for the determination of manganese? was adopted as an
official method. (First action as an official method.)
III. WATERS.
(1) A method for the determination of iodine in the presence of chlorine
and bromine’ was adopted as a tentative method.
(2) The tentative method for reporting results of analysis‘ was de-
leted and in place thereof the new form suggested by the referee in his
report for 1921>, was adopted as a tentative method.
(3) Methods for the determination in salt® of moisture, matters
insoluble in water and matters insoluble in acid were adopted as tenta-
tive methods.
IV. TANNING MATERIALS.
No additions or changes were made at the 1921 meeting.
V. LEATHERS.
No additions or changes were made at the 1921 meeting.
VI. INSECTICIDES AND FUNGICIDES.
(1) The mercury-thiocyanate method’ for the determination of zinc
oxide in zinc arsenite was adopted as an official method. (First action
as an Official method.)
(2) The bromate method’, procedures 1 and 2, for the determination
of arsenious oxide in zinc arsenite was adopted as an official method.
(Final action.)
1 Assoc. Official Agr. Chemisis, Methods, 1920, 14.
2 J. Assoc. Official Agr. Chemists, 1921, 4: 393.
3 Ibid., 1922, 5: 381.
4 Assoc. Official Agr. Chemists, Methods, ae 38.
' J. Assoc. Official Agr. Chemists, 1922, 5
6 Tbid., 384.
7 Ibid., 392.
' 8 Tbid., 394,
234 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
(3) The official method! for the determination of water-soluble arsenic
in lead arsenate was made an official method for the determination of
water-soluble arsenic in zine arsenite. (Final action.)
(4) The bromate method? for the titration of the acid distillate in the
official distillation method for the determination of total arsenic was
adopted as an official method. (Final action.)
(5) The bromate method’, procedures 1 and 2, for the determination
of arsenious oxide in calcium arsenate was adopted as an official method.
(Final action.)
(6) Two methods, (1)? and (2)!, for the determination of calcium
oxide in calcium arsenate were adopted as official methods. (First
action on both methods as official methods.)
(7) Under the heading, ‘‘General Procedure for the Analysis of a
Product Containing Arsenic, Antimony, Lead, Copper, Zinc, Iron,
Calcium, Magnesium, etc.’, methods® for the determination of lead
oxide and copper were adopted as official methods. (Final action.)
(8) Under the heading, ‘General Procedure for the Analysis of a
Product Containing Arsenic, Antimony, Lead, Copper, Zinc, Iron,
Calcium, Magnesium, etc.”’, an official method® was adopted for the
determination of zinc oxide. (First action as an official method.)
(9) The zinc oxide-sodium carbonate method® for the determination
of total arsenic in London purple was adopted as an official method.
(Final action.) .
(10) The bromate method’, procedures (a) and (b), for the determina-
tion of arsenious oxide in Paris green was adopted as an official method.
(Final action.)
(11) The phrase “‘Not applicable in the presence of nitrates’ was
inserted over the present official distillation method for the determination
of total arsenic wherever this method appears in the Book of Methods.
(12) The distillation method’, suggested by Graham and Smith for
the determination of total arsenic in the presence of nitrates was adopted
as a tentative method with a view to its adoption as an official method
after it has been tested by cooperative work. (A tentative method—
first action as official.)
1 Assoc. Official Agr. Chemists, Methods, 1920, 59.
2 J. Assoc. Official Agr. Chemists, 1922, 5: 394.
8 Tbid., 395.
4 Tbid., 396.
5 Thid., 398.
6 [bid., 1921, 4: 397.
7 Ibid., 399.
8 Tbid., 402.
1923] REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 235
VII. FOODS AND FEEDING STUFFS.
(1) The official method! for the determination of crude fiber was
deleted and in place thereof the method? proposed by Bidwell and Bopst
was adopted as an official method. (First action as an official method.)
(2) The microscopic method* for the determination of rice hulls in
rice bran was adopted as a tentative method.
VII. SACCHARINE PRODUCTS.
No additions or changes were made at the 1921 meeting.
IX. FOOD PRESERVATIVES.
No additions or changes were made at the 1921 meeting.
X. COLORING MATTERS IN FOODS.
No additions or changes were made at the 1921 meeting.
XI. METALS IN FOODS.
No additions or changes were made at the 1921 meeting.
XII. FRUITS AND FRUIT PRODUCTS.
(1) A method‘ for the determination of moisture in dried fruits (for
dried fruits in general) was adopted as an official method. (First action
as an official method.)
(2) A method‘ for the determination of moisture in dried apples was
adopted as a tentative method.
XIII. CANNED VEGETABLES.
The wording of the method? for the micro-analysis of tomato pulp,
catsup, purée, sauce and paste was corrected to make the details of
operation clearer and the method as corrected was adopted as official.
(First action as an official method.)
? Assoc. Official Agr. Chemists, Methods, oe 97.
2 J. Assoc. Official Agr. Chemists, 1922, 5
3 Ibid., 77.
‘ Ibid., 6: 48. i
5 Assoc. Official Agr. Chemists, Methods, 1920, 164; J. Assoc. Official Agr. Chemisis, 1922, 6: 49.
236 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
XIV. CEREAL FOODS.
A method! for the determination of fat in baked cereal products was
adopted as a tentative method.
XV. WINES.
No additions or changes were made at the 1921 meeting.
XVI. DISTILLED LIQUORS.
No additions or changes were made at the 1921 meeting.
XVII. BEERS.
No additions or changes were made at the 1921 meeting.
XVIII. VINEGARS.
No additions or changes were made at the 1921 meeting.
XIX. FLAVORING EXTRACTS.
No additions or changes were made at the 1921 meeting.
XX. MEAT AND MEAT PRODUCTS.
(1) A modified method? for the determination of nitrates and nitrites
calculated as sodium nitrate was adopted as a tentative method in place
of the present ferrous chloride method? for the determination of nitrates.
(2) The tentative phenoldisulfonic acid method‘ for the determination
of nitrates and nitrites calculated to sodium nitrate, was changed by
substituting the word “‘sodium’’ for “‘potassium’”’ throughout the text
for the purpose of making the comparison with a standard solution of
sodium nitrate and expressing the results in terms of sodium nitrate as
is the trade practice.
XXI. DAIRY PRODUCTS.
(1) The cryoscopic method’ for the determination of added water in
milk was adopted as an official method. (First action as an official
method.)
1 J. Assoc. Official Agr. Chemists, 1922, 6: 63.
2 Thid., 74.
3 rn eet (al Agr. Chemists, Methods, 1920, 210.
4 Tbid., 211.
5 J. Assoc. Official Agr. Chemists, 1922, 5: 173.
1923] REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 237
(2) The tentative method! for the determination of moisture in cheese
was modified to provide that either 10-15 grams of sea-sand or 2-3
grams of asbestos be used, and that the sample be dried either in a vac-
uum or at atmospheric pressure at the boiling point of water.
(3) The Schmidt-Bondzynski method? for the determination of fat in
cheese was adopted as an official method. (Final action.)
XXII. FATS AND OILS.
(1) The Wijs method? for the determination of the iodine absorption
number was made official. (Final action.)
(2) An alternative method‘ for the preparation of the Wijs solution
was adopted as a part of the official method. (First action as an official
method.)
XXIII. SPICES AND OTHER CONDIMENTS.
The tentative method’ for the determination of volatile oil in mustard
seed was made official. (Final action.)
XXIV. CACAO PRODUCTS.
A microscopical method® for the determination of cacao shells in cacao
and chocolate products was adopted as a tentative method.
XXV. COFFEES.
The Power-Chesnut method’ for the determination of caffeine in
coffee was adopted as an official method. (Final action.)
XXVI. TEA.
(1) The Power-Chesnut method’ for the determination of caffeine in
tea was adopted as an official method. (Final action.)
(2) The Stahlschmidt method? for the determination of caffeine in
tea was dropped.
2 pate! Official Agr. Chemists, Methods, 1920, 234.
3 Tbid., ri
‘J. Ind. Eng. Chem., 1918, 10: 318.
5 Assoc. Official Agr. ‘Chemists, Methods, 1920, 259.
§ J. Assoc. Official Agr. Chemists, 1922, 5: 257.
7 Ibid., 271.
8 Ibid., 290.
® Assoc. Official Agr. Chemists, Methods, 1920, 274.
238 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
(3) The Bailey-Andrew method! for the determination of caffeine in
tea was adopted as an official method. (First action as an official
method.)
XXVII. BAKING POWDERS AND BAKING CHEMICALS.
The modified Chittick method? was adopted as a tentative method for
the determination of lead in baking powder.
XXVIII. DRUGS.
(1) Under the heading, ‘‘Acetylsalicylic Acid’’, the following additions
to the methods for analysis of drugs were made:
(a) A qualitative test® for free salicylic acid was adopted as a tenta-
tive method.
(b) A method? for the quantitative determination of salicylic acid
was adopted as a tentative method.
(c) The iodine method® for the determination of total! salicylates was
adopted as a tentative method.
(d) The bromine method’ for the determination of total salicylates
was adopted as a tentative method.
(e) The double titration method‘ for the determination of acetyl-
salicylic acid was adopted as a tentative method.
(2) Under the heading, ““Camphor”, methods* for the determination
of monobromated camphor were adopted as tentative methods.
(3) Under the heading, “Alkaloids”, a method® for the separation of
quinine and strychnine was adopted as a tentative method.
(4) Under the heading, ‘“‘Physostigma’’, a method’ for the assay of
the drug and its preparations was adopted as a tentative method.
(5) Under the heading, ‘‘Hyoscyamus”’ a method? for the assay of the
extract of hyoscyamus and its preparations was adopted as a tentative
method.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 292.
2 [hid., 514.
3 Thid., 582.
4 [bid., 583.
5 Tbid., 587.
6 Ibid., 1921, 4: 416.
7 [bid., 418.
8 [bid., 1922, 5: 569.
1923] REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 239
(6) Under the heading, “Strychnine’’, the following methods were
adopted:
(a) A method! for the assay of strychnine in tablets, including the
volumetric procedure, as an official method. (First action as
an official method.)
(b) A method? for the assay of strychnine in liquids, including the
volumetric procedure, as an official method. (First action as
an official method.)
(7) Under the heading, ‘‘Morphine, Codeine and Diacetylmorphine’’,
methods’ for the qualitative test and the quantitative determination of
morphine, codeine and diacetylmorphine were adopted as tentative
methods.
(8) Under the heading, “‘Arsenicals”’, the following additions were
made to the methods:
(a) Qualitative tests‘ for the identification of arsphenamine and
neoarsphenamine were adopted as tentative methods.
(b) A method’ for the determination of arsenic in arsphenamine and
neoarsphenamine was adopted as a tentative method.
XXIX. SOILS.
No additions or changes were made at the 1921 meeting.
XXX. REFERENCE TABLES.
No additions or changes were made at the 1921 meeting.
Respectfully submitted,
R. E. Doourrtte, J. W. SALE,
B. B. Ross, G. W. Hoover,
A. J. Patren, W. H. MacIntire.
Committee on Editing Methods of Analysis.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 564.
2 Thid.; 566.
3 Ibid. 150.
‘Ibid, 526.
5 Ibid., 527.
240 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
Later, after extended discussion as to policy, expense likely to be
sncurred and form of publication, it was moved that the Association
approve the plan of the American Public Health Association for a joint
publication of the bacteriological and chemical methods for the examina-
tion of milk on condition that the identity of the chemical methods as
the A. O. A. C. methods be retained in such a publication and that the
Board of Editors be authorized to attend to the details of such a publica-
tion.
The motion was seconded and carried.
1923] REPORT OF THE BOARD OF EDITORS 241
REPORT OF THE BOARD OF EDITORS.
By R. W. Batcom (Bureau of Chemistry, Washington, D. C.), Chairman.
Not long after the convention last year the association lost the services
of Miss Nellie A. Parkinson, who resigned her position in the Bureau of
Chemistry to become assistant to the editor of the Journal of Industrial
and Engineering Chemistry. For some time Miss Parkinson had acted
as associate editor of The Journal and upon her as such had devolved
the work of editing and preparing for publication the material published
therein. This work is now being very ably done by Miss Marian E. Lapp.
No. 3 of Volume V of The Journal, or the February, 1922 issue, carried
the last of the proceedings of the 1920 meeting and the first of the pro-
ceedings of the 1921 meeting. No. 2 of Volume VI, which is the Novem-
ber, 1922 number, is about ready for mailing and, in additionto the
final part of the proceedings of last year’s convention, will contain a
few contributed articles. Thus, for the first time in the history of
The Journal, it will be possible to begin the editing of current proceed-
ings just as soon as the convention closes. The irregularity in the dates
of issuance during the past year has been due to no fault of the editorial
office, but to indifferent service on the part of the printer. The material
for the August number, for example, was in the hands of the printer
before the end of June, but that number was not ready for mailing until
a few days ago, some four months later. It was recognized some time
ago that this condition of affairs could not be allowed to continue, and
negotiations with other printers were begun. These have not as yet
been concluded, but there is every prospect that better service and a
material reduction in charges for printing will soon be obtained, either
from the company now doing the work or from another.
The present list shows 856 subscriptions to The Journal. Of these
745, including 34 Canadian, are domestic. This is a decrease of 37 in
the domestic subscriptions reported last year, but the Canadians are
not responsible for the decrease, as they have increased their subscrip-
tions by four. The foreign subscriptions have increased from 86 to
111, distributed as follows: Africa, 2; Argentina, 2; Australia, 20;
Brazil, 2; Chile, 1; China, 2; Czechoslovakia, 1; Denmark, 2; Egypt, 3;
England, 21; France, 2; Germany, 1; Holland, 4; India, 28; Ireland, 3;
Italy, 1; Japan, 6; Mexico, 1; Norway, 2; Scotland, 5; West Indies, 2.
Doubtless the decrease in domestic subscriptions is to be attributed
largely to the business depression from which the country now seems to
be emerging. Chemists and the chemical industries have been particu-
larly hard hit by this depression. Many individuals have been forced
to economize in every possible way. The members of this association,
however, have probably suffered less than the chemists in industrial
242 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
laboratories, and the Board of Editors must again direct your attention
to the imperative necessity for increased support of The Journal on the
part of the individual members of the association. Personal subscrip-
tions from individual members of the association constitute, at the
present time, less than 15 per cent of the total number of subscriptions
to The Journal. Each member should constitute himself a committee
of one for the solicitation of subscriptions, including perhaps his own,
and bear in mind that The Journal now offers a medium of publication
for any good papers, particularly of an analytical character, of general
or special interest to agricultural chemists.
While the inability to report an increase of subscriptions to The
Journal is disappointing, there is some consolation in the fact that more
than 600 copies of the Book of Methods have been sold during the past
year. It was reported last year that 1000 additional copies were being
printed, but 1224 copies were actually run off by the printer, so that we
still have some 600 copies of the Book of Methods with which to meet
the demand for the coming year. These are all bound and entirely
paid for.
As an offset to this, the board has to report that shortly after the
meeting of the association last year, Messrs. Frank, of Frank, Emory
and Beeuwkes of Baltimore, and Sherier of Leckie, Cox and Sherier of
Washington, presented a bill for $500 for legal services rendered in con-
nection with the suit brought by the Williams & Wilkins Company,
former publishers of The Journal. The Executive Committee, to whom
the association had delegated power to act in the matter, decided, and
it is thought wisely, to authorize the payment of this bill and close this
unfortunate episode in The Journal’s history. The bill has been paid,
as stated in the Secretary-Treasurer’s report, in part with funds from
dues and in part from funds credited to The Journal’s account.
Another matter that should be recorded is the closing out of the
so-called guaranty fund established during the years 1914 and 1915.
Its purpose, inferred from its name, was to create a fund from which, in
case of necessity, the association could draw to make up any deficit
incurred in financing The Journal. The amounts pledged and actually
paid into this fund were not sufficient to increase materially the associa-
tion’s assets. The $127.80 paid in was deposited in a savings bank and
carried as a separate account. The Executive Committee, at the 1921
convention, authorized the return of this money on a pro rata basis to
the original contributors. The chairman of the Board of Editors, then
serving also as the secretary of the association, transferred this fund,
which with accrued interest amounted to $148.54, to The Journal account
and checked it out to the original contributors or their heirs or, as was
done in two instances at the contributor’s request, credited their share
toward current subscriptions to The Journal. This disposition of the
1923] REPORT OF THE BOARD OF EDITORS 243
guaranty fund seemed to be both expedient and just since this money
was not donated outright to the association and necessitated the carry-
ing of an additional account. It was also believed that this evidence of
appreciation on the part of the association of the conditions under which
the money was contributed would be of equal or greater value to the
association at this time than the fund itself.
A financial statement covering receipts and disbursements in con-
nection with the association’s two publications, The Journal and The
Book of Methods, is appended as a part of this report. This does not
show the amount of the unpaid bills. The bill of July 27 for the printing
of No. 4 of Volume V is still unpaid and that of May 31 for No. 3 of
Volume V is paid only in part. The bill for No. 1 of Volume VI has not
as yet been rendered. It has not been possible to get out of debt during
the past year, but the new association year will begin without some of
the difficulties and complications that were confronted a year ago.
The Board of Editors is doing its utmost to reduce expenses and at the
same time maintain, or even improve, the quality and usefulness of
The Journal, but it must have the active, earnest support of every mem-
ber of the association. It is handicapped by the deficit, which could
not be decreased during the past year, and it will be restricted in inde-
pendence of action until that deficit has been wiped out. The board
will welcome and appreciate any suggestions either now or in writing
at any other time.
This report can not be closed without a word of appreciation of the
services of Dr. William Frear, of Pennsylvania. Dr. Frear took a most
active part in the deliberations of the association which led to the estab-
lishment of The Journal and served as a member of the Board of Editors
until he died. The news of his sudden death in January came as a pro-
found shock to the other members of the board. A fitting tribute to
Frear as a scientist and as a man, prepared by one of the members of
the association, was printed in the May issue.
Approved.
244 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
FINANCIAL REPORT ON PUBLICATIONS FROM
By R. W. Batcom (Bureau of Chemistry,
RECEIPTS.
1921
Octsalbes Bank, balances 5.2 4)0 05.8. castorate acne Oe ae $ 162.63
Totalydepasttsie s\. hycwe «ner ead eee steele $ 7,686.22
Less redeposited checks................... $ 24.00
Less exchange on check for $5.00........... -10
a 24.10
7,662.12
$7,824.75
DETAILED STATEMENTS RELATIVE TO RECEIPTS.
Journal Subscriptions.
No. Price Total
Ordered Each Cost
56 $5.50 $ 308.00
457 5.00 2,285.00
73 4.40 321.20
221 4.00 884.00
70 3.75 262.50
35 3.00 105.00
9 2.50 22.50
6 1.75 10.50
18 1.50 27.00
4 1.40 5.60
15 1.25 18.75
otal tee pee eee hess Peseckis eR eee $ 4,250.05
Plus gain through exchange...................... 1.40
Oban hs FHSAA Ib dein 5 HAASE POLE Aer RSS SETAE te oA oct $ 4,251.45
1923] BALCOM: FINANCIAL REPORT ON PUBLICATIONS | ~ 245
‘7
en
é
OCTOBER 16, 1921 TO NOVEMBER 1, 192 eaF
Washington: D. C.), Chairman, Board of Biliions,
DISBURSEMENTS. Amount Check
1921 No.*
INov. 2) INaAs\ParkinsonSoffice expenses ..\.2..5....<..)- O80 ta old ines nak $ = 25.00 ° 117
Nov 5 C.L. Alsberg, refund on Guaranty Fund.................. 1216° | 118
Nov. 5 Edmund Burke, refund on Guaranty Fund................ 5.81 119
Nov. 5 Mrs. W. C. Burnett, refund on Guaranty Fund............ aoe 120
Nov. 5 G. W. Hoover, refund on Guaranty Fund................. 26:90 121
Nov. 5 W. M. Cobleigh, refund on Guaranty Fund......:........ Reon gbZ2
Noy. 5 RiE?Rosesrefund on Guaranty Fund... .... 0. ...4.. 49% 5:82, 123
Nov. 5 G.S. Fraps, refund on Guaranty Fund.................5. 11.62,; 124
Nove 5) HAGS.Gore;‘refundion Guaranty Mund)... 25s.) eae Dsl 25
Nov. 5 Herman Harms, refund on Guaranty Fund................ 5.08 126
Nov. 5 E. H. Jenkins, refund on Guaranty Fund..........2...:.... Tell peel AE
Nov. 5 C.H. Jones, refund on Guaranty Fund...........0.6.56... 11.62- 128
Noy. 5 H.M. Loomis, refund on Guaranty Fund........ 2 aan 11.638 129
Nov. 5 P.S. Tilson, refund on Guaranty Fund....... 5... 0/26... pot, yA130
Nov. 5 A.S. Wells, refund on Guaranty Fund.............:...3: 5.81 131
Nov. 5 H. E. Wiedemann, refund on Guaranty Fund............. HS 1S2
Nev 7) A.-T<Charron; refund'on subscription. ....... 3.050322. 28° 3.00 133
Nov. 7 City Treasurer, Dallas Tex., refund on subscription........ 1.00 134
Novas Se Rio We Hiltssrefund’ on subscription’: ;..:..: #462. 5.5... G00) S135
Nov. 8 R.S. Hollingshead, refund on subscription................ 1,00 . 136
Noy. 8 Industrial Printing Co., 1000 stickers for Book of Methods. . . 9°75 137
Noy. 14 Fritzsche Bros., refund on subscription................... 25. 138
Noy. 15 Louise Calouge, refund on subscription. ................ 085 2.50 139
Nov. 16 Schwarz Laboratories, refund on subscription............. : 1.25 140
Nov. 16 C. Milan Morse, refund on subscription .2 24 o5.-.<a.'. See 1225" 141
Noy. 17 Industrial Chemical Institute of Milwaukee, refund on. ‘sub-
BEEIDLON! Oat AOS, FORTIS. OD AOR PII a os ROME ee 1.25 142
Nov. 19 Charles H. LaWall, refund on subscription. ............... 1.25 143
Nov. 19 H.H. Hanson, refund on subscription...........0..:..... 2.00 144
Nov. 19 H. Kohnstamm & Co., refund on subscription.,........... P25 145
Ney=.19> N2A> Parkinson, office expenses! qi.o0: 22 SSBB. oo... 25.00 146
Dec. 10 Moore-Cottrell Subscription Agencies, refund on subscrip-
OHTA es. See: Sea Je WSR es ISS ee bli oe ae es 1.00 147
Dec. 10 Crescent Manufacturing Co., refund on subscription........ 1225 148
Dec. 10 George A. Olson, refund on subscription.................. 1.25 149
Dec. 10 Ware Brothers, refund on subscription...............-....-. 1225) 150
Dec. 18 Fred W. Nestelle, refund on subscription.................. i250 15!
Dec. 13 Francis H. Leggett, refund on subscription................ 1 152
ee 159 Cashwvaliice @xpenses'.2...9219 PORN. < sooc as bc tpt. HeS 10.00 153
Dec 15y IndustrialiPrinting/Co:; on/accounts, «. . 2. stdee ee © ae 1,000.00 154
1922
Jan. 4 R. W. Balcom, reimbursement for freight charges on Journal Sikes GSES
Jane fo Brentano's, retund onsubscriptions-.....-. ssaschee | an 50 156
Jan. 6 Cash, office EXPENSES Sis 2c). 1. Ae aw Ae ets OS eet RES eee 2o-OOn ead
Jan. 6 Postmaster, box rent for quarter ending Mar. 31........... 2.00 158
Jan. 6 National Biscuit Co., refund on subscription...........:.. 1.25 159
Jan. 7 State of Minnesota, refund on SUDSCEEp LION re ee ortecr: 12.00 160
Jan. 12 C. A. Browne, refund on subscription ...........2.......- 1:25 161
Jan. 14 EH. Berry, refund on'subscription’..<.<. 2... 225424. 2.00 163
Jan. 16 R.S. Thompson, refund on subscription...............". 5 1.25 164
Jan. 21 Industrial Printing Co., on account. .......... «3887. ..2. 643.85 165
Feb. 1 C.H. Jones, refund on subscription...........i4% Pies 2.00 166
Keb: =¢ WJ: Jones; refund on Guaranty Fund)... ....4 2276. 2: 5:01. 167
Feb. 7% J. W. Watson, refund on Guaranty Fund... -.......4..... 1.16 168
Feb. 7 Mrs. A. M. Davidson, refund on Guaranty Fund.......... 1.16 169
Feb. 7 Mississippi A. and M. College, refund on Guaranty Fund... 5.81 7
Feb. 9 University of Tennessee, refund on Guaranty Fund........ PG 7a
246 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
RECEIPTS—Continued.
Methods Subscriptions.
No. Price Total
Ordered Each Cost
35 $5.50 $ 192.50
445 5.00 2,225.00
44 . 4.40 193.60
145 4.00 580.00
Dotalke 5 cia degul decide oc 1. DR ee $ 3,191.10
Plus gain ‘through’ exchange ....... 208 3. Yee. Oe. 1.60
OCDE oa 5) auch aren stcl ctatien eh drier ct ch d's MUTE se a Rees ae BOON
Total, Journal and’ Methods... .«..#2¢ 3.220... ee, GS $ 7,444.15
Foecess payMients se. 5 hae vec vs donne AY PRO SA 71.75
Plas bank: balances accross ie ere See ae 162.63
Guaranty Pand less $2.32* »....). <0: RPA, Be ae 146.22
380.60
*Credited at contributor’s request toward payment on subscription to Journal.
$7,824.75
1923] #ALCOM: FINANCIAL REPORT ON PUBLICATIONS 247
DISBURSEMENTS—Continued. Amount Check
1922 No.*
Feb. 18 Robert Stewart, refund on Guaranty Fund................ L1G; - 172
Beb.2i27+ Industrial \Printing:Co, on-account/ cf ...........5..... 500.00 173
Feb. 28 George P. Gray, refund on Guaranty Fund............... 1.16 174
Feb. 28 Lucy S. Patrick, refund on Guaranty Fund............... 5.81 175
iebs 28) (E235 Lealirefundiomw GuarantyaHund cn..46 ee ls. sees ee LIGS AG
Reb 28n Janetuke Smithy OMmicerexpenses: oo Sees aces sic sein sine PASO Oa! Lire
iNMarsl7_ Janet, Ke smith officelexpenses'!;. .2 455. =e cisco osu. 25.00 178
Mar. 18° Industrial Printing @o:,/on account 203 98-.5 525.2. 500.00 179
Mar. 23 Armour and Co., reimbursement on duplicate payment on
OLd ers INONMOZGTORE rears a aki Reema aint asada 5.00 180
Mar. 24 Franklin Institute, refund on subscription................. 1.25. 181
Mar. 29 American News Co., reimbursement on duplicate payment on
drder No? G250G iS 9 See Ee OE Bd 4.00 182
Mar. 30 Postmaster, box rent for quarter ending June 30........... 2.00 183
Apr. 7 Tennessee Coal, Iron and Rail Road Co., reimbursement on
Order: NOMFSO9DE 255 SEH Ls Fe aR sorte) ce en 5.00 184
Apr. 20) Janet Ks Smith, office: expenses 9,2) P2815 2 PPR) oc). 25.00 185
pre 2 industrial Printing Go onlaccountes) sae ate <6. aac. - 619.86 186
May 10 R. W. Balcom, reimbursement on trip to Baltimore........ 2.50 187
May 12 - Industrial: Printing Co: on accdtiht’y : Ph fe. FPP a. PP: 500.00 188
May 16 Leckie, Cox and Sherier, lawyers’ fees. ................... 250.00 189
June 2 Janet K. Smith, office expenses...............5..0 02.0005 10.00 190
fone. 2 Industrial Printing Co., on account. : 5.6.26. scene ose ee 584.09 191
June 8 Farran’s Transfer and Storage, delivering Journals......... Beil ep.
June 8 Janet K. Smith, office expemses..............0.. 000000 cee 25.00 193
July 1 Postmaster, box rent for quarter ending Sept. 30........... 2.00 194
July 8 Williams & Wilkins, back numbers of Journal............. 5.45 195
tolva, Industrial Printing Co, on account..o...0 e645 ceca. ass se oe 500.00 196
July 27 Williams & Wilkins, back number of Journal.............. 1.25 197
AUG Re F.Rose, refund on subscription: 6.22, 225 -46.6- si. see 1.00 198
Aug. 7 Williams and Wilkins, back number of Journal............ 1:25 199
Aug. 7 Farran’s Transfer and Storage, delivering Journals......... 4.11 200
Aug. 10 Louis A. Voorhees, refund on subscription................. 1.00 201
Aue lio. iManson, refundon subscription... ..- 24-660 440 1.00 202
Auer) vanes, Ke smith; oltice expenses 4....4 7a sess eice + ae 30.00 203
auc 14) Industrial Printing Co.,:on account . (6.00.65 55 oe eos 500.00 204
Aug. 14 Ontario Agricultural College, refund on subscription........ 1.00 205
Septeoe industrial Printing Co:, on account... oy... 6 oes ees 400.00 206
Sept. 22 Postmaster, box rent for quarter ending Dec. 31........... 2.00 208
Bemieoe industrial Printing Co., on account... ..,..¢6. 42.0% 0. «0005s 218.65 209
Sepise2) Janet Ko Smith, office expenses... 24.... 0. o40ek senses 25.00 210
Seiwa. lt Wi. Eilts, refund on subscription: - .<..s0s eee 6 ss a 1.00 211
et= 10. industrial Printing Co., om account. .....265.00.06-<0 00+. 342.95 212
Oct. 19 Paul Elder & Co., refund on Book of Methods.............. 100 2s
Oct l9) Industrial Printing Co: onjaccount). 2.42. 005 04400554. 5% 400.00 214
rrr s). KOASN. (OICe: EXPENSES... osc. F 5 o5 ks sien s odu,9 aG4 ucla aon se 25.00 215
Pee MsARK: DHIANEE. |. ¢ 0/5.) 20 6 aS Soe ee eave Be oes 332.58
$7,824.75
*Checks 162 and 207 cancelled.
248 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
FINANCIAL REPORT OF THE SECRETARY-TREASURER
1921
Oct. 16
1922
Mar. 18
Aug. 8
Oct. 31
By W. W. Skinner (Bureau of Chemistry,
RECEIPTS.
Bank: balances: <6: 6 -azic ooo bee ee aS eee Lec $ 299.15
Dues from 6 Canadian and State institutions received too
late, forinclusion sin;1921, report<cijsctrscee aa: | eee $ 30.00
Dues for 1922 from 37 Canadian and State institutions*.. 185.00
215.00
Dues from 2 State institutions received too late for inclusion
In ODT TEMONE, «sb vere cdecaeesua sespeaskekoie Use ee ee $ 10.00
Dues for 1922 from 9 State institutions................ 45.00
55.00
Dues for 1922 from 9 Canadian and State institutions............ 45.00
Total receipts. esa dh so RR es set ce Gee $ 614.15
*Check for $5.00 from University of California for Journal deposited in Secretary-
Treasurer account in error.
1923]
SKINNER: REPORT OF SECRETARY-TREASURER
FROM OCTOBER 16, 1921 TO NOVEMBER 1, 1922.
Washington, D. C.).
DISBURSEMENTS.
1921 Amount
Nov. 23 N. A. Parkinson, reimbursement for expenses, 1921 meeting.$ 51.60
1922
Mar. 17 Cash, cost of telegram sent to State College by F. P. Veitch. 91
May.16 Leckie, Cox and Sherier, lawyers’ fees.................... 250.00
Aug. 16 R. W. Balcom, check for $5.00 from University of California
deposited to Secretary-Treasurer account in error. Check
given Dr. Balcom to be credited to Journal account...... 5.00
Sept. 25 Janet K. Smith, cash for postage for mailing announcements
Ok: meeting Wek Rae Ee SA ee 20.00
Oct. 4 Byron S. Adams, 1500 programs, 1922 meeting............ 41.75
Oct- 25° Bastian Bros., badges, 1922%meeting.. >... - +... S 28.02
Gereate Bank balance: 59M. GR 8h Roe. Le 216.87
60127 | hepa RMR ada rete ae eae Re iin A en SG 3 A aR $ 614.15
Approved.
“3
249
250 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 3
President Veitch: I should like to speak again of what the Chairman
of the Board of Editors referred to. The success of The Journal is an
important matter to us and to this association. In the report this
morning it was brought out that somewhere between 10 and 15 per
cent—nearer 10 per cent—only of the subscriptions are from individual
members of the association. Now, The Journal can not go on in that
way without increasing the deficit rather than decreasing it and I am
sure you will all be interested to know this and to help all you can.
R. E. Doolittle: I wonder if, as a member of the Board of Editors, I
might add a word in that connection. The Board of Editors met and
we spent half a day in discussing this matter. The matter is really
serious. The Board of Editors—Dr. Balcom principally—has laid out
plans for the coming year to reduce expenses just as much as possible.
We hope to accomplish something in that way and also by increasing
the number of subscribers. The appeal has been made by Dr. Balcom
and by your president but I want to tell you now that if we come here
next year with no better financial condition than we are showing ibis
year, some radical change will have to be made. We want the earnest
support of every member of this association if we are going to succeed.
President Veitch: A world’s dairy congress is to be held in October,
1923. Mr. Van Norman, President of the World’s Dairy Congress
Association, will tell us very briefly something about this coming congress,
because chemists are interested in dairy matters.
H. E. Van Norman: The plans are to hold this congress next October
near whatever city is chosen as the site for the National Dairy Show of
that year. I do not know just which city it will be. We had some
hopes of Philadelphia. The thought is to develop a program for the
discussion of the things relating to the dairy cow and her products,
the program to be so arranged as to interest four groups of people:
first, those who view these problems from the scientific and educational
standpoint, such as college men, research men, etc.; second, those who
view them from a business standpoint, all the way from the farmer,
manufacturer, distributor, equipment man, etc.; third, those who view
them as law enforcement officials with all the things relating thereto;
and fourth, those who are interested in these problems only from the
standpoini of their relation to public welfare.
It is our hope to bring to this country some of the leading men interested
in these aspects of the problem internationally. I invite those of you
who are interested in these subjects as chemists to cooperate with us in
making this a worth-wnile program. Perhaps you would like to appoint
a committee which would be interested in these aspects of the meeting
to cooperate in our program work.
1923] WALLACE: ADDRESS BY THE SECRETARY OF AGRICULTURE 251
A motion was made, seconded and carried that a committee of three
members be appointed by the president to collaborate in formulating
the program of the World’s Dairy Congress.
Later A. J. Patten, the newly elected president of the association,
appointed the following to serve on this committee: E. M. Bailey, New
Haven, Conn., Chairman; E. L. Van Slyke, Geneva, N. Y.; and H. W.
Redfield, New York, N. Y.
No report was made by the Committee on Quartz Plate Standardiza-
tion and Normal Weight.
President Veitch: If there is any work which requires more courage
than being a farmer, it is that of being the Secretary of Agriculture. It
has been my privilege to work under four successive Secretaries of
Agriculture, all of whom have contributed something of value to agri-
culture and to the work of the Department. They have always extended
their encouragement to this association and to its members, and not
one has been more active and successful in this particular than has the
present Secretary of Agriculture, Secretary Wallace, whom it is now my
great pleasure to introduce to you.
ADDRESS BY THE SECRETARY OF AGRICULTURE—THE
HONORABLE HENRY C. WALLACE.
I am glad of an opportunity to come to you once a year and make due
acknowledgment of the fine service we have received from you. Our
Departmental work would go along much more slowly and much less
efficiently but for your fine cooperation. I am under personal obliga-
tions to you in the benefit I am getting from the committee which you
appoint on standards. It gives me, very frequently, the opportunity
to “pass the buck” to your strong hands. I want to express my appre-
ciation in this public way to the members of the committee as well as
to the members of the association from which the committee springs.
We are your beneficiaries in the manner in which you work out stand-
ards of analysis—beneficiaries in two ways: First, those methods are
helpful to us in our administration of certain of the regulatory laws with
which we are charged; and second, they are helpful to the entire cause of
agriculture in that they are necessarily fundamental and help to establish
methods which can be used not alone by you in your official capacity
but by scientists in that field everywhere. I believe that the develop-
ments of the past two years emphasize more than ever before the import-
ance of that sort of work.
If you will permit me, Mr. Chairman, I want to speak just a moment
of the general conditions in agriculture at this time and how I think the
252 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
chemists are going to tie into the work that is being done to help bring
about improved conditions. I just completed my annual report yester-
day. I completed it yesterday because it had to be completed yesterday
by law. I have wondered sometimes, if it were not due on an exact
day, how long it would take to get out an annual report. As compared
with a year and a year and a half ago, farm prices have advanced very
considerably. In some cases, especially in the case of cotton, the advance
has been very substantial; but when we size up the whole matter from
the economic side as the farmer is affected we find this—that whereas
farm prices have advanced, prices of other things have advanced in just
about the same proportion. So, if we compare the farmer’s buying
capacity, his purchasing power—that is, what he can get for what he
grows—with his situation a year ago, we find that with the exception
of the cotton region, there has not been that improvement that we had
hoped there might be. We have been studying that situation in the
Department with a great deal of intensity, because we feel under obliga-
tion to help make a prosperous as well as a productive agriculture.
You can not have a continuing productivity in agriculture unless it is
also prosperous. Thus, our study has developed a movement in which
I think you may be interested.
We are setting up commodity councils. We are bringing in once or
twice a week, for example, every one in a position of large responsibility
in the Department who touches cotton in any way in the effort to work
out a definite Departmental policy as regards cotton so that we will be
able to give to our extension people certain definite Departmental poli-
cies. We bring in the soil people, who display their maps showing the
different kinds of soils and how cotton growth is influenced by soil. We
bring in the varieties people, the cultural people, and the entomologists
whose work deals with the boll weevil and other insect pests. Now,
after we have worked these matters out to our own satisfaction within
the Department, we are expecting to have conferences in the regions
interested in cotton, that is with the agricultural college people and the
State boards of agriculture where that particular crop is grown. They
will check up on our policy by making suggestions or modifications and
contributing whatever views they have to contribute. From our
Departmental program, after it is formed, we will have a definite pro-
gram to carry out through the various extension agents. I think that
this development will lead to the consideration of the entire agriculture
of the region also, that is the effects of changes in cotton on other crops.
We are starting another commodity council in the Northwest based on
wheat primarily, because that is the one big crop.
It is evident from the economic developments growing out of the war,
both over seas and at home, that the changes in freight rates are going
to have a profound influence on both our agriculture and industry. It
1923] WALLACE: ADDRESS BY THE SECRETARY OF AGRICULTURE =. 253
is also evident that there must be much more definite and concrete
policies affecting the agriculture of various crops and of various regions.
When we get into that phase of the subject, if it works as we think it
will, the chemist will have an increasingly important part. The question
of the best utilization of the crops grown in a particular section and the
question of the utilization of other crops which may be grown to meet the
needs of the section will be important.
I was greatly interested the other day in a report brought to me by a
man from Arizona. He, as secretary, came to ask me down to their
industrial conference. He said: ‘““We found many of our industries, as
well as our agriculture, in bad shape during the past two years and we
called a meeting asking delegates from all the various industries. That
meeting was composed of three delegates from each of the major indus-
tries of the State. Our packing industry was in bad shape. We set up
a movement to promote the consumption of meat from our own packing
houses within the State. The packers now are in a fairly prosperous
condition. Then the lumber people said that their mills were shut down
as they had no work to do. Our manager went to the railroad people
first and got an order from them for four million ties; through that
order our Jumber mills started up again. Now most of our industries
are in good shape. In other words, the people of Arizona are consider-
ing the interests of Arizona as well as of all the industries in it and mesh-
ing them into one another. In the case of potatoes, our potato growers
were marketing them without regard to the interests of one another.
We organized them into commodity councils. The potatoes from one
section are now marketed at one time and those from another section
at another time’. What is the result? It is just an attempt to put the
agriculture of the country on a sound basis. The chemists will have to
mesh into the work in innumerable ways, and as time goes on and as
modifications which must come, do come, the chemist’s office in the
work will assume increasing importance.
So I am glad to have an opportunity to come and pay my respects to
you, to lay a larger responsibility on you, and to wish you all possible
success in your meeting here.
President Veitch: I should like to call attention to the fact that we
have three amendments to the by-laws to be voted upon. These amend-
ments were also read on Wednesday.
The first amendment is as follows:
A Board of Editors of The Journal of the association, consisting of five members,
one of whom shall be designated the chairman, shall be appointed by the president
upon recommendation of the Executive Committee. These five members shall serve
one, two, three, four and five years, respectively, and each following appointment
shall be for five years.
254 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
The motion to adopt this amendment to the by-laws was seconded
and carried.
President Veitch: The two following amendments were presented by
the Committee on Definitions of Terms and Interpretation of Results
on Fertilizers:
(1) A fertilizer definition or interpretation shall not be adopted as tentative or a
tentative definition or interpretation amended until such definition or interpretation
has been recommended by the Committee on Definitions of Terms and Interpretation
of Results on Fertilizers and published in the proceedings of the association.
(2) A fertilizer definition or interpretation shall not be adopted as official or an
official definition or interpretation be amended until such definition or interpretation
has been recommended by the Committee on Definitions of Terms and Interpretation
of Results on Fertilizers for at least two annual meetings.
The motion to adopt these two amendments to the by-laws was
seconded and carried.
REPORT OF COMMITTEE ON VEGETATION TESTS ON THE
AVAILABILITY OF PHOSPHORIC ACID IN BASIC SLAG.
Results of the cooperative vegetation pot and field experiments, made
under the direction of your committee, have been assembled in abbre-
viated form, in accordance with a vote of the association taken in 1921.
The committee has been over the work and some changes have been
made with reference to the form of presenting the final summaries.
This will necessitate revising the manuscript before it passes into the
hands of the publishers of The Journal. This work can likely be ac-
complished, however, so that it will not delay publication of the report.
It would not seem necessary to continue the services of the committee
after the manuscript is in final form for publication, and it is hoped that
the association may so vote. Your committee would make the follow-
ing formal report at this time:
The Basic Slag Committee, after carefully reviewing the work of the different col-
laborators, as incorporated in the final report which has been prepared for publication
in the association’s journal, wishes to recommend that the Wagner method for the
determination of the available phosphoric acid in high-grade basic slag phosphate be
adopted by the association as official. (Second reading.)
H. D. Haskins, B. L. HartweE tt,
J. A. BrzzE.1, C. B. WILLIAMS.
W. B. ELvett,
Committee on Vegelation Tests on the Avail-
ability of Phosphoric Acid in Basic Slag.
Approved.
1923] METHODS OF ANALYSIS FOR LIMING MATERIALS 255
After the formal report was presented, by vote of the association the
-committee was discharged. The association voiced an expression of
thanks for the services of the committee.
REPORT OF COMMITTEE TO COOPERATE WITH THE AMERI-
CAN SOCIETY FOR TESTING MATERIALS IN REGARD
TO METHODS OF ANALYSIS FOR LIMING MATERIALS.
The committee held several meetings and conferences with two sub-
committees of Committee C-7, Sub-Committee for Agricultural Lime
and Sub-Committee for Methods of Analysis of Liming Materials, of
the A. 8. T. M. Two members of the committee also held a conference
with officials of the Bureau of Standards who have collaborated with the
A. 8S. T. M. in the preparation of tentative methods. It was agreed
that uniformity in the methods of the two bodies would prove desirable.
It was further agreed, however, that precision requirements are not
identical for liming materials for industry and agriculture.
Your committee desires to stress the fact that liming materials have
received no recognition by promulgation of methods for their control
though a number of States have in operation regulatory lime laws in
parallel to those for fertilizer control. The already extensive and rapidly
expanding usage of lime materials necessitates the adoption of official
methods for the sampling and analysis of the several commercial lime
products.
Your committee does not feel sure that it was empowered to compile
a chapter of methods on the analysis of liming materials. It is unani-
mous, however, in the belief that there exists an imperative need for
such a chapter. Most of the determinations necessary to such a com-
pilation are already official as related to other materials. Your com-
mittee, therefore, recommends that it, or a superseding personnel, be
directed to compile a chapter on “Liming Materials”, adapting present
official procedures to the analysis of liming materials, and that such
additional methods as may be necessary be subject to collaborative
study with a view to tentative or official adoption.
Respectfully submitted,
W. H. MacIntire,
F. P. Verrcn,
J. B. WEEms.
Approved.
No report was made by the Committee on Revision of Methods of
Soil Analysis.
256 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
REPORT OF COMMITTEE ON RECOMMENDATIONS OF
REFEREES.
By R. E. DooxrirtLeE (Food and Drug Inspection Station, Chicago,
Ill.), Chairman.
You have heard the reports of the chairmen of Subcommittees A,
B and C which represent the real work of your Committee on Recom-
mendations of Referees. Due consideration has been given to all
referee reports submitted and each and every recommendation has been
carefully examined not only in connection with the analytical data and
other information submitted in the reports of this year but also with
that of former years in order that the high standard of excellence which
the methods of the association enjoy in the scientific and industrial
fields shall be upheld.
Your committee desires to congratulate the referees and associate
referees on the splendid reports which have been submitted this year.
To single out an individual report would be unfair, but your committee
can not pass the opportunity to call attention to the number of col-
laborators and the completeness of their analytical results as reported
by the referee on crude fiber. To your committee this illustrates the
interest and enthusiasm the members of the association have in methods
of primary importance in agricultural and analytical chemical work.
Your committee has noted from reports submitted that there appears
to be some confusion or misunderstanding as to the form of action to be
recommended for making a method tentative or official. In this con-
nection the attention of the referees is called to the following sections
of the by-laws of the association.
(5) A method shall not be adopted as official or an official method be amended
until such method or amendment has been recommended for at least two annual meet-
ings by the appropriate referee.
(7) A method shall not be adopted as tentative or a tentative method amended
until such method or amendment has been reported by the appropriate referee and
published in the proceedings of the association.
Taking the two classes of methods in the inverse order, it is to be
noted that the requirements for a tentative method are two: First,
that it shall be recommended by the appropriate referee; and second,
that it shall have been published in the proceedings of the association.
Your committee notes an occasional recommendation that a method be
adopted as a tentative method, second action. Such a recommenda-
tion is incorrect. A method once adopted as a tentative method remains
tentative until changed, deleted or made official. If, as the result of
study of a tentative method, a referee concludes that the method should
remain tentative, a recommendation that it be continued as a tentative
1923] DOOLITTLE: RECOMMENDATIONS OF REFEREES 257
method should be made, not that it be a tentative method, second action.
If, as a result of his study, he desires to change a tentative method, he
should recommend that the changed or modified method be adopted as
a tentative method. In other words, a method may be adopted as a
tentative method by one action of the association, or a change may be
made in a tentative method by one action of the association. This is
one of the points of distinction between an official and a tenta:ive method.
A method can be made official only when so recommended by the appro-
priate referee for at least two annual meetings of the association. Your
committee interprets this provision of the by-laws to mean that to
become official a method must be recommended for adoption as an
official method at at least two annual meetings. The adoption of a
method as a tentative method at one meeting does not entitle it to be
adopted as a final official method at the next meeting or, in other words,
a method must be recommended for adoption as official by two referees
or by the same referee at two different meetings. A method may be
adopted as a tentative method and as an official method, first action, at
the same meeting. When this is desired, a definite recommendation to
that effect should be made in the referee’s report. Section 2 of the
by-laws of the association provides:
These by-laws or any portion of them may be suspended at any regular meeting of
the association without previous notice by a vote of three-fourths of the active mem-
bers present.
Under this by-law, the provisions above referred to may, by a three-
fourths vote of the active members present, be suspended and a method
adopted as a tentative method or as an official method immediately.
This apparently is intended to take care of emergencies that may arise
from time to time. When such an action is desired a definite recom-
mendation to that effect with the reasons therefor should be incorporated
in the referee’s report.
These forms of procedure are referred to for the information of the
referees and associate referees in order that their recommendations may
be uniform, thus expediting the work of the Committee on Recom-
mendations of Referees in the consideration of reports, the time for
which is necessarily limited.
In accordance with the provisions of Article III of the constitution
of the association, your committee has prepared a list of referees and
associate referees for the coming year, which list will be announced by
the president.
Approved.
258 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
REPORT OF COMMITTEE A ON RECOMMENDATIONS OF
REFEREES.
By B. B. Ross (Alabama Polytechnic Institute, Auburn, Ala.), Chairman.
[Fertilizers (boric acid in fertilizers, preparation of ammonium citrate, nitrogen, potash,
potash availability, precipitated phosphates, vegetation tests on availability of
phosphoric acid in basic slag), inorganic plant constituents (calcium,
magnesium, iron and aluminium in the ash of seed; sulfur
and phosphorus in the seeds of plants), water, tan-
ning materials and leather, insecticides
and fungicides, and soils (sul-
fur in soils).]
FERTILIZERS.
BORIC ACID IN FERTILIZERS.
It is recommended—
(1) That as boron compounds not soluble in water but soluble in
weak acids appear to be as injurious to plants as the water-soluble com-
pounds and since the Bartlett distillation method! as now carried out
determines the boron in such compounds, it be adopted as an official
method in its present form to determine boron in mixed fertilizers and
fertilizer materials. (First action as an official method.)
Approved.
(2) That a further study be made of the modification of the Ross-
Deemer method outlined in the second recommendation of the referee
with a view to determining its adaptability to the estimation of boron
in boron compounds insoluble in water, but soluble in weak acids.
Approved.
(3) That the Ross-Deemer method as given by the referee for 1921?
be adopted as an official method to determine water soluble boron in
mixed fertilizers and fertilizer materials. (First action as an official
method.)
Approved.
PREPARATION OF AMMONIUM CITRATE.
The committee recommends the approval of the recommendation of
the associate referee that the method for the preparation of ammonium
citrate solution’ be adopted as official, but does not recommend the
deletion, at this time, of the present official method. (First action as
an official method.)
Approved.
1 J. Assoc. Official Agr. Chemists, 1921, 5: 90.
2 Tbid., 1922, 5: 327.
3 [bid., 445.
1923] ROSS: COMMITTEE A ON RECOMMENDATIONS OF REFEREES = 259
Fi NITROGEN.
It is recommended—
(1) That the referee for 1923 be instructed to study the Devarda
method! as applied to the nitrates of commerce.
Approved.
(2) That the Moore method? for nitrates be studied with collaborators
next year.
Approved.
(3) That the referee on nitrogen for 1923 be instructed to study the
use of sodium thiosulfate as a substitute for sodium or potassium sul-
fide in precipitating mercury in the Kjeldahl method.
Approved.
POTASH.
It is recommended—
(1) That the investigation of the centrifugal method by Sherrill be
discontinued.
Approved.
(2) That the general referee on fertilizers for the ensuing year study
the literature with regard to the use of alcohol stronger than 80 per cent
for washing the potash precipitate with a view to ascertaining if col-
laborative investigation of the question is desirable.
Approved.
POTASH AVAILABILITY.
No report or recommendations.
PRECIPITATED PHOSPHATES.
It is recommended—
That the determination of insoluble phosphoric acid in precipitated
phosphates be carried out according to the present official method for
the determination of insoluble phosphoric acid in fertilizers’, with the
exception that a 1-gram charge be employed. (Second action as an
official method.)
Adopted.
VEGETATION TESTS ON AVAILABILITY OF PHOSPHORIC ACID IN BASIC SLAG.
The committee recommends the final adoption of the following recom-
mendation of the Committee on Vegetation Tests presented at the
meeting in 1921:
1 J. Assoc. Official Agr. Chemists, 1922, 5: 451.
2 JEInd. Eng. Chem., 1920, 12: 669.
3 Assoc. Official Agr. Chemists, Methods, 1920, 4.
260 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
It is the opinion of your committee that the tentative Wagner method! is a reliable
procedure for measuring the available phosphoric acid in basic slag phosphates and it
would, therefore, recommend that it be adopted by the association as official. (Second
action as an official method.)
Adopted.
INORGANIG PLANT CONSTITUENTS.
CALCIUM, MAGNESIUM, IRON AND ALUMINIUM IN THE ASH OF SEED.
It is recommended—
(1) That the incoming referee make a study of the entire chapter,
(II)?, before another general revision is made, with a view to deleting
any unnecessary methods.
Approved.
(2) That the methods for iron, aluminium, calcium and magnesium, as
given in the referee’s report, be further studied with a view to their
adoption as tentative methods.
Approved.
SULFUR AND PHOSPHORUS IN THE SEEDS OF PLANTS.
It is recommended—
(1) That the magnesium nitrate method for the determination of
sulfur in plant material including the seed of plants, as outlined in the
report of the associate referee, be adopted as a tentative method.
Approved.
(2) That the determination of phosphorus from the sulfur determi-
nation be also adopted as a tentative method.
Approved.
WATER.
It is recommended—
(1) That the following methods be adopted as tentative:
(a) Lead and zinc’*.
Approved.
(b) Copper, as given on page 107.
Approved.
(2) That additional methods for the analysis of salt* be studied next
year.
Approved.
1 Assoc. Official Agr. Chemists, Methods, 1920, 14.
2 [bid., 15.
3 J. Assoc. Official Agr. Chemists, 1922, 5: 382.
4 Ibid., 384.
1923] | ROSS: COMMITTEE A ON RECOMMENDATIONS OF REFEREES 261
TANNING MATERIALS AND LEATHER.
It is reeommended—
That the work on the determination of tannin in tanning materials
be continued.
Approved.
INSECTICIDES AND FUNGICIDES
The committee recommends the adoption of the suggestions of the
referee that a study be made of methods of analysis of dusting mix-
tures.
Approved.
It is further recommended—
(1) That the mercury-thiocyanate method for zine oxide in zine
arsenite, as given in the referee’s report for 1921', be adopted as an
official method. (Second action as an official method.)
Adopted.
(2) That Method 1 for the determination of calcium oxide in calcium
arsenate, as given in the referee’s report for 1921°, be adopted as an
official method. (Second action as an official method.)
Adopted.
(3) That Method 2 for the determination of calcium oxide in calcium
arsenate, as given in the referee’s report for 1921°, be adopted as an
official method. (Second action as an official method.)
Adopted.
(4) That in the “General procedure for the analysis of a product
containing arsenic, antimony, lead, copper, zinc, iron, calcium, mag-
nesium, etc.’’, the method for zinc oxide, as given in the referee’s report
for 1921*, be adopted as an official method. (Second action as an official
method.)
Adopted.
(5) That the hydrazine distillation method for the determination of
total arsenic be adopted as an official method. (First action as an
official method; adopted as a tentative method in 1921.)
Approved.
SOILS.
It is reeommended—
That further study be made in an effort to secure a mode of procedure
which may be used in removing all the sulfates which are carried by a
nitric acid soil, or synthetic soil, solution.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 392.
Ibid. 396,
4 [bid., 398.
5 [bid., 402.
262 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
REPORT OF COMMITTEE B ON RECOMMENDATIONS OF
REFEREES.
By H. C. LytHeor (State Department of Public Health, Boston, Mass.),
Chairman.
Foods and feeding stuffs (crude fiber, starch, stock feed adulteration), saccharine
products (sugar, honey, maple products, maltose products, sugar-house prod-
ucts), dairy products, fats and oils, baking powder, chemical reagents,
non-alcoholic beverages, eggs and egg products, drugs.
FOODS AND FEEDING STUFFS.
It is recommended—
(1) That Recommendations 1 and 2 of 1922, relative to sulfur dioxide
and chlorine in bleached grain and the acidity of grains other than
corn be dropped.
Approved.
(2) That the referee be appointed to study the existing official general
methods for water in foods and feeding stuffs with a view to rewording
and fixing rigidly the conditions of temperature, pressure and other
factors.
Approved.
(3) That a definite method applicable to the determination of water
in dried food be designed and submitted to the association.
Approved.
(4) That the work on the comparison of the C. R. Smith! and the
official? methods for the determination of ether extract be continued
next year.
Approved.
(5) That further study be made of the effect which grinding the
sample finer will have upon the ether extract determinations.
Approved.
CRUDE FIBER.
It is reeommended—
That the referee consider the criticisms made of the proposed new
method?’ by the collaborators this year and make such studies as may be
necessary in order to make a final report relative to the substitution of
the proposed method for the official method.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 6: 61.
2 Assoc. Official Agr. Chemists, Methods, 1920, 72.
3 J. Assoc. Official Agr. Chemists, 1922, 5: 421.
1923] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 263
STARCH.
It is reeommended—
That a referee be appointed to report upon methods for the determi-
nation of starch in linseed meal and similar subjects, as reported in a
paper by G. P. Walton.
Approved.
STOCK FEED ADULTERATION.
It is reeommended—
(1) That the microscopic method for the determination of rice hulls
in rice bran be continued as a tentative method.
Approved.
(2) That the method for the estimation of grit in poultry and similar
feeds! be adopted as tentative.
Approved.
(3) That the method for the estimation of bone in meat scraps be
adopted as tentative’.
Approved.
(4) That further study be made of microscopic methods for the
examination of mixed feeds.
Approved.
SACCHARINE PRODUCTS.
SUGAR.
It is reeommended—
(1) That the modifications proposed in 1916 for determining sucrose
by acid and invertase inversions be further studied.
Approved.
(2) That the work upon determining small amounts of reducing
sugars in the presence of sucrose be continued.
Approved.
HONEY.
It is recommended—
(1) That the work on resorcin and aniline chloride tests? for the
detection of invertase sugar sirup in honey be further studied in con-
nection with honey heated to a comparatively high temperature. It is
suggested that directions to collaborators be more specific as to details
of technique and color.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 424.
2J. Assoc. Official Agr. Chemists, Methods, 1920, 112.
264 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
MAPLE PRODUCTS.
It is recommended—
That further study be made of the Canadian lead number and the
conductivity value’.
Approved.
MALTOSE PRODUCTS.
It is recommended—
That the work begun by the referee be continued.
Approved.
SUGAR-HOUSE PRODUCTS.
It is recommended—
(1) That Method ITI, 12?, to determine sulfated ash be discontinued
as an official method. (First action in modification of an official method. )
Approved.
(2) That Methods I, 10 and II, 112, relative to ash in molasses, etc.,
be modified by adding at the end of each method the words: ““Take up
the residue with a little ammonium carbonate solution, re-evaporate,
and heat again in the muffle at a very dull red heat to constant weight’.
Approved.
DAIRY PRODUCTS.
It is recommended—
(1) That the cryoscopic method for the examination of milk be adopted
as Official. (Second action as an official method.)
Adopted.
(2) That the referee on cryoscopic examination of milk be dropped.
Approved.
(3) That the neutral modification of the Roese-Gottlieb method for
the determination of fat in malted milk’ be adopted as tentative.
Approved.
(4) That a further study be made of the Roese-Gottlieb method as
applied to dried milk.
Approved.
(5) That a further study be made of the proposed change in the
method for fat in unsweetened condensed milk‘ reported upon at the
1921 meeting.
Approved.
(6) That the methods for moisture in cheese reported upon at the
1 J. Assoc. Official Agr. Chemists, 1921, 4: 428.
Be ong Official Agr. Chemists, Methods, as 105.
3 J. Assoc. Official Agr. Chemists, 1922, 5: 508
4 Tbid., 509.
1923] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 265
1921 meeting! be subjected to collaborative studies during the coming
year.
Approved.
FATS AND OILS.
It is reeommended—
(1) That the alternative method for the preparation of the Wijs
solution (iodine trichloride method) be not adopted, and further that a
statement be inserted in the A. O. A. C. official Wijs method? calling
attention to the undesirability of using iodine trichloride for the Wijs
solution on account of its unstable character.
Approved.
(2) That the sentence beginning “‘Add 3 cc. of bromine to 200 ce. of
acetic acid’, 15, (a)’, be changed to read: “Add 3 cc. of bromine to
200 cc. of acetic acid and titrate 5 cc. of the solution against 0.1N sodium
thiosulfate, adding 10 cc. of potassium iodide solution (15 per cent)
before titrating’. It is recommended thai no other change be made in
the Hanus method.
Approved.
(83) That the modified Villavecchia test be made official. It is recom-
mended also that the description of the Baudouin and modified Villa-
vecchia tests be changed to read as follows:
SESAME OIL.
Baudouin Test—Official.
Dissolve 0.1 gram of finely powdered sugar in 10 cc. of hydrochloric acid (sp. gr.
1.2), add 10 cc. of the oil to be tested, shake thoroughly for 1 minute and allow to stand
for 10 minutes. In the presence of even a very small admixture of sesame oil, the
aqueous solution is colored crimson. It should be observed that some olive oils, es-
pecially those of African or Spanish origin, give pink or crimson colors which can be
readily differentiated from that due to sesame oil by applying the following modifica-
tion of the Villavecchia method:
Villavecchia Test—Official.
Add 2 cc. of furfural to 100 cc. of 95% alcohol by volume and mix thoroughly 0.1 cc.
of this solution with 10 cc. of hydrochloric acid (sp. gr. 1.2), and 10 cc. of the oil to be
tested by shaking them together for 14 of a minute. Allow mixture to stand 10 minutes
and observe color. Add 10 cc. of water, shake and again observe color. If the crimson
color disappears, sesame oil is not present.
Approved.
(4) That further work be done on the determination of the unsaponi-
fiable matter.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 498.
2 Assoc. Official Agr. Chemists, Methods, 1920, 245.
3 Thid., 244.
266 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
(5) That a study be made of the Baudouin and Villavecchia tests
using hydrochloric acid of varying specific gravity.
Approved.
BAKING POWDER.
It is reeommended—
(1) That Method 2 for the neutralization of monocalcium phosphate
as described by the referee be adopted as tentative.
Approved.
(2) That further study be made of the electrolytic method for the
determination of lead.
Approved.
(3) That further study be made of volumetric methods for the determi-
nation of carbon dioxide in baking powder.
Approved.
(4) That further collaborative study be made of methods for the
determination of fluorine in baking powder.
Approved.
CHEMICAL REAGENTS.
It is reeommended—
That the work on reagents be continued as formerly and that the
members of the association cooperate as fully as possible with the referee
in maintaining the high standards of purity and dependability for
chemicals.
NON-ALCOHOLIC BEVERAGES.
It is recommended—
That the subject of flavoring extracts and non-alcoholic beverages be
combined under one heading, “Flavors and Non-alcoholic Beverages’.
Approved.
EGGS AND EGG PRODUCTS.
It is recommended—
That a referee be appointed to study collaboratively the methods
proposed for the examination of eggs and egg products'.
DRUGS.
ACETYLSALICYLIC ACID.
It is reeommended—
(1) That the method for the preparation of acetylsalicylic acid for
the determination of the melting point? be adopted as a tentative method.
1 J. Assoc. Official Agr. Chemists, 1922, 6: 5.
2 Tbid., 5: 582.
1923] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 267
(Determination of the melting point is made in accordance with direc-
tions of the U. S. P.)
Approved.
(2) That the tentative method for the quantitative determination of
free salicylic acid! be considered by the referee next year with a view to
its adoption as official.
Approved.
(3) That the tentative iodine method for the determination of total
salicylates! be studied by the incoming referee with a view to its adop-
tion as an official method.
Approved.
(4) That the bromine method for the determination of total salicy-
lates! be studied by the incoming referee with a view to its adoption as
an official method.
Approved.
(5) That the double titration method for the determination of acetyl-
salicylic acid? be studied by the incoming referee with a view to its
adoption as an official method.
Approved.
(6) That further study be made of methods for the determination of
free acetic acid’.
Approved.
(7) That the problem of determining acetylsalicylic acid in the pres-
ence of possible interfering substances be given consideration by next
year’s associate referee.
Approved.
PHENOLPHTHALEIN.
It is recommended—
That further study be made of the methods submitted for the examina-
tion of phenolphthalein.
Approved.
CAMPHOR.
It is recommended—
That the methods suggested for the determination of camphor in
pills and tablets’ be further studied during the coming year.
Approved.
MONOBROMATED CAMPHOR.
It is reeommended—
That the tentative methods adopted at the 1921 meeting’ be made
the subject of collaborative study during the coming year.
Br ad Agr. Chemists, 1922, 5: 582.
3 Tbid., 544.
4 Tbid., 587.
268 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
MERCURY.
It is recommended—
That an associate referee be appointed to study the methods for the
examination of mercurous chloride, mercuric chloride and mercuric
iodine, already reported to the association, or such methods as may be
available elsewhere for the purpose of developing a satisfactory method.
Approved.
TURPENTINE.
It is reeommended—
(1) That the fuming sulfuric acid method! as modified by the referee
be adopted as tentative.
Approved.
(2) That the sulfuric-nitric acid method! as published in The Journal
be adopted as tentative.
Approved.
(3) That the method of Grotlisch and Smith? for the determination
of coal tar, oils and turpentine be studied.
Approved.
ALKALOIDS.
SEPARATION OF QUININE AND STRYCHNINE.
It is recommended—
That the methods submitted’ be further studied.
PHYSOSTIGMA, FLUID EXTRACT OF HYOSCYAMUS, OINTMENT OF STRAMONIUM, BELLADONNA OINTMENT,
BELLADONNA LINIMENT, IPECAC AND ATROPINE.
It is recommended—
(1) That the method for the assay of physostigma and its prepara-
tions, and that for fluid extract of hyoscyamus‘, as submitted by the
associate referee, be referred to the chairman of the appropriate com-
mittee of the U. S. P. Revision Committee for consideration in con-
nection with the revision of the U. S. P., and further that these methods
remain tentative until such time as they appear in the Pharmacopceia.
Approved.
(2) That further study be made of the methods for the assay of oint-
ment of stramonium, belladonna ointment, belladonna liniment, and
ipecac.
Approved.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 552.
2 J. Ind. Eng. Chem., 1921, 13: 791.
3 tia eas Official Agr. Chemists, 1922, 5: 567.
4 Thi
1923] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 269
(3) That the methods for the determination of atropine in tablets
be studied.
Approved.
STRYCHNINE.
It is reeommended—
(1) That the method for the assay of strychnine in tablets', including
the volumetric method, be adopted as an official method. (Second
action as an official method.)
Adopted.
(2) That the method for the assay of strychnine in liquids?, including
the volumetric method, be adopted as an official method. (Second
action as an official method.)
Adopted.
MORPHINE, CODEINE AND DIACETYLMORPHINE.
It is recommended—
(1) That the methods submitted for the qualitative and quantitative
determination of morphine, codeine and diacetylmorphine’, be adopted
as official. (First action as official methods.)
Approved.
PROCAINE.
It is reeommended—
That the two methods submitted! be adopted as official. (First
action as an official method.)
Approved.
MEDICINAL PLANTS.
It is recommended—
(1) That a study of volume weight of medicinal plants be continued
with the assistance of collaborators.
Approved.
(2) That a further study be made of the sublimation of plant products.
Approved.
SANTONINE.
It is reeommended—
(1) That the tentative method for the detection of santonine in
wormseed® be studied by collaborators with a view to making it official.
Approved.
1 Assoc. Official Agr. Chemists, Methods, 1920, 301.
2 Ibid., 300.
3 J. Assoc. Official Agr. Chemists, 1922, 5: 150.
4 Tbid., 590.
5 Ibid., 557.
270 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
POLLEN GRAINS.
It is recommended— ;
(1) That the method for the use of pollen grains as the means of
identification of plants and plant products! be further studied.
Approved.
BITTER TONIC AND LAXATIVE DRUGS.
It is recommended—
(1) That the gravimetric method evolved for assaying the anthra-
quinone drugs? be given a more exhaustive study during the coming
year.
Approved.
(2) That conjointly with the study of gravimetric assay, the col-
laborative work be extended to the colorimetric determination.
Approved.
(3) That the method for estimating aloin® be submitted to the asso-
ciation for study and criticism.
Approved.
ARSENICALS.
It is recommended—
(1) That the qualitative and quantitative methods‘ submitted be
adopted as official. (First action as an official method.)
Approved.
(2) That the designated modification of the quantitative method®
be adopted as a tentative method.
Approved.
(3) That further study of organic sulfur and toxicity tolerance of
arsphenamine be discontinued.
Approved.
SANDALWOOD OIL.
It is reeommended—
That the methods submitted and studied by C. W. Harrison for the
determination of the acetyl value of sandalwood oil® be further studied.
Approved.
1 J. Assoc. Official Agr. Chemists, 1921, 5: 157.
2 Thid., 1922, 5: 575.
3 Tbid., 580.
4 Tbid., 526.
5 Tbid., 528.
6 Tbid., 545.
1923] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 271
SILVER PROTEINATES.
It is recommended—
That further work be carried out on Method 31.
Approved.
ALCOHOL IN DRUGS.
It is recommended—
That the method for the determination of alcohol in drugs? be further
studied.
Approved.
CHLOROFORM.
It is recommended—
That the method for the determination of chloroform’ be further
studied.
Approved.
CINCHONA ALKALOIDS.
It is recommended—
That further study be made of the separation of the principal cinchona
alkaloids’.
Approved.
METHYLENE BLUE.
It is recommended—
That the iodine method for the determination of methylene blue be
adopted as tentative.
Approved.
PHENYLCINCHONINIC ACID (ATOPHAN).
It is recommended—
That the method of assay reported by the referee be studied col-
laboratively.
Approved.
CHLORAMINE PRODUCTS.
It is recommended—
That further study be made of the tests and methods reported by the
referee.
Approved.
DIMETHYLAMINOANTIPYRINE (PYRAMIDON).
It is reeommended—
That the extraction method and the precipitation methods reported
by the referee be further studied.
Approved.
Se paretai doon Agr. Chemists, 1922, 5: 543.
3 [bid., 539.
4 Tbid., 594.
272 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
REPORT OF COMMITTEE C ON RECOMMENDATIONS OF
REFEREES.
By R. E. DoonirrLte (1625 Transportation Building, Chicago, IIl.),
Chairman.
[Food preservatives (saccharin), coloring matters in foods, metals in foods (arsenic),
fruits and fruit products (pectin in fruits and fruit products, moisture in dried
fruit), canned foods, cereal foods, limits of accuracy in the determination of
small amounts of alcohol, vinegars, flavoring extracts, meat and
meat products (separation of meat proteins), gelatin, spices
and other condiments, determination of shells in cacao
products, methods for the examination of
cacao butter, coffee, tea, and nitrogen
in foods.]
FOOD PRESERVATIVES.
SACCHARIN.
It is reeommended—
That the studies of methods for the determination of saccharin be
continued.
Approved.
COLORING MATTERS IN FOODS.
It is recommended—
(1) That the tentative methods for the separation and identification
of soluble coloring matters and their lakes! be studied during the coming
year.
Approved.
(2) That the tentative methods for the separation and identification
of oil-soluble dyes? be studied during the coming year.
Approved.
METALS IN FOODS.
It is recommended—
That the zinc-iron precipitation method, as described by the referee,
for the determination of tin be studied collaboratively during the coming
year.
Approved.
ARSENIC.
It is reeommended—
(1) That the Gutzeit method for arsenic*® be modified in the following
manner to permit the use of hydrochloric acid as an alternate acid in the
determination:
“1 Assoc. Official Agr. Chemists, Methods, 1920, 131, 136.
2 Thid., 132, 136
% [bid., 147.
1923] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 273
(a) Chapter XI, 1 (b) add “or hydrochloric acid, arsenic-free (1 to 1)”, making the
sentence read “(b) Sulphuric acid, arsenic-free (1 to 2) or hydrochloric acid,
arsenic-free (1 to 1)’.
(b) Chapter XI, 4, line 3 after the phrase ‘‘and add 20 cc. of the dilute sulphuric
acid” insert “or 20 cc. of the 1 to 1 arsenic-free hydrochloric acid”, making the
sentence read ‘“‘and add 20 cc. of dilute sulphuric acid or 20 cc. of the 1 to 1
arsenic-free hydrochloric acid’’.
Approved.
(2) That the tentative Gutzeit method for the determination of
arsenic as revised be adopted as an official method. (First action as an
official method.)
Approved.
FRUITS AND FRUIT PRODUCTS.
PECTIN IN FRUITS AND FRUIT PRODUCTS.
It is recommended—
(1) That further studies be made by the method of Carré and Haynes
for the determination of calcium pectate! and the method of Wichmann
and Chernoff for the determination of pectic acid? to determine the
composition of pectin.
Approved.
(2) That the methods for preparation of sample, alcohol precipitate,
pectic acid, ash, sulfur in ash, total sulfur and water-insoluble solids?
submitted at the 1921 meeting for the determination of pectin in fruits
and fruit products be studied by the referee during the coming year.
Approved.
MOISTURE IN DRIED FRUITS
It is recommended—
(1) That the following method for the determination of moisture in
all dried fruits by drying in vacuo be adopted as an official method.
(Second action as an official method.)
Weigh 5-10 grams of the sample into a metal dish about 8.5 cm. in diameter, pro-
vided with a cover, breaking down any large lumps. Dry in vacuo at 70°C. for 12
hours at as low a pressure as possible, not to exceed 4 in. (100 mm.) of mercury. During
the drying admit to the oven a slow current of air, about 2 bubbles per second, dried
by bubbling through concentrated sulfuric acid. The metal dish must be placed in
direct contact with the metal shelf of the oven. Replace cover, cool in a desiccator
and weigh. Disregard any temporary drop of oven temperature which may occur
during the fore part of the drying period owing to rapid evaporation of water. With
raisins and fruit similarly rich in sugar use about 5 grams of sample and about 2 grams
1 Biochem. J., 1922, 16: 60.
2 J. Assoc. Official Agr. Chemists, 1922, 6: 36.
3 Ibid., 35.
274 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
of finely divided asbestos dried with the dish. Moisten with hot water, mix sample
and asbestos thoroughly, evaporate on the water bath barely to dryness and complete
drying as above.
Approved.
(2) That the following method for the determination of moisture in
dried apples only be continued as a tentative method:
Weigh 5-10 grams of the sample into a metal dish about 8.5 cm. in diameter, pro-
vided with a cover, breaking down any large lumps, and dry for 4 hours in an oven at
the temperature of boiling water. Replace cover, cool in a desiccator and weigh.
Place dishes on shelves and not on oven bottom. ‘The oven should have a vent on
top to secure ventilation and the temperature should not be below 96°C.
Approved.
(3) That further consideration be given to the determination of
moisture in dried fruits by methods based upon an entirely different
principle.
Approved.
CANNED FOODS.
It is reecommended—
That studies of the methods for the microanalysis of tomato pulp,
catsup, purée, sauce and paste as corrected! at the 1921 meeting be
continued.
Approved.
CEREAL FOODS.
It is recommended—
(1) That the tentative method? adopted at the 1921 meeting for the
determination of fat in baked cereal products be made official. (First
action as an official method.)
Approved.
(2) That the method for the determination of chlorine in bleached
flours as given in the referee’s report be adopted as a tentative method.
Approved.
(3) That further studies be made of the methods for the determination
of chlorine in bleached flour.
Approved.
(4) That the official method for the determination of moisture in
wheat flour? be amplified as follows:
Dry 2 grams of flour in a tared metal dish about 40 cm. in diameter by 25 cm. high,
and provided with a tight fitting cover, to constant weight in a vacuum oven at a
1J. Assoc. Official Agr. Chemists, 1922, 6: 49.
2 Thid., 63.
*Assoc. Official Agr. Chemisis, Methods, 1920, 167.
1923| DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 275
pressure of not to exceed 5 cm. of mercury, and at a temperature of 100°C. Cool the
dish in a desiccator, and weigh immediately after the dish and contents reach the
temperature of the air in the laboratory.
(First action as change in an official method.)
Approved.
(5) That the official method for the determination of ash in wheat
fiour! be amplified as follows:
Ignite a crucible; when cooled, weigh, and rapidly weigh into it 5 grams of the flour.
Ignite in a muffle at approximately 550°C. taking care that no portion of the mufile
becomes sufficiently hot to fuse the ash. A light-gray, fluffy ash should result. Cool
the crucible and contents in a desiccator, and weigh immediately after it reaches the
temperature of the laboratory air.
(First action as change in an official method.)
Approved.
(6) That the official method for the determination of protein in wheat
flour! be amplified to cover the same determination in wheat in order to
provide that the percentage of nitrogen in wheat as well as flour shall
be multiplied by 5.7 to obtain the percentage of protein. (First action
as an official method.)
Approved.
LIMITS OF ACCURACY IN THE DETERMINATION OF SMALL AMOUNTS OF ALCOHOL.
It is recommended—
That the studies of the methods for the determination of small amounts
of alcohol be continued.
Approved.
VINEGARS.
It is reeommended—
(1) That the method for the physical examination of vinegar? be
made official. (Second action as an official method; first action taken
in 1919.)
Approved.
(2) That the methods’ for the determination of alcohol, reducing
sugars, polarization and color, be studied by the referee during the
coming year.
Approved.
(3) That methods for the determination of sulfates and barium be
considered by the referee during the coming year.
Approved.
1 Assoc. Official Agr. Chemists, Methods, 1920, 167.
2 Tbid.. 191.
3 Tbid., 191-195.
276 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 3
FLAVORING EXTRACTS.
It is reeommended—
(1) That the subjects of ‘Flavoring Extracts’ and “Non-Alcoholic
Beverages” be combined under one heading, “Flavors and Non-Alco-
holic Beverages’.
Approved.
(2) That the referee give consideration to methods for the analysis
of non-alcoholic flavors, as for example the determination of orange oil
and lemon oil in mineral oil, cottonseed oil, etc.
Approved.
(3) That the referee give consideration to the method adopted at the
1919 meeting of the association, as official, first action, for the determina-
tion of alcohol in orange and lemon extracts consisting only of alcohol,
oil and water! to the end that final action may be taken on the method
at the 1923 meeting.
Approved.
MEAT AND MEAT PRODUCTS.
It is recommended—
That the tentative method for the determination of sugar in meat and
meat products? and the modifications of the method suggested by the
referee in 1921% be studied during the coming year.
Approved.
SEPARATION OF MEAT PROTEINS.
It is recommended—
(1) That further work be done on the relation of the concentration
of acid and protein to the coagulation by salt of proteins of meat soluble
in cold water‘.
Approved.
(2) That zinc sulfate be compared with ammonium and sodium
sulfates for the separation of meat proteins‘.
Approved.
(3) That further work be done with the sodium chloride and tannic
acid method for the determination of the amino-acid and extractive
nitrogen to determine all the conditions necessary to give comparable
results.
Approved.
1 J. Assoc. Official Agr. Chemists, 1921, 4: 472, 579.
2 Assoc. Official Agr. Chemists, Methods, 1920, 213.
8 J. Assoc. Official Agr. Chemists, 1922, 6: 72.
4 Tbid., 76-85.
1923] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 277
GELATIN.
It is recommended—
(1) That the present tentative method! for the determination oi
copper be continued as a tentative method.
Approved.
(2) That further study be made of the tentative method for the de-
termination of zinc? and the alternate method for copper and zinc’.
Approved.
SPIGES AND OTHER CONDIMENTS.
It is recommended—
(1) That the following details for the determination of crude fiber in
prepared mustard be adopted tentatively:
Weigh 10 grams of the sample and transfer to an 8 ounce nursing bottle with 50 cc.
of strong alcohol, stopper and shake vigorously. Add 40 cc. of ethyl ether, shake and
let stand about 5 minutes with occasional shaking. Centrifuge and decant off the
alcohol-ether mixture. Treat twice more with 40 cc. portions of ether, shaking, centri-
fuging and decanting as before. Rest the bottle on its side for a short time, without
heat, to allow the ether largely to evaporate. Transfer the material to a 1000 ce.
Erlenmeyer flask using 200 cc. of the boiling dilute sulfuric acid and proceed as directed
in VII, 66°.
Or treat the sample with the alcohol and ether in a small beaker; transfer to a har-
dened 11 cm. filter paper, wash several times with ether, and finally transfer to a 1000 cc.
Erlenmeyer flask with 200 cc. of the boiling dilute sulfuric acid.
Approved.
(2) That during the coming year the referee consider the above
described method in comparison with that printed in the Methods of
Analysis, A. O. A. C.4, for crude fiber in prepared mustard, for the pur-
pose of determining if both are acceptable methods or if either should
be dropped.
Approved.
(3) That the methods submitted by the referee in his report for the
examination of salad dressings be subjected to further study during the
coming year, employing samples differing from those used by contain-
ing a small proportion of oil and a binding material.
Approved.
(4) That the method for the determination of lecithin phosphoric
acid in salad dressings given by the referee in his report be further
studied together with any available modification thereof.
Approved.
ae ae Official Agr. Chemists, 1922, 5: 344.
27Tbi
t Assoc. OF Official Agr. Chemists, Methods, 1920, 98.
4 [bi
278 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
CACAO PRODUCTS.
DETERMINATION OF SHELL.
It is recommended—
That the tentative method for the determination of cacao shells in
cacao products! be further studied during the coming year together with
the supplemental methods outlined by the referee this year for the
preparation for microscopic examination of sweet and sweetened milk
chocolates.
Approved.
METHODS FOR THE EXAMINATION OF CACAO BUTTER.
It is recommended—
(1) That the following critical temperature of dissolution in acetic
acid test be adopted as a tentative method:
REAGENTS.
(a) Glacial acetic acid, as free as possible from water.
(b) 0.1N potassium hydroxide solution.
APPARATUS.
Insert a thermometer reading to 0.1°C. into a cork that fits a 6x34 inch test tube.
The thermometer should extend far enough into the tube that the bulb will be covered
by 10 cc. of liquid. Place the test tube in a larger tube (4x114 inch) containing glycerine
and hold firmly in place with a cork having a groove cut in the side to equalize the
pressure when heat is applied.
DETERMINATION.
Filter a portion of the sample to be examined through a dry filter paper in an oven
where a temperature of about 110°C. is maintained, to remove traces of moisture.
Allow the filtered sample to cool until barely warm, and weigh (a pulp balance is accu-
rate enough) 5 grams of the sample and 5 grams of the acetic acid reagent (@) into
the test tube. Insert the cork holding the thermometer and place the test tube in the
glycerine bath. Heat and shake the apparatus frequently until a clear solution of the
fat and acetic acid is obtained. Allow the solution to cool with constant shaking
without removing from the glycerine bath. Note the temperature at which the first
sign of turbidity appears. Make a similar test with the same acetic acid on a sample
of pure cacao butter. Free fatty acids lower the turbidity temperature. A correction
must therefore be made for the acid value of the sample.
CORRECTION FACTOR.
If the strength of the acetic acid reagent is such that the turbidity temperature of
the pure cacao butter is, approximately, 90°C. one unit of acid value will cause a re-
duction of 1.4 degrees in the critical temperature of dissolution. If the turbidity
temperature is approximately 100°C., one unit of acid value will cause a reduction of
1.2 degrees. For intermediate temperatures the reduction is proportional.
1 J. Assoc. Official Agr. Chemists, 1922, 6: 99.
1923] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 279
CORRECTED CRITICAL TEMPERATURE OF DISSOLUTION.
Determine the acid value (mg. of potassium hydroxide required to neutralize the
free fatty acids in 1 gram of the sample) of both the sample and the pure cacao butter
as directed under X XII, 301. Multiply the acid value by the correction factor and
add the result to the observed turbidity temperature. The figure obtained is the true
critical temperature of dissolution. If the true critical temperature of dissolution of
the sample is lower by more than 2 degrees than that of the pure cacao butter, adultera-
tion with coconut, palm kernel, cottonseed oils or stearines, corn oil, peanut oil or
other vegetable oils is indicated.
Approved.
(2) That the following acetone-carbon tetrachloride test be adopted
as a tentative method:
REAGENT.
A mixture of equal parts of acetone and carbon tetrachloride.
DETERMINATION.
Dissolve 5 cc. of the warm fat, which has been previously filtered through dry filter
paper in an oven at about 110°C. to remove traces of moisture, in 5 cc. of the acetone-
carbon tetrachloride reagent in a test tube. Allow the solution to stand in ice water
for 20-30 minutes. Run a blank ona sample of pure cacao butter at the same time.
If hydrogenated oil, tallow, oleostearine or paraffin is present a white flocculent pre-
cipitate will soon appear. If the water is cold enough, cacao butter may solidify. Ifa
precipitate is formed remove the sample from the ice water and allow to remain at
room temperature for a time. Solidified cacao butter will soon melt and go into solu-
tion but if the precipitate is due to any of the above-mentioned possible adulterants a
much longer time will be required for it to go into solution.
Approved.
(3) That the studies of the critical temperature of dissolution in acetic
acid and acetone-carbon tetrachloride tests be continued.
Approved.
COFFEE.
It is recommended—
That the studies of the acids of coffee be continued.
Approved.
TEA.
It is recommended—
(1) That the Bailey-Andrew method for the determination of caffeine
in tea? be adopted as an official method. (Second action as an official
method.)
Approved.
1 Assoc. Official Agr. Chemists, Methods, 1920, 250.
2 J. Assoc. Official Agr. Chemisis, 1922, 5: 292.
280 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
(2) That the following method for the determination of water extract
in tea be adopted as an official method. (First action as an official
method. )
To 2 grams of the ground sample in a 500 cc. graduated flask add 200 cc. of hot
water and boil over a low flame for 1 hour, rotating occasionally. The flask should be
closed with a rubber stopper through which passes a glass tube 30 inches long for a
condenser. Boil very slowly so that no steam escapes from the top of the air condenser.
Cool, dilute to volume, mix thoroughly and filter through a dry filter paper. Take an
aliquot of 50 cc. and evaporate to dryness over a steam bath. Then place in oven and
heat at 100°C. for 1 hour, cool and weigh.
Approved.
(3) That suggestions for further studies on tea be left to the incoming
referee.
Approved.
NITROGEN IN FOODS.
It is recommended that this subject be discontinued.
Approved.
THIRD DAY.
FRIDAY—AFTERNOON SESSION.
REPORT OF COMMITTEE TO COOPERATE WITH THE
REVISION COMMITTEE OF THE UNITED STATES
PHARMACOP@GIA.
Shortly after the last annual meeting, the chairman advised E. Fuller-
ton Cook, Chairman of the United States Pharmacopoeia Revision Com-
mittee, of the appointment by this association of a committee of five to
cooperate with the committee of revision dealing with matters having
to do with methods of analysis, physical constants and other analytical
features. His attention was also called to the fact that the A. O. A. C.
methods of analysis contained directions for analyzing drugs which are
different in some respects from those contained in the present Pharma-
copeeia.
The suggested plan of placing copies of monographs at the disposal of
the members of the committee for criticism appealed to Chairman Cook
and the monographs were sent to the members of our committee. The
criticisms were submitted to the A. O. A. C. chairman, assembled and
transmitted to the chairman of the Revision Committee.
In April a communication was addressed to Chairman Cook, criti-
cizing certain features contained in the monograph submitted and making
suggestions.
In this communication the committee discussed the following sub-
jects: Brevity of statements consistent with clarity and definiteness;
suitable sub-headings to enable workers to find at a glance what is
wanted; the necessity of stating definitely the condition of a substance
used in making tests; avoidance of duplication; consistency in using the
final e; assay methods for acetanilid and antipyrine; a standardization
of connectives so that they will have a definite meaning wherever used;
avoidance of the use of indefinite words and loose phrases; replacement
of such phrases as “should contain’? with the word ‘‘contains’’; avoid-
ance of necessity of analyst interpreting loose statements; the inadequacy
of the tests proposed for detecting certain forms of adulterants; recast-
ing of monographs of botanicals to bring them into harmony with the
monographs on other subjects; and the desirability of discontinuing the
centigrade abbreviation when this is practically the only scale used.
Monographs received later did not seem to contain anything of a
material character, not covered by the communication of your committee.
These monographs are in tentative form for criticism and revision.
281
282 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
Your chairman discussed at length the idea of a general uniform
working temperature for laboratory work in which temperature ‘is
involved, such as alcohol tables, specific gravities, optical readings,
refractive indices, refractometer observations, etc. He also communi-
cated with F. M. Farmer, Chairman of the Sub-committee on Specific
Gravities of the American Society for Testing Materials.
The more the subject was discussed and considered, the more complex
and difficult the probabilities of getting together on a uniform tempera-
ture became and agreement on such a temperature seemed very remote.
In order to obtain an expression from the members of this association
and subscribers to The Journal of the association, a questionnaire was
sent to all persons or institutions of record and also to a number of other
persons known to be interested in this work. About 1300 questionnaires
were sent out; 381 replies have been received to date. The question-
naire follows:
UNIFORM TEMPERATURE FOR MAKING DETERMINATIONS AND A VOTE
ON THE U.S. P. vs. A. O. A. C. ALCOHOL TABLES.
At the last meeting of the A. O. A. C., criticism was made of the A. O. A. C. and
U. S. P. alcohol tables. The sentiment appeared to be in favor of the A. O. A. C.
tables. The Chairman of the Committee to Cooperate with the U. S. Pharmacopeeial
Committee on Revision, appointed at the last meeting, has discussed the question
considerably with the conviction that a conclusion is not so easily arrived at. The
committee itself is divided; two are in favor of the A. O. A. C. alcohol tables and two in
favor of the U. 8. P. alcohol tables. The chairman has not yet been called upon to
cast his vote but favors the 20°/4° tables from a purely scientific point of view, yet
trade conditions play an important part and must be considered.
In view of the unsatisfactory outcome so far, the chairman is submitting the matter
to the A. O. A. C. membership for discussion, criticism and a vote.
It is conceded that the most convenient temperature for making routine observa-
tions is the laboratory temperature, but this temperature varies considerably from
time to time and in different sections of the country. A compromise temperature
should be agreed on.
The A. O. A. C. tables are based on the Bureau of Standards table 20°/4°, and rep-
resent true specific gravities, whereas the U. S. P. tables are based on the Bureau of
Standards tables 15.56°/15.56°, and are apparent specific gravities, barometer at
760 mm. with 50% air saturation. The Bureau of Standards, so far as your chairman
has been able to ascertain, has not committed itself to any temperatures for alcohol
tables or for determining specific gravities of alcoholic mixtures, but has adopted 20°
as the temperature for standardizing apparatus. 20°/4° is considered the more scien-
tific, but 15.56°/15.56° is more largely used in the industries and by industrial chemists
and 60°F ./60°F. is written into the Internal Revenue law dealing with alcohol products.
The Gauger’s Manual tables are also based on this temperature.
The question of a uniform temperature for alcohol tables is important in case of
per cent by volume, but percentage of alcohol by weight is independent of temperature.
It is true that specific gravities of alcoholics may be made at any temperature desired
but uniformity is highly desirable and the alcohol tables should be based on a uniform
temperature.
1923] REVISION OF UNITED STATES PHARMACOP(C@IA 283
The A. O. A. C. methods of analysis provide that specific gravities, whenever prac-
ticable, be determined on the basis of 20°/4° and that refractive indices and optical
rotations be made at 20° whenever practicable. This certainly makes for uniformity.
The U. S. Interdepartmental Committee on Paint Specification Standardizations
(consisting of representatives of the War, Navy, Agricultural, Interior, Post Office,
Treasury and Commerce Departments; the Railroad Administration; the Panama
Canal; and the War Service Committee of the Paint Manufacturers Association of
the United States) has adopted 15.5°/15.5° for linseed oil and oil of turpentine.
U. S. Pharmacopceial optical rotations are to be made at 25°; refractive indices at
20°; and specific gravities, unless otherwise provided, at 25°/25°. See Page LII of the
present Pharmacoporia.
F. M. Farmer, Chairman of the Subcommittee on Specific Gravity of the American
Society for Testing Materials, writes:
On the question of temperature there are so many standards already established in industry that it
seems hopeless to get standardization on any one temperature. I am proposing therefore that our com-
mittee simply recommend that where there is no particular reason for adopting other values, the standard
temperature of reference for the material be 25° and for the water 4°.
In order that the committee may have your views, please answer the following
questions, etc., and return in enclosed franked envelope.
i. Are vousn favorof the.A. O. A.C. alcohel tablésh 20s)... 2705 a ein aoe
2. Are you in favor of the U.S. P. 9th Revision, alcohol tables?.................
3. What single working temperature do you consider best for determining specific
gravities, optical readings, refractive indices, immersion refractometer read-
ings, etc.?
Suggestions and comments:
Your chairman presented the results obtained by the committee at a
general meeting of the American Pharmaceutical Association last Sep-
tember, the idea being to bring the information so far obtained to the
attention of all interested at the earliest practical date. This course
was taken with the advice of President Veitch. The report was printed
in the journal of the association!. A short notice of the work of the
committee was also printed in the Journal of Industrial and Engineer-
ing Chemistry?.. In each communication a request was made that all
interested in these matters communicate their views to your chairman
as early as possible. It is with extreme reluctance that he reports that
only one vote has been received in response to the information published
in these two journals.
The total number of votes received to date is 382, tabulated as follows:
Results of Vote on Alcohol Tables.
inutavorol AWOL AGC. tales gs oo 4s siya a Oe Bivona ae Pon 287
INO: IMPLAVOLOL foe Sk cis tee a See ee eS cet od Sty Tata Ce 35
INOt WOU Be hia Ssshael5 che aS oie) doses char 2) aR ay Pana eae Oe cae Nae era 60
mnpfavorof WS. 2s Oth Revision: 8.3 jo o4a en «aia eer ce eck sare ee 40
INO TATA OTAOL Hos rate. cer Bers a sosnadees) > sued oes Cae ds PRoNe enka ck gets edd 184
INCA ER OUT a7 ee eS Ena Ts eRBIy score es Cert eID on eee i Bromo. 158
1 J. Am. Pharm. Assoc., 1922, 11: 859.
2 J. Ind. Eng. Chem., 1922, 14: 988.
284. ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
The results of a vote on best working temperature show that 261
favor 20°; 83 favor 25° and 14 favor 15.5.
These results are so different from what was anticipated that the
committee feels greatly encouraged.
The report presented at the American Pharmaceutical Association
meeting has been mimeographed by Chairman Cook and sent to the
members of the U. S. P. committee, but no definite action has been
taken so far as is known to your chairman.
The United States Pharmacopeial convention in its adoption of
general principles to govern in revising the Pharmacopceia, unfortu-
nately stipulated that 25° should be used except in the alcohol tables.
Some of the members of the Committee of Revision are definitely in
favor of the 20° temperature, but do not see how it is possible to adopt
this temperature in view of the fact that the convention itself voted 25°.
The vast majority of those voting favor the A. O. A. C. alcohol tables,
but this vote may not be representative and therefore no conclusion is
drawn at present.
The vote on Question 3, covering the best temperature for making
determinations, is very definitely in favor of 20°, nearly 3 to 1, as against
all other temperatures.
To satisfy a natural curiosity concerning the personnel of this vote a
partial list of representative voters, selected at random, is given.
Partial list of votes on best working temperature.
Allyn, L. B. Analytical Laboratories, Westfield, Mass....................0.. 20°
American Sugar (Refining Go., New Yorke.) jaa th (ly egieves « dae siden aes 20
Americans PobaccoColiNe wily On eid ii tea | asi ea ee ele Re eee Saale 20
Antoine Chiris 'Co,,Eissential (Oils) New) ark ne 20s Wile ae tates ses cues 20
Armour & Co., Packers and Manufacturers of Foods and Drugs, Chicago...... 20
Ash, Charles S., Analytical Laboratory, San Francisco...................004- 15.56
Bartlett) J: MmExperiment Station; Orono;/Menymiin e750 hee eh ee 20
Browne, C. A., The New York Sugar Trade Laboratory, New York........... 20
Bureau tof Chemistry, Washington: Dy Coe Sie dui gil aes oe tar Nee sie ee ee ae 20
Bureau of Standards, Washington): (Gina). ace. scion: clelee eieretet ait) eee crenane 20
Galifornia State Board of! HealthiBerkeley agin. seen aeien eis elects cheer onal 20
Campbell Co., Joseph, Soup Manufacturers, Camden, N. J................... 25
Department ‘of Health, ‘Garieday (ith epi eney awe FRM Bins Sse. s Rie eieabesi ce pai GO 20
Doolittle, RB: Bditor A; OA. Cy Methods, Chicago. isis cit Tek See eee 2
General Chemical Co., Chemical Manufacturers, San Francisco office.......... 20
Gorton Pew Fisheries, Gloucester, Mass.........0...0000 000 cece eee eee ee eee 20
Great Western Suger'Got,! Denver, Coles. Tasiiiine Se ey kus fe aie een re 20
Heinz, H. F. Co., Pickle Manufacturers, Pittsburgh......................... 20
Hilton, S. L., Druggist, President of the American Pharmaceutical Association
1922; Washirigton) Ds Cues WE Wk Pe Sarat Se GUN, see tar 20
Iowa State Dairy and Food Commission, Des Moines....................05. 20
Johns; CHO.) Standard Oli Gon New Wonk sae aetna laretemie net ake 20
Langley & Michaels, Wholesale and Manufacturing Druggists, San Francisco... 20
1923] REVISION OF UNITED STATES PHARMACOP@IA 285
Lehn & Fink, Wholesale and Manufacturing Druggists, New York............ 20
Loomis, H. M., National Canners Association, Washington, D. C.............. 20
Massachusetts State Board of Health, Boston.....................c-ceeeees 20
National Biseuif Go: Ciaicapaw er ne ce te ck ese Pose a ben wee Cale eee Oy ay 20
Pacific American Fisheries Laboratories, South Bellingham, Wash............. ies
Parke, Davis & Co., Pharmaceutical Manufacturers, Detroit, Mich............ 25
Powers, Weightman & Rosengarten, Chemical Manufacturers, Philadelphia. ... 25
Proctor & Gamble, Soap Manufacturers, Cincinnati......................... 25
oyster, !.'5., Guano Co., Fertilizers, NOMolk, Va. je. 2,025.0 82% Pleas 20
Sears, Roebuck & Co., Mail Order and Manufacturers, Chicago............... 20
Sharp & Dohme, Pharmaceutical Manufacturers, Baltimore.................. 20
Sherwin Williams Co., Paint Manufacturers, Cleveland...................... 20
Solvay Process Co., Heavy Chemical Manufacturers, Syracuse, N. Y.......... 20
Sprague Warner & Co., Wholesale Food Manufacturers, Chicago.............. 25
United Drug Co., Retailers and Drug Manufacturers, Boston................. 20
Warversicy or viontrear. 2. 208) 4)", 2 OP ORT Tae OES AE RN Ae 20
WMettcehs Heb: President: Ati@: A. @2 ark Far eA sy. el OT AREER LiSey. | Beant 20
Warner, Wm. R. & Co., Drug Manufacturers, New York.................... 25
Woodman, A. G., Massachusetts Institute Technology, Boston............... 20
The vote as given shows practically the same ratio as the entire vote
and is 3 to 1 in favor of 20°, as against all other temperatures.
Other chemists than those in the United States are annoyed by the
multiplicity of temperatures prescribed by various authorities for making
observations. The same condition exists in other countries and some
efforts are being made to obtain uniformity. F. Auerbach, a member of
a Committee for Physical Constants!, calls attention to the chaos exist-
ing in Germany. After studying conditions the committee concluded
that 20° is best suited for a general working temperature. This “normal
temperature”, as Auerbach calls it, is to be used for standardizing
apparatus, tools, electric cells, optical readings, specific gravities, etc.,
unless there are some definite reasons for selecting another temperature.
Your committee feels that the outlook for ultimately agreeing on 20°
as a general working temperature by the vast majority of scientists and
industries is excellent and recommends the work of the committee be
continued.
Respectfully submitted,
L. F. Keser, A. R. Buss,
H. C. Lytueoer, W.S. Hupparp.
H. C. Futter,
Committee to Cooperate in Revision of the
U. S. Pharmacopeia.
Approved.
A motion that this committee be continued was made, seconded
and carried.
1 Pharm. Z., 1922, 67: 303.
286 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
REPORT OF REPRESENTATIVES ON THE BOARD OF
GOVERNORS OF THE CROP PROTECTION INSTITUTE
OF THE NATIONAL RESEARCH COUNCIL.
In the last report, the objects of the Crop Protection Institute were
outlined briefly and.need not be repeated. Without special mention it
might not be realized that ‘“‘crop” is interpreted rather broadly by the
institute to include animal as well as vegetable products of the farm.
In fact, a part of the necessary funds is already available for an investiga-
tion of the control of the ox warble.
A method of procedure by which scientific investigations could be
conducted for the industrial organizations, by direction of the institute,
has been determined.
This was a matter requiring very careful attention in order that the
contemplated service should not in any way embarrass other public-
service activities, for example, inspection or control work, with which
this association is so largely concerned.
Fortunately, a conference was made possible with the Federal Insecti-
cide Board, and invaluable suggestions were received from those who
have had long experience with proprietary articles. Suggestions and
criticisms were so carefully considered and the decisions so universally
endorsed that there would seem to be no reason for difficulties to arise
concerning the interests of public-service organizations dealing with
similar materials.
It can be imagined that if, for the purpose of investigation, a pro-
prietary material is submitted by an industrial concern, with a state-
ment of its composition and expected usefulness, an awkward situation
might arise as to whether claims were justified or not. It seems ap-
propriate, therefore, to quote the following section of the method of
procedure:
It is understood that the Institute will at all times conduct its investigations and
reach its findings in full understanding with Federal and State officials directly con-
cerned.
Three sulfur-producing companies, by cooperating in furnishing funds
for basic investigations of the value of sulfur in combatting crop pests,
have made possible full-time fellowships for well-trained men during a
period of two years.
Investigations have also been arranged to determine the comparative
value of dry chemicals for the treatment of cereals for smut eradi-
cation.
Orchard dusting work done in 1921 was reported by the institute in
Bulletin No. 2, February 1922. This research has been continued.
1923] SKINNER: REPORT OF SECRETARY-TREASURER 287
Other projects under consideration concern lime, miscible oils, sub-
limed sulfur, nickel compounds and cobalt compounds.
Now that methods of procedure have been determined, the institute
is in a position to give satisfactory attention to problems which are
of sufficient interest for industry to provide funds for their investiga-
tion. Intelligent supervision and laboratory equipments are available.
Burt L. Hartwe tt,
H. J. Parrerson.
Approved.
REPORT OF SECRETARY-TREASURER.
By W. W. Skinner (Bureau of Chemistry, Washington, D. C.),
Secretary-Treasurer.
The report of the secretary-treasurer this year includes a brief review
of the activities of the Executive Committee of the association since the
date of the 1921 convention. The purpose of this is to inform the mem-
bers and also to provide for the insertion in the proceedings of a record
of the Executive Committee’s work, since this committee to a certain
extent represents the association in the intervals between its regular
meetings.
Early in 1922 the association suffered an irreparable loss in the death
of Dr. William Frear of Pennsylvania, one of its most active and honored
members. His death created a vacancy in the Committee to Cooperate
with Other Committees on Food Definitions and in the Committee to
Cooperate with the American Society for Testing Materials on the
Subject of Agricultural Lime. The Executive Committee filled these
vacancies by appointing E. M. Bailey of Connecticut a member of
the Committee to Cooperate with Other Committees on Food Definitions,
and J. B. Weems of Virginia, a member of the Committee to Cooperate
with the American Society for Testing Materials on the Subject of
Agricultural Lime. A vacancy in the position of Referee on the De-
termination of Shells in Cacao Products, caused by the resignation of
B. H. Silberberg, was filled by the appointment of V. A. Pease, of the
Bureau of Chemistry, Washington, D. C.
At the meeting last year it was reported that the suit brought against
the association by the Williams & Wilkins Co. of Baltimore, Md., for-
mer publishers of The Journal, had been dropped by that firm and the
decision as to the action which the association should take in the matter
was left to the Executive Committee with power to act. As had been
anticipated, it soon became necessary to make a decision. A bill for
$500 for legal services was presented by the attorneys who had been
288 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
engaged to represent the association in that suit—Messrs. Frank, of
Frank, Emory and Beeuwkes of Baltimore and Sherier, of Leckie, Cox
and Sherier, of Washington—and these gentlemen began to press for
payment. The members of the Executive Committee felt that a charge
of $500 for the services rendered was excessive, but as this bill was sub-
mitted after these attorneys had been informed of the status of the
association’s finances and requested to make their charge as low as
possible, there seemed to be little prabability that they could be pre-
vailed upon to modify it. Nevertheless an attempt was made to secure
a reduction. Messrs. Frank and Sherier contended, however, that the
bill was a most reasonable one and that it would have been larger except
for the considerations which had already been brought to their attention.
Under the circumstances, the Executive Committee decided that the
best and practically the only thing to do was to authorize the payment
of this bill and to consider the whole matter closed. This was done by
a unanimous vote of the committee and the bill was paid in part from
dues and in part from funds credited to the account of The Journal.
The secretary has found that there seems to be an impression on the
part of some that membership in the association, as represented by the
payment of dues, carries with it a subscription to The Journal. Such is
not the case, and as misunderstandings of this kind becloud the signifi-
cance of the dues and increase the difficulty of financing The Journal, a
statement concerning the dues payable to the association may not be
out of place.
By-law 3 of the constitution and by-laws adopted at the 1916 meet-
ing! states that “Only such colleges, experiment stations, bureaus,
boards or other institutions whose members are active members of this
association shall be entitled to enter motions and vote’. By-law 10
says: ‘Each college, experiment station, bureau, board or other insti-
tution entitled to representation in the association shall contribute
annually $5.00 prior to the first of January following the regular annual
meeting’. It would appear to follow from this by-law that only those
units which have paid the required dues can claim the right to the active
participation in the affairs of the association mentioned in By-law 3.
This view is supported by the fact that By-law 7 of the old by-laws?
states that the representatives of the various units entitled to repre-
sentation shall not be qualified to vote or hold office in the association
unless such annual dues have been paid. The purpose of the dues is
mainly to provide funds for various expenses in connection with the
meetings of the association, such as the printing of programs, etc., and
for postage and other expenses incidental to the secretary’s work, and
1 J. Assoc. Official Agr. Chemists, 1920, 3: 586.
2 [bid., 1915, 1: iit.
1923] SKINNER: REPORT OF SECRETARY-TREASURER 289
dues are collected only from such units as have sufficient interest in the
affairs of the association to pay them.
Nothing is said in the constitution or by-laws about subscriptions to
The Journal. It appears from the discussion and reports which preceded
and attended its establishment! that the proposition of increasing the
dues to $10 or more for the purpose of financing The Journal was dis-
cussed. This, however, was not done. It is true that the dues are now
$5.00 instead of $2.00 as formerly, but this increase was not made for
the purpose of financing The Journal, as such an increase in dues would
have been entirely inadequate for the purpose. The dues paid to the
association have the same significance that they had before The Journal
was established. If these dues included a subscription, not only would
the burden of the association in financing The Journal be increased, but
the purpose of the dues would in large measure be defeated, since dues
then, would not be a direct contribution to the support of the association
by those institutional units by which it is controlled, but would assume
largely the character of a subscription to the association’s journal.
Subscriptions to The Journal by any of these institutional units or mem-
bers must be paid for just as if they were individual subscriptions.
The subscription rate to institutional as well as to individual members
is, however, $4.00, whereas the rate to non-members of the association
is $5.00.
In connection with the preparation of the program of the convention
for this year the question arose as to the propriety of giving a place on
the program to certain attorneys who desired to present matters in
which their clients were interested. In this particular instance the
matter was probably entirely legitimate, and one in which some of the
members of the association are undoubtedly much interested, but as the
program was already a full one, the request to present the argument
was refused. In this connection attention is called to By-law 9, ““Chem-
ists and others interested in the objects of the association may attend
its meetings, take part in its discussions, and present papers, if permis-
sion is secured from the Executive Committee’. The Executive Com-
mittee at its meeting Monday night expressed the opinion that the pro-
grams should be restricted to members and associate members of the
association so far as possible, but that the fullest discussion of subjects
presented should be invited and encouraged.
The Executive Committee at its recent meeting considered it neces-
sary to present to the association a by-law definitely providing for the
selection of the Board of Editors, as follows:
A Board of Editors of The Journal of the association, consisting of five members,
one of whom shall be designated the chairman, shall be appointed by the president
1 J. Assoc. Official Agr. Chemists, 1915, 1: 523, 531.
290 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
upon recommendation of the Executive Committee. These five members shall serve
one, two, three, four and five years, respectively, and each following appointment shall
be for five years.
The committee approved of a joint publication with the American
Public Health Association on “Standard Methods of Milk Analysis’.
The matter was referred, with power to act, to R. E. Doolittle, Chair-
man of the Committee on Revision of Methods, and R. W. Balcom,
Chairman of the Board of Editors.
The customary financial statement covering receipts of dues and dis-
bursements from that fund will be found following a similar statement
covering receipts and disbursements in connection with the association’s
publications, submitted by the chairman of the Board of Editors. (See
page 248.)
Approved.
G. S. Fraps: It might be well to raise the total sum so it would include
the subscription to The Journal and then both of these sums could be
paid in one transaction.
R. W. Balcom: One reason for not increasing the dues is the fact that
they are now fixed by the by-laws, but it might be well to mail the two
bills, one for the dues and one for the subscription to The Journal at
the same time. The dues can not be increased without changing the
by-laws.
W. W. Skinner: I do not believe it would be advisable to increase the
dues for the purpose suggested for several reasons. I think it was
brought out yesterday that the association is supported, as it was always
the intention it should be supported, by institutions and not by indi-
viduals, but the subscription to The Journal is almost entirely individual.
As only 15 per cent of the subscription list of The Journal represents the
individual members of the association, it seems to me that every member
should attempt to increase the subscriptions. Otherwise, The Journal
will be in serious difficulty. Really the support of The Journal now
comes from libraries, private institutions, commercial concerns and
others interested in the proceedings of this association. Only 15 per
cent of our own membership believes it sufficiently worth while to sub-
scribe for The Journal.
R. W. Balcom: It is less than 15 per cent, I think it is nearer 10, in
fact it is less than our foreign subscription list. Our domestic sub-
scriptions have fallen off. The point I wish to make is that if individual
members connected with institutions in our various States realized our
need we should receive additional subscriptions from the various States
that would jump the subscription list up at once to over one thousand.
This number would just about finance The Journal.
1923] SKINNER: REPORT OF SECRETARY-TREASURER 291
H. D. Haskins: It seems unfortunate that this could not be brought
up when we had a larger number of people here to consider this matter.
The fact that it has been brought up when there is such a small attend-
ance leads me to suggest that a letter be sent to individual members,
which will state the plain facts that have been presented here.
R. W. Balcom: That matter was very carefully considered in the con-
ference of the Board of Editors, and it seemed best, as Dr. Haskins has
suggested, to send a letter to the people of our various states, presenting
the facts to them and asking for their earnest cooperation in doing what
they legitimately can to solicit subscriptions. It would also give us
evidence of the interest of the individual members of the association in
the association’s journal. It is not sufficient for members to place sub-
scriptions for the libraries and to be sure that The Journal is there; we
need the support of the individual by a four-dollar subscription, and most
of us can afford it.
I. K. Phelps: I should like to inquire concerning the income from the
Book of Methods.
R. W. Balcom: Last year, as I stated, our supply of the first 3,000
copies of the Book of Methods was practically exhausted. We informed
you that we found it necessary to order 1000 additional copies. The
printer ran off 1,224. During the past year we have sold over 600
copies at $5.00, in most cases. We make a 20 per cent reduction to
book dealers. We have paid for the 1,224 copies, so that the net profits
during the past year have been something like $1500. This year we
have on hand approximately 600 copies and if we have as good luck as
last year we will dispose of them during the next year and our profits
will be practically net. We are depending on that to reduce our deficit.
We want to make our Journal self supporting so that on future editions
of the Book of Methods we may be able to reduce the cost.
President Veitch: What is the deficit, Dr. Baleom?
R. W. Balcom: Last year we reported approximately $950. That has
been increased. We have not held our own, owing, largely, to the bill
for legal services. The deficit is probably in the neighborhood of $1600.
If we can sell 600 copies of the Book of Methods during the next year or
get 100 or 150 individual subscriptions, we can practically wipe out
our deficit.
292 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
REPORT OF COMMITTEE TO COOPERATE WITH OTHER
COMMITTEES ON FOOD DEFINITIONS.
Your committee respectfully submits the following report of the
proceedings of the Joint Committee on Food Definitions and Standards
for the period since the 1921 meeting of this association.
During the past year the following change in the membership of
the committee has occurred: In November, 1921, by reason of a
rearrangement in the Bureau of Chemistry affecting the Office of Food
Control, F. C. Blanck, appointed in charge of this division, was designa-
ted to represent the Department of Agriculture on this committee,
vice I. K. Phelps.
Another change, which comes closely home to this association, was
in consequence of the lamentable death, on January 7th of this year, of
Dr. William Frear, chairman of the committee. Reorganization was
effected through the selection of W. W. Skinner, Assistant Chief of the
Bureau of Chemistry, as chairman, and of E. M. Bailey, chemist in
charge, State Agricultural Experiment Station, New Haven, Conn., to
represent this association.
For many years Dr. Frear was your senior representative on this
committee, and his work and achievements in this connection are well
known to you. Although his associates knew that he had been in ill
health for a long period, his death, occurring as it did but a few hours
following his call convening a special meeting of the committee for the
following week, came as a surprise and was received with deep sorrow.
The following resolutions were adepted by his associates on the com-
mittee:
Whereas, The sudden death of its chairman, William Frear, in the midst of a most
useful life, deprives this committee of the services of its most experienced and capable
member, and
Whereas, This committee shares with every association in America devoted to
science, to agriculture, to improvement in the quality of food products, and to the
enactment and enforcement of pure food legislation, a deep sense of the loss which has
befallen us in the death of so distinguished a leader; therefore, be it
Resolved, That this committee extends to the members of the family of William
Frear its profound sympathy at this time of their bereavement, and desires to record
its affectionate esteem of his sterling honesty, his profound knowledge, his administra-
tive ability and his kindliness of heart; and be it further
Resolved, That, in common with the many scientific organizations of which William
Frear was a member or to which his was a familiar name, this committee laments the
loss of one whose intellectual clarity, fine sense of justice and breadth of sympathy
made him a unique figure among his associates and acquaintances; and be it also
Resolved, That these resolutions be spread upon the minutes of this committee, and
that a copy thereof be sent to his family, one to the Secretary of Agriculture of the
United States, and one to the Secretary of Agriculture of the State of Pennsylvania.
1923] COMMITTEE TO COOPERATE ON FOOD DEFINITIONS 293
During the past year three meetings of the committee were held in
Washington, in January, June and September. Hearings were given in
January to the Association of Cocoa and Chocolate Manufacturers and
to representatives of the baking interests. Much of the January meeting
was devoted to consideration of a schedule of bread definitions and
standards as developed by one of your representatives on the committee.
This schedule has been published and, as a result of criticisms and sug-
gestions thereafter received, the standards have been modified in certain
minor details and as now presented represent the best judgment of the
committee.
In connection with the evaporated milk schedule hearings were given
in June to the interests concerned. Following extended hearings upon,
and consideration of, the subject of ginger ale, the committee was con-
vinced as to the need of revision of the original definitions and such
revision has been effected.
At the September meeting representatives of the spice trade appeared
to protest concerning the present ash limits for capsicum and cumin
seed and to ask for particular consideration of the specifications for
American sage. Affirmative action was taken by the committee as to
capsicum, the other topics being reserved for further study. Affirma-
tive action was taken concerning the cinnamic aldehyde content of oil
of cassia, and also concerning the revision of definitions and standards
for cacao products, butter and renovated butter.
Other subjects still under consideration include macaroni, sirups,
mustard, fruit pies, sausage, jams and jellies, almond paste, soy bean
flour, fruit juices, ice cream and certain tomato products. The present
flour schedule is also due for early revision.
An important change in the policy of the committee, as adopted at
the June meeting, involves the prompt publication of all affirmative
action. The object of this procedure is to bring the schedules adopted
to the attention of all concerned as soon as possible, and thus enable
the committee to avail itself of whatever criticisms may be offered
before the definitions and standards are presented in final form.
Following full publication to food control officials and to the trade
interests concerned, the Joint Committee has finally adopted the fol-
lowing schedule of definitions and standards:
CONDENSED MILK, EVAPORATED MILK, CONCENTRATED MILK.
Definitions and Standards adopted by the Joint Committee on Defi-
nitions and Standards, June 22, 1922.
Condensed milk, evaporated milk, concentrated milk, is the product resulting from the
evaporation of a considerable portion of the water from milk, or from milk with adjust-
ment, if necessary, of the ratio of fat to non-fat solids by the addition or by the abstract-
ion of cream. It contains, all tolerances being allowed for, not less than seven and
294 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
eight-tenths per cent (7.8%) of milk fat, nor less than twenty-five and five-tenths per
cent (25.5%) of total milk solids: provided, however, that the sum of the percentages
of milk fat and total milk solids be not less than thirty-three and seven-tenths (33.7).
BUTTER.
Butter is the clean, sound product made by gathering in any manner the fat of fresh
or ripened milk or cream into a mass, which also includes a small portion of the other
natural milk constituents, with or without salt, and contains, all tolerances provided
for, less than sixteen per cent (16.0%) of water, and not less than eighty per cent (80.0%)
of milk fat. By acts of Congress, approved August 2, 1886, and May 9, 1902, butter
may also contain added coloring matter.
RENOVATED BUTTER.
Renovated butter, process butter, is the clean, sound product made in semblance of
butter, from melted, clarified or refined butter-fat, without the addition or use of any
substance other than water, milk, cream, or salt, and contains, all tolerances provided
for, less than sixteen per cent (16.0%) of water, and not less than eighty per cent (80.0%)
of milk fat.
GINGER ALE FLAVOR.
Ginger ale flavor, ginger ale concentrate, is the flavoring product in which ginger is
the essential constituent, with or without other aromatic and pungent ingredients,
citrus oils, and fruit juices.
GINGER ALE.
Ginger ale is the carbonated beverage prepared from Ginger Ale Flavor, sugar (su-
crose) sirup, harmless organic acid, potable water and caramel color.
CACAO PRODUCTS.
Definitions and standards adopted by the Joint Committee on Defi-
nitions and Standards, September 29, 1922.
1. Cacao beans, cocoa beans, are the seeds of trees belonging to the genus Theobroma,
especially those of Theobroma cacao L., and closely related species.
2. Cacao nibs, cocoa nibs, ‘“cracked cocoa’, are roasted or dried cacao beans, broken
and freed from germs and from shell or husk.
3. Chocolale, plain chocolate, bitter chocolate, chocolate liquor, chocolate paste, bitter
chocolate coating’, is the solid or plastic mass obtained by grinding cacao nibs and con-
tains not less than fifty per cent (50%) of cacao fat and, on the moisture and fat-free
basis, not more than eight per cent (8%) of total ash, not more than four-tenths per
cent (0.4%) of ash insoluble in hydrochloric acid and not more than seven per cent
(7%) of crude fiber.
4. Sweet chocolate, sweet chocolate coating, is chocolate mixed with sugar (sucrose),
with or without the addition of cacao butter, spices, or other flavoring materials, and
contains, on the moisture-, sugar- and fat-free basis, no greater percentage of total ash,
ash insoluble in hydrochloric acid, or crude fiber, respectively, than is found in moisture-
and fat-free chocolate.
5. Milk chocolate, sweet milk chocolale, is the product obtained by grinding chocolate
with sugar, with the solids of whole milk, or the constituents of milk solids in pro-
1 Definitions and standards for alkalized products will form a separate schedule.
1923] COMMITTEE TO COOPERATE ON FOOD DEFINITIONS 295
portions normal for whole milk, and with or without cacao butter and/or flavoring
material. It contains not less than twelve per cent (12%) of milk solids.
6. Cocoa, powdered cocoa, is chocolate deprived of a portion of its fat and pulverized,
and contains, on the moisture- and fat-free basis, no greater percentage of total ash,
ash insoluble in hydrochloric acid, or crude fiber, respectively, than is found in mois-
ture- and fat-free chocolate.
7. “Breakfast cocoa” is cocoa which contains not less than twenty-two per cent
(22%) of cacao fat.
8. Sweet cocoa, sweelened cocoa, is cocoa mixed with sugar (sucrose), and contains
not more than sixty-five per cent (65%) of sugar in the finished product, and, on the
moisture-, sugar- and fat-free basis, no greater percentage of total ash, ash insoluble in
hydrochloric acid, or crude fiber, respectively, than is found in moisture- and fat-free
chocolate.
9. Sweet milk cocoa is the product obtained by grinding cocoa with sugar, with the
solids of whole milk, or the constituents of milk solids in proportions normal for whole
milk, and with or without flavoring material. It contains not less than twelve per
cent (12%) of milk solids.
C. EDIBLE VEGETABLE OILS AND FATS},
Cacao butter, cocoa butter, is the edible fat obtained from sound cacao beans (seeds of
Theobroma cacao L., or other closely related species), either before or after roasting.
BREADS.
Bread is the sound product made by baking a dough consisting of a leavened or
unleavened mixture of ground grain and/or other clean, sound, edible farinaceous
substance, with potable water, and with or without the addition of other edible sub-
stances.
In the United States the name “bread’’, unqualified, is understood to mean wheat
bread, white bread.
Wheat bread dough, white bread dough, is the dough consisting of a leavened and
kneaded mixture of flour, potable water, edible fat or oil, sugar and/or other fermentable
carbohydrate substance, salt and yeast, with or without the addition of milk or a milk
product, of diastatic and/or proteolytic ferments, and of such limited amounts of
unobjectionable salts as serve solely as yeast nutrients?, and with or without the re-
placement of not more than three per cent (3%) of the flour ingredient by some other
edible farinaceous substance.
Wheat bread, while bread, is the bread obtained by baking Wheat Bread Dough in
the form of a loaf or of rolls or other units smaller than a loaf. It contains, one hour
or more after baking, not more than thirty-eight per cent (38%) of moisture, as deter-
mined upon the entire loaf or other unit.
Milk bread is the bread obtained by baking a wheat bread dough in which not less
than one-third (14) of the water ingredient has been replaced by milk or the constituents
of milk solids in proportions normal for whole milk. It conforms to the moisture
limitations for Wheat Bread.
Rye bread is the bread obtained by making a dough which differs from Wheat Bread
Dough in that not less than one-third (14) of the flour ingredient has been replaced by
rye flour. It conforms to the moisture limitation for Wheat Bread.
1U. S. Dept. Agr. Circular 136, 17. ;
* NoreE—The propriety of the use of minute amounts of oxidizing agents as enzyme activators is reserved
for future consideration and without prejudice.
296 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
Raisin bread is the bread obtained by baking Wheat Bread Dough, to which have
been added sound raisins in quantity equivalent to at least three (3) ounces for each
pound of the baked product and which may contain proportions of sweetening and
shortening ingredients greater than those commonly used in Wheat Bread Dough.
Brown bread, Boston brown bread, is a bread made from rye and corn meals, with or
without flour, whole-wheat flour, and/orrye flour, with molasses, and in which chemical
leavening agents, with or without sour milk, are commonly used instead of yeast.
In some localities the name Brown Bread is used to designate a bread obtained by
baking a dough which differs from Wheat Bread Dough in that a portion of the flour
ingredient has been replaced by whole-wheat flour.
D. CONDIMENTS (OTHER THAN VINEGAR AND SALT)!.
Definitions and standards adopted by the Joint Committee on Defi-
nitions and Standards, September 29, 1922.
b. FLAVORING EXTRACTS?.
5a. Oil of cassia is the lead-free volatile oil obtained from the leaves or bark of
Cinnamomum cassia Bl., and contains not less than eighty per cent (80%) by volume
of cinnamic aldehyde.
a. SPICES.
10. Cayenne pepper, cayenne, is the dried, ripe fruit of Capsicum frutescens L.,
Capsicum baccatum L., or some other small-fruited species of Capsicum. It contains
not less than fifteen per cent (15%) of nonvolatile ether extract, not more than one and
five-tenths per cent (1.5%) of starch, not more than twenty-eight per cent (28%) of
crude fiber, not more than eight per cent (8%) of total ash, nor more than one and
twenty-five hundredths per cent (1.25%) of ash insoluble in hydrochloric acid.
Respectfully submitted,
Jutius Hortvet, C. D. Howarp,
E. M. Baiwey.
Committee to Cooperate with Other Com-
mittees on Food Definitions.
Approved.
Following the report of the Committee to Cooperate with Other Com-
mittees on Food Definitions, E. M. Bailey also read the following com-
munication, which had been sent to the secretary September 16, 1922:
GENTLEMEN:
The three members of your association who are your representatives upon the Joint
Committee on Definitions and Standards, desire to call your attention to a difficulty
which has in the past seriously hampered their work and to request of you such formal
action as will relieve the situation.
At each of the annual conventions of this association it has been the custom to have
the chairman of the group of your representatives upon the Joint Committee report
to the association the definitions and standards which that committee has formulated
since the last convention. By vote of the convention these definitions and standards
1U. 8S. Dept. Agr. Circ. 136, 11.
2 [bid., 15.
1923] COMMITTEE TO COOPERATE ON FOOD DEFINITIONS 297
have then been approved, and, after similar approval by the Dairy, Food and Drug
Officials, they have been submitted to the Secretary of Agriculture for consideration
and for such action as he may see fit to take in the premises. No definitions or stand-
ards have been submitted to the secretary except after formal approval by the two
associations.
Until recently, the committee has taken the stand that, after agreement had been
reached upon the formulation of any item, it was incumbent upon the members to
refrain from giving out any information concerning such action until the matter had
been formally presented to one or other of the associations for its approval. Applica-
tions made during the interval for information with regard to the action taken, were
therefore met with refusal, explanation being given that the decisions were only tenta-
tive until approval by the association had been secured.
At a recent meeting, the committee considered this matter anew and decided that
such a rule was disadvantageous to all concerned. It was bound to result in the pre-
sentation to that association, whose annual meeting came first, of matters of which the
members of such association had no previous knowledge, and in calling upon them to
approve or to disapprove of action into the reasonableness of which they had had no
opportunity to examine. As a result, the vote of the association was of necessity per-
functory, and its value practically negligible. In the same way the trade, having no
knowledge of the action of the committee prior to the annual convention of the asso-
ciation, were stopped from bringing criticism to bear at the very time when such criti-
cism should be heard.
Accordingly, the committee decided to publish its decisions as soon as possible
after its sessions, and thus to show its desire that its action receive prompt considera-
tion and be subjected to proper criticism. Under the procedure hereinafter proposed,
should valid objection from any source be made to the definition or standard formu-
lated, there would be opportunity for the committee to withhold its recommendation
and to reconsider the matter before its presentation to the secretary.
Since the meetings of the associations take place but once a year, while those of the
Joint Committee are held three or four times in each year, it follows that the decisions
of the committee must, under the present arrangement, lie in abeyance anywhere up
to a year before they can be recommended to the secretary. This delay is frequently
a source of great annoyance to administrative officials and to the trade. If there were,
in our opinion, any compensating advantage gained through this method of handling
the matter, we should hesitate to bring the question before you; but, so far as we have
been able to observe, the associations have in each case felt that they were not in a
position to pass judgment upon the work of the committee and hence have given their
formal approval practically without discussion of any kind.
In order, therefore, to eliminate this delay, we request that you grant to your rep-
resentatives upon the Joint Committee on Definitions and Standards the authority,
for you and in your name, to approve such definitions and standards as, after careful
consideration, they believe to have been couched in satisfactory form.
In conclusion, let it be said with all emphasis, that your representatives upon the
Joint Committee do not, in asking the association to grant them this power to act,
desire to arrogate to themselves an authority which should not be theirs. Their aim
is simply to remove an impediment which is a cause for delay and therefore a source of
annoyance and which serves no useful purpose so far as they can see. They know,
and they believe the association recognizes, that they have given the matters upon
which they have come to a decision prolonged consideration; have secured a mass of
information from all available sources known to them; have consulted with repre-
sentatives of the trade in public conferences; and have used their best ingenuity to
put their conclusions into clear, terse wording. They do not believe—and the history
298 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
of this question seems to bear them out in this—that hasty consideration, at a busy
convention, of the definitions and standards proposed, is likely to result in any good at
all comparable with that secured through the speedy reference of the matter to the
consideration of the Secretary of Agriculture and his advisers.
We are
Very respectfully,
Juxtius Hortver,
C. D. Howarp,
E. M. BatrLey.
It was moved, seconded and carried that the power of approval re-
quested be granted to the Committee to Cooperate with Other Com-
mittees on Food Definitions.
W. W. Skinner: The following letter, dated Nov. 13, 1922, relating
to the subject of evaporated milk was received from the Van Camp
Packing Co.:
Mr. W. W. SKINNER, Secy-Treas.,
Bureau of Chemistry,
Association of Official Agricultural Chemists,
Washington, D. C.
Dear Sir:
Due to the fact that the question of the proposed change in the existing regulation
governing the manufacture of Evaporated Milk is to be brought before the meeting
of the Association of Official Agricultural Chemists at Washington, D. C. for its con-
sideration, we desire to register our continued protest against any change being made
in the existing regulation which would tolerate manipulation in modifying the fat and
solids of the whole milk which enters into the manufacture of Evaporated Milk, thereby
nullifying the existing regulations which require that Evaporated Milk shall be manu-
factured from whole milk only.
We are enclosing copy of written argument which we submitted to the Joint Com-
mittee on Definitions and Standards in Washington, D. C., June 19, 1922 in protest
against. any change in the existing regulation, and request that this letter and our
protest be read before the open meeting; also referred to the committee having this
matter in charge.
Yours very truly,
The Van Camp Packing Company, Inc.
(Signed) C. W. Mann,
Vice President.
The secretary brought this letter to the attention of the Executive
Committee Monday night, the matter was carefully considered and it
was decided that it should be read before the general meeting, but that
the argument which had been previously considered by the Standards
Committee should not be read unless it was demanded by some member
of the association. The Executive Committee believed that the open
meeting was no place to present such an ex parle statement.
President Veitch: The question is on the adoption of the report of
the Committee to Cooperate with Other Committees on Food Defi-
nitions.
1923} COMMITTEE TO COOPERATE ON FOOD DEFINITIONS 299
H. C. Lythgoe: I wrote a letter to the secretary of the association
shortly after these new proposed changes were submitted. The objec-
tion I have is that the definition for evaporated milk is apparently in
conflict with the law. The law regards as adulterated any article of
food from which anything has been taken away. The various laws of
the different States and the standards of this association recognize milk
as whole milk from which no cream has been removed and to which no
water has been added. The statutes of many States require the law-
enforcing body to adopt the standards of this association, or rather the
standards of the Secretary of Agriculture, whenever those standards do
not conflict with the law. The adoption of these standards by such
law-enforcing bodies comes under the same provision of law as the
making of regulations. All such regulations must, in the first place, be
reasonable and, in the second place, must conform with the law in order
to be effective. I question very seriously whether this change could be
legally adopted by any of the States having such statutes as I have
quoted. In the State of Massachusetts I am sure we could not. We
shall not have this problem, because we have a special statute covering
the sale of condensed milk and under that statute all condensed milk
that has not all the cream in it must be labelled condensed skim milk.
I had a talk with the Chairman of the Standards Committee and we
decided the question was merely an academic one. I am convinced
that not only condensed milk but uncondensed milk is greatly manipu-
lated. If we can get the evidence of such manipulation, the seller of
such milk can be prosecuted. I see no reason why a special name could
not be devised which would recognize that practice and legalize it.
President Veitch: The whole argument from all points of view has
been considered by the Standards Committee. Now, do we, in view
of all these facts and in view of the fact that we won’t get the informa-
tion and have not the time to do it if we could get the information, want
to get into this thing at this time? I think there is nothing to do but
leave it to the Standards Committee.
W. W. Skinner: May I say a word? Naturally I would hesitate to be
drawn into an argument or controversy with my good friend from Massa-
chusetts or any other member of the association about the work of the
Joint Committee on Definitions and Standards and I hesitate somewhat
to attempt an explanation, although I believe it is due. The reason
the Executive Committee did not attempt to review this matter is
that it can not possibly consider questions of this kind intelligently
unless it is going to devote a large amount of time to them. Let me
say to you that this milk situation has been discussed for many years
by those in the industry and officials interested in evaporated milk.
The Bureau of Chemistry alone, I think, has given it consideration for
300 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
some ten or twelve years, and for more than two years, in cooperation
with the Milk Committee of the National Canners Association and the
Committee of the Milk Producers’ Association, has conducted elaborate
experiments. So a great mass of information has accumulated and is
available to the Standards Committee. It would take any one of you
more than a week to digest the accumulated data which have been
collated and critically reviewed by the Standards Committee over a
period of several sessions. I do not care to carry this argument very
far at this time because, as Mr. Lythgoe has said, it is somewhat of an
academic question. We could argue indefinitely about these things.
At times the members of this association and others may overlook the
philosophy which must govern the deliberations of the Standards Com-
mittee and fail to appreciate the significance of the title Joint Committee
on Definitions and Standards. The question generally is in regard to
definitions. Now, as I have stated before, we have to define things, not
necessarily as they are in the literal sense but as they exist under present
conditions, and we have no authority or right to set up ideals and attempt
to translate them into either definitions or standards. So, I would say
to my friend, Dr. Huston, in regard to the amount of raisins in raisin
bread, or currants in currant bread—which he questioned after hearing
the definition—that we have investigated the matter thoroughly and
have interviewed the people who could give us information. We have
learned what the industry means by raisin bread and what the public
thinks is the best raisin bread and upon the evidence we have determined
the limit of the quantity of raisins in a product called raisin bread. The
Committee on Definitions and Standards must sit in judgment as a
court basing its judgment upon the evidence. The evidence in this
case shows that 3 ounces per pound is about the lowest limit of raisins
a product should contain which is called, and made and sold as, raisin
bread. You may say, “I do not want that, I want a 50 per cent raisin
bread’. Someone else would call 50 per cent raisin bread a fruit cake.
I merely use raisin bread as an illustration. We are trying to define the
bread which has been known and sold by the best bakers as raisin bread,
and if you get a pound loaf with 3 ounces of raisins in it, the committee
is ready to say that you are getting about all you are entitled to. At
the bakers’ convention in Chicago, I was taken to task for our definition
of rye bread. In the investigations made we found that a small amount
of rye bread baked for certain of our foreign population is made, as a
rule, of all-rye flour, but that generally no all-rye-flour bread is sold to
the American people and marketed under that name. A limited quan-
tity of so-called rye bread is also made by certain bakers for the Jews
who like less than 20 per cent of rye. These bakers say, “What are we
going to do?”’ The committee had to draw the line somewhere and so
concluded from the best evidence that the limit should be 33 per cent
1923] COMMITTEE TO COOPERATE ON FOOD DEFINITIONS 301
rye flour for American rye bread, a standard which would conform to
the best baking practice.
I am only telling you these things to show you what the philosophy
of the committee has to do with the making of definitions and stand-
ards. The proposed standard for evaporated milk is higher than the
present standard; under it either the solids or fat, or both, must be
increased. The old standard was based upon the data for sweetened
condensed milk; this was unwise since such data are not always applica-
ble. The present standard has been complied with by modifying the
milk—adjusting it to meet the numerical limits prescribed. Mr. Lyth-
goe knows, and I am sure he will verify this, that most of the milk sold
in Boston and other cities is made to comply with the numerical stand-
ards by adjustment. The milk may be adjusted by the farmer, by the
distributor, and by the factory.
The question seems to be: ““What is evaporated milk and what ought
evaporated milk to be when you buy it?” Certainly you would not
regard as an undesirable practice the addition of cream to a milk too
poor in cream to make a satisfactory evaporated product; that has been
the attitude of the committee. On the other hand, in a certain section
of the country, it is alleged, the end of the lactation period of the cows
occurs at about the same time for the entire herd; under these conditions
the milk is so high in fat in relation to the solids that it can not be evap-
orated successfully without causing trouble from granulation. Adjust-
ment of this milk is of no detriment to the consumer under the proposed
standard. He will get a higher product than he has in the past, and the
product of the herds may be used for the entire lactation period. The
committee believes that this proposed standard for evaporated milk is
a fair and just one.
H. D. Haskins: Your Committee on Definitions of Terms and Inter-
pretation of Results on Fertilizers held a meeting and considered the
questions which had been proposed by control officials and by commercial
and trade chemists and we propose to make a short, formal report at
this time. In making definitions and interpreting results, I think this
committee should go slow in what it officially recommends for adoption
by the association. It was rather a question as to how this committee
could best function. We finally decided that it would be wise to fol-
low the procedure of the Association of Feed Control Officials—that
is, to allow a free and full discussion on any subject that may be pro-
posed, in an open meeting of the committee, and prior to this meeting
to furnish a list of subjects to the control fertilizer chemists, the trade
chemists and the commercial chemists. Then, after a full and free dis-
cussion, allow the committee to go into session and formulate its defi-
nitions and interpretations of results and bring them before the asso-
ciation, as provided in the amendments to the by-laws that were pro-
302 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
posed this morning. It will be understood that there will be no dis-
cussion at this time on the subjects which will be mentioned in the for-
mal report, but that there will be opportunity for free and full discussion
by everybody interested a year hence; provisions will be made for that
in a suitable place, probably prior to the next meeting of the associa-
tion. I shall now read the formal report which this committee wishes
to make to the association this morning.
REPORT OF THE COMMITTEE ON DEFINITIONS OF TERMS
AND INTERPRETATION OF RESULTS ON FERTILIZERS.
The committee, after organization, considered a list of questions which
had been submitted for its deliberations. It was the unanimous opinion
of the committee that full and free discussion should be allowed on any
appropriate subject, and it was therefore voted that suggested questions
should be considered for a term of one year, then to be discussed in the
presence of the committee by any one interested, prior to any recom-
mendations as tentative definitions and rulings. The following subjects
for definition and ruling are therefore submitted for consideration and
study:
1. BASIC PHOSPHATIC SLAG.
Basic phosphatic slag is a by-product in the manufacture of steel from phosphorus-
containing iron ores. The product shall be finely ground and shall contain no admix-
ture of materials other than what results in the original process of manufacture. It
shall contain not less than 12% of total phosphoric acid, and not less than 80% of the
total phosphoric acid shall be soluble in 2% citric acid solution according to the Wagner
method of analysis. Any phosphatic slag not conforming to this definition shal! be
designated as low grade.
2. INTERPRETATION OF THE WORD “LIME” AS APPLIED TO FERTILIZERS.
The term ‘‘lime’’ shall not be used in the registration, labelling, or guaranteeing of
fertilizers or fertilizing materials, unless the “‘lime”’ is in a form to neutralize soil acidity,
such as the oxide, hydroxide, or carbonate, or equivalent magnesia compounds.
3. DRIED PULVERIZED OR SHREDDED MANURES.
Dried pulverized or shredded manures shall be only what the name indicates, and not
mixtures of pulverized manures and other materials.
Definitions for the following proposed subjects have not yet been
formulated:
Unleached wood ashes.
Leached wood ashes.
Ashes from leached wood.
Double manure salts.
Manure salts.
Dissolved bone and potash.
1923] REPORT OF AUDITING COMMITTEE 303
Additional questions which have been considered:
(1) Shall the committee encourage and urge the practice of including the formula grade
of fertilizer with the brand name?
The committee recommends and urges the practice of including the formula grade of
fertilizer with the brand name, depending upon the section of country where the product
is sold; for example, grade 4-8-4 or 8-4-4.
(2) The question of a uniform plan of reporting fertilizer analysis in control work.
What should constitute a proper detailed analysis report?
The committee would encourage not only a study of the quantity of plant food
guaranteed in any fertilizer, but also a study by any methods that might result in the
improvement of the quality of said plant food, even though this was not called for in
the fertilizer law.
(3) Interpretation of results on nitrogen availability. The committee does not feel
prepared at this time to offer any suggestions on this subject.
Proposed subjects which the committee feels could be more appro-
priately handled by the fertilizer referee and so recommends:
(1) The consideration of grinding analytical fertilizer samples finer
than through a 1 mm. round-hole sieve.
(2) A suggestion that the official method for the determination of
ammonia in fertilizers be interpreted as being applicable to sulfate of
ammonia, and that further study be made on the determination of
moisture in this salt.
(3) A further investigation of the determination of total and insoluble
phosphoric acid in vegetable meals and in mixtures containing them.
The committee welcomes suggestions and further subjects by any
one interested.
H. D. Haskins, E. G. Provu.x,
R. N. Brackett, J. W. KELLoGG,
G. S. Fraps.
Committee on Definition of Terms and
Approved. Interpretation of Results on Fertilizers.
REPORT OF AUDITING COMMITTEE.
The Auditing Committee has had submitted to it the financial report
on publications of R. W. Balcom, Chairman, Board of Editors, covering
the period from October 15, 1921, to October 31, 1922. The report was
found to be in good order, with proper and sufficient vouchers for all
disbursements.
The committee has also examined the report of W. W. Skinner, Secre-
tary-Treasurer, covering the same period, and has found the account to
be correct, with proper vouchers for all disbursements.
Respectfully submitted,
C. M. Brappury,
J. B. REEp.
Approved. Auditing Committee.
504 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
R. N. Brackett: When the general referees were first appointed, I
understood that the appointment was intended primarily to enable us
to have some one in authority to take up any new work that might
arise between the annual meetings of the association. The question of
general referees arose at the time of the borax trouble. If there had been
a general referee he might have taken up the subject and appointed
appropriate referees. I took the liberty last year of adding an extra
referee on potash, but as some members of the association considered
that by this action I was overstepping my authority, Dr. Skinner thought
it would be well to decide whether the general referee had any authority
to appoint another referee on a subject.
J. W. Kellogg: If it is in order, I will make a motion to the effect that
it is the sense of the association that the general referee has the authority
to appoint associate referees as the occasion arises.
P. F. Trowbridge: I take exception to that. We should encourage
the work but it seems to me that the referee should wait another year,
or report any extra work under his name. I do not believe that any
individual member of the association ought to assume the responsibility
of naming an associate referee. I think it does not need any action.
B. B. Ross: It was my understanding that the point was made that
the general referee, in investigating work before the association meet-
ing, would have the authority either on his own initiative or through
the Executive Committee to secure an associate referee.
President Veitch: Yes, on points not covered by a referee.
B. B. Ross: If it is understood that he has that authority, that is
all right.
P. F. Trowbridge: It ought to come to the Executive Committee.
President Veitch: It is the sense of the meeting, if I may voice it,
that when an additional associate referee is needed in the interim,
referees should be designated by the Executive Committee on the recom-
mendation of the general referee.
B. B. Ross: This is unofficial business which some of us have dis-
cussed informally on the outside. It has been suggested that inasmuch
as we attend here in a very large group and have no opportunity to get
together in a social way at any time it would be well to set apart one
night for a smoker or Dutch lunch for the members and chemists at-
tending the meeting. We could get together in an informal social way,
become better acquainted and do some reminiscing. I move that this
step be taken and that in the notice of the meetings to be sent out in
advance mention be made of the fact that some evening, say the second
evening of the convention, be set apart for such a social gathering.
It was moved, seconded, and carried that the second evening of the
association’s convention be set apart for an informal social meeting.
1923] REPORT OF COMMITTEE ON RESOLUTIONS 305
REPORT OF NOMINATING COMMITTEE.
Your committee respectfully submits the following names:
President: A. J. Patten.
Vice-President: R. E. Doolittle.
Secretary-Treasurer: W. W. Skinner.
Additional Members of the Executive Committee: E. M. Bailey and
P. B. Dunbar.
R. W. Batcom, J. W. KELLocc.
J. B. WEEms,
Nominating Committee.
It was moved, seconded and carried that the secretary be directed to
cast a unanimous ballot for the officers nominated.
REPORT OF COMMITTEE ON RESOLUTIONS.
Since the last meeting, the association has lost by death one of its
oldest and most valued members.
Dr. William Frear, Professor of Agricultural Chemistry in Pennsyl-
vania State College, and Vice-director of the Agricultural Experiment
Station, died suddenly of apoplexy at his home at State College, on Jan-
uary 7, 1922.
As a member of the Association of Official Agricultural Chemists for
nearly thirty-five years, Dr. Frear rendered notable and conspicuous
service as referee, as a member of the Executive Committee, chairman
of the Committee on Abstracts, chairman of the Committee on Food
Standards, member of the Board of Editors of The Journal, member of
numerous special committees, and as president of the association. He
had also served as editor of Agricultural Science and as president of the
Society for the Promotion of Agricultural Science, while as chemist in
charge of fertilizer control work and as chemist for several State boards
in Pennsylvania he contributed in a notable way to the development and
progress of scientific agriculture in his own State and in the Nation.
Your committee recommends the adoption of the following resolution:
Resolved, That in the death of Dr. William Frear this association
has lost a member who, throughout a large part of the life of the asso-
ciation, was a conspicuous factor in promoting the progress and success
of this organization, giving unstintedly of his time, his talents and his
energy to the furtherance of its work along many of its lines of service.
As an officer and member of the association, he was at all times earnest,
diligent and faithful in the performance of the tasks allotted to him,
306 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
leaving behind him a record of conspicuous fidelity and efficiency in
the discharge of duty. As a friend and colleague, he was sincere, loyal
and true, while in his uprightness of life and character he was worthy
of the emulation of all who knew him.
Resolved, That the secretary of the association be instructed to send
a copy of this resolution to the family of our deceased colleague.
Resolved, That this association expresses to the Honorable Henry C.
Wallace, Secretary of Agriculture, its thanks for his valuable and in-
spiring address.
Resolved, That this association appreciates the impartial, skilful and
courteous manner in which the president, F. P. Veitch, has discharged
the duties of his office.
Resolved, That this association is indebted to the Chairman of the
Board of Editors, R. W. Balcom, for the excellent preparations made for
this convention and for the efficient manner in which the affairs of
The Journal have been conducted.
Resolved, That the association desires to express its commendation of
the efficient work of the secretary and his various assistants for their
untiring efforts in making this meeting a success.
Resolved, That the thanks of this association are due the management
of the Raleigh Hotel for the use of the various rooms and other courtesies
extended to it and its members.
Resolved, That this association go on record as heartily endorsing the
campaign recently inaugurated by the American Chemical Society to
educate the American people to a better understanding of chemistry,
its possibilities and its applications to every-day life.
B. B. Ross, H. B. McDonneELt.
G. L. BripwEtL,
Committee on Resolutions.
Approved.
FIRST DAY.
WEDNESDAY—MORNING SESSION.
REPORT ON WATER.
By J. W. Saxe! (Bureau of Chemistry, Washington, D. C.), Referee.
Last year it was recommended that the quantitative methods for the
determination of lead, copper and zinc? be studied during the present
year. Four synthetic samples of water were prepared and sent to the
cooperating analysts, together with detailed methods of procedure.
However, prior to issuance of these samples, preliminary work showed
conclusively that it would be necessary to revise the procedure for
copper as published*. It was found that frequently sufficient iron was
occluded with the precipitate of copper sulfide to produce an interfering
blue color (Prussian blue) when the reagents were added. The method
was usually satisfactory when the sample contained only small amounts
of iron, but the procedure was not suitable for general application. The
method was modified, therefore, to eliminate residual traces of iron and
in the new procedure the evaporation to dryness was avoided. The
revised method follows:
COPPER.
(To be substituted for the method for copper?)
Boil the moderately acid filtrate, which contains iron, copper and zinc, to remove
alcohol; adjust solution to a volume of about 200 cc. and add 1 gram of ammonium
chloride. Heat to boiling, saturate with hydrogen sulfide gas, boil to remove pre-
cipitated sulfur, cover beaker, let stand about 2 hours or until supernatant liquid
becomes clear, filter and wash the copper sulfide without intermission with water con-
taining hydrogen sulfide. Collect filtrate in a porcelain casserole. Dissolve the cop-
per sulfide in hot dilute nitric acid (1 to 5). Cool, add a few drops of phenolphthalein,
and make the solution slightly alkaline with a 2}% solution of ammonium hydroxide,
added carefully from a dropping bottle. Add 10 cc. of a 10% solution of ammonium
nitrate, adjust the volume to 100 cc., and boil gently until a test with red litmus paper
shows the solution to be neutral. Filter the solution to remove any iron which may
be present, and adjust the filtrate to a volume of 100 cc. Add to an aliquot, 3 drops of
potassium ferrocyanide solution (C)?.. Compare color obtained with standards con-
taining 0.1, 0.2, 0.3, 0.4 and 0.5 mg. of copper. Prepare these standards by measuring
out the appropriate amounts of standard copper solution; add phenolphthalein, a
slight excess of dilute ammonium hydroxide and 1 cc. of a 10% solution of ammonium
nitrate, boiling the solution until neutral to red litmus, litics and adding three drops
of potassium ferrocyanide. Make the colorimetric comparison in 100 cc. Nessler jars.
1 Presented by W. W. Skinn
Bes face. Official Agr. Chemie 1922, 5: 382.
3
307
308 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
This method for copper and the methods for lead and zinc referred to
previously, together with the synthetic samples, were sent to the fol-
lowing analysts: 1. W. H. Simms (S. H. Wilson), 2. J. B. Wilson,
3. C. H. Badger, 4. A. E. Mix, 5. W. E. Shaefer, 6. J. W. Sale. The
data obtained are given in Table 1.
TABLE 1.
Collaborative results on analysis of synthetic water samples.
(All figures are expressed in milligrams
per 10 cc. of sample.)
MAXI-| MINI- ) AVER- | PRES-
ANALYST NO. 1 2 3 4 5 6 uum | MUM | AGE ENT
Sample 1*
Leads, ok.2): 5.0 5.0/5.0 4.6/4.3 4.4/4.7 4.7/5.0 5.1/4.5 4.5) 5.1 | 4.3 | 4.8 | 4.7
5.0 5.0/4.4 5.0 4.8 4.8/5.1
Copper..... 5.0 5.0\5.0 5.3/6.0 6.0/5.5 5.5 520} 1575] 16.0105 Om eae ila
6.0 5.5 Da) O25
ANG ee 5.0 5.0/6.0 7.0/5.0 5.0/5.0 5.0 4.8 4.6] 7.0 | 46 |] 5.3 | 5.0
5.0 5.0/6.0 7.0 5.0 5.0
Sample 2*
Weeds. cre 5.0 5.0/5.4 5.0/4.9 5.0/5.3 5.4/5.1 5.4/4.8 5.0} 5.5 | 4.8 | 5.2 | 5.5
5.0 5.0/5.4 5.0 5.5 5.5/5.4
ANE: eae 5.0 5.0/4.4 4.4/5.1 5.1/5.5 5.5/5.0 5.2/5.2 5.41 5.5 | 4.0 | 4.9 | 5.5
4.0 5.0|4.0 4.2 eo Oo
Sample 3*
(0 Uae SA 15.0 5.0/4.8 4.8]4.7 4.7/5.0 5.0/5.1 4.9/4.8 5.0) 6.0 | 4.0 | 5.0 | 5.0
6.0 6.0/4.0 4.4 50 5.0)5.4
iron ee Py sifla Ll abo
Color e ae l
Sample 4
Mend yer: 6.0 6.0/3.6 3.6/4.5 4.5/4.0 4.2/4.7 4.5/4.5 4.5) 6.0 | 3.6 | 4.6 | 4.2
6.0 6.0/4.0 3.6 4.2 4.2/4.6
*Sample 1 contained also 4.5 mg. of aluminium, 5.5 mg. of iron, and color; Sample 2, 5.0 mg. of iron;
and Sample 3, 1.0 mg. of iron and color. These metals and color were added because of their possible
interference with the accuracy of the determination of lead, copper and zinc.
DISCUSSION.
The results are fairly satisfactory when several factors are given con-
sideration. In the first place, Samples 1 and 3 are quite complex solu-
tions, iron and caramel color being decidedly interfering ingredients in
the determination of lead, copper and zinc. In the second place, the
methods are colorimetric or more especially turbidimetric, and subject
to the limitations of these types of methods. When the color of a sample
has a slightly different shade from that of the standard, the accuracy of
the color comparison is diminished. For example, a difference of 0.005
mg. of lead in the form of lead sulfide in a Nessler tube can easily be
detected in a set of standards ranging from 0.01 to about 0.1 mg. of
lead, whereas the actual reading error of the samples may be twice this
amount or about 0.01 mg., due to the samples possessing a slightly
different shade. This reading error is multiplied by 25, 50 or even 100,
depending on the aliquot taken, so that there is an unavoidable reading
1923] VEITCH: REPORT ON TANNING MATERIALS AND LEATHER 309
error ranging from 0.2 to 1.0 mg., although 1.0 mg. is considered un-
necessarily high. The referee is of the opinion that the variations from
the correct figures in Table 1 are due chiefly to the error in comparing
the color and turbidities of the samples and not to the separation of
the metals. Then, finally, the inexperience of the analysts with these
methods must be considered. Analyst No. 2, for instance, is an organic
chemist who never had occasion to determine metals quantitatively.
On the other hand, the excellent results obtained by Analyst No. 4 may
be attributed to long experience in exact analytical work. It would
appear that the acceptability of the methods should be based largely on
the results obtained by those who have had experience in this kind of
work. In view of all the circumstances, however, the referee will recom-
mend that the methods for lead and zinc and the method for copper be
adopted as tentative methods only and not as official methods.
The referee does not recommend any specific procedure to be followed
by the Referee on Water for 1923, but suggests that the methods for
salt! be extended.
RECOMMENDATIONS.
It is recommended—
(1) That the method for lead and zinc be adopted as a tentative
method.
(2) That the method for copper, as given in this report, be adopted as
a tentative method.
(3) That additional methods for the analysis of salt be studied next
year.
REPORT ON TANNING MATERIALS AND LEATHER.
By F. P. Verrcn* (Bureau of Chemistry, Washington, D. C.), Referee.
As has been the case for several years, all cooperative work on tanning
materials and leather has been carried on with and in the American
Leather Chemists Association. While the detailed reports of the work
can be found in the journal of that association, it is believed that it will
be of interest to you to summarize briefly the findings and points raised
within the last year, in so far as they relate to analytical procedures.
It will be recalled that in the last report reference was made to some
data which strongly indicated an influence of relative humidity upon
moisture determinations in leather. Further work, both individually
and cooperatively, has confirmed this. The collaborator who obtained
the lowest moisture result worked under the highest average relative
humidity conditions, while the one who operated under the lowest
average relative humidity got the highest percentage of moisture. The
1 J. Assoc. Official Agr. Chemists, 1922, 5: 384.
2 Presented by R. W. Frey.
310 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
differences, however, were too great to be attributed entirely to varia-
tions in humidity. Unknown factors of equipment and manipulation of
greater disturbing influences were indicated. They were further evi-
denced by detailed individual work under varied relative humidities
which showed that a single operator can obtain closely agreeing results
under any given humidity and that under different humidities the
variations in percentage of moisture are reasonably within the expected
range from the influence of relative humidity.
Since the determination of magnesium is so general it may be of
interest to mention the essential points in the report of a committee of
the American Leather Chemists Association on the determination of
epsom salts in leather. As you know, the presence of excessive quanti-
ties of ammonium salts and precipitant gives inaccurate results when
precipitating magnesium as ammonium magnesium phosphate. It was
shown that the time for double precipitation or the trouble of removing
the excess of ammonium salts could be avoided by the simple expedient
of using an aliquot of the ash solution equivalent to two grams of leather
instead of the original ten-gram charge. This so reduced the concen-
tration of magnesium that single cold precipitation without removal of
salts gave as accurate results as did double cold precipitation. It was
also shown, regardless of the concentration of magnesium up to that
given by the full ten-gram ash charge, that a single hot precipitation as
phosphate without previous destruction of excess ammonium salts gave
results in very close agreement with those by double cold precipitation,
The estimation of glucose is another item of general interest. Among
the difficulties with this determination in leather analysis is one which
you have frequently met in food analysis. It has long been recognized
in the gravimetric determination of sugar by reduction with Fehling
that with impure solutions the presence of inorganic constituents, such
as iron and magnesium, will give inaccurate and high results. You
will recall several papers given before this association dealing with this
feature. In the report of the Referee on Tea and Coffee', it was found
that in working with coffee the effect of magnesium and iron was so
great as to make the gravimetric results for sugar worthless. Of course,
in such instances, recourse is had to the volumetric or electrolytic pro-
cedures for determining the actual copper thrown down. There remains,
however, the objection that if the magnesium, especially, is not pre-
viously removed, its precipitation in the Fehling solution does, at times,
seriously interfere with the filtration of the cuprous oxide. Aside from
this, there is also a rather insistent demand for a gravimetric procedure
on more or less of an assumption of greater convenience and time saving.
For the past several years committees of the American Leather Chemists
1 J. Assoc. Official Agr. Chemists, 1920, 3: 498.
1923] VEITCH: REPORT ON TANNING MATERIALS AND LEATHER 311
Association have been working on this problem without a great deal of
success. Attempts to remove the magnesium present from the added
epsom salts, as hydroxide and phosphate, have at times looked promising
but have not always given consistent results. The results have indicated,
however, that sodium phosphate is an excellent deleading agent. Work
is being continued on this problem but it begins to look as if the object
in mind hardly justifies the immense amount of detailed work it will
require.
In the determination of chromium in leather ash it has been shown
that fusion with sodium peroxide gives low results in the presence of
barium salts unless a second fusion is made. It has been recommended
that the peroxide fusion be discarded, and that a fusion mixture of equal
parts of sodium carbonate, potassium carbonate and borax glass be
retained.
The question of the best solvent for the extraction of oils and greases
from leather is still an open one, though much committee work has been
done on it. The latest report is in favor of retaining petroleum ether
in preference to chloroform. Though previous work has shown the
decided superiority of chloroform as an oil and grease solvent, it has
also been found that it extracts from leather appreciable quantities of
materials other than oils and greases. This extraction depends largely
upon the moisture present in the leather, a point which the data of the
last American Leather Chemists Association committee confirmed. These
shortcomings of chloroform do not, however, make the results with
petroleum ether any more accurate. Results with chloroform may be
high; results with petroleum ether may be low.
Considerable interest has been shown lately in the hide powder method
of tannin analysis which it is hoped will result in changes making for
greater accuracy. Wilson and Kern! have proposed quite a departure
from the present procedure and have offered data to indicate that the
latter may at times be in error to the extent of 200 per cent with some
extracts. This and other work has given issue to quite a controversy,
the sum and substance of which emphasizes the dire need of an accurate,
direct method for determining tannin.
In passing, it is desired to present to you briefly some recent findings
which, while not of a chemical nature, are of importance in connection
with the physical testing of leather. The influence of relative humidity
on the physical properties of paper has been recognized for some time,
and testing of paper has therefore been done under controlled conditions
of relative humidity and temperature. Of late interest has also been
shown in the possible influence of relative humidity in testing other
materials. In a recent publication? the Bureau of Chemistry has shown
1 J. Ind. Eng. Chem., 1920, 12: 465; J. ie sbeulher Chem. Assoc., 1920, 15: 295.
2 J. Am. Leather Chem. Assoc., 1922, 17:
312 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS |[Vol. VI, No. 3
that, for at least an unfilled, unoiled vegetable tanned leather, the
relative humidity exerts an influence surprisingly great. Working at a
constant temperature of 70° F. but different relative humidities, exten-
sive data were obtained to show that for an increase of 20 per cent
relative humidity, from 35 per cent to 55 per cent, the average increase
was 12.9 per cent in tensile strength and 15.7 per cent in elongation;
and for an increase of 40 per cent relative humidity, from 35 per cent to
75 per cent, the average increase in tensile strength was 42.3 per cent
and in elongation it was 53.1 per cent. You will thus see that humidity
exerts a very material influence which can not be safely ignored. While
this work was done with only one tannage, there can be little doubt that
humidity has a significant effect upon all leathers. It will also be noted
from the above figures that the influence of relative humidity was not
directly proportional to the increase of the same. That is, for 20 per
cent relative humidity the strength gain was 12.9 per cent, while for
40 per cent relative humidity the strength gain was not practically
double 12.9, but more nearly three and one-half times as much. The
same applies to the elongation figures. In this connection it is interest-
ing to note that the moisture content of the leather pieces, as shown
by change in weight at the different relative humidities, was in prac-
tically the same relationship. When conditioned at 55 per cent relative
humidity the leather showed a gain in weight or moisture of 1.92 per
cent, based on the weight at 35 per cent relative humidity, but when
conditioned at 75 per cent relative humidity the gain in weight, upon
the same basis, was 8.2 per cent, instead of roughly twice 1.92. The
importance of this influence of humidity or moisture content of the
test samples needs emphasis and more general appreciation; for this
reason your referee feels justified in bringing it to your attention.
In conclusion, your referee desires, in order to be absolved of any
taint of plagiarism, to emphasize that while the work described has been
carried on principally within the American Leather Chemists Asso-
ciation, it is, nevertheless, work in which the scientists of the Bureau of
Chemistry, who are members of both the Association of Official Agri-
cultural Chemists and the American Leather Chemists Association have
taken and hope to continue to take an active part. As referee, in this
association, on a subject in which the other members, while having an
inherent interest, have had little opportunity to participate, the writer
hopes to be pardoned for this possible digression in presenting a brief
review of work largely for another organization and he would like to
feel that it has been of more interest than the stereotyped statement,
““No report to make’.
1923] GRAHAM: REPORT ON INSECTICIDES AND FUNGICIDES 313
REPORT ON INSECTICIDES AND FUNGICIDES.
By J. J. T. Grauam (Bureau of Chemistry, Washington, D. C.), Referee.
The work on insecticides and fungicides for 1922 consisted of a co-
operative study of the official distillation method for total arsenic! and
the hydrazine distillation method? on samples of lead and calcium
arsenates containing nitrates. Previous work had shown that the official
distillation method was not accurate in the presence of nitrates’, and the
hydrazine distillation method, which is unaffected by nitrates, was
recommended to take its place. The association, at the 1921 meeting,
upon recommendation of the referee, adopted this as a tentative method,
but before final action it was necessary that it be submitted to the mem-
bers for cooperative study.
PREPARATION OF SAMPLES.
Lead arsenate—Commercial lead arsenate was mixed with a solution of lead nitrate,
and the resulting paste evaporated on the steam bath until most of the moisture was
expelled. The drying was completed in an electric oven at 105°C. and the sample
then ground to pass a No. 40 sieve and thoroughly mixed. The nitrogen content of
this sample was shown by analysis to be equivalent to 3.49 per cent of nitrogen pen-
toxide. The arsenic oxide, determined after heating to fuming with sulfuric acid to
destroy the nitrates, was 27.30 per cent.
Calcium arsenate-——Two samples of calcium arsenate were prepared by adding a
mixture of arsenic and nitric acids to milk of lime and drying the resulting paste as in
the case of lead arsenate. These were ground to pass a No. 40 sieve and were analyzed
for nitrogen and arsenic oxide in the same way as the lead arsenate. Sample 1 of
calcium arsenate contained 4.74 per cent of nitrogen pentoxide and 40.82 per cent of
arsenic oxide, and Sample 2 contained 1.00 per cent of nitrogen pentoxide and 38.75
per cent of arsenic oxide.
Portions of these samples, with the following directions, were sent to 17 laboratories
for cooperative work.
DIRECTIONS FOR ANALYSIS.
TOTAL ARSENIC.
REAGENTS.
(a) Starch indicator.—Prepare as directed under Paris green‘.
(b) Standard arsenious oxide solution.—Prepare as directed under Paris green‘.
(C) Standard iodine solution—Prepare as directed under Paris green‘.
(d) Hydrazine sulfate and sodium bromide solution—Dissolve 20.0 grams of hydra-
zine sulfate and 20.0 grams of sodium bromide in 1 liter of dilute (1 to 4) hydrochloric
acid.
1 Assoc. Official Agr. Chemists, Methods, 1920, 54.
2 J. Assoc. Official Agr. ga aoe 5: 402.
3 J. Ind. Eng. Chem., 1922, 14:
4 Assoc. Official Agr. "Chemists, Mie ood, 1920, 53.
314 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
ANALYST
J. C. Bubb, Bureau of Chemistry, Washing-
ton, D. C.
IEVOTA DO 208 AAR leu Tere clea sok as
G. E. Colby, Department of Agriculture, Sac-
ramento, Calif.
R. P. Cope, Agricultural Experiment Station,
Pullman, Wash.
J. J. T. Graham.
PRVETORO os a ese cence soon and eee nate ae
Rosewell Jinkins, Bureau of Chemistry, Wash-
ington, D. C
1 EE ge ee ERS Ae
A. P. Kerr, Agricultural Experiment Station,
Baton Rouge, La.
Averages, deus cea Ph. 401 2 em act Laer
W. G. Marshall, Department of Agriculture,
Sacramento, Calif.
A. C. Nothstine, Bureau of Chemistry, Wash-
ington, D. C.
Average SSO 5 coed... ese Se, ee
R. H. Robinson, Agricultural Experiment Sta-
tion, Corvallis, Ore.
Average.) SU oe ee
R. D. Scott, Department of Health, Colum-
bus, Ohio.
Average. 220A OAS. S20, OTe Be.
Arthur Shaver, Bureau of Chemistry, Wash-
ington, D. C
Ty 12) a Oe en MC MER oe ore ert ns
*Titrated after 48 hours.
tTitrated after 72 hours.
TABLE
Cooperative results on total
CALCIUM ARSENATE, SAMPLE 1
Official Distillation
Method
Titrated | Titrated
Imme- after 24
diately hours
per cent per cent
40.71 39.94
40.71 40.30
40.71 40.12
34.37 20.17
40.58 40.11
40.82 40.26
40.82 40.21
40.82 40.24
40.60 38.48
40.22 36.94
40.41 BY Aral
41.55 32.55
41.30 35.02
41.43 33.79
34.57 20.05
39.70 37.85
40.78 40.01
39.24 38.72
39.91 38.86
40.77 40.77
40.79 40.80
40.78 40.79
40.43 37.27
40.37 37.88
40.40 37.58
39.08 39.08
40.23 40.03
39.66 39.56
Titrated
Imme-
diately
per cenl
41.02
40.91
40.97
40.50
40.90
41.08
41.13
41.11
40.70
40.60
40.65
41.37
41.50
41.55
41.47
40.33
40.78
40.88
40.83
40.97
41.07
41.10
41.05
40.91
40.81
40.86
40.99
40.99
40.99
Hydrazine Distillation
Method
Titrated
after 24
hours
per cent
41.07
40.91
40.99
40.89
40.93
41.08
41.13
41.11
40.70
40.60
40.65
41.28
41.50
41.61
41.46
41.11
40.83
40.88
40.86
40.97
41.10
40.96
41.01
40.85
40.81
40.83
40.99
40.99
40.99
1923]
r
arsenic, calculated as arsenic oxide.
CALCIUM ARSENATE, SAMPLE 2
GRAHAM: REPORT ON INSECTICIDES AND FUNGICIDES
Official Distillation
Method
Titrated Titrated
Imme- after 24
diately hours
per cent per cent
38.60 38.70
38.70 38.50
38.65 38.60
36.87 27.59
38.66 38.53
38.56 38.61
38.61 38.66
38.59 38.64
39.06 38.58
38.87 37.90
38.97 38.24
38.47 35.75
38.47 35.75
37.00 25.10
38.11 37.54
38.31 36.46
37.90 37.54
38.11 37.18
38.52 38.50
38.54 38.51
38.53 38.51
38.49 38.19
38.42 37.94
38.46 38.07
36.89 36.79
38.70 38.70
37.80 37.75
Hydrazine Distillation
Method
Titrated
Imme-
diately
per cent
38.81
38.81
38.81
38.40
38.75
39.02
39.02
39.02
38.77
38.77
38.77
39.10
39.16
39.13
38.60
38.72
38.72
38.62
Titrated
after 24
hours
per cent
38.96
38.86
38.91
38.40
38.75
39.02
39.02
39.02
38.77
38.77
38.77
39.12
39.22
39.17
38.70
38.72
38.72
38.62
LEAD ARSENATE
Official Distillation
Method
Titrated | Titrated
Imme- after 24
diately hours
per cent per cent
27.09 27.02
27.21 26.98
27.15 27.00
23.89 11.66
27.10 26.81
26.92 26.49
26.92 26.03
26.92 26.26
27.20 25.75
26.83 25.03
27.02 25.39
24.74 19.09
24.81 19.50
24.78 19.30
34.18 12.00
26.62 25.77
26.96 26.11
26.04 19.33
26.54 23.74
27.02 27.02
26.91 26.95
26.97 26.99
26.66 26.08
26.69 24.47
26.68 25.28
26.69 26.69
26.12 26.12
26.41 26.41
315
Hydrazine Distillation
ethod
Titrated | Titrated
Imme- after 24
diately hours
per cent per cent
27.25 27.17
Zea 27.25
27.23 21.21
26.88 2S
27.18 27.18
27.30 27.30
27.38 27.34
27.34 27.32
27.34 27.41
27.41 27.56
27.38 27.49
27.38 27.40
27.45 27.50
27.38 27.35
27.40 27.41
26.88 27.15
27.00 27.04
27.08 27.04
27.04 27.04
27.18 27.18
27.18 Paral
27.18 27.20
26.94* | 26.94*
26.947 | 26.94F
26.94 26.94
27.26 27.26
27.26 27.26
27.26 27.26
316 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 3
TABLE
Cooperative results on total
CALCIUM ARSENATE, SAMPLE 1
Official Distillation |Hydrazine Distillation
ANALYST ethod Method
Titrated | Titrated | Titrated | Titrated
Imme- after 24 Imme- after 24
diately hours diately hours
per cent per cent per cent per cent
W. A. Stone, Agricultural & Mechanical Col- 40.12 24.36 40.72 40.72
lege, College Station, Tex. 40.13 26.08 40.72 40.72
SOM cua tints AGT 2 Heenan
SS AS iho ed, h, 40:73 ))| gis
ABELERE oeichs ORE site leech. Setem 4 39.48 25.22 40.72 40.72
L. R. Streeter, Agricultural Experiment Sta- |} 41.85 40.70 42.35 42.35
tion, Geneva, N. Y. 41.80 39.06 42.40 42.40
BSP Ke 42.40 REN
INNOTOGO edicts Athan rouscaleiche nuseeuscaital iano aekens 41.83 39.88 42.38 42.38
E. R. Tobey, Agricultural Experiment Station, || 40.44 38.77 40.39 40.35
Orono, Maine.
O. B. Winter, Agricultural Experiment Sta- || 41.08 40.27 41.09 40.89
tion, E. Lansing, Mich. ADO Whee 40.90 41.28
AD OO) Tate nea. 40:90 | |. See
Averagedinge 72m oe eae, Sa 40.96 40.27 40.96 41.09
General AWEFARES. nce shee aie tecoyels Shawl ons 39.76 35.54 40.94 41.02
Referee’s analysis after destroying nitrates.. |} 40.82 | ..... | ..... | 2.2...
tJ. J. Taylor, Department of Agriculture, 41.02 40.23 40.99 41.09
Atlanta, Ga. 40.90 40.19 41.09 41.09
AVOTOR OE C48 ode SelM. af Ma ans Se > oes 40.96 40.21 41.04 41.09
tReceived after report was completed.
DETERMINATIONS.
Hydrazine distillation method.
Weigh 1.5 grams of calcium arsenate (or 2.0 grams of lead arsenate) and transfer
to a distilling flask. Add 50 cc. of the hydrazine sulfate and sodium bromide solution
and close the flask with a stopper through which passes the stem of a dropping funnel.
Connect to a well-cooled condenser, the delivery end of which is attached to the system
of flasks used in the official distillation method!, omitting the third flask. Boil for 2 or
3 minutes and then add 100 cc. of concentrated hydrochloric acid by means of the drop-
ping funnel and distil until the volume in the distilling flask is reduced to about 40 cc;
add an additional 50 cc. of concentrated hydrochloric acid and continue the distillation
until the contents of the flask are again reduced to about 40 cc. Wash down the con-
1 Assoc. Official Agr. Chemists, Methods, 1920, 54.
1923] GRAHAM: REPORT ON INSECTICIDES AND FUNGICIDES 317
1—Continued.
arsenic, calculated as arsenic ozide.
CALCIUM ARSENATE, SAMPLE 2 LEAD ARSENATE
Official Distillation Hydrazine Distillation Official Distillation |Hydrazine Distillation
Method Metho Method Method
Titrated Titrated Titrated Titrated Titrated | Titrated | Titrated | Titrated
Imme- after 24 Imme- after 24 Imme- after 24 Imme- after 24
diately hours diately hours diately hours diately hours
per cent per cent per cent per cent per cent per cent per cent per cent
38.23 33.07 38.68 38.67 26.52 15.24 27.03 27.03
37.94 34.75 38.67 38.67 26.48 14.32 27.03 27.03
ERO OT nN West. 3 Bteplitey all aaa Pa All Re ee PALMA UY: ai i ec tw
SEO! API) 38.67 Np Lae ZOOM HE: 27 OS Ad eee
37.96 33.91 38.68 38.67 26.09 14.78 27.03 27.03
39.34 39.20 39.45 39.50 27.60 27.25 27.80 27.80
39.35 38.90 39.45 39.44 27.45 27.15 27.80 27.75
39.40 te 11 Ngee Wie Sener ce 2 as EE eae 27.40 27.10 2 ea, SE
39.65 SOTA ae ee Nilba ieee 5 (31 Sm e408 Dg
39.44 39.20 39.45 39.47 27.44 27.17 27.78 27.78
38.72 36.69 38.63 38.55 26.85 25.25 26.92 26.75
38.98 34.94 38.78 38.78 26.93 26.35 27.07 27.07
38.88 38.40 38.78 38.98 27.07 26.35 27.07 PAPA
BOS ee Ate! vyanlis tas re lsusmten 27.07 sae see," on
38.93 36.67 38.78 38.88 27.02 26.35 27.07 27.14
38.34 36.03 38.79 38.81 26.34 22.96 VAT EMT 27.20
3S (ela Malt Pali al ie? oa a) | ve eh 7A (er 0 Ma eprens <ilal |p cle Ra
39.03 38.65 39.01 39.01 27.36 27.07 27.59 27.78
39.08 38.69 38.91 38.91 Dla 27.12 27.59 27.70
39.06 38.67 38.96 38.96 27.32 27.10 27.59 27.74
denser, transfer the contents of the receiving flasks to a 1-liter graduated flask, make to
volume and mix thoroughly. Pipet a 200 cc. aliquot into a 500 cc. Erlenmeyer flask
and nearly neutralize with a 40% solution of sodium hydroxide, using phenolphthalein
as indicator and keeping the flask well cooled. If the neutral point is passed, add
hydrochloric acid until again slightly acid. Finish the neutralization with sodium
bicarbonate, add 4—5 grams in excess, and titrate with standard iodine solution using
starch solution as indicator. Calculate the results in terms of arsenic oxide.
_ Nore.—If more convenient, the receiving flasks may be cooled by running water during the distillation
instead of the cracked ice as shown in the illustration!.
Make determinations by both methods on each of the three samples, titrating as
soon as possible after the distillation. Report the time elapsed between the end of the
distillation and the titration of the distillates. Allow all the distillates to stand for
24 hours and again titrate aliquots of each.
Reports from ten laboratories are shown in Table 1.
1 Assoc. Official Agr. Chemists, Methods, 1920, 54.
318 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
COMMENTS BY ANALYSTS.
George E. Colby and W. G. Marshall.—On the lead arsenate the nitrates appear to
throw the official method out somewhat in direct proportion to their content.
On Sample 1 of calcium arsenate, with the highest nitrates of the series, the official
method appears to yield only about 80% of the arsenic oxide present, as set by the
hydrazine test.
On Sample 2 of calcium arsenate, containing the least quantity of nitrate, the result
by the official test is out only about 5%.
It is obvious that the official method of distillation for total arsenic oxide is not
generally applicable in the presence of nitrates, but it is unlikely that commercial
samples of arsenate of lead or calcium will often be found in the market with such
quantities of nitrates as this series of arsenates.
R. P. Cope.—Heat is produced in the neutralization of the hydrochloric acid, and
the time necessary for cooling may give opportunity in the official method for additional
oxidation by any nitrates present. The hydrazine method is more pleasant to run.
R. H. Robinson.—Titrations on all determinations were made as soon as possible
after the distillation, which was about 15 minutes. After allowing to stand 24 hours,
titrations were again made. No differences were observed after standing 24 hours at
about 20°C. No trouble was experienced with the hydrazine distillation method, and
excellent checks were obtained in the duplicate determinations. Since the receiving
flasks were cooled by running water at 10°C. instead of with packed ice, it was necessary
to exercise care in watching that there was no loss of the copious fumes that came over
in the official distillation method. This precaution was not necessary in the hydra-
zine distillation method.
R. D. Scott-—The hydrazine method is evidently more satisfactory than the official
method in the presence of nitrates. A slightly higher blank was noted with the hydra-
zine method than with the official method.
E. R. Tobey.—The reagents submitted by the referee were used. The arsenious
oxide was heated 5 hours at 105°C. before the portion used in standardization was
weighed out. From the standpoint of manipulation the hydrazine sulfate method is
preferable.
O. B. Winter—The two methods check very closely. The time which elapses
between the distillation and the titration causes no change in the results by the hydra-
zine method but gives rise to a slight loss by the official method. The hydrazine method
requires somewhat less time for the distillation.
DISCUSSION.
The most striking fact shown by the results in the table is the un-
reliability of the official distillation method in the presence of nitrates.
Of 15 analysts participating in this work, only two obtained as high
results by the official method as they obtained by the hydrazine method.
Two analysts obtained distillates which gave good checks when titrated
immediately, and after a period of 24 hours; but the distillates obtained
by all other analysts gave lower results after standing for that period.
No uniformity, however, is shown in the rate of change in the results
on standing. The loss of arsenic in the distillates varied among the
different analysts from a few tenths of a per cent to 50 per cent of the
arsenic present. In contrast to this, is the uniform behavior of the
distillates from the hydrazine method. With two exceptions, the
1923] GRAHAM: REPORT ON INSECTICIDES AND FUNGICIDES 319
titrations at the end of 24 hours checked those obtained immediately
after distillation, and the results not only agreed well among themselves,
but they checked the results obtained by the referee using the official
distillation method on charges in which the nitrates were destroyed
before the analysis was made.
The only objection to the use of the hydrazine method is the increased
cost of hydrazine sulfate over cuprous chloride, and this is somewhat
offset by the saving in the quantity of hydrochloric acid used. Hydra-
zine sulfate can be made in the laboratory with very little trouble and
expense by the action of sodium hypochlorite on ammonia water!.
SUGGESTIONS FOR FUTURE WORK.
A number of insecticides and fungicides known by the general term of
dusting mixtures are now on the market. These preparations vary
considerably in their formulae, but usually consist of two or more of the
following substances: lead arsenate, calcium arsenate, Paris green,
Bordeaux mixture, sulfur, lime, calcium sulfate, kaolin, tobacco powder
and nicotine. The association has adopted no methods for the analysis
of these mixtures, and the referee suggests that a study be made of
methods for this class of compounds.
RECOMMENDATIONS.
It is recommended—
(1) That the mercury-thiocyanate method for zinc oxide in zinc.
arsenite as given in the referee’s report for 19212 be adopted as an official
method.
(2) That the method (1) for the determination of calcium oxide in
calcium arsenate as given in the referee’s report for 19213 be adopted as
an official method.
(3) That the method (2) for the determination of calcium oxide in
calcium arsenate as given in the referee’s report for 1921‘ be adopted as
an official method.
(4) That in the “General procedure for the analysis of a product con-
taining arsenic, antimony, lead, copper, zinc, iron, calcium, magnesium,
etc.”’, the method for zinc oxide as given in the referee’s report for 19215
be adopted as an official method.
(5) That the hydrazine distillation method for the determination of
total arsenic® be adopted as an official method.
1 University of Illinois Bull., 1920, 18: 6.
a Agr. Chemists, 1922, 5: 392.
‘ Tbid., 396.
5 Ibid., 398.
§ Ibid., 403.
320 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
REPORT ON SOILS.
By W. H. MacIntire (Agricultural Experiment Station, Knoxville,
Tenn.), Referee.
No particular problem has been under investigation during the past
year. The Committee on Revision of Methods for Soil Analysis expects
to make further report and recommendations at the next meeting of
the association. It was, therefore, thought advisable to await such
action before undertaking additional work under the general heading
of ‘Soils’.
REPORT ON SULFUR IN SOILS.
By W. H. MacIntme, Associate Referee and W. M. SHaw (Agricultural
Experiment Station, Knoxville, Tenn.).
The work upon sulfur in soils during the past year has been directed
toward the study and perfection of technique which will afford complete
oxidation of all forms of sulfur in soils and insure complete removal of
the oxidation products from the soil mass. Pursuing further the study
of the digestion of soils in nitric acid, the plan has been to adapt the pro-
cedure to charges of sufficient bulk to insure workable quantities of the
sulfate precipitate, even from soils of very low total sulfur content.
With this basic thought, the collaborative work was planned to determine
(1) the length of time required for the digestion of soil with concentrated
nitric acid; (2) the probability of occlusion of sulfates in the ammoniacal
precipitation and reprecipitation of iron; and (8) the possible inter-
ference of native soil barium which may be dissolved from some soils
by the process of acid digestion.
The following outline of procedure was sent out to those who expressed
willingness to collaborate:
Concentrated Nitric Acid Method of Procedure for the Determination of Total Sulfur in Soils.
Introduce 50 grams of soil low in organic matter, or 25 grams of soil high in organic
matter, into a 500 cc. Kjeldahl flask. Insert a small funnel in the neck of the flask.
Add about 125 cc. of concentrated nitric acid; heat slowly and boil for 1 hour. Follow
the same procedure in parallel, by boiling for a 2-hour period and also for 3 hours.
Cool, dilute to 400 cc. and pour off the clear liquid through a Biichner funnel. Add
250-300 cc. of hot water; agitate; throw upon Biichner and wash with hot water to a
combined volume of 1 liter. Evaporate filtrate to dryness at a low temperature. Add
10 cc. of concentrated hydrochloric acid and again evaporate. Repeat the addition of,
and evaporation with, hydrochloric acid. Take up with a few drops of hydrochloric
acid; bring into solution and precipitate iron, by addition of 1 to 1 ammonium hydroxide,
from a volume of 400 cc. Pour onto a Biichner and wash twice. Transfer the filter to
original beaker; dissolve; macerate the filter and again precipitate from a volume of
1923] MACINTIRE: REPORT ON SULFUR IN SOILS 321
about 300 cc. and filter into original filtrate, washing to a volume of 1 liter. Acidify
filtrate with a slight excess of hydrochloric acid; concentrate to a volume of 400 cc;
add hot barium chloride (1+9) and agitate vigorously. Permit barium sulfate to
stand 18 hours and filter through an acid-washed asbestos Gooch filter. Report as
grams of barium sulfate.
Norte.—In studying this method it would be well to add a small amount of freshly precipitated barium
sulfate to the soil prior to the digestion and determine the point at which it may be lost to the procedure,
in order to ascertain what may be expected from any barium sulfate formed during the digestion because
of the occurrence of barium compounds native to the soil. The method should also be tested by the
addition of known amounts of sodium, potassium, calcium and magnesium sulfates.
COLLABORATIVE RESULTS.
A. L. Prince, New Jersey Agricultural Experiment Station.—The in-
fluence of length of the period of nitric acid digestion was tried out at
this station, using a 50-gram charge of acid silt loam. The results are
given in Table 1.
TABLE 1.
Barium sulfate determined from nitric acid soil extract.
1-hour digestion 2-hour digestion 3-hour digestion
gram gram gram
A 0.0802 0.0665 0.0750
B 0.0816 0.0762 0.0778
Average... . 0.0809 0.0714 0.0764
Assuming all other conditions constant, it is evident that boiling with
nitric acid for one hour will produce a sulfate yield as great as that
brought about by boiling for a period of 3 hours. No results were
reported on a fortified soil.
D. E. Bullis, Oregon Agricultural Experiment Station.—The results
from the Oregon station as to the influence of time upon the complete-
ness of oxidation of the soil sulfur, from a Williamette loam are given
in Table 2.
TABLE 2.
Barium sulfate determined from nitric acid soil extract.
1-hour digestion 2-hour digestion 3-hour digestion
gram gram gram
A 0.0406 0.0338 0.0344
B 0.0397 0.0355 0.0389
Average... . 0.0402 0.0347 0.0367
Again, as in the case of the New Jersey results, the highest sulfate
determinations were secured from the solution derived from a 1-hour
322 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
digestion. ‘These analyses were carried out by the elimination of iron
through ammoniacal precipitation. It is quite probable that less iron
was dissolved during the 1-hour digestion than during the digestion for
the longer periods; and since, as will be shown by results from the ref-
eree’s laboratory, the amount of iron influences the extent of occlusion,
a smaller iron occurrence in the 1-hour digestion may be responsible
for the larger sulfate yield obtained from the solution digested for that
period of time.
TABLE 3.
Barium sulfate fraction received from that added to a 25-gram charge of soil.
1-hour digestion 2-hour digestion 3-hour digestion
A B A B A B
gram gram gram gram gram gram
Soil +.0963 gm. BaSO. 0.0735 0.0681 0.0761 0.0743 0.0713 0.0747
Soil alone (average). 0.0401 0.0401 0.0346 0.0346 0.0366 0.0366
BaSQ, recovered.... 0.0334 0.0280 0.0415 0.0397 0.0347 0.0381
per cent per cent per cent per cent Per cent per cent
Recovery.......... 34.7 29.1 43.1 41.2 36.0 39.7
Recovery calculated
to barium in soil.. 0.0816 0.0684 0.1013 0.0969 0.0845 0.0934
In Table 3 are given the results reported from the Oregon station
relative to the carry-through of barium sulfate which may be formed
during the acid digestion as a result of occurrences of native barium in
soil. From additions of 0.0963 gram of freshly precipitated barium
sulfate respective recoveries of 31.9 per cent, 42.2 per cent and 37.9 per
cent were secured after 1-, 2-, and 3-hour digestions of soil and addi-
tions. These respective recoveries calculate to native barium occur-
rences of 0.0750 per cent, 0.0991 per cent and 0.0890 per cent. No
data showing such extensive amounts of barium present in soils
were found. The foregoing results are in harmony with those secured
by the referee and associates and indicate that the amounts of barium
occasionally to be found in soils would not interfere with the accuracy
of the method, if it should prove otherwise adaptable.
W. M. Shaw, University of Tennessee Agricultural Experiment Station.—
Duplicate digestions were made of fairly fertile loam soil for periods of
1 hour, 2 hours and 3 hours, according to the outline previously given.
Fifty-gram charges of soil alone and soil fortified with calcium sulfate
equivalent to 0.0845 gram of barium sulfate were used in the digestions.
Iron was eliminated through double precipitation. Ammoniacal salts
were removed by evaporation with nitric acid and two evaporations with
hydrochloric acid, prior to the barium sulfate precipitation from a
nitrate-free solution. The following results were obtained:
1923] MACINTIRE: REPORT ON SULFUR IN SOILS 323
TABLE 4.
Barium sulfate determined—gram per 50 grams of soil.
1-hour digestion 2-hour digestion 3-hour digestion
gram gram gram
Sailonly. (23) 3s ETA ee 0.0454 0.0483 0.0444
Soil plus calcium sulfate equiva-
lent to 0.0845 gram of barium
Rute AI)? Pe AF, SRA TOE, AS, SMT fa a ty Agar 0.1079
From these results it would appear that a 1-hour digestion period is
as effective as one continued for two additional hours. It is also apparent
that but 0.0625 gram of barium sulfate equivalent of the 0.0845-
gram addition was recovered. This represents a recovery of approxi-
mately 74 per cent of the addition. The data do not demonstrate,
however, whether the partial recovery was due to incomplete washing
out of sulfates from the acid insoluble residue, or to their occlusion in
the ammoniacal precipitate of hydrated iron oxide. The results of
experiences with the thorough washing with acid and hot water through
the thin soil layer upon the Biichner indicated that the first assumption
is hardly tenable. The probability of occlusion of sulfates in the hy-
drated iron precipitate was therefore studied. Sulfates were determined
separately in the filtrate from the first ammoniacal precipitation and
also in the filtrates from the second and third re-precipitations.
No variable was introduced during precipitation of barium sulfate
because of the presence of different amounts of ammoniacal salts; each
filtrate was freed of ammonium chloride by evaporation with nitric
acid, nitrates being then eliminated by two evaporations with concen-
trated hydrochloric acid, prior to the taking up with dilute hydrochloric
acid, from which solution the sulfates were precipitated. The results
obtained are given in Table 5.
TABLE 5.
Barium sulfate determinations upon separate filtrates from three hydrated iron precipitates.
Soil only—50-gram charge Analysis A AnalysisB Average
gram gram gram
MRMPENSCHENUTALGS 5 Fotfotgro'e a sa 2 solareoles v wave aatara 0.0345 0.0325 0.0335
LE SCE ECG 0 0) ae eae ae 0.0106 0.0158 0.0132
RrmereRT RPP ULE E AES 6 Fc 25s Female a Basel Ontens 0.0110 0.0065 0.0088
CCIE ae EID Tce Sve re 2: J ae aa ee 0.0561 0.0548 0.0555
Soil—50 grams plus magnesium sulfate equiva-
lent to 0.1300 gram of barium sulfate
npurstenliratess. se eer ae ee 0.1057 0.0914 0.0986
Secon Mltrate- pee 2 88 SEN ey 0.0449 0.0565 0.0507
fuethmobtitrates 261.) ....eeireid ila ieee oe 0.0248 0.0251 0.0250
1521 oe ie ial ca AP Oa IR ob Pa 0.1754 0.1730 0.1742
324 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
When from the average total of 0.1742 gram of barium sulfate obtained
from the fortified soil, is subtracted the barium sulfate average of 0.0555
gram recovery—inclusive of the blank from the unfortified soil—0.1187
gram of barium sulfate is found, or a recovery of 91.3 per cent of the
sulfate addition. Since the barium sulfate yield from the filtrate from
the third ammoniacal precipitation is about three times that from the
third and corresponding filtrate from the unfortified soil it would appear
that this discrepancy is accounted for by occlusion of the sulfate in the
mass of hydrated iron oxide thrown down the third time. In round
numbers, the recovery from each successive filtration is about one-half
that secured in the respective preceding filtrate, for both soil and forti-
fied soil. The occlusion was further studied by means of a synthetic
soil solution of the following composition per 100 cc.
gram
Iron and aluminium oxides: .......;-.....:.-- 6.063
Galera oxide en ee eas Mice ker ier tonal San 1.250
Magnesium oxides Seng sees Se ee) ate wh 1.250
Potassium yond eb Cet lie ae aNe ea SU ane 0.500
SOGTUINVOXTGE eee ee a Me est au aap an 0.500
In using 100 ce. aliquots of this synthetic solution, to which magnesium
sulfate was added, in equivalence to 0.1300 gram of barium sulfate, iron
and aluminium were removed by three ammoniacal precipitations from
the larger volume of 400 cc., rather than a volume of 200 cc., which was
used in the previous work witn the soil extractions. The sulfate determi-
nations were made upon the combined filtrates, ammoniacal salts having
been first eliminated. It was thought possible to decrease the occlu-
sion to a minimum through the greater dilution. The results are given
in Table 6.
TABLE 6.
Barium sulfate recovered from 0.1300 aan of barium sulfate equivalent of magnesium
sulfate.
Analysis A <AnalysisB Average
gram gram gram
Barium sulfate in aggregate of three filtrations.. 0.1088 0.1083 0.1085
Barium|sulfateviniagerecate) blanky inci i ee oh ennai 2 0.0268
Corrected barium sulfate recovery............. 0.0817
Amount UNEECOVELEG yleis ice euyaieenennie ale aide cee 0.0483
It is evident from these results that the increase in volume was not
sufficient to eliminate extensive occlusion of sulfates by the hydrated
oxides, even with three ammoniacal precipitations. The same number
of ammoniacal precipitations were carried out upon another set of
synthetic aliquots, the 100 cc. aliquot first having been made to a volume
1923] MACINTIRE: REPORT ON SULFUR IN SOILS 325
of 800 cc. In this instance, the three filtrates were analyzed separately
in duplicate. The separate sulfate determinations and totals are given
in Table 7.
TABLE 7.
Barium sulfate recovered in each filtrate from three ammoniacal precipitations.
Analysis A AnalysisB Average
gram gram gram
Peiifersty Gltrabe 202i! QS ok, Ue eee Wes 0.0804 0.0830 0.0817
Dasecondl fli nabe soi yyie duty sede «er kuti MANE 0.0502 0.0405 0.0453
MOEA LET AGE ea ro Ne as alec tox Sas eT ete 0.0160 0.0208 0.0184
Liar Eel MIN RPS Cam CesT RU ROR SALAS CVA 3 0.1466 0.1443 0.1454
WotsU reapent DIAM wake Ue Ue cle ten at aaa ae le te) aN RE 0.0268
Total correct recovery of added barium sulfate equivalent............ 0.1186
Barium sulfate equivalent of sulfates, unrecovered from three filtrates. 0.0114
From these results it is apparent that three precipitations of iron and
aluminium will not afford a complete yield of the added sulfates to the
several filtrates from the masses of the hydrated oxides of the two
elements, in the diminished concentration effected by increasing the
volume of aliquots from 100 cc. to 800 cc. It is apparent, however, that the
greater dilution has been effective in causing a distinct diminution in the
amounts of sulfates occluded.
Influence of amount of iron and aluminium upon sulfate occlusion.
The influence of the bulk of the hydrated iron and aluminium upon
the amounts of sulfate occluded was studied by the use of different
aliquots of the synthetic soil solution, each made to a volume of 400 cc.
before removal of iron and aluminium, through two precipitations by
additions of ammonium hydroxide, with a constant addition of mag-
nesium sulfate, equivalent to 0.1300 gram of barium sulfate, but with a
necessarily varying reagent blank.
TABLE 8.
Barium sulfate recoveries frem iron and aluminium variables and barium sulfate
constant.
Synthetic solution Analysis A Analysis B Average
ce. grams gram gram gram
100 6.063 ferric and aluminic oxide 0.0972 0.0910 0.0941
50 3.032 ferric and aluminic oxide 0.1173 0.1173 0.1173
25 1.516 ferric and aluminic oxide 0.1260 0.1248 0.1254
From these data it will be seen that the 100 cc. aliquot, carrying
6.063 grams of ferric-aluminic oxides was responsible for an occlusion of
326 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
0.0359 gram of barium sulfate equivalent; the 50 cc. aliquot, containing
3.032 grams of the oxides of the two elements caused an occlusion of
0.0127 gram of barium sulfate equivalent, while the 25 cc. aliquot,
carrying but 1.516 grams of the two oxides, induced an occlusion of only
0.0046 gram barium sulfate equivalent. Each gram of the two oxides
would appear to have effected occlusion of 0.0059 gram, 0.0042 gram and
0.0030 gram, respectively, in each of the three diminishing aliquots. It
is evident from these results that the amount of iron and aluminium
present in a soil would have a very important bearing upon the recovery
of sulfates from its nitric acid digestion. It is quite possible that the
hydrated oxides of iron and aluminium may vary decidedly in their
ability to occlude. However, the two elements occur in parallel, if in
varying proportions, in all soils, and their properties need not be con-
sidered separately for the purpose at hand.
Precipitation of barium sulfate without elimination of iron and aluminium.
It is generally recognized that the presence of ferric chloride is detri-
mental to the determination of barium sulfate, more especially when
the precipitate is filtered by gravity through paper. C. B. Williams!
has shown that sulfate results are much higher when iron is eliminated
by ammoniacal precipitation than when the precipitations are made
without such elimination. It has not been made altogether clear whether
the cause may be assigned to the minus error introduced by the presence
of a double sulfate, as maintained by Talbot?, or to the solvent action
of ferric chloride upon the barium sulfate precipitate. The difficulty
of removing all iron from the filter was not encountered in these studies,
since an asbestos Gooch was used for all the barium sulfate determina-
tions, except those from the 1 liter volume. It was thought possible
to vary the volume and temperature of the barium sulfate precipita-
tion, in the presence of a constant amount of iron, so as to effect con-
ditions which would permit of complete sulfate recovery without the
interference of the ferric salts. Aliquots of 100 cc. of the synthetic
solution carrying a barium sulfate equivalence of 0.1300 gram were
used. The several duplicates were diluted to 250 cc. and 1000 cc. in
the cold and barium sulfate precipitations made and permitted to stand
for 18 hours.
TABLE 9.
Barium sulfate recovered by precipitation in the cold from dilutions of 100 cc. aliquot of
synthetic solution.
Aliquot Analysis A AnalysisB Average
gram gram gram
100 ce; diliktéd 1025006. 5.. bovmeranen towican: 0.1532 0.1490 0.1511
100 ce-diluted to T0GU Ce. i isiccveat ads se ae 0.1241 0.1204 0.1223
1J. Am. Chem. Soc., 1902, 24: 658.
2 Talbot, H. P., Quantitative Chemical Analysis, 1908.
1923] MACINTIRE: REPORT ON SULFUR IN SOILS 327
These analyses might be taken to indicate either an incomplete pre-
cipitation from the larger volume at room temperature, or else a greater
solvent action of the ferric and aluminic chloride in the more dilute
solution. However, after ignition, the barium sulfate precipitate from
the smaller volume carried much more iron than that from the larger
volume. Again, it is quite probable that the occlusion of salts of cal-
cium, magnesium, sodium and potassium in the barium sulfate precipi-
tate was much greater in the case of the precipitation from the more
concentrated solution.
The effect of temperature upon the precipitation was observed by
making precipitations at room temperature and at boiling. using a
100 cc. aliquot of the synthetic soil solution and making to a volume of
250 cc. in each case. The results so obtained are given in Table 10.
TABLE 10.
Precipitation of barium sulfate from constant volume of synthetic solution at room tem-
perature and at boiling, without removal of iron and aluminium.
Aliquot Analysis A Analysis B Average
gram gram gram
wen ce, diluted 16/250 ce. cold’) :.). 227 IPL ve. 0.1532 0.1490 0.1511
100 ée., diluted t0}250 ce. hot. : . boc iesc. ose veg 0.1468 0.1401 0.1434
The barium sulfate recoveries from the cold solution containing ferric
and aluminic chlorides are appreciably heavier than those made by pre-
cipitation at boiling temperature. The precipitates from the cold
solution being finer than the more granular ones from the hot solution,
it would be expected that they would occlude larger amounts of the
alkali and alkali-earth bases. However, it was not possible to repeat
and amplify this phase of the work.
Repetition of nitric acid digestion of soil residues.
After the compilation of the data obtained by collaboration, additional
work was done relative to the influence of the period of digesting soil
with concentrated nitric acid. In the later work the effect of repetition
of boiling after removal of the digestant by filtration was tried instead
of continued boiling for a longer period, as was done in the earlier work.
After boiling for one hour the insoluble residue was thrown upon a
Buchner and the thin layer of soil thoroughly washed with hot water.
The residue was then returned to the Kjeldahl and the digestion, filtra-
tion and washing repeated. Iron and aluminium were removed by four
precipitations. The first three ammoniacal filtrates were combined and
analyzed for sulfates. The sulfate content of the fourth filtration from
the iron and aluminium precipitation was also determined. The data
of Table 11 represent the determinations after application of the several
blanks for reagent.
328 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
TABLE 11.
Barium sulfate determination upon nitric acid digestion for one hour and upon repeti-
lion of the digestion of insoluble residues.
Loam soil Clay subsoil
A B A B
gram gram gram gram
First, extraction, 3 filtrates.........-..5.. 0.0577 0.0655 0.0454 0.0383
First extraction, 4th filtrate only.......... 0.0030 lost 0.0032 0.0050
First extraction, 4 ammoniacal filtrates.... 0.0607 ...... 0.0486 0.0433
Repetition extraction, 3 filtrates.......... 0.0162 0.0172 0.0079 0.0104
Repetition extraction, 4th filtrate only... .. 0.0003 *0.0002 0.0005 0.0004
Repetition extraction, 4 ammoniacal filtrates 0.0162 0.0172 0.0084 0.0108
*Considered as identical with reagent blank.
The data of Table 11 demonstrate that the amounts of native sulfur
recovered by two hours of digestion are greater than those recovered by
a digestion of but one hour, when filtration is carried out after the first
hour’s boiling. The repetition of digestion differs in this respect from
the continuous boiling for the longer period. The results obtained are
also relatively different, for continued boiling for the 2-hour and 3-hour
periods failed to produce any greater yield of sulfates than was obtained
in the 1-hour period. It would appear that either the extent of oxida-
tion of sulfureous materials is greater after two hours, or else the varia-
tion in the method of extraction is responsible for a greater recovery
from equal amounts of end-products.
MISCELLANEOUS.
Additional work was also done in an attempt to remove iron by a
feasible procedure, other than precipitation in a gelatinous bulk charac-
teristic of the iron and aluminium precipitation. The following tech-
nique was carried out:
The nitric acid extract was evaporated to near dry condition, diluted, neutralized
with ammonia and the iron precipitated by hydrogen sulfide. The sulfide was then
quickly filtered and the ammoniacal solution containing emmonium sulfide, calcium
sulfide, magnesium sulfide, thiosulfates and sulfates was acidified, boiled and filtered.
The filtrate was concentrated and excess ammonium salts removed by evaporation with
nitric acid. The residue was twice taken up and evaporated with concentrated hydro-
chloric acid and the sulfates precipitated from a dilute hydrochloric acid take-up.
The results secured were high owing to thiosulfate and some sulfate
formations during the procedure. The method appears worthy of some
study, however, since it may be that a small correction, secured as a
blank, will enable the analyst to obtain results very close to the absolute.
1923] FRAPS: CROPPING AND ACTIVE POTASH OF SOIL 329
The variation in the iron occurrences does not affect this method, differ-
ing therein from the removal of that element by ammoniacal precipita-
tion.
It is apparent from the data submitted that the usual method of pre-
cipitation of iron and aluminium prior to the determination of sulfates—
ammonium chloride having been eliminated—will not permit of the
complete recovery of sulfates present. It is, furthermore, patent that
the proportion of iron to sulfate and the volume from which the ammo-
niacal precipitation is made are factors of moment as vitiating influences.
Using the figures obtained relative to the amounts of sulfates precipi-
tated from a volume of 250 cc., as compared with those from a volume
of 100 cc., with a constant amount of iron, it is quite possible that a
definite concentration may obtain, at which point the absolute amount
of barium sulfate recoverable may be precipitated.
RECOMMENDATION.
It is recommended that further study be made in an effort to secure a
mode of procedure which may be used in removing all the sulfates which
are carried by a nitric acid soil, or synthetic soil, solution.
E. T. Wherry: May I say a word about the hydrogen ion concentra-
tion? It is being determined more on soils than on other agricultural
chemical products. So many methods are published that it is very
difficult in starting out in this work to determine which method to use.
It seems to me this association should study the subject and have a
referee not only for soil but for all agricultural products in which it is
expected to determine active acidity—for instance, in plant juices,
extracts of plants and dried plant tissue and nutritive media, etc. So
if it is in order, I should like to make a motion that this association
appoint such a referee, namely, on the determination of active acidity
or hydrogen ion concentration for agricultural chemical products.
The motion was seconded and carried.
EFFECT OF CROPPING UPON THE ACTIVE POTASH OF
THE SOIL.
By G. S. Fraps (Agricultural Experiment Station, College Station,
Texas).
The active phosphoric acid or active potash of the soil is that soluble
in 0.2N nitric acid. A method for this determination was worked out
by various referees of this association and incorporated in previous
methods, but it was removed by the Committee on Revision of Methods
of Soil Analysis.
330 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
It has been shown that the potash removed by crops from soils in Texas
pot experiments was related to the active potash of the soil’ and that a
similar relation holds for minerals containing potash and the potash
taken from them by plants’.
It has also been shown that the active potash is less after the soil has
been cropped than before cropping’. Further study of this relation is
reported in this paper.
METHOD OF WORK.
The crops were grown in pots containing 5000 grams of soil, to which
phosphoric acid and nitrogen were added so that the size of the crop
would be limited by potash and not by phosphoric acid or nitrogen.
Corn and sorghum were grown, in some cases for only one year, and in
other cases for several years in succession. The crops were harvested,
weighed, and their potash content estimated. The estimation of the
potash in the crops is absolutely necessary, for the reason that wide
variations occur in the percentages of potash in plants grown on differ-
ent soils. Some crops may contain less than one per cent of potash,
while others may contain over seven per cent. The active potash of
the soil has a great effect upon the percentage of potash present in the
crop, as shown in Bulletin 145.
At the end of the experiment the soils in the pots were prepared for
analysis, and the active potash was estimated. The decrease in active
potash is the difference in the amount present before and after crop-
ping.
The soils were arranged in groups according to the potash removed
by the crops, and the decrease of active potash tabulated and averaged.
The average results with 409 samples are given in Table 1.
TABLE 1.
Effect of cropping on active potash lost in the soil.
POTASH DECREASE | DECREASE IN ACTIVE| NUMBER OF
GROUPS—POTASH REMOVED IN IN POTASH DIVIDED BY SOILS
CROPS ACTIVE POTASH IN CROPS AVERAGED
POTASH
Parts Parts
Parts per million per million | per million per cent
ODO nie ccvote che yrercmecarancr siscatore 1 19
Hl LOOM tect ee eo eee 78 30 38.4 59
TOL=2OO STAI ae AE, Seah 148 61 41.2 153
201-8004. AUR RE 242 100 41.3 77
SOL 400 ees keys cies ans Shee 348 153 43.7 39
ANTI BUO eo vate cataspeis syn oacuare 451 199 44.1 20
SOL GOO ea trae ce ae clos oie tere 552 212 38.4 18
GOT=700) Bee Bk ie hee, te 641 195 30.4 15
COT=S00) Siac aero icnsteeet circu at eves 741 201 2a 3
SOU iran eeniisie aie eeeuectite 882 577 65.4 3
QOL=1LO00 7. OS AIRE Se 964 338 35.0 3
1 Texas Agr. Expt. Sta. Bull. 145.
2 Thid., 284.
1923] FRAPS: CROPPING AND ACTIVE POTASH OF SOIL 331
The relation between the potash removed by the crops and the de-
crease of potash from the soil was also studied by statistical methods.
For this purpose a correlation table was prepared, and the factors of
correlation were calculated. The correlation factor between potash
removed by the crops and the active potash removed from the soil,
R, is 0.7219 =0.0160. The nearer this factor approaches + 1, the better
is the correlation. These figures show that there is a close relation
between the potash removed from the soil and the decrease of active
potash in the soil.
The decrease of active soil potash should not equal the potash removed
by the crops. If a soil is subjected to several successive treatments
with 0.2N acid, the amount of potash removed becomes smaller with
each successive extraction, but in no case does it become zero. If a
crop removed all the active potash represented by the first extraction,
there would still remain the amount of active potash obtainable in a
second extraction. For this reason, the decrease of active soil potash
could only be a fraction of the amount of potash removed by the plants,
and the size of this fraction would vary with different soils.
The fact that the active potash of the soil is reduced by cropping is
further evidence of the importance of the determination of the active
potash in the soil analysis. It has already been shown that the amount
of potash removed by the crops is related to the active potash present
in the soil. These two lines of experimental evidence are favorable to
the use of the determination of active potash in the soil analysis. The
fact that active potash is reduced by cropping should also be of import-
ance in connection with the study of field experiments on potash, but
the matter is badly complicated by the difficulty in securing proper
samples of the soil cropped. It is an easy matter to secure representa-
tive samples of soil used for experiments in pot work, but it is very diffi-
cult to sample a field so as to represent accurately the character of the
soil. This matter of sampling of land has not received the attention
that it deserves. The effect of the subsoil is also difficult to allow for.
It is probable that many results of chemical studies of field work are
complicated and obscured through the use of samples which did not
really represent the situation.
CONCLUSION.
The potash removed by crops, in pot experiments, is related to: the
active potash of the soil; and the decrease of active soil potash is related
to the potash removed by the crops.
332 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
REPORT ON FOODS AND FEEDING STUFFS.
By J. B. Reep (Bureau of Chemistry, Washington, D. C.), Referee.
The committee recommended that the Referee on Foods and Feeding
Stuffs study methods for the determination of ether extract in various
foods and feeding stuffs this year with the view to ascertaining whether
or not the official method for the determination of ether extract! is
applicable to all the products for which it is now being used.
Ether extract determinations were made by the official method and
by the C. R. Smith method? on entire wheat and the various products
and by-products obtained in the milling of wheat into flour. The
average results obtained by the two methods are shown in Table 1.
TABLE 1.
Results of ether extract determinations comparing two methods.
Product Official method C. R. Smith method
per cent per cent
Entire wheat ./isareiies sition Lz 2.33
First break stream.......... 0.62 1.09
Second break stream........ 0.71 1.17
First middlings stream....... 0.86 1.38
Second middlings stream... .. 0.82 1.37
Middlings (semolina)........ 1.07 1.65
SPAR fb ih cl er oes aera eueaiob 2.91 3.01
Shorts (standard middlings). . 4.33 4.51
These results indicate that the use of the more complicated and
expensive Smith method is not warranted in making ether extract
determinations on bran and shorts, since the less complicated official
method gives practically the same results.
The collaborative work of this investigation was done by L. E. Bopst,
assisted by C. E. Goodrich, both of the Bureau of Chemistry, Washing-
ton, D. C.
The effect of using isopropyl chloride as a solvent in place of ethyl
ether in the official method was tried on various products with average
results as shown in Table 2.
TABLE 2.
Results of ether extract determinations with different solvents.
Isopropyl
Product chloride Ethyl ether
per cent per cent
VALTER Cole an be 0.24 0.19
Goth nidat?') OS OVOP Fs 0.52 0.45
Cottonseed meal............ 7.90 7.83
Toarro feed isi josie dhodlelone mate 3.63 3.70
Pamseed meal sis se ease 6.44 6.16
1 Assoc. Official Agr. Chemists, Methods, 1920, 72.
2 J. Assoc. Official Agr. Chemists, 1922, 6: 61.
1923] FRAPS: REPORT ON CRUDE FIBER 333
The results indicate that isopropyl chloride as an extraction reagent
compares favorably with ethyl ether. It has advantages over ether in
that it does not burn so rapidly and the fire risk is less.
A study was made of the effect upon ether extract determinations of
grinding the samples finer. Different types of samples were tried by
the official method using the Knorr apparatus. The results are shown
in Table 3. :
TABLE 3.
Results of ether extract determinations on different type samples.
20 mesh 40 mesh 60 mesh
per cent per cent per cenl
| BUSEY 18 see ae ANIA ERR Abels MRE esl 4.70 4.79 4.90
alta yeas ek bi Adige oat ie Aes 0.93 1.06 1.03
AEOTITOMERNS Heed sere se ccs oon ae 4.43 4.68 4.70
REOLLONSCEU NCAA ees ea ere t cie orci: 7.83 7.93 7.92
Digerro fee Okt YEE Ake AS, POR A. Ra 3.71 3.83 3.93
Fuaxtsectl .meal).« lise. asia este) adalat 5.95 6.14 6.69
It would seem that the finer the sample is ground, up to the point
where it is impracticable to grind it further, the more ether extract is
obtained.
The collaborative work in this investigation was done by L. E. Bopst.
RECOMMENDATIONS.
It is recommended—
(1) That work on the comparison of the official method and the C. R.
Smith method for ether extract determinations be continued next year.
(2) That a further study be made of the effect that grinding the
sample finer will have upon the ether extract determinations.
REPORT ON CRUDE FIBER.
By G. S. Fraps (Agricultural Experiment Station, College Station,
Texas), Associate Referee.
The associate referee sent out samples of wheat bran, cottonseed meal
and alfalfa meal to collaborators, with the request that they test these
samples by three methods. Method No. 1 had a first reading for adopt-
ion as official in 1921; Method No. 2 requires boiling in a beaker and
filtering through asbestos; and Method No. 3 should be the regular
method used in the collaborator’s laboratory. Later on, samples of
linen cloth and cotton filtering cloth, which had been previously digested
with equal parts of water and 114 per cent of caustic soda, were sent
with the request that they be tested. The linen used is called butcher’s
linen or dress linen, about 50 threads to the inch, and the cotton filter-
334 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
ing cloth was furnished by G. L. Bidwell of the Bureau of Chemistry.
The referee received splendid cooperation, as is shown by this report.
Especial mention should be made of the cooperation of G. L. Bidwell.
The results of the analyses are shown in Table 1.
REMARKS OF COLLABORATORS.
A. L. Flenner, Maryland.—Method No. 8 differs from No. 2 in that the first filtration
is made on linen instead of asbestos. The linen cloth is preferred when using suction
and the cotton without suction. When the cotton cloth is used without suction on a
4-inch funnel, filtration is quick and the residue washes off easily.
C. S. Cathcart, New Jersey —Method No. 1 suggested by the referee was not satis-
factory. It was impossible to get satisfactory results and doubts are felt as to the
outcome of this method.
N. C. Hamner, Dallas, Texas.—The usual laboratory method is much more con-
venient, quicker and less liable to error. There is too much frothing. It is difficult to
keep the sample in the solution when the flask is used, as it is hard to shake the sample
from the side of the flask. A tall 600 cc. beaker was used with a 500 cc. flask for con-
denser.
C. E. Shepard, Connecticut.—The laboratory method differs from the official in no
essential particular except that boiling is not done under a water-cooled condenser.
No trouble was experienced with Method No. 2 but the filtration was slow. The
alkali digestion gave trouble on account of violent bumping, probably due to the large
amount of asbestos present.
F. B. Porter, Fort Worth, Tex.—The laboratory uses a tall 600 cc. beaker covered
with a 500 ce. flask filled with water. The proposed official method is inconvenient and
unsatisfactory on account of frothing. With a reflux condenser attached to each flask,
it is difficult to rotate the flask and keep sample in the solution.
J. J. Vollertson, Chicago.—The results by Method No. 2 varied more from the pro-
posed official and the official method than they did from each other but this may be
due to lack of practice in the method and not to anything fundamentally incorrect.
The use of asbestos and a Biichner funnel is an advance over the linen filter in that the
sample may be handled more easily and without loss. The use of Liebig condensers
in the proposed official method requires a special set-up of apparatus and the results
do not show an increased accuracy to justify it. The asbestos added in the proposed
official method is of help in filtering through linen in case of such material as cotton-
seed meal. However, the amount used must be small to avoid filling the Gooch cruci-
ble too full. It is suggested that the proposed official method might be used for check
or disputed samples. In case of an ordinary analysis, the substitute method would be
better because of the superior ease of manipulation and the sufficient accuracy of the
results. The method used in this laboratory is the old official method. The linen
cloth is preferred as the sample can be more easily removed, but either cloth would be
satisfactory.
L. D. Haigh, Missouri.—The 7.5 cm. Biichner funnel was found to be rather large,
as it required so much asbestos. The large amount of asbestos from two filtrations
taxed the capacity of the ignition crucible to hold it. A Biichner funnel, 6 cm. outside
diameter, was used. This had smaller holes than the 7.5 cm. and required much less
asbestos. Asbestos present with the feed in the boiling process seemed to increase the
amount of bumping. In the laboratory method the liquid was heated in a tall 800 ce.
lipless beaker covered with a flask filled with water, filtered both times on linen and
transferred to a Gooch.
1923] FRAPS: REPOT ON CRUDE FIBER 335
P. S. Tilson, Houston, Texas——Methods 1 and 2 are not an improvement over the
present official method. The sample of linen sent is admirably adapted to the pur-
ose.
x A. J. Patten, Michigan.—In the laboratory method (No. 3) an air condenser is used
and both filtrations made on linen. The residue is then transferred to a Gooch.
J. L. St. John, Washington.—Our laboratory method follows the proposed official
method; the second filtration is made on linen and then transferred to a Gooch.
W. G. Friedemann, Oklahoma.—No saving in time is effected by No. 2 and bumping
was also observed. In Method No. 3 we used an 800 ce. lipless beaker.
W. F. Hand, Mississippi.—The cotton cloth works fairly well with ordinary feeds
but it is very slow with cottonseed meal. The linen sent is thicker than the quality
used in the laboratory and filters more slowly, but both give results closely in accord.
The following results were secured with the filtering medium sent:
Cotton Linen Mississippi linen
per cent per cent per cent
MIPIASSESIECD 3h yc ottod oslo Aoievcas eoeehe 10.15 10.31 10.27
WNT PGT RCL TOY a ICT Oa hI 4.66 4.71 4.71
Wa itomseed MMA 5555 (5 055505.5 0.0 218 abe oie ties WAG 13.28 12.80
J. W. Kellogg, Pennsylvania.—The linen cloth is practically equal to the one used
here. The cotton cloth filters much faster and gives very desirable results. The
filtration of cottonseed meal and animal by-products is especially good.
B. J. Owen, Florida.—Both samples of cloth were used in official work for two months.
The cotton cloth permits a more rapid filtration than the linen cloth because of its
rougher texture and greater thickness, but the fiber clings to the cotton cloth to such
an extent that it is difficult to separate the fiber from the cloth into the dish used for
drying the fiber. The sample of linen filters much more slowly than the linen used
in Florida.
J. B. Smith, Texas.—Method No. 2 is quicker and more convenient than Method
No. 1. There seems to be no advantage in the use of asbestos with Method No. 1.
The liquid filters quickly without it and there is less bumping. The work on Method
No. 1 was done by the writer and that on No. 2 by Mrs. Graham, each determination
on a different day.
R. F. Korfhage, Minnesota—The laboratory method differs from the proposed
ofticial method in filtration on alundum crucibles, porosity R. A. 98, and washing with
114% sulfuric acid after the second filtration. An acid wash hastens the filtration of
bone, tankage and meat scraps, which tend to clog the crucibles. Method No. 2 is
very unsatisfactory because of the possibilities of loss of material although it does
give higher results than the other methods. The cotton cloth sent is preferred as it
filters more quickly.
H. D. Spears, Kentucky—Amy] alcohol was used instead of air blast to prevent
foaming. In the laboratory method the substance is added to the acid before it is
heated; the first filtration is made on linen in a Hirsch funnel, the second on an alundum
crucible, and the heating is performed in beakers. The beakers and flasks are more
efficient than the Liebig condensers and certainly more practical. Addition of asbestos
causes bumping. The sample of cotton is the most desirable filtering cloth used. On
a sample of wheat feed, the laboratory method gave 7.50 and 7.45 per cent; filtering
twice through alundum, 7.80 and 7.75 per cent.
J. D. Turner, Kentucky.—Comparisons of the cotton sent, the linen sent, and cloth
regularly used were made on 12 regular feed samples. The results are given below.
The two linens were about the same in texture and took the same length of time for
filtration; the cotton was thicker and more porous and took less time for completing
the work.
336 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
Cotton Linen Kentucky linen
per cent per cent per cent
Mixed feed ciate tietiniersce i alelerenr ts 5.23 5.10 5.05
Mixed feeds ager bas aii Mate hide ciel (cs dle 7.73 7.85 7.88
TIL OR TEOMA giclss is onedans rouekveusbene cucictiancua ious 4.98 4.93 4.85
Digesterstankagen nce a ons ccs cone 1.75 2.04 1.85
Poultry scratchy. cae ee ee ee eee 3.65 3.40 3.44
Poultryichick) 6) Oe eran ee ea ae 2.80 2.70 2.85
Cottonseed feed 2M iad ioe rend lee 21> wisien te 14.51 14.72 14.43
Cottonseed feed ie ie le dices tual eval 16.83 16.93 16.79
Brewers dried grains chicicie ais cess een 16.75 17.20 . 16.31
IMriddlingsiser tarts crmemr. cf ke aete 5.30 5.55 4.48
Dairy feed y MeeVee Rae, Oe 13.63 13.50 13.55
baying mash yy skraatnvde eee alls a a ee i 5.80 5.65 5.69
H. R. Baker, Wyoming.—This station is at the altitude of 7,200 feet, which affects
the boiling point. To study this a 500 cc. Erlenmeyer flask, containing the liquid to
be tested, was placed under a reflux condenser, just as in the crude fiber determination.
A thermometer was lowered through the condenser until the bulb was immersed in the
liquid, which was then heated to boiling.
The temperature of the sulfuric acid and caustic soda seemed to vary in proportion
to the amount of water in the condenser at any one time.
When the liquid boiled at a constant rate as in the crude fiber determinations, the
temperatures noted were as follows:
1.25% sulfuric acid varied between 97.5°C. and 98.0°C.;
1.25% sodium hydroxide varied between 96.5°C. and 97.0°C.;
Distilled water—no variation—temperature 96.0°C.
The boiling point of distilled water—determination in the usual manner by taking
the temperature of the vapor arising from boiling water—was found to be 92.8°C.
The barometer reading when making these determinations was 23.285.
From these observations of the temperatures of the boiling solutions it would seem
that the rate of boiling will have an effect on the results obtained in crude fiber work.
J. M. Bartlett, Maine-——The proposed official method does not meet with very much
favor in this laboratory. The principal objection is the time that is required to carry
out the filtrations with the large amount of asbestos that is proposed to use. Perhaps
with more experience the method would meet with more favor but from the present
amount of work done, it is not considered that the method is as accurate or convenient
as the one now used. This consists in heating in a 500 cc. Erlenmeyer flask connected
to a block tin condenser, filtering both times on linen and transferring to a Gooch.
G. L. Bidwell, Washington, D. C.—In your letter you ask for comments and sug-
gestions. We are giving some of each with the hope that you will accept them in the
spirit intended.
We were surprised to find a sample of alfalfa being used in this cooperative work,
which was so coarsely ground. We have had difficulty in this laboratory securing
checks on crude fiber upon straight alfalfa meal even when finely ground. This is
due, no doubt, to the inability of the analyst to secure uniform charges, that is, charges .
containing the same amount of leaves and stems, for as you know stems run higher
in fiber than leaves. Alfalfa ground to pass a 40-mesh sieve will give closer checks
than the coarser material.
We have found the use of flasks for condensers to be unsatisfactory as well as in-
efficient; this was shown in our reports before the A. O. A. C. in 1920.
When asbestos was used as a filtering medium an additional transfer of the sample
was necessary; also the charge became very bulky and would barely go into a Gooch
crucible.
1923] FRAPS: REPORT ON CRUDE FIBER 337
We do not see that the modifications suggested for trial improve the method, and
the extra transfer certainly lengthens the time necessary for a determination.
DISCUSSION.
Table 1 contains the results reported by the individual laboratories.
The average for each laboratory was used in making up the final averages.
The proposed official method gives on an average slightly lower results
than the method of filtration on asbestos. Eight of the 17 laboratories
secured results within 0.3 per cent by the two methods applied to wheat
bran, 10 on cottonseed meal and 2 on alfalfa meal.
The difference between the maximum and minimum is practically
the same for the proposed official method and for the varied methods
now used in the laboratories cooperating, when applied to wheat bran
and cottonseed meal. The difference when filtering on asbestos is
greater than that secured by the official method with wheat bran, but
less with cottonseed meal. The difference between maximum and mini-
mum averages with the proposed official method is 1.30 per cent for
wheat bran, 2.05 per cent for cottonseed meal, and 3.97 per cent for
alfalfa meal. The alfalfa meal was not ground fine enough. These
differences are between the averages of the different laboratories, and
not between the maximum and minimum of separate determinations.
Table 2 shows the distribution of the determinations with respect to
the average for the proposed official method. The groups differ by
0.3 per cent, the average being approximately midway the median
group. The distribution of the determinations is better for the pro-
posed official method, especially with wheat bran, than for the other
methods, but the distribution still leaves much to be desired. In other
words, the agreement between the different laboratories is not so great
as could be desired for a new official method, although it is better than,
with the variety of methods now in use.
The writer is favorably disposed towards the proposed official method
as he realizes that it is based upon a large amount of careful work by the
previous referee. But the number of criticisms of the method and the
wide variation in results secured from different laboratories prevent
the writer from recommending this method for final adoption as official.
While the proposed official method gives somewhat better results than
the variety of methods in use in the different laboratories, these results
leave much to be desired. It is possible that some of the differences
will disappear with more familiarity with the method, and with the use
of a uniform grade of filtering cloth. The method should appear so
desirable to the various laboratories that they will be induced to adopt
it in all essential details, for little advantage would be gained in adopt-
ing a method to be used by one or two laboratories.
338 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
TABLE
Results of cooperative
WHEAT BRAN
ANALYST ——$—$—$ <$——
1-Proposed | 2-Asbestos | 3-Laboratory
fficial Filter Method
J. J. Vollertson, Morris & Co., Chicago.......... 7.69 7.98 7.68
Tre 7.38
AVELORG e)oe ye Tera 7.98 (53
A! P. Kerr, Louisiana: $:) shane ete eek Dae 8.20 8.60 9.00
Claude R. Engle, Pennsylvania Department of
Mericultuire }s vous ey se Res Me ie oe 8.07 8.66 7.72
8.40 8.33 7.65
Averages. iis uns 8.24 8.50 7.69
WUE and MIssissiinph crt ky). eta ore ee 7.57 8.20 8.31
P.S. Tilson, Houston Laboratories, Houston, Texas 8.23 9.13 7.95
Percy @’Meara, Nichigan nists lotrel 8.30 8.05 7.65
8.18 8.55 7.78
PV GTO Vis el) 5 8.23 8.30 7.72
#-E. St. Johny Washinigtont!! tos 24 eo ee 8.10 8.75 7.64
7.97 8.68 7.86
Mveragesieesvieed 8.04 8.72 Gad
W. G. Friedemann, Oklahoma.................. 8.62 8.75 8.77
8.85 8.67 8.93
9.05 8.55
Averages 0) as 6M 8.84 8.71 8.75
L. E. Bopst, Bureau of Chemistry, Washington, 8.57 8.69
Pou Oe ain Ole TI LSI: NARA BEU NMR Bec), HRY. 8.50 8.52
Average.) . aotula. 8.53 8.60
CoE. Stepard, Connecticut... 02. oe eet 7.91 8.22 7.97
F. W. Porter, Ft. Worth Laboratories, Ft. Worth,
PRO NEES chk Omer INC Ue cote ROLE SAP A ae 8.18 9.01 8.20
N.{C.]Hamner, Southwestern Laboratories, Dallas,
NSS TE gees AST NEO Rey IME, iene 8.05 8.98 8.05
Rot Haigh, (Missourts, te tee eee ee 7.97 8.46 7.73
7.79 8.57 7.58
8.41 8.74 7.97
8.42 7.95
Average. 0 ga 8.15 8.59 7.81
A. Li Rlenner, Marylandi¢)is: ddan oho, 7.75 8.00 7.70
Averagesii. oi Quat
FE. Re Pebey,, Maine .:3/0)3), vais sae (ae ae 8.33 7.89
8.15 7.81
AVEGREG, cn kane oe 8.24 7.85
1923] FRAPS: REPORT ON CRUDE FIBER 339
work on crude fiber.
COTTONSEED MEAL ALFALFA
1-Proposed 2-Asbestos 3-Laboratory 1-Proposed 2-Asbestos 3-Laboratory
Official Filter Method Official Filter Method
10.65 11.20 10.03 35.80 34.92 35.42
11.05 10.32 36.30 35.10
11.35 11.20 10.17 36.05 34.92 35.26
11.65 11.85 11.50 IZ, 36.45 35.00
10.94 1152 10.18 35.41 37.26 33.93
10.59 10.92 9.61 34.05 35.83 34.05
WLOse 11.22 9.90 34.73 36.55 33.99
9.80 11.22 11.35 33.62 34.84 34.86
10.48 10.59 9.85 34.02 35.65 34.35
11.05 10.97 10.28 35.92 37.01 35.82
11.08 JUL 13? 10.22 35.93 36.18
11.07 11.05 10.25 35.92 36.80 35.82
11.40 11.64 10.44 33.94 37.04 34.90
11.20 12.05 10.50 33.28 37.47 35.14
11.30 11.86 10.47 33.61 37.25 35.02
11.77 11.41 11.67 38.40 Blot lz 37.79
11.55 11.50 11.80 37.10 38.90 37.95
11.35 37.25 38.60
11.56 11.46 11.74 37.58 38.22 37.87
10.94 11.05 36.36 34.42
11.26 11.07 37.90 36.37
11.09 11.06 35(fo1 (5° 35.40
10.59 10.70 10.46 34.56 30.02 36.13
10.79 10.79 10.30 34.66 35.25 35.48
10.62 1121 11.14 34.80 34.97 34.25
10.72 11.18 10.29 36.56 37.56 35.26
10.85 122 9.94 StH} 34.69 34.53
11.40 12.24 10.42 37.02 37.50 36.90
HEGS 11.87 GR 37.56 39.45
11.15 11.63 11.59 36.72 37.30 35.56
10.75 10.50 10.85 35.15 34.45 33.60
35.45 33.50
35.30 33.00
10.89 9.46 37.10 36.09
iMlasie 9.74 35.76 35.42
340 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
TABLE
Results of cooperative
WHEAT BRAN
ANALYST Se ee ne ea
1-Proposed | 2-Asbestos | 3-Laboratory
Official Filter Method
Howell D. Spears, Kentucky..................- 8.45 8.23
8.59 8.17
IA VeNAge (oc js: wok 8.52 8.20
Smithy&; Graham; Mexas-s05.5 .s2chis «ase woes 8.69
8.76
8.72
TANS) (21 Late 8.72
Roy F. Korfhage, Department of Agriculture, Min-
TIE SOCAN Cis fey 5 PRR ORE ocd oe i ewe tire clk ania eilameate ls 8.39 8.30
8.39 8.34
AVErAge. js! a ics uae 8.27 8.32
Average (of averages). <2 08.0 in jen ce ced as sme 8.19 8.05
Maximum (average) ire.) sas heacnvaehs ded sec otine 8.87 9.60
Minimum) (average) icisscs cree cr cicina eee (eta 7.69
Difference, maximum and minimum......... 1.30 lees
Harold R. Baker, Assistant State Chemist, Wyo-
TINT pais 2 cats ob eae aes is Ste ete sttaet sore ehrevactev ogee 9.70 8.59
9.80 8.61
G. Bitterman, Department of Agriculture, Wis-
COTISLEN Te iron ae REA Le taco veo geal eteiores 9.75 9.50
9.81 9.68
9.36 9.33
IAVETARE. Waa tonieeie: 9.64 9.50
W. G. Moore, Experiment Station, + Geneva, N. Y. S227, 7.10
8.47 7.08
ANETARE sco sie so eo 8.37 7.09
*Owing to the high altitude these results are not included in the averages.
+Received too late to be included in the average.
The crude fiber method has been termed a definitive method by the
previous referee, meaning that the results secured depend upon the
exact details of the method used. If such is the case, the method should
be defined in such a way as to be convenient and easy of manipulation.
However, the results should not differ widely from the previous method,
and this procedure should give agreeing results in the hands of different
analysts. For example, there is no more reason for taking the method
of boiling in a flask with a Liebig condenser as the standard, than for
1923] FRAPS: REPORT ON CRUDE FIBER 341
1—Continued.
work on crude fiber.
COTTONSEED MEAL ALFALFA
1-Proposed 2-Asbestos 3-Laboratory 1-Proposed 2-Asbestos 3-Laboratory
official Filter Method Official] Filter Method
11.50 12.23 11.49 35.84 35.85 36.41
11.80 12.35 11.48 36.78 34.79 37.05
38.91
38.78
11.65 12.29 11.49 36.31 35.32 37.79
11.09 11.48 35.06 35.56
11.10 1 sy4 35.37 35.74
11.55 35.78 34.66
11.25 11.50 35.46 35.32
12.57 12.99 11.29 36.08 38.60 37.05
10.52 PAU 11.28 35.95 38.26 37.16
E27, 11.46 10.93 36.00 39.02 37.83
11.60 12.20 36.46 36.86
11.49 12.19 Ii alz/ 36.30 38.18 37.35
11.02 TES 10.74 35.46 36.03 35.50
11.85 12.29 11.74 37.58 38.22 37.87
9.80 10.50 9.60 33.61 34.45 33.55
2.05 1.79 2.14 3.97 oetits 4.32
13.31 10.61 39.67 39.23
13.06 10.88 39.45 38.25
12.40 11.84 10.59 36.10 36.60 36.62
12.01 11.76 10.50 38.22 38.22 36.45
12.65 174333) 10.68 36.91 36.91 37.00
12.35 11.97 10.59 37.24 37.24 36.69
10.66 10.90 9.55 Soe 32.88 33.48
10.72 11.52 9.58 35.04 36.82 33.50
10.69 11.21 9.56 35.18 34.85 33.49
taking the method of boiling in a beaker with a round condenser. One
method might give slightly different results, but either method could be
adopted as a standard. If more uniform results could be secured by
one, or by the other method, it should be given the preference.
The assay flask mentioned in the method is no longer available, and
reference to it should be omitted.
The cotton filtering cloth suggested by Bidwell seemed to be highly
satisfactory, but the referee should not consider it good policy to pre-
342 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
TABLE
Deviation of averages from average by
WHEAT BRAN
GROUP a ne =
1-Proposed 2-Asbestos 3-Laborator
Official Filter Method _
Set] a> onal Bi: iy ag es ee nr Spel ss aa —
RM Os L's ostrich ele teres = =: =
Oita —1Obs ee os oR. ives = --- —
OMG ONDE as fice eee atom So 3
wb) Ue: 2 Bon RO ot aka 3
7
= SO HPO Oa. See eieei ee cupineet o 3 5
=O ae tO COs ol miareiebs 50 esa aia ie 2 3
crime AC ham be US MM dies PE an, GO Ue = 3
Sa CU heart] Jaro OB Cae» ALR ey Ae = 0
afloat OO Beez cick ksi. Bile\ nate ce aa 1
cal GO =A sOo ta rio sn cee er — = —
fo eyre OO S 2 een te ene eee == = —
Ste DOG DO anes UN nist git ata Rhea at oe = =
pacer atRe OO Act. een ess wie ae as =e —
scribe a particular kind of cloth made by a particular manufacturer as
the only kind of cloth to be used in an official method. There is no other
way of describing such a filtering cloth.
At the meeting last year the associate referee on crude fiber was
requested to incorporate the variation in the method necessary for pre-
pared mustard. A recommendation has been made with this object
in view.
L. E. Walter of the Wyoming station has called attention to the differ-
ent results caused by high altitude. The lower boiling point of the
liquid leaves a higher percentage of crude fiber. A note should be
added to the method calling attention to this fact.
Bone meal comes under some feeding stuff laws, which require the
guarantee of crude fiber in it, although it should contain practically no
crude fiber, except from contamination. The present method gives from
1923] FRAPS: REPORT ON CRUDE FIBER 343
7
proposed official method.
COTTONSEED MEAL ALFALFA
Soenr | ae [eee | Seer | eae | “aes
—~ = — 2 ~ 1
_ — 1 1 1
— 2 0 2
0 1 2 2 1 0
1 1 3 2 3 2
4 3 1 2 1 2
4 1 1 1 5 2
3 4 1 0 1 2
5 3 4 2 0 1
— 2 _ 3 1 0
- 2 - 1 2 0
- a 0 0 0
- _ = 1 1 1
_ _ 1 0 0
-- -- — ~ 1 2
0 vt i b 1 a
4 to 6 per cent crude fiber, but if one-gram substance is used the amount
of crude fiber is reduced to about 1 per cent. The quantity of sulfuric
acid is probably not large enough to dissolve all the phosphate of lime
from two grams. This matter is brought up for consideration with-
out recommendation.
RECOMMENDATIONS.
It is recommended—
(1) That references to the assay flask be removed from Method
No. 1, the proposed official method.
(2) That the paragraph concerning linen be changed as follows:
Filtering cloth should be of such character that while filtration is rapid no solid mat-
ter passes through. Either butcher’s linen or dress linen with about 45 threads to the
inch could be used, or No. 40 filtering cloth, made by the National Filter Cloth & Weay-
ing Company, 57 Hope Street, Brooklyn, N. Y.
344 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 3
(3) That in accordance with the request of the committee on recom-
mendations, the following description of the method for. prepared mus-
tard is offered for incorporation in the method when adopted. (It
might be better to permit this variation to come in under the head of
spices. )
In prepared mustard or similar pasty material, high in fat, proceed
as follows:
Weigh 10 grams of the sample and transfer to a tall 8 ounce nursing bottle with
50 cc. of strong alcohol, stopper and shake vigorously. Add 40 cc. of ethyl ether, shake
and let stand about 5 minutes with occasional shaking. Centrifuge and decant off the
alcohol-ether mixture. Treat twice more with 40 cc. portions of ether, shaking, centri-
fuging and decanting as before. Rest the bottle on its side for a short time, without
heat, to allow the ether to evaporate. Transfer the material with 114 sulfuric acid
and determine crude fiber by the regular method.
If preferred, the sample may be treated with the alcohol and ether in a small beaker,
finally transferred to a hardened 11 cm. filter paper and washed two or three times
with ether.
(4) That the method be further studied with the view to its adoption
on final reading as an official method. (This method was offered for
first reading in 1921.)
G. L. Bidwell—I am very much interested in the results obtained.
I hope that those who are considering the method will take into con-
sideration the one fact that no method will give as good results when
first tried as it will later; in other words, when the analyst is more ac-
customed to using it.
Concerning the cotton cloth used for filtering, we saw the advertise-
ment of it and wrote to the firm. We selected three samples of cloth
from the collection sent and tested them. No. 40 was the one that
seemed to suit the best. I realize the undesirability—if you want to
use the word—of recommending any particular firm’s cloth. However,
we all realize the difficulty in getting a uniform cloth. In fact I do not
remember that I have ever seen two lots of linen exactly alike. This
cotton cloth is made for a specific purpose and is always uniform. Ar-
rangements may be made whereby it can always be obtained and thus
the problem of a uniform filtering medium may be solved.
On the question of condensers and boiling vessels, I do not think these
have to be just as the original method specified. The beaker is just as
good as the flask and any efficient condenser will do as well as the Liebig.
Any changes along these lines will have our support. However, I
should like to see the same types of apparatus specified for all labora-
tories, because this is the important point.
1923] GENSLER: REPORT ON STOCK FEED ADULTERATION 345
REPORT ON STOCK FEED ADULTERATION.
By H. E. Genser (Bureau of Chemistry, Department of Agriculture,
Harrisburg, Pa.), Associate Referee.
The work on stock feed adulteration for this year includes a continued
study of the method for the determination of hulls in rice bran as pro-
posed by your former referee, B. H. Silberberg!, and also of the method
for the determination of grit in scratch feeds and bone in meat products
formulated by your present referee’. As these methods were recom-
mended for further study, samples were prepared and sent, with instruc-
tions, to 23 collaborators.
It was impossible to obtain rice bran which was absolutely free from
hulls; however, that secured contained only a trace. This material was
used as the basis for the samples in determining the amount of rice
hulls present. The collaborators were advised to follow the Silber-
berg method, which requires the counting of hull particles in a 4 milli-
gram portion of the sample, placed on a ruled slide and gently heated
with chloral hydrate solution. Counts are made using samples which
contain a known amount of hulls and, from the average number of
particles observed per centum, a factor is obtained which is then used
in computing the amount of hulls present in samples of unknown hull
content.
Five samples of rice bran containing various amounts of rice hulls
were sent to the collaborators for this work. Sample No. 1 was used as
a basis for the other four samples; therefore the collaborators were
instructed to obtain a count which should be used as a “‘blank”’ to be
deducted from the counts obtained in subsequent determinations.
Samples Nos. 2 and 3 were “standards” containing 10 per cent and 15
per cent of hulls, respectively; and Nos. 4 and 5 were ““unknowns’’ and
contained 8 per cent and 12 per cent, respectively. The collaborators
were advised to familarize themselves with the appearance of rice hulls
before making actual counts.
The results obtained are given in Table 1. It will be noted that while
the counts obtained vary considerably, the reports upon the unknowns
are in close agreement. The “blank” showed counts varying from 5 to
30 with an average count of 18 for the results of nine collaborators.
The figures for Sample No. 2, containing 10 per cent of hulls, vary from
60 to 131, with an average of 98; and for Sample No. 3, containing 15
per cent of hulls, from 80 to 216, with an average of 150. In the case
of the unknowns, counts ranging from 60 to 129 were reported for Sample
No. 4, containing 8 per cent of hulls with an average of 87, and in the
1 J. Assoc. Official Agr. Chemists, 1921, 5: 77.
2 Tbid., 1922, 5: 424.
346 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
case of No. 5, containing 12 per cent of hulls, the figures range from 64
to 167, with an average of 118.
The results reported for the percentage amount of hulls present are
very close and in the case of Sample No. 4 are, with the exception of
the report of Analyst No. 21, within 2.4 per cent of the amount known
to be present. In the case of Sample No. 5, containing 12 per cent of
hulls, percentages were reported ranging from 10 per cent to 14.1 per
cent. All the results are within a range of 2.1 per cent. The average
percentage of all the results on No. 4 is 9.3 and on No. 5, 11.6.
It is interesting to note the close results obtained by Analyst No. 12;
notwithstanding that, in submitting his report, he stated that nothing
more than an approximation could be made because the samples were
manufactured from a bran which contained hulls as a contamination.
The referee considers that unless a rather large amount of hulls was
present in the sample used as a base, his suggestion of deducting the
count obtained upon it from the other samples would only be in con-
formity with a practice often adopted in chemical work where correc-
tion factors are employed.
Probably the most striking feature of the averages is the fact that
the ratio between the number of particles counted to the percentage
of hulls present in each sample is as ten to one. One might assume,
in other words, that every ten particles would represent the presence of
1 per cent of hulls.
It may fairly be concluded, from the figures obtained in this year’s
work as well as in the work previously done, that the method in question
is very well adapted to the purpose intended and that the analyst can,
with its use, ascertain quite accurately the amount of rice hulls present
in a sample of rice bran. One or two rather wide variations from the
actual amount of hulls present have been noted, but it is believed that
these variations are the exception rather than the rule and should not
be considered.
For the purpose of studying the method for the determination of
grit in scratch feeds, devised by the referee, Samples Nos. 6 and 7, con-
sisting of scratch feed and grit, were prepared. The results obtained in
last year’s work were unusually good for determinations of this charac-
ter, but the question arose as to whether or not similar results would be
obtained in an unground sample containing grit. One collaborator
proposed the use of carbon tetrachloride. Accordingly, samples were
prepared to prove the correctness of this suggestion. Sample No. 6
was an unground sample of scratch feed containing 10 per cent of grit.
No. 7 consisted of a ground scratch feed to which was added 10 per cent
of ground grit. It was the opinion of your referee that if results which
approached 10 per cent could be obtained on both of these samples the
method would be justified.
1923] GENSLER: REPORT ON STOCK FEED ADULTERATION 347
Table 2 is a condensed report of the results secured on these samples.
Those obtained with the use of carbon tetrachloride check very closely
the results obtained with the use of chloroform and demonstrate that
either liquid can be used with equal advantage. Although variation
of from 6.1 to 13.6 per cent existed in the analysis of Sample No. 6, the
averages 9.4 per cent and 9.4 per cent correspond closely with the amount
of grit present. The range is without a doubt due to the difference in
the sample tested rather than in a failure of the method. This opinion
is borne out in the reports on Sample No. 7 which had a definite content
of grit. Most of the results are within a range of 0.5 per cent of the
correct figures with no greater difference than 1.9 per cent. It is of
interest to note that the averages for this sample are the same as those
for No. 6. It might be well to recall at this time that eleven analysts
working on samples prepared similarily to Sample No. 7, and con-
taining 1, 3.5, 5 and 8.2 per cent of grit, respectively, obtained results
which averaged 1.6, 3.6, 4.9 and 8 per cent for the respective samples.
It is evident that all the results secured on samples prepared to test
this method justify its use in practical work.
The study of the application of the method for the determination of
bone in meat products was arranged (1) further to test its accuracy;
(2) to make a trial of the use of carbon tetrachloride as compared with
chloroform; (3) to apply it to actual commercial samples; (4) to test
its accuracy in estimating small amount of bone; and (5) to determine
the analyst’s ability to identify tankage in meat products.
Sample No. 8 consisted of 80 per cent of “‘cracklings”’ or “‘meat scrap”’
and 20 per cent of tankage. No. 9 consisted of No. 8 diluted with a
high grade bone meal so as to contain exactly 10 per cent additional
bone. The referee requested the collaborators to determine the amount
of bone in both samples in order to estimate how nearly the difference
of these two results would approach 10 per cent. Consultation of
Takle 3 will show that these figures were all very close to 10 per cent,
only two out of eighteen showing any degree of variation. Averages of
all results were 9.9 per cent and 10.2 per cent, using chloroform and
carbon tetrachloride, respectively. Furthermore, it is of special interest
to note that all analysts reported correctly the presence of tankage.
Sample No. 10 was prepared to test the utility of the method in esti-
mating small amounts of bone and contained only 2 per cent of bone.
The results of work on this sample are also included in Table 3.
Collaborator No. 9 carried on experiments to determine whether any
bone floated off with the supernatant liquid, by analyzing the “‘floats’’
for phosphoric acid and found its content to be “much higher than the
phosphoric content of meat, blood or ‘stick’”’. Further, he reported
that the proposed method was tried on steamed bone and the percentage
of phosphoric acid in the floats was relatively high. He also called
348 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
attention to the fact that ‘“‘sand, soil and cinders will sink and be weighed
up with the bone’. In reference to the first statement, it is not doubted
that his results verify a condition wnich exists. However, the results
just noted in the tabulation indicate that this loss is not serious. As
indicated in the method, the residue is to be examined to insure its
being bone. This clause will obviate any danger that contaminating
ingredients will be included in the final results.
CONCLUSIONS.
The results on all samples are very gratifying. The percentages
reported in the estimation of rice hulls indicate that a method has been
found that is workable and dependable. The same thing is true in the
determination of grit and bone. The use of carbon tetrachloride as an
alternative liquid is approved and your referee has deemed it advisable
to amend his method to include its use. He also has amended the method
to include an examination of the residue of either bone or grit for the
presence of impurities.
In the use of any micro-analytical method the operator must always
bear in mind that if he can obtain a result which is a close approximation
to correct content of ingredients, he has secured the most that can be
expected from recourse to the use of such methods.
TABLE 1.
Determination of rice hulls in rice bran.
COUNTS ON STANDARDS COUNTS ON UNKNOWNS
res beds Sample 1—Rice Bran | Sample 2— | Sample 3— Sample 4— Sample 5—
oa (Blank) 10% Hulls | 15% Hulls 8% Hulls 12% Hulls
per cent per cent
2 17 91 137 63 Ce Rd
5 11 79 120 68 Sup 95%
8 12 101 153 87 8.6 | 106 10.5
10 5 80 108 74 10.4 93 Fe aG
12 Pe 128 216 112 8.5 | 167 12.0
14 aN 131 204 129 9.6 | 135 10.1
16 24 119 203 119 10.0 | 191 14.1
17 20 80 110 60 SeOhl) LOO) memes nO
19 30 110 165 80 (Sa ae) 10.0
21 15 60 80 80 15.0 64 10.7
Average.... 18 98 150 87 2s a fe = G0
The results obtained on all of the samples submitted to the collabora-
tors fully justify the use and adoption of the methods employed.
1923] GENSLER: REPORT ON STOCK FEED ADULTERATION 349
TABLE 2.
Determination of grit in scratch feeds.
SAMPLE 6-10% OF GRIT—UNGROUND SAMPLE 7-10% oF GRIT—GROUND
Analyst Chloroform eecey Chloroform Tone ae
per cent per cent per cent per cent
2 9.0 9.3 9.7 9.8
5 9.9 9.7 9.6 9.1
8 VSD 13.6 9.4 9.4
9 6.1 8.8
10 10.6 10.4 9.6 9.1
11 8.1 7.8 9.3 8.1
14 9.8 9.6
16 ne? 9.4
17 7.4 6.7 8.9 10.3
19 9.0 8.5 10.4 9.8
21 9.1 8.8 9.2 9.3
Average. - . 9.4 9.4 9.5 9.4
TABLE 3.
Determination of bone in meat products.
SAMPLES 8
SAMPLE 8—UNKNOWN AMOUNT OF | SAMPLE 9—NO. 8 WITH AND 9— SAMPLE 10—MEAT
BONE—TANKAGE PRESENT 10% BONE ADDED DIFFERENCE MEAL—BONE 2 %
(4)
Estimated
Bone Bone Difference Bone
o o o oO
g z g = g Ae g 35)
Analyst 3 a6 Tankage 5 £5 | Tankage 5 a6 & &5 | Tankage
° | £6 3° | 246 So | 44 S$ | a5
a | ee 5 | 8 5 | ss| 8 | as
2 [05 a | 95 a | SE) 2 |°%
a aa pee Tf I a = d=
per per per per per per per per
cent cent cent cent cent cent cent cent
2 42.2 | 42.0] Present | 48.5 | 48.8} Present | 10.5 | 11.0} 2.2 | 1.9 | Trace
5 42.1 | 40.5 | Present | 47.4 | 46.8} Present | 9.5] 10.4] 2.1 | 2.1 | None
6 ; :
AN DW AOA er, eae: ATR \V AO.9 leone TOS LOD u aly oak lemme
9 SSeS Mek AGA5 | one TH DSI Neen PA WT ee 3 ae eee
10 38.6 | 37.8 | Present | 44.3 | 43.5 | Present] 9.6] 9.5] 3.9 | 3.8 | None
11 42.9 | 40.2 | Present | 49.1 | 46.3 | Present | 10.5 | 10.1] 2.4 | 2.0 | None
14 ADO eee a Spa 46.4 | 46.3] Present] 8.6]|..... 2.2 | 2.1 | None
16 F420 eee eee ee ee ZU a (mega ee, ty Cn aie (oe 0 eee OAL BSF Ives Raee| hal Clndiat mUnieaeS®
17 ASTAg Ale GHiens ae ae 49:4 | AS Sine eee Sa Ty Disa ROD) | epee
19 41.5] 41.0] Present | 46.6 | 45.6 | Present | 9.3} 8.7] 2.3 | 2.1 | None
PAl 41.2 | 39.9 | Present | 46.9 | 46.5 | Present} 9.8 | 10.6] 1.9 | 1.9 | None
350 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
RECOMMENDATIONS.
It is receommended—
(1) That the method for the determination of rice hulls in rice bran
as devised by B. H. Silberberg be adopted by this association as a tenta-
tive method.
(2) That the method for the determination of grit in scratch feeds and
bone in meat products as devised by H. E. Gensler be adopted as a
tentative method.
(3) That the incoming referee proceed along the lines already fol-
lowed, either presenting some method for the micro-analytical quanti-
tative determination of ingredients or perhaps applying the methods
just proposed for the determination of different ingredients, such as
cottonseed hulls in cottonseed meal or oat hulls in oat feed.
THE DETERMINATION OF STARCH CONTENT IN THE
PRESENCE OF INTERFERING POLYSACCHARIDES,
AS IN IMPURE LINSEED PRODUCTS.
By G. P. Watton and M. R. Cor (Bureau of Chemistry,
Washington, D. C.).
As indicated by the title, this study had its origin in an investigation
of the production and handling of linseed by-products. The seed of the
flax plant contains no starch. Therefore, any starch found in a linseed
meal or cake is non-flax material and, in a general way, it may be con-
sidered a rough measure of the foreign matter present. Owing to the
presence of important quantities of mucilage, it was found to be im-
possible to determine the starch content of linseed cake or meal by the
official starch methods?. The linseed mucilage seriously interferes in
two ways: (1) Moistened with water or weak alcohol it forms an im-
pervious mixture which prevents the leaching out of sugars by these
solvents and makes impossible the preliminary extraction required by
the official methods; (2) the mucilage, itself a polysaccharide, yields
dextrose on hydrolysis and hence must be eliminated before the acid
hydrolysis, or the figures obtained for starch will be erroneously in-
creased.
The important facts brought out by the investigation are: (1) It is
possible to extract the sample of linseed meal with 35 per cent alcohol
for the elimination of sugars; (2) it was found that the mucilage could
be coagulated and precipitated by 60 per cent alcohol and eliminated
1 Abstract only; the complete paper will be published in the Journal of Agricultural Research.
2 Assoc. Official Agr. Chemists, Methods, 1920, 95.
1923] WALTON: DETERMINATION OF STARCH CONTENT 351
by means of filtration; and (3) it was definitely established that the
starch conversion products obtained by properly conducted malt dias-
tase digestion remain in solution in 60 per cent alcohol.
In using the method, painstaking attention should be given to details,
more particularly to those dealing with the colloidal substances involved.
Such are the operations of gelatinizing to a smooth paste and the thorough
discomposing of coagula and subsequent mixing. It is also highly im-
portant to control the conditions that prevail during the dissolving and
conversion of the starch. It has been demonstrated in the Bureau of
Chemistry that the starch is best brought into solution by starting the
first digestion with malt infusion at a temperature well below 55°,
then slowly raising to 70°, and after maintaining this temperature for
the specified time, continuing to increase the temperature to 80°. While
the sugar-forming enzymes, e. g., the maltase, are believed to be de-
stroyed by temperatures of 70° and above, other starch liquefying
enzymes present in the malt infusion are more active at the higher
temperatures, and complete solution of the starch is attained. The
second saccharifying digestion is conducted at 55°.
Owing to the care that must be exercised in its use, the method of
analysis is described in far more detail than ordinarily would be justi-
fiable.
The method follows:
Method for the Determination of the Content of Starch in the Presence of
Interfering Polysaccharides.
PREPARATION OF MALT EXTRACT.
Select clean, new barley malt of known efficacy, and grind only as needed. Grind
the malt well, but not so fine as greatly to retard filtration. Prepare an infusion of
the freshly ground malt immediately before it is to be used. For every 80 cc. of the
malt extract that will be required, digest 5 grams of the ground malt with 100 cc. of
distilled water, at room temperature, for 2 hours. (The time of digestion may be
shortened by use of an electric mixer. If the malt and water mixture is stirred by the
machine for periods of 5 minutes, 3 or 4 times in the course of an hour, the extraction
should be sufficiently complete.) Filter to obtain a clear extract. (It may be neces-
sary to return the first portions of the filtrate to the filter.) Mix the infusion well.
DETERMINATION.
(a) Preparation and extraction of the charge.
Grind the material to a very fine powder and mix well. (The entire sample should
be ground to pass freely through a sieve of not less than 40 mesh to the inch, and it is
preferable that it be fine enough to pass a 60-mesh sieve.)
Weigh out a definite charge of from 2 to 6 grams of the finely pulverized sample, using
the smaller charges in the case of materials containing much gel-forming substance.
(Charges of 4 grams for linseed meal, or 3 grams for dried apple pomace, have been
found to be satisfactory.) The weight of starch in the charge should not exceed 1.5
352 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 3
grams. Transfer to a dry filter paper held in place in a glass funnel of the usual type’.
It is not necessary to use a hardened filter; any tight, high-grade paper, 12} or 15 cms.
in diameter will be found satisfactory.
Extract the charge with 5 successive portions of ethyl ether, using more than enough
to cover the charge. Use a cover glass to retard evaporation. After completing the
extraction, allow the ether to evaporate and extract with weak alcohol. The con-
centration of the alcohol may be varied to suit the material under examination. In
the case of linseed meal it is necessary to use 35% alcohol (by volume), while for dried
apple pomace 25% served best. Use 300 cc. of the alcohol to obtain the required
thoroughness of extraction. Follow this with several filterfuls of 95% alcohol and
finish the leaching operations with a second ether extraction. (It is desirable at this
point to allow the charge to stand overnight so that the ether and alcohol may evapo-
rate, since alcohol must be eliminated before starting the digestion with malt.)
At this stage start the preparation of the malt infusion.
A correction for the dextrose in the malt extract is obtained by conducting a con-
trol determination (preferably in duplicate). Starting with a piece of the filter paper
extracted with alcohol, add distilled water and carry out the control side by side with
the actual starch determination, subjecting it to the gelatinization temperature, adding
the same quantities of malt extract, and treating it similarly in every respect.
(b) Gelatinization.
To return to the primary determination, transfer the paper and charge (practically
freed from the alcohol) to a 300 cc. Erlenmeyer flask, and mix well with from 20 to
30 cc. of distilled water—macerating paper and material so as to obtain a perfectly
smooth paste. Add 100 to 120 cc. of boiling water; mix quickly but thoroughly and,
with constant stirring, heat the contents of the flask until boiling freely. (In the case
of mucilaginous materials like linseed meal it is necessary to transfer the flask to a
boiling water bath to complete the gelatinization without scorching.) Gelatinize
thoroughly without scorching or adhesion of material to the bottom of the flask. The
mixture should be smooth and free from lumps.
(c) Malt-diastase digestion.
Cool to 50° or below, add 20 cc. of the malt infusion to controls as well as charges,
and place the flasks in a temperature-controlled water bath. Keeping the “mash”
thoroughly mixed, gradually raise the temperature to 70°, taking from 20 to 30 minutes.
Maintain at 70° for 30 minutes, stirring the mixture from time to time; then increase
the temperature to 80° and maintain for ten minutes. Finally heat to the boiling
point. Keep the mixtures well stirred as this is equivalent to a second gelatinization.
Cool the contents of the flasks, and the water bath as well, to 55°. Add 20 cc. of
the malt extract, mix well, and maintain at 55° for 1 hour, stirring about once every
10 minutes. At the termination of the digestion rapidly increase the temperature to
above 80°.
(d) Defecation with 60% alcohol.
The total volume of the hot “‘mash”’ should not exceed 200 cc. Transfer each ‘‘mash”’
to a 500 cc. volumetric flask. (A little hot water may be used for rinsing provided the
total volume of the mixture does not exceed 200 cc. Reserve the flask for subsequent
rinsing.) Measure out 316 cc. of 95% alcohol and add this, a little at a time, to the
contents of the flask, with thorough shaking after each addition. As soon as enough
alcohol has been added to coagulate colloidal matter, allow the coagulum to settle
somewhat, and pour a little of the supernatant liquid back into the Erlenmeyer flask
used in the digestion, thoroughly rinsing the contents into the volumetric flask. Com-
1 An ordinary paper clip serves well to clamp the paper in place.
1923] WALTON: DETERMINATION OF STARCH CONTENT 353
plete the addition of the 316 cc. of strong alcohol with constant mixing, avoiding any
loss of material and, after cooling to room temperature, adjust the volume with water
so that the quantity of liquid is 500 cc., i. e., allow for the volume occupied by the solid
material by adding 3 cc. of water for every 4 grams of charge present, after bringing
the contents of the flask up to the 500 cc. mark.
At this stage of the procedure the starch conversion products from the original
charge should be contained in the 500 cc. of 60% alcohol. (The determination may be
interrupted at this stage for several days, but the volume of solution would have to
be readjusted if a change in temperature occurred.)
Mix thoroughly, breaking up any ropy coagulum as much as possible by pouring
back and forth from one large beaker to another. Filter through dry paper. (Test
the solid residue for starch, either microscopically or by the iodine color test after
elimination of alcohol and gelatinization with water. If more than the merest trace
of starch is found, reject the entire determination.) Evaporate exactly 200 cc. of the
filtrate on a steam bath to a volume of from 15-20 cc., or until practically all alcohol
has been expelled. Do not allow the evaporation to proceed to dryness.
(e) Acid Hydrolysis.
Transfer the aqueous residue of starch conversion products to a 200 cc. volumetrié
flask with hot water, using a rubber policeman to recover all the dextrine. Allow to
cool somewhat and complete the volume to 200 cc. Transfer the entire contents to a
suitable digestion flask; add 20 cc. of hydrochloric acid (sp. gr. 1.125) and connect
with a reflux condenser. Heat in a boiling water bath for 23 hours.
(f) Purification of the dextrose solution and determination of dextrose
by copper reduction.
Cool, and in the case of linseed meal or other material yielding solutions which at
this stage need further purification, add not more than 1 cc. of a 10% solution of phos-
photungstic acid in 1% hydrochloric acid. Mix, and allow to stand at least 15
minutes. Increase the volume with water to 250 cc. in a volumetric flask; mix well
and filter through dry paper. Take 200 cc. of the filtrate and, while stirring, partially
neutralize by adding 10 cc. of a heavy solution of caustic soda (44 grams of sodium
hydroxide per 100 cc. of the cooled solution) and then nearly complete the neutraliza-
tion with a little powdered sodium carbonate. (The anhydrous carbonate will be
found preferable, as it dissolves rapidly.) Transfer to a 250 cc. flask with water, cool
to room temperature, make up to mark, and mix well. Filter, if necessary, and de-
termine the dextrose in a 50 cc. aliquot of the filtrate by copper reduction, employing
the gravimetric method of either Munson and Walker’, or Allihn?. Correct the weight
of dextrose obtained by the weight of dextrose* found for the same aliquot of the malt
control and multiply the corrected weight of dextrose by 0.90 to obtain the weight of
starch. (This factor 0.90 represents the theoretical ratio between starch and dex-
trose and was used throughout this study; but it has been shown by a number of in-
vestigators! that the factor 0.93 more nearly represents the actual yield.)
Aliquots:
200 20 | 50
500 250 250
Charge X 0.064.
Charge X
tr Ge ee Official Agr. Chemists, Methods, 1920, 78.
id., 90.
3In the Diastase Method, Assoc. Official Agr. Chemists, Methods, 1920, 96, the direction to ‘‘correct the
weight of reduced copper’’ by that found in the malt blank is erroneous.
4 Assoc. Official Agr. Chemists, Methods, 1920, 95.
354 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
SUMMARY OF RESULTS.
The following results have been obtained by this method:
For a traced linseed cake known to contain approximately 3.3 per
cent of nonflax matter, 1.34 per cent of starch was found; for a sample
of prepared starch containing 87.5 per cent of starch there was found
87.2 per cent, a recovery of 99.6 per cent; and with 3.8 grams of the
linseed cake and 0.2 gram of the prepared starch, having a theoretical
starch content of 5.65 per cent, there was found 5.5 per cent, a recovery
of 97.2 per cent. With 3.5 grams of the linseed cake and 0.5 gram of
the starch (theoretical starch content 12.11 per cent), there was found
11.9 per cent of starch, a recovery of 98 per cent; and for a charge of
3 grams of linseed cake and 1 gram of the starch (theoretical starch con-
tent 22.88 per cent), there was found 22.85 per cent of starch, a recovery
of 99.9 per cent.
The results obtained on a few samples of dried apple by-products
indicate that the method may be applied equally well to substances
containing important quantities of pectin, such as dried apples and dried
apple pomace.
READING THE FAT COLUMN IN THE BABCOCK TEST FOR
MILK.
By C. F. Hoyr (Dairy Laboratory, Department of Agriculture,
Sacramento, Calif.).
The Babcock test for the estimation of butter fat in whole milk has
assumed a position of great importance in the dairy industry of this
country and because of its simplicity, ease of operation and cheapness
it fills an uncontested place. Since the test is not based on exact analy-
tical methods, as is necessary for the separation and weighing of a pure
chemical substance, the conception concerning it from the beginning has
been that the details of operation should give results equivalent to those
obtained by more rigorous analytical methods. Therefore, specifica-
tions for the graduation of test bottles, speed of tester, time of centri-
fuging, temperature of reading and manner of reading the meniscus
must be made.
The dairy industry of the country is indebted to 8. M. Babcock of
the University of Wisconsin for this test. He gave a description of his
new centrifugal method in 1890! and again in 18927. He checked the
method against the gravimetric asbestos method on 30 samples of whole
milk and found practically exact agreement between average values.
The maximum positive deviation from the gravimetric was 0.3 per cent
and the maximum negative deviation was 0.2 per cent.
1 Univ. of Wisconsin Agr. Expt. Sta. Bull. 24.
2 Thid., 31.
1923] HOYT: BABCOCK TEST FOR MILK 355
REVIEW OF LITERATURE.
In the years immediately following the publication of the test various
investigators made comparisons of values obtained by ‘it with those
obtained by other methods. The Connecticut Agricultural Experiment
Station', in 1891, reported comparisons between the “‘standard method
used in chemical laboratories’ and the Babcock method which showed
an average difference of 0.01 per cent on 32 samples. The greatest
difference in any individual case was 0.18 per cent. In six cases the
difference exceeded 0.1 per cent; in 18 cases it was less than 0.05 per
cent; and in 17 cases the “standard method” gave lower, and in 15
cases higher results than did the Babcock. No details were given as to
the ‘“‘standard method” used and very few on the Babcock.
B. H. Hite?, in 1890, reported comparisons of the Babcock method
with several other similar methods and with the Adams method. Three
analyses of whole milk were given in which both the Babcock and the
Adams methods were used. The original instructions given by Bab-
cock were followed and the same type of centrifuge was used. It was
stated that difficulty was encountered in obtaining fat free from
casein and that the results differed widely from those obtained by the
Adams method.
E. H. Farrington’, in 1891, reported comparisons of the Babcock
method with those of Patrick and Beimling and with the sand, asbestos
and Adams extraction methods on 12 samples of milk and found close
agreement. The details of operation were not given but it is to be
presumed that Farrington followed in general the original instructions
of Babcock and used the same type of apparatus.
Harry Snyder‘, in 1891, reported comparisons between the Babcock
method and the gravimetric asbestos method on 28 samples of milk.
He obtained close agreement but did not give details of operation.
John Sebelien and Kristoffer St6ren®, in 1894, reported comparisons
of the Babcock and Adams methods on 35 samples. They apparently
departed somewhat from the directions of Babcock and stated that
they read the tests from “hot”? water. They obtained closely agreeing
results.
It would appear that little work has been done on the method in
recent years—that is since modifications have been made in the centri-
fuge and more rigid standards for manipulation have been established.
It is true that Julius Hortvet®, in 1917, reported the results of collabora-
tive work on milk done by 10 different men, showing comparisons of
1 Annual Report, Connecticut Agr. Expt. Sta., 1891.
23rd Annual Report, West Virginia Agr. Expt. Sta.
3 Univ. of Illinois Agr. Expt. Sta. Bull. 14.
4 Cornell Univ. Agr. Expt. Sta. Bull. 29.
5 Chem. Z., 1894, 18: 1816.
6 J. Assoc. Official Agr. Chemists, 1917, 2: 238.
356 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
results obtained with the Babcock method with those obtained by the
Roese-Gottlieb and some other methods. The different collaborators
were instructed to carry out the method “‘according to procedure com-
monly recognized as correct’? and to use an 8 per cent bottle. The
results reported were obtained by averaging the readings to the top and
to the bottom of the upper meniscus. Although one or two of the col-
laborators obtained results widely at variance with those obtained by
the Roese-Gottlieb method, an average of the results by the Babcock
method read as indicated was 0.04 per cent lower than the average
of the results obtained by the Roese-Gottlieb method.
D. E. Bailey! also reported, in 1919, a study of the Babcock test for
butterfat in milk, giving the results of 190 comparisons involving
1,476 tests where both the Babcock method and the gravimetric method
were used. The average of all Babcock readings made by one individual
was 0.076 per cent higher than the average of all gravimetric determina-
tions. When readings of the same tests by several individuals were
made the average became 0.060 per cent higher than the gravimetric
determinations. Many data were presented concerning the effect of
different factors on the appearance and the reading of the test.
With more extended use of the test in various fields, especially for
the purpose of providing a basis of payment for milk, the matter of
controlling the various details of its operation so as to secure uniform
and accurate results has been assuming increased importance. In
California the advantage of a close adherence to uniform practice in
relation to these details has been recognized to the extent that an elab-
orate set of rules to cover the matter has been enacted into law. These
rules provide exact specifications as to the construction and accuracy
of graduation of glassware, the speed of the centrifuge, the temperature
of reading, the point on the meniscus to which the reading is to be made
and the keeping of records. Moreover, operators of the test are subject
to examination and licensing.
It is evident, however, from a reading of the original publications
and from several specific facts that Babcock did not contemplate a
degree of accuracy such as that required today. For example, bottles
graduated to only 0.2 per cent instead of to 0.1 per cent were used; a
variation in accuracy of graduation of the test bottle of as much as
0.3 per cent in the whole length of the scale was permitted; the bottles
were whirled five minutes, filled to the 7 per cent mark and whirled one
minute; and the reading was made at any temperature between 110°F.
and 150°F. No readings were made to less than 0.1 per cent.
Changes in the form of apparatus used and in some of the details of
conducting the test have been made since the original work on the
1 J. Dairy Science, 1919, 2: 331.
1923] HOYT: BABCOCK TEST FOR MILK 357
method was done and since the various investigators reported the results
of their findings. The first centrifugal machines used were those in
which the bottles were inclined at an angle of about 30 degrees from the
horizontal and they were turned by hand or driven by a belt. The
machines in common use today are driven by a steam turbine or by
electricity, and the bottles lie in a horizontal position during the whirl-
ing. The bottle required by law in California is the 8 per cent bottle
graduated to 0.1 per cent instead of the 10 per cent bottle graduated to
0.2 per cent, which was originally used. The standard of graduation
requires that 13.5471 grams of clean, dry mercury shall fill the space
equivalent to 5 per cent, instead of 13.59 grams as originally specified.
It is definitely known that one of the principal makers of glassware in
the country has until recent years used a standard of graduation at
variance with that used at present; moreover it is reasonable to suppose
that the glassware made now is much more uniform and accurate than
it was formerly. A time of whirling somewhat different from the original
is set in the standard method! for conducting the test, and the tempera-
ture of reading is more definitely fixed.
SCOPE OF INVESTIGATION.
In view of the changes made in the apparatus and in the directions for
conducting the test, a further study of the percentages obtained by the
Babcock method as compared with those obtained by other methods is
demanded. In fact, serious question has been raised as to the complete
accuracy of the test using the present apparatus and specifications for
manipulation. The work reported in this paper was undertaken in
order to obtain information on the effect of one of these specifications,
namely, that requiring the reading of the fat column from the bottom of
the lower meniscus to the top of the upper meniscus.
Samples of milk were obtained, some composite and others from the
complete milking of individual cows; all were fresh and in perfect con-
dition. No sample was used which showed any indication of churning
or on which the cream had risen sufficiently to become hardened. The
percentage of fat was obtained by the following methods: Babcock;
Roese-Gottlieb, run on the Mojonnier apparatus; Adams paper coil;
and asbestos gravimetric.
The writer wishes to acknowledge encouragement and advice given
him throughout the investigation by George P. Gray, Chief of the
Division of Chemistry. He is also indebted to N. C. Smith, R. W.
Newman and M. B. Kennedy for making some of the tests and assisting
in a review of the literature and in the preparation of the manuscript.
1 Method of the American Dairy Science Association, J. Dairy Science, 1922, 5: 178; it is also true of
a of the Association of Official Agricultural Chemists, Assoc. Official Agr. Chemists, Methods,
1920, 228.
358 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
METHODS.
Babcock method.
The milk test bottles used were the 18-gram, 6-inch, 8% bottles graduated
to 0.1%. They conformed to the specifications of the Association of Official
Agricultural Chemists!. These specifications are as follows: “The total per cent
graduation shall be 8. The total height of the bottle shall be 150-165 mm. (54%-61%
inches). The capacity of the bulb up to the junction with the neck shall be not less
than 45 cc. The graduated portion of the neck shall have a length of not less than
63.5 mm. (23 inches) and the neck shall be cylindrical for at least 9 mm. below the
lowest and above the highest graduation marks. The graduations shall represent
whole per cents, halves,and tenths of a per cent”. Each bottle was found to be com-
pletely accurate for the interval between the 0 and the 4% line and for the interval
between the 4% and the 8% line. The examination for accuracy was made by the
official method of the Association of Official Agricultural Chemists. The bottle was
filled with mercury to the 0 line, and 10.8377 grams of clean, dry mercury for the inter-
val between 0 and 4% and the interval between 4% and 8% were weighed on an accu-
rate balance The reading at the line was observed by a glass having a low magnifica-
tion.
The pipets used conformed to the specification of the Association of Official Agri-
cultural Chemists and to the more detailed specifications of the Bureau of Standards?
These specifications are as follows:
Milli-
meters
Total length of pipet not more than---_.---------------- 330
Outside diameter of suction tube_----------------------- 6-8
Lengthiof: suction tubes. 2642. 322 ae Sea a 130
Outside diameter of delivery tube-----.------------------ 4.5-5.5
Lengthof.delivery tube. 2222 S2255 2s a ee ee 100-120
Distance of graduation mark above bulb-_---------------- 30-60
Tolerance—0.05 millileters.
Nozzle straight.
Delivery 17.6 millileters of water at 20°C. in 5 to 8 seconds.
The delivery was well within the tolerance, the variations from exact accuracy in
millileters, being as follows: +0.01, +0.02, +0.03, +0.04. Nearly all the measure-
ments were made with pipets having a delivery which varied from exact accuracy by
+0.03 or less.
The testing was conducted according to the specifications and directions of the
American Dairy Science Association® except that chemically pure sulfuric acid, specific
gravity 1.82—1.83, instead of the commercial variety was used. The tester was of the
24-bottle, steam-turbine, Facile type made by D. H. Burrell & Co. The diameter of
the wheel was 20 inches. The speed was held as nearly as possible to 760 revolutions
per minute.
The milk was pipetted into the test bottles, and the weights were obtained and re-
corded. Acid was added (both milk and acid being at a temperature between 60° and
70°F.), and the milk and acid were mixed. The bottles were whirled for 5-, 2- and
1-minute periods, respectively, sufficient distilled water at a temperature of about
200°F. being added after the first whirling to fill the bottle to the bottom of the neck,
and after the second whirling to near the top graduation. The temperatures during
whirling were approximately as follows:
1 Assoc. Official Agr. Chemists, Methods, 1920, 227.
2U.S. Bur. Standards Cire. 9: 7th ed.
3 J. Dairy Science, 1922, 5: 175.
1923} HOYT: BABCOCK TEST FOR MILK 359
°
F.
Begimnmp first pened] 2 = es one meson set ose 115
Pind first perilous ese pea ee eee dt ae x 124
Beginning second period 163
Pd second periid seer e ree Eee ee Ree). Sek 2 eve4o
IBegimming thirds period] sane eee 5 a ke ee 165
nd Chirds period se ae Bee en See eee eee oe 142
The test bottles were placed in a water bath, maintained at a temperature of 135°
to 140°F., for at least 10 minutes before reading. Readings were made with a pair of
dividers, first from the bottom of the lower meniscus to the top of the upper meniscus
and then from the bottom of the lower meniscus to the line of separation between the
fat column and an overlying layer of glymol. All readings were made by two or by
three men, and the average of these readings is reported. No reading was made on a
fat which was not perfectly clear and free from charred and white substances.
Roese-Gottlieb (Mojonnier) method.
The Roese-Gottlieb is an official method of the Association of Official Agricultural
Chemists. It was run on the Mojonnier apparatus. A pipet holding 10 grams of
milk was weighed on an analytical balance, the milk transferred to the extraction flask
and the empty pipet weighed. The reagents were added in the following order: 1.5 cc.
of ammonia; 10 cc. of 95% alcohol; 25 cc. of ethyl ether; 25 cc. of petroleum ether.
Thorough shaking followed the addition of each reagent, the flasks being closed with
cork stoppers which had been extracted with ether. The ether solution was separated
from the other liquid by centrifuging for about a minute. The ether solution was
poured into dried and weighed aluminum dishes and the extraction repeated twice,
using 15 cc. of each of the ethers for these extractions, making 3 extractions in all.
The ether was evaporated from the dishes on a hot plate, and the fat was dried on a
hot plate in an oven at 135°C. for 5 minutes, under 29 inches of vacuum. The dishes
were cooled in a desiccator and weighed. Blank determinations were made using the
same flasks, reagents and cork stoppers, and the results were corrected by the blank
obtained.
Adams paper coil method.
Schleicher and Schiill fat-free paper was used. A pipet containing 5 grams of milk
was weighed; the milk was spread over the paper in such a way that the borders were
not wet by the milk and the empty pipet weighed. The paper was then set on edge
and left at slightly above room temperature until nearly dry. It was then rolled up
and dried in a water oven to constant weight, after which it was transferred to a Soxh-
let apparatus and extracted for a length of time equivalent to at least 4 hours when the
ether syphons over from the extraction tube 10 times per hour. When the syphoning
proceeded at a lower rate than this the time of extraction was prolonged accordingly.
Ethyl ether was used for extraction. This was first washed repeatedly with dis-
tilled water and then allowed to stand several days, first over sticks of sodium hy-
droxide and then over metallic sodium. The flasks were nearly freed from ether on
a hot plate and finally dried to constant weight in a water oven. Blank determina-
tions were made using the same fat-free paper, ether and time of extraction. Results
were corrected by the blank obtained.
Asbestos gravimetric method.
About 2 grams of freshly ignited woolly asbestos were placed in a previously ignited,
coarse, alundum thimble, to which about 5 grams of milk, weighed from a pipet as in
the Adams method, was transferred. It was dried to constant weight in a water oven
and transferred to a Soxhlet apparatus with small wads of dried absorbent cotton
placed over the asbestos and in front of the syphoning tube. The ether, time of ex-
traction and drying were the same as in the Adams method. Blanks were made and
results corrected accordingly.
360 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
RESULTS.
Table 1 shows the results found by the Babcock and the Roese-Gottlieb (Mojonnier)
methods. The averages of the percentages found are as follows: Babcock, reading to
top of meniscus, 4.204; Babcock, reading with glymol, 4.063; Roese-Gottlieb (Mo-
jonnier), 4.088. Table 2 shows the results found on those samples run not only by
the Babcock and Roese-Gottlieb (Mojonnier) methods but also by the Adams and
asbestos methods. The average percentages are as follows: Babcock, reading to top
of meniscus, 4.129; Babcock, reading with glymol, 3.992; Roese-Gottlieb (Mojonnier),
4.050; Adams, 4.038; asbestos, 3.956. Table 3 shows the variations in percentages
found by the Babcock method from those found by the Roese-Gottlieb (Mojonnier)
method. The plus sign indicates that the percentages by the Babcock method are
higher and the minus sign, that they are lower than the percentages found by the
Roese-Gottlieb (Mojonnier) method. The averages of the readings to the top of the
meniscus are 0.116 above, and of those with glymol 0.025 below, the Roese-Gottlieb
(Mojonnier) figures. Table 4 shows the variations found on those samples run not
only by the Babcock and Roese-Gottlieb (Mojonnier) methods but also by the Adams
and asbestos methods. The average of the readings to the top of the meniscus is
0.079 above the Roese-Gottlieb (Mojonnier) figures, 0.091 above the Adams and 0.173
above the asbestos; the average of the readings with glymol is 0.058 below the Roese-
Gottlieb (Mojonnier) figures, 0.046 below the Adams and 0.036 above the asbestos
TABLE 1,
Percentages of fat found in milk by the Babcock and the Roese-Goltlieb (Mojonnier) methods.
BABCOCK—
GRAMS RN GTOnTOE READING WITH ROESE-GOTTLIEB
BAMPER TAKEN HPS ERTIES GLYMOL (MOJONNIER)
NO. | O
A B A B Average] A B Average} A B Average
1 18.04 18.00 | 3.64 3.55 3.595 | 3.50 3.39 9.445) 3:52 (3.52) SseoZ20
2 | 18.00 18.00 | 3.84 3.84 3.840] 3.70 3.64 3.070'| 3:69) 3:66. S675
SU Le OS Uae 4.71 4.69 4.700| 4.57 4.60 4.585|3.56 4.52 4.540
= | Miele ue SIR 3:60 3.59 3.595 | 3.43 3.438 3.43013.43 3.45 3.440
BD Vale OA: UT aieh 3.38 3.40 3.390 | 3.23 3.26 Si245)3.25/)) Se2en ies 245
CaM se Mie es Sie 3.39 3.36 Sain)! 285 Bee BEPTAD Aon ype | | Er yrelO)
12 | 18.04 18.01 | 5.00 5.02 5.010| 4.87 4.86 4.865|}4.90 4.94 4.920
15 | 18.00 18.01 | 3.42 3.42 3.420 | 3.32 3.31 SPoNeTley1om ways § ax77(0)
16 | 18.12 18.01 | 3.81 3.79 3.800 | 3.67 3.66 3.665/3.69 3.66 3.675
17 ‘| 18.00 18.01 | 4.14 4.14 4.140} 4.05 4.04 4.045/4.05 4.06 4.055
19 | 17.97 Po ne eal 5.110} 4.99 4.98 4.985|4.94 4.96 4.950
20 | 17.96 UP PUPA Fe UAL 7.115| 6.98 6.93 6.955| 7.03 7.05 7.040
21 18.01 18.06 |} 4.41 4.42 4.415|4.380 4.33 4.315| 4.28 4.33 ~ 4.305
22 | 17.99 18.00 | 4.85 4.82 4.835 | 4.69 4.69 4.690| 4.75 4.79 4.770
23 | 17.99 17.98 |5.45 5.43 5.440} 5.28 5.27 DATO) Vea eee eee to
24 | 18.00 18.00 | 4.87 4.88 4.875 | 4.73 4.72 4.725|4.70 4.63 4.665
PA PASTY) ISI || GLIDAY SIs} 3-125 1'3.00 2:95 2.975|3.05 3.03 3.040
26 18.01 18.01 | 3.24 3.28 Si PAo OS pili bs Sys bil Syl (Os sive iliiny Se ils),
27 118.01 18.00 |3.48 3.43 3.455 | 3.382 3.30 SLOW Sts4 Stoo Morcoe
28 17.98 18.04 | 3.388 3.39 S080)! loola wens $2245 8.25) 3525) 93250
29 18.04 18.05 | 3.95 3.93 3.940) 3.80 3.80 3.800/3.83 3.82 3.825
30 | 18.07 18.06 |.3.64 3.67 3.655 | 3.50 3.51 OMIO Psyaee Sissy Taya
31 18.01 ISM OPT We WB isl 3.220) 3.12 3.06 D090 Selon wioclOnonloa
32 18.05 18.02 |3.41 3.41 3.410 | 3.24 3.24 3-240) |"s20 ozs on
a) 17.98 18.00 | 6.48 6.43 6.430 | 6.30 6.30 6.300/6.41 6.40 6.405
34 18.05 18.02 |}6.11 6.13 6.120} 6.00 6.00 6.000} 6.05 6.05 6.050
35 | 17.99 18:00); 3.20) 3.15 3.175 | 3.10 3.00 3.050/3.08 3.09 3.085
36 18.02 18.03 | 3.87 3.89 3.880) 3.72 3.72 32720) S38) soulon,) oeu
Avge..|18.014 18.016 4.204 4.063 4.088
1923] HOYT: BABCOCK TEST FOR MILK 361
TABLE 2.
Percentages of fat found in milk by the Babcock, Roese-Golllieb (Mojonnier), Adams
and asbestos methods.
BABCOCK— ROESE-GO1TT-
SARS GRAMS READING TO | READING WITH LIEB ADAMS Reanaros
mR TAKEN TOP OF GLYMOL (MOJONNIER)
° MENISCUS
A B A B Average} A B Average| A B Average} A B Average} A B Average
29 18.04 18.05/3.95 3.93 3.94 |3.80 3.80 3.80 |3.83 3.82 3.825/3.82 3.80 3.810/3.72 3.72 3.720
31 18.01 18.02/3.23 3.21 3.22 |3.12 3.06 3.09 |3.15 3.16 3.155/3.11 3.09 3.100/3.09 3.09 3.090
33 17.98 18.00/6.43 6.43 6.43 |6.30 6.30 6.30 |6.41 6.40 6.405/6.45 6.43 6.440/6.30 6.34 6.320
35 17.99 18.00)3.20 3.15 3.175/3.10 3.00 3.05 |3.08 3.09 3.085)/3.12 3.04 3.080]2.94 2.99 2.965
36 18.02 18.03}3.87 3.89 3.88 |3.72 3.72 3.72 |3.78 3.78 3.780/3.74 3.78 3.760/3.68 3.69 3.685
Average |18.008 18.02 4.129 3.992 4.050 4.038 3.956
TABLE 3.
Variations in percentages of fat found in milk by the Babcock method from those found bY
the Roese-Gottlieb (Mojonnier) method.
SAMPLE NO. READING TO TOP OF MENISCUS READING WITH GLYMOL
1 +0.075 —0.075
2 +0.165 +0.005
3 +0.160 +0.045
4 +0.155 —0.010
5 +0.145 0.000
6 +0.135 —0.015
12 +0.090 —0.055
15 +0.150 +0.045
16 +0.125 —0.010
We +0.085 —0.010
19 +0.160 +0.035
20 +0.075 —0.085
Dit +0.110 +0.010
22 +0.065 —0.080
23 +0.165 0.000
24 +0.210 +0.060
25 +0.085 —0.065
26 +0.110 — 0.040
PH +0.120 —0.025
28 +0.135 —0.005
29 +0.115 —(0.025
30 +0.110 —0.040
31 +0.065 —0.065
32 +0.140 —0.030
33 +0.025 —0.105
34 +0.070 —0.050
35 +0.090 —0.035
36 +0.100 —0.060
Average i502) +0.116 —0.025
362 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
TABLE 4.
Variations in percentages of fal found in milk by the Babcock method from those found by
the Roese-Gotilieb (Mojonnier), Adams and asbestos methods.
READING TO TOP OF MENISCUS READING WITH GLYMOL
R - R “i
ee te Gottlieb Adams Asbestos Gottlieb Adams Asbestos
i (Mojonnier) (Mojonnier)
29 +0.115 +0.1380 +0.220 —0.025 —0.010 +0.080
31 +0.065 +0.120 +0.130 —0.065 —0.010 0.000
33 +0.025 —0.010 +0.110 —0.105 —0.140 — 0.020
35 +0.090 +0.095 +0.210 —0.035 —0.030 +0.085
36 +0.100 +0.120 +0.195 —0.060 —0.040 +0.035
Average....| -+0.079 -+0.091 +0.173 —0.058 — 0.046 +0.036
CONCLUSIONS.
(1) The results obtained by the Babcock method reading to the top
of the meniscus are higher than those obtained by any of the other
methods used in this investigation.
(2) The results obtained by the Babcock method reading to the line
of separation between the fat column and the overlying glymol agree
more closely with those obtained by the other methods than do the
results obtained by reading to the top of the upper meniscus.
(3) It would be advantageous to read the fat column to the line of
separation between it and an overlying layer of glymol, (1) because of
the distinctness of the line and the ease of reading and (2) because it
conforms with the well-established practice of reading cream samples.
(4) The present specifications for conducting the Babcock test should
be modified if the results here reported are confirmed by other workers
and the writer suggests that similar work be done in laboratories in
other parts of the country.
The following publications are also cited for reference:
Fifth Annual Report, Vermont State Agricultural Experiment Sta-
tion, 1891
Vieth, P., Fat-free paper for use in Milk Analysis. Analyst, 1891, 16:
127:
Liebermann, Leo and Székely, 8S, Neue Methode zur Bestimmung des
Fettgehaltes der Milch. Z. anal. Chem., 1893, 32: 168.
Rohrig, Armin., Verbesserter Apparat zur Milchfett-Bestimmung nach
Gottlieb-Roese. Z. Nahr. Genussm., 1905, 9: 531.
Nilson, L. F., Der Lactokrit im Vergleiche mit einigen anderen Method-
en zur Bestimmung des Milchfettes. Chem.-Zeitung., 1891, 15: 649.
Farrington, E. H. and Woll. F. W., Testing Milk and its Products.
Van Slyke, L. L., Modern Methods of Testing Milk and Milk Products.
Leach, Albert E., Food Inspection and Analysis.
1923] PAINE: REPORT ON SACCHARINE PRODUCTS 363
REPORT ON SACCHARINE PRODUCTS.
By H. S. Paine (Bureau of Chemistry, Washington, D. C.), Referee.
Owing to delay in securing the necessary collaboration and to the
fact that reports have not been received from all the collaborators, the
Associate Referee on Honey is unable to present a final report at this
meeting. It is recommended that the work outlined on honey be con-
-tinued in expanded form next year.
No report has been received from the Associate Referee on Maple
Products. It is recommended that steps be taken to have the work
outlined on this subjeci actively prosecuted next year and brought to
a definite conclusion.
A method which has important possibilities has recently been de-
veloped by F. W. Reynolds of the Carbohydrate Laboratory, Bureau
of Chemistry, for simultaneous purification and concentration of enzymes.
This method involves the use of a collodion ultra-filter of such per-
meability as to retain enzymes and at the same time permit the passage
through the filter of water and various dissolved substances, including
sugars, salts, pigments, etc. By this means, enzyme solutions can be
washed with water on the ultra-filter until free from color, and can then
be finally concentrated by permitting as much of the water acting as
solvent to pass through the filter as is required in order to secure the
desired degree of concentration.
This method has been very successfully applied to the concentration
and purification of the enzymes invertase and melibiase. The latter is
notoriously a weak enzyme, in the sense that it has heretofore been
impossible to obtain concentrated and stable solutions of it. Never-
theless, this enzyme has now been obtained in highly active and stable
form, and has been successfully employed in conjunction with in-
vertase in the analytical determination of raffinose in beet molasses,
invertase being first employed to produce cleavage of fructose from
raffinose, and the enzyme melibiase being then used to hydrolize the
resulting melibiose. Quantitative enzymic hydrolysis of raffinose and
sucrose in beet molasses has been effected in as short a period as one-
half hour, thereby permitting rapid and accurate analytical determina-
tion of raffinose by use of enzymes. Since beet molasses contains the
two sugars, sucrose and raffinose, determination of these two sugars can
be made simultaneously on the basis of the difference in change of
polarization between two portions of a given sample, to one of which
the enzymes invertase and melibiase have been added and to the second
of which only the enzyme invertase has been added.
The enzyme method for the determination of raffinose and sucrose
has been discussed in the foregoing detail since it is believed that the
use of a concentrated and purified solution of the enzyme maltase has
364 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
important possibilities in solving the problem of the accurate determina-
tion of maltose in glucose and maltose sirups, permitting thereby the
accurate determination of the other carbohydrate constituents.
O. S. Keener, appointed at the last meeting as Associate Referee on
Maltose Products, resigned last May and H. C. Gore was appointed to
succeed him. Owing to this fact, the work on maltose products has not
been advanced as rapidly as would otherwise have been the case.
Adoption of the recommendations by the Associate Referee on Sugar-
House Products is recommended.
No report on honey was made by the associate referee.
No report on maple products was made by the associate referee.
REPORT ON MALTOSE PRODUCTS.
By H. C. Gore (Bureau of Chemistry, Washington, D. C.),
Associate Referee.
None of the analytical methods so far proposed for the determination
of maltose, dextrose and dextrines in products such as maltose sirup
and glucose are sufficiently promising from the standpoint of accuracy
and ease of manipulation to justify extended work in testing them.
The ideal method would be one which permits selective hydrolysis
of maltose, without at the same time causing hydrolysis of dextrines.
Enzymes are ideal reagents for the analysis of polysaccharides. Pre-
cise determination of maltose in mixture with dextrose and dextrines
would apparently be possible if a sufficiently concentrated and stable
preparation of the enzyme maltase were available. More extended
use of enzymes such as maltase for analytical purposes would readily
be possible if enzyme reagents of suitable character were available.
This appears the more promising in view of the recent work of Will-
stitter! in improving existing methods for the extraction of maltase
from yeast.
Your associate referee has commenced work along the lines indicated,
but since he started his investigation about the first of June, subsequent
to the resignation of O. S. Keener, formerly associate referee, and was
able to devote only a portion of his time to this matter, he has not yet
had opportunity to test thoroughly the possibilities of this method.
It is recommended that investigation along the lines indicated be actively
continued next year. While this proposal involves the working out of
a new method, rather than the testing of a method already proposed,
it is possible that the matter will lend itself to collaborative effort in
certain of its phases at least.
1 Z. physiol. Chem., 1921, 111: 157.
1923] BREWSTER: DETERMINATION OF ASH IN CANE SIRUP 365
THE DETERMINATION OF ASH IN CANE SIRUP AND
MOLASSES.
By J. F. Brewster (Louisiana Sugar Experiment Station, New Orleans,
La.), Associate Referee on Sugar-House Products.
The report of the previous Associate Referee on Sugar-House Products,
F. W. Zerban!, contained results of cooperative work on determinations
of ash in cane sirup, first molasses and final molasses. These results
were obtained by employing the three official methods? with slight
modifications to ascertain (1) which of the three yields the most con-
cordant results in the hands of different analysts, and (2) how well the
results obtained agree.
The tabulated results showed that agreement among different analysts
was not nearly so good as that between duplicates of the same analyst.
This appeared to hold for all chree methods.
In discussing the results, Zerban pointed out that no advantage is
gained by the use of Method II (leaching the carbonized material) over
Method I, the direct ash method, except when necessity compels. In
regard to Method III (sulfated ash method), it was found that the
amount of ash increased with the quantity of sulfuric acid used and
also that the correction factor would vary with the purity of the product
analyzed and is evidently nearer 20 per cent than the 10 per cent recom-
mended in the official method. Zerban’s report showed that the sul-
fated ash method has no advantage over the direct ash method from the
standpoint of close agreement among different analysts or from that of
ease of manipulation, and furthermore, that the sulfated ash method
may give results widely divergent from those obtained by the direct
ash method.
The present associate referee desires to report a continuation of the
ash determination work based upon Zerban’s conclusions and recom-
mendations’.
Three samples of sugar-house products—one a cane sirup, one a first
molasses and one a final molasses—were sent to each collaborating
analyst who was requested to determine the ash in each sample by the
three methods published in Zerban’s report and to incinerate at tem-
peratures of 475°, 500°, 525° and 550°C., reporting the results for each
temperature.
The four analysts who reported results and to whom the writer desires
to express his thanks are the following: (1) S. H. Champlin, Cape Cod
Preserving Co., Boston, Mass.; (2) H. Z. E. Perkins, American Sugar
1 J. Assoc. Official ger: Chemists, 1921, 4: 444.
2 Thid., 1916, 2: 12
3 Ibid., 1921, 4: 451.
366 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
TABLE 1.
Collaborative results on the determination of ash.
TEMPERA- METHOD METHOD METHOD METHOD METHOD 3
ANALYST TURE 1* lft 2* 2t Platinum Silica
Dishes Dishes
Cane sirup
°C. per cent per cent per cent per cenl per cent per cent
1 } 2.43
, 2.42
2 2.46 2.44
2p: 2.45
mara 475 2.26 2.25 2.27 2.30
3 500 PPE 2.28 2.13 2.15 2.56
525 2.26 2.19 2.08 2.09 2.53
550 2.20 2.17 2.04 2.06 W574
1.98 1.98 ie ei
475 2.05 2.10 2.49
2.01 2.03
2.00 2.00
4
1.96 1.76
1.99 1.84
550 2.03 1.93
2.04 1.91
First molasses
1 5.59
5.50
2 5.48 5.42
5.59 5.48
475 4.90 4.93 4.95 4.91 ek
3 500 4.90 4.89 4.46 4.45 5.72
525 4.76 4.85 AN alr it Se 5.66
550 4.68 4.71 4.66 4.68 5.67
4 ea
5.45
Final molasses.
1 9.02
8.92
ae 9.35 9.07
9.16 9.10
475 7.96 7.88 7.69 7.49 ee
3 500 (ale 7.74 Tato TATE 9.37
525 Their 7.88 7.65 Tou 9.16
550 7.69 7.39 7.61 1.00 9.23
4 475 7.24 7.22 9.27
20 7.20 9.28
*Without ammonium carbonate.
+With ammonium carbonate.
1923] BREWSTER: DETERMINATION OF ASH IN CANE SIRUP 367
Refining Co., New Orleans, La.; (3) W. G. Raines, Jr., Louisiana Sugar
Experiment Station, New Orleans, La.; (4) G. F. Snyder, Bureau of
Standards, Washington, D. C.
The results are given in Table 1.
DISCUSSION.
It is seen at once that very good agreement occurs in the results of
Method III reported by all the analysts, regardless of whether platinum
or silica dishes had been used. The average sulfate ash in the sirup was
2.49 per cent; the lowest was 2.42 and the highest, 2.56. In the sample
of first molasses the average is 5.55 per cent, with lowest and highest
5.41 and 5.67 per cent, respectively. In the sample of final molasses
the average is 9.17 per cent, with lowest 8.92 per cent and highest 9.37
per cent. It happens that the lowest results were obtained with silica
dishes and the highest when platinum dishes were used. The results of
Analyst 2, who determined the ash by the sulfate method in both plati-
num and silica dishes, show in all cases that the figures are slightly
lower when silica dishes were used. The differences in most cases may
be only slight, but it seems advisable to recommend the use of platinum
dishes.
Although very concordant results were obtained by the four analysts
reporting at this time upon sulfated ash, such was not the case in the
last report by Zerban!; in his report the disagreement among ten analysts
was much greater, the maximum variation ranging from 0.35 per cent
in cane sirup to 0.62 per cent in final molasses where the same amount
of sulfuric acid had been used in ashing. It would not, therefore, appear
justifiable to recommend exclusive employment of the sulfate method on
the basis of satisfactory agreement among four analysts when such dis-
parity had appeared among the results of ten.
Referring to the results for Methods [ and II it is found that increasing
the temperature at which the material is ashed shows a tendency to
lower the results. This is readily noted by reading vertically down the
columns of the table for Methods I and II, especially in the more con-
centrated products, while with cane sirup, using Method I, practically
no differences are observed between temperatures of 475° and 550°C,
For cane sirup, results for direct ash, using Method I, were reported only
by Analysts 3 and 4. Each analyst was able to check his own results
closely. However, there is a considerable disagreement between the
results of the two analysts, the average for one being 2.19 per cent, for
the other 1.97 per cent. These discrepancies are not likely to be due
to differences in temperature.
The effects of higher ashing temperatures than those usually recom-
mended are to be observed by reference to Table 1, Methods I and II,
1 J. Assoc. Official Agr. Chemists, 1921, 4: 447.
368 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
where results for the more concentrated substances are shown. Even
here the decrease in ash does not vary uniformly with increase of tem-
perature. The results reported by Analyst 3 were obtained by use of
a gas-heated muffle furnace; those of Analyst 4, with an electric furnace.
It is well known that by use of an electric furnace of the type employed
for ash determinations an oxidizing atmosphere is readily obtained,
whereas with a gas-heated muffle—usually made of porous material and
surrounded by combustion gases—the supply of air may be insufficient
for complete oxidaton of the carbon formed although no unburned
carbon may be detected by casual inspection of the ash. The dis-
crepancies in the results cited may, therefore, be due to the use of two
different heating devices and the consequent differences in air supply.
The latter should be sufficient, particularly toward the end of the ashing,
to insure complete removal of carbon. To this end a carefully con-
trolled electric furnace is to be recommended.
Since ashing at the lower temperatures requires practically no more
time than at the higher temperatures, the lower temperatures, 475° to
500°C., are to be recommended. What may be called incipient red
begins at 475°C.; at 500°C. a distant dull red is attained. With an
adequate air supply, ashing takes place rapidly at these temperatures.
If the results in Table 1 for direct and carbonated ash by Methods I
and II are compared it would appear that no advantage is to be gained
in an attempt to convert alkali earths to carbonates. The differences
are negligible and seem just as likely to be lower after treatment with
ammonium carbonate. In fact, in only 15 out of 33 cases is the car-
bonated ash higher, and then the differences are only slight.
In connection with the direct determination of ash in sugar-house
products the paper by W. L. O. Whaley, read at this meeting, (page 370)
demonstrates certain advantages in using nickel instead of platinum or
silica dishes for the incineration.
Not only are the results concordant, but the ashing takes place more
quickly than in platinum or silica dishes, and nickel has the obvious
advantage of lower cost.
Returning to the subject of sulfated ash (Method IIT) it appears that
the temperature of ashing makes practically no difference in the results
unless, perhaps, when silica dishes are used. The presence of sulfuric
acid may be counted upon to assist in the oxidation of carbon. How-
ever, the question of the proper conversion factor of sulfated ash to true
ash must remain unanswered, so far as the present results are concerned.
The average results obtained by Methods I and II and those by
Method III are shown in Table 2, with the factor for ascertaining the
amount to be deducted from sulfated ash to convert the latter to true ash.
The variation in the conversion factor for the different products is
seen at once by reference to Column 4 of Table 2 and, also confirming
1923] BREWSTER: DETERMINATION OF ASH IN CANE SIRUP 369
TABLE 2.
Average results of determination of ash.
FACTOR FOR
FACTORS
METHODS METHOD CONVERTING
PRODUCT REPORTED BY
I—II Ill SULFATE ASH
ZERBAN
TO TRUE ASH
per cent per cent per cent per cenl
SIMU Dr et siais <flaso tion 2.09 2.49 16.06 16.6
First molasses. ..... 4.77 5:55 14.05 17.6
Final molasses...... 7.47 9.17 18.54 18.9
the results reported by Zerban and others, it is seen to be much higher
than the 10 per cent recommended in the official method. For sulfated
ash where 0.5 cc. sulfuric acid had been used, the factors 16.06 for sirup
and 18.54 for final molasses agree fairly well with those reported by
Zerban, which were 16.6 and 18.9, respectively, while for the first mo-
lasses the factor given is 14.05 and that of Zerban is 17.6.
Although the results for sulfated ash given in this report show satis-
factory agreement, it can not be argued, in view of the discrepancies
reported by Zerban, that the sulfated ash method has any advantages
over the direct ash method, particularly when the former is known to
give results which may be widely at variance with the true ash content
of the material analyzed.
RECOMMENDATIONS.
It is recommended—
(1) That Method I be given official preference for the determination
of ash in cane sirups and molasses; and that Method II be used only
when it is found impossible to get a carbon free ash by the shorter method.
(2) That Method III, the sulfated ash method, be discontinued as
an official method.
Suggested Cooperative Work upon Sugar-House Products.
Our present methods for the determination of total solids in sugar-
house products may be grouped under three heads, namely, drying
methods, aerometric methods and methods employing the pycnometer.
No doubt all these methods should be compared particularly with a
view to establishing their reliability when applied to the analysis of
the more concentrated products such as sirups, massecuites and mo-
lasses. To that end it is recommended that cooperative work be under-
taken to compare the following methods:
1. Drying upon pumice stone.
2. Drying upon sand.
3. By means of the Spencer oven.
4. By means of a pycnometer—Walker, Newkirk (with Newkirk’s
method) or other type.
370 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
THE USE OF NICKEL DISHES FOR ASHING SACCHARINE
PRODUCTS.
By W. L. O. WHatry (Penick and Ford Laboratories, New Orleans, La.).
This investigation of the possibility of using nickel instead of plati-
num dishes for the ashing of saccharine products was undertaken pri-
marily for the purpose of eliminating, if possible, the inconvenience and
financial loss caused by occasional thefts of platinum which sometimes
occur in spite of the constant vigilance which our own, in common with
other laboratories, have to exercise to guard against such thefts. The
results obtained are so satisfactory and of such general interest that it
seems desirable to make them public.
A brief review of the subject of the estimation of ash in saccharine
products reduces the choice really to two methods!: direct incineration
and ignition with sulfuric acid.
‘In the direct incineration method the material, either with or without
the addition of olive oil or water at some stage of the process, is directly
ignited. In the other method the material after being subjected to
preliminary charring with concentrated sulfuric acid is ignited and the
residue weighed, after which an arbitrary correction to compensate for
the conversion of chlorides, carbonates and other salts to sulfate is
applied. Almost any text containing chemical methods for the analysis
of saccharine products gives these two methods for the determination
of ash, and generally 10 per cent is recommended as the correction to
be applied to the sulfated ash. It has been shown conclusively by
Zerban? and others that in most cases this 10 per cent deduction
factor leads to incorrect results. If the varied composition of the
different saccharine products on which an ash determination is made is
taken into consideration it is not to be expected that a method which
involves the use of any arbitrary correction of this kind will prove to
be satisfactory. The work in our laboratories includes the examina-
tion of a great variety of saccharine products, differing in composition
as much, for example, as a mixture of corn sirup with standard granu-
lated sugar, with less than 0.25 per cent of ash, and the heaviest final or
‘black strap” molasses, with more than 10 per cent of ash. Any method
of ashing used for products of every gradation in composition between
these extreme types must be one that will give reasonably accurate
results with any of these products. The sulfated ash method, in the
opinion of the writer, does not meet this requirement and for that reason
was not given further consideration.
1 Assoc. Official Agr. Chemists, Methods, 1920, 105; Browne, Handbook of Sugar Analysis, 1917, 495.
2J. Assoc. Official Agr. Chemists, 1921, 4: 444.
1923] WHALEY: NICKEL DISHES FOR ASHING SACCHARINE PRODUCTS 371
AVAILABLE DISH MATERIAL.
None of the various alloys used as platinum substitutes has proved
very durable under constant use. The first sign of deterioration is
usually the appearance of a speck; next an incrustation around this
spot is seen and finally a pit is formed, in appearance something like a
spring in a limestone country with a deposit of calcite built up around
it. Alloy dishes require as much care as is given to platinum, and,
unlike platinum, the damaged alloys have no market value. Conse-
quently alloy dishes are very expensive when their durability is taken
into consideration.
Silica dishes may be used for sulfated ash work but in ash determina-
tions by the direct ignition method the silica is attacked by the alkaline
constituents of the ash with liberation of carbon dioxide and consequent
loss in weight of ash and progressive loss in weight of the dish.
Since nickel as well as silver dishes are used successfully in alkali
fusions the recommendation to investigate the utility of nickel was
accepted, and one dozen nickel dishes were obtained for this purpose.
EXPERIMENTAL
The new dishes were flat-bottomed, 5 cm. in diameter and 1.9 cm. in
height, polished, and had a pure white metallic luster. They were
given identifying marks and subjected to a preliminary heating. [ri-
descent colors appeared at once, but after heating for about 2 hours,
cooling and desiccating, the dishes had the usual dull yellowish-gray
appearance of used nickel ware. This coloring, followed by the change
in appearance, did not look promising, but after the dishes were weighed,
and the weights recorded, samples were weighed into them and ashed.
Since the first ash results appeared concordant for the products used
the use of the nickel dishes was continued, although at no time was the
weight of any dish compared with its original weight until the labora-
tory sample numbers showed that 535 ash determinations had been
made. In all these determinations a Hoskins Replaceable Unit Muffle
Furnace was used for the final incineration. This furnace had been
standardized previously by marking the positions of the rheostat lever
when the furnace had attained and was maintaining a temperature of
427°C. (800°F.), 482°C. (900°F.), and 649°C. (1200°F.,) as indicated by
a thermocouple pyrometer. Instead of the few drops of the less vis-
cous olive oil usually recommended, a small piece of paraffin the size
of a match head was added to the material being ashed. The paraffin
does not spatter with products having an excessive moisture content, as
does the oil, and is equally efficient for reducing frothing. After the
paraffin was added, the samples were heated gently by applying a flame
from above until the product was charred. This usually required less
372 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 3
than a minute. The dishes were then placed in the muffle furnace with
the door left open to permit free access of air.
The ashes were burned at temperatures varying from 427°C. to 482°C.,
except occasionally with low grade products the temperature was raised
to 538°C. (1000°F.). On two occasions the muffle door was inadvert-
ently left closed and the temperature rose to nearly 1093°C. (2000°F.),
fusing the ash. On these occasions the dishes were washed with a warm,
dilute solution of sulfuric acid (1 volume of acid, sp. gr. 1.84, and 9
volumes of water), and again heated to 649°C. before being used again.
After 535 ash determinations had been made in these 12 nickel dishes
the dishes were cleaned with the dilute sulfuric acid previously men-
tioned, heated at 649°C., desiccated and weighed. The appearance of
the dishes remained the same as after the first heating to which they
were subjected before being used. Since all the dishes had been used
to approximately the same extent, it is safe to assume that at least 40
ash determinations had been made in each. Data showing the loss in
weight of the dishes and the calculated effect of this upon the ash de-
terminations are given in tabular form below. Column 1 of the table
shows the identifying marks on the dishes; Column 2, the initial weights
of the dishes after the preliminary heating; Column 3, the weights after
at least 40 ash determinations had been made in each; Column 4, the
difference in milligrams between these weights; and Column 5, this
difference expressed in percentage of the original weight. In Column 6
Data showing change in weight of nickel dishes when used for the ashing of sirups and
molasses by the direct ignition method and the effect of this change in weight
upon the ash results.
AVERAGE
CHANGE | pERCENTAGE OF SAMPLE
INITIAL FINAL IN WEIGHT
roe WEIGHT WEIGHT pre PER
DETERMI- 6-Gram 1-Gram
NATION Charge Charge
grams grams milligrams | per cent | milligrams
INogseae eer 26.4470 26.4555 +8.5 0.032 +0.21 0.0035 0.021
INON2* tee. 28.3011 28.3080 +6.9 0.024 +0.17 0.0029 0.017
INOW ah anisec: 27.1889 27.1752 —13.7 0.050 —0.34 0.0057 0.034
Nora an: 27.9964 27.9960 —0.4 0.001 —0.01 0.0002 0.001
INOSSH sei: 26.0603 26.0552 —5.1 0.020 —0.13 0.0022 0.013
INOn Gide 26.5366 26.5220 —14.6 0.055 —0.37 0.0062 0.037
Ov Pil sielateass 28.4808 28.4800 —0.8 0.0038 —0.02 0.0003 0.002
OOM: PO 26.0806 26.0715 —9.1 0.035 —0.23 0.0038 0.023
OOO}: 5 he as 27.7479 27.7306 —17.3 0.062 —0.43 0.0072 0.043
pet hye spe at 26.3412 26.3394 —1.8 0.007 —0.05 0.0008 0.005
OOO tee. ee 26.8934 26.8854 —8.0 0.030 —0.20 0.0033 0.020
rebate ta ian 26.9952 26.9900 —5.2 0.019 —0.13 0.0022 0.013
Total. ...| 325.0694 | 325.0088 | —60.6 QOL viene, tee [yee ahve Mae
es | ee | ee | |
Average..| 27.0891 27.0841 —5.1 | 0.019 | —0.13 0.0022 0.013
1923] WHALEY: NICKEL DISHES FOR ASHING SACCHARINE PRODUCTS 373
is given, in milligrams, the average change in weight per determination,
on the assumption that the dish had been used for 40 determinations.
The dishes were of such size that with corn sirup which intumesces
violently one gram is the maximum weight that can be burned safely
while with a final molasses six grams may be used. Columns 7 and 8
of the table give the percentages of a 6-gram charge and a 1-gram charge,
respectively, which this average change in the weight of the dish rep-
resents.
DISCUSSION.
It was observed at once when the use of these nickel dishes was begun
that the time required to burn the charge completely to a gray ash was
very short. Only 15 to 20 minutes was required for a high-grade mo-
lasses or sirup. On four different occasions the same charge of the same
product was ashed in pla.inum dishes in the same muffle and at the
same time. The difference in the ash results was in no case as great as
0.1 per cent and the time required for complete incineration in platinum
was sometimes twice as long as that necessary for complete incineration
in the nickel dishes.
It was thought that the rapidity with which the sample burned in
the nickel dishes might be caused by the catalytic action of oxides of
nickel formed but the appearance of the dishes at the conclusion of the
tests and the slight losses in weight shown do not seem to justify this
assumption since no material oxidation of the nickel could have occurred.
The results here reported appear to show that nickel dishes can be
used with entire satisfaction for the direct ignition of saccharine products
in control work. The accuracy of the results is comparable with that
obtainable when platinum dishes are used, and the initial cost is only
about 2 per cent of that of platinum. Nickel dishes are far superior to
dishes made of fused silica for work of this kind and cost only about
two-thirds as much.
Committee on nominations: R. W. Balcom of Washington, D. C.,
J. B. Weems of Virginia, and J. W. Kellogg of Pennsylvania.
Committee on resolutions: B. B. Ross of Alabama, H. B. McDonnell
of Maryland, and G. L. Bidwell of Washington, D. C.
Auditing committee: C. M. Bradbury of Virginia and J. B. Reed of
Washington, D. C.
Committee to wait upon Secretary of Agriculture: J. B. Weems of Vir-
ginia, W. W. Skinner of Washington, D. C., and H. C. Lythgoe of Massa-
chusetts.
Committee to wait upon Honorary President: J. K. Haywood of Wash-
ington, D. C. and R. N. Brackett of South Carolina.
Committee to wait upon Senator Ladd: W. W. Skinner of Washington,
D. C., G. S. Fraps of Texas, and C. H. Bailey of Minnesota.
di
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JOURNAL
OF THE
ASSOCIATION OF OFFICIAL AGRICULTURAL
CHEMISTS
Yor. VI MAY 15, 1923 No. 4
CONTENTS
PROCEEDINGS OF THE THIRTY-EIGHTH ANNUAL CONVENTION,
NOVEMBER, 1922
WEDNESDAY—AFTERNOON SESSION PAGE
meneauabertiizers.. “By EN. Brackett seg ties clog. ac) ini 2s) o oo Binns Se eee Oa 315
Summary of Work on the Determination of Iron and Alumina in Phosphate Rock by the
Association of Official Agricultural Chemists. By R. N. Brackett................... 377
Report on Boron in Fertilizers. By. LeMil- Bashlebicreers 2 i te Vos. ey ee eR 381
Report on the Preparation of a Neutral Solution of Ammonium Citrate. By C.S. Robinson.. 384
Peremone nr ropens) oban ks -K--Phelpsyu iiss Perea iol. eh Be ore Se 391
Report on Potash. Pie he, Kod Sores eee be (cS: lol aa tee De 399
Summary Relating to Strength and Kind of Alcohol Used in Official Potash Methods, 1884—
1921. By H. A. ERRSAS P9002 RRR RV AS i oon. 9b 403
Availability of Potash in Mixed Fertilizers. By N.E. Gordon.......................... 407
The Volumetric Determination of Phospharussbyy-We a. burner... "55.0 ee eee 409
Maney Pertiizer Sampling Tube. By L. D; Haigh... :.... 0.2... ocd ee nee 410
Report on Inorganic Plant Constituents. By A. J. Patten: 2.4; 020 2 0 eee 414
Report on Sulfur and Phosphorus in the Seeds of Plants. By W. L. Latshaw............. 414
Report on the Determination of [ron and Aluminium, Calcium and Magnesium in the Ash
Bierce sob voAenie eb ablelis <cyoe eg garg cS). . i e 418
Report on Dairy Products. By Julius Hortvet........-.....-0.0c0.ceeccs cect eer 422
Mem cp oniiilic < Eyibi. > Batley | 66 )cap ites. c,h ee Se ee ees. 429
Methods for Fat in Malted Milk and Dried Milk. By J. T. Keister..................... 435
Data Secured with the “Turbidity Point” of Butter Fat. By Armin Seidenberg .......... 437
Beorwonebats and Oiler * By G! SoJaniteson’ 2025: oo lh co oe 440
Reerieonabakine Powder: by LE: Dailey = oe 2c.) e es oo. oe ee ces ie A ee 445
Report on Fluorides in Baking Powder. By J. K. Morton ...........................-- 457
DruG SEcTION
nmolinelenips. “Vena CSW IOOVER., ini aime Ao om ok es a ed 2 oe ae eee 460
Report on Methods of Qualitative and Quantitative Analysis of Arsphenamine (Salvarsan)
and Neoarsphenamine Kistemsal vy arscn yy: ss test 3 0-0 Sine te eee aah 461
Peprmombunpenime. by. 5. ©. Clarkee 0 0. poe fe tess big oe Be ee 465
A New Sedimentation Tube and Its Use in Determining the Cleanliness of Drugs and Spices.
Bear IttG REC HORVEE Hebe cca hi) @, -. Soke Se ert. Se Uh oe Acasa 7 oe Se 466
Sublimation of Plant and Animal Products—Third Report. By Arno Viehoever.......... 473
Sublimation as an Analytical Procedure. By Julius Hortvet.........................---. 481
Domestic Sources of Cantharidin. By Viehoever and Capen............................ 489
Quantitative Determination of Acetic Anhydride. By G. C. Spencer .................... 493
CONTRIBUTED PAPERS
The Effect Produced Upon the Fat of Hogs by Feeding Fish Meal. By J. B. Martin....... 498
mmminicrraridtes Men eh: AL. MCGISEER 5 =... sists teins os. MON te et eee ee 502
Determination of Fat in Alimentary Paste, Flour and Dried Egg. By R. Hertwig........ 508
PUBLISHED QUARTERLY BY
THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS
BOX 290, PENNSYLVANIA AVENUE STATION
WASHINGTON, D. C.
INFORMATION FOR SUBSCRIBERS AND CONTRIBUTORS.
THE JOURNAL OF THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS is issued quar-
terly. Each volume will contain approximately 600 pages. Subscriptions are taken by the
volume and not by the year.
Reprints of articles will be furnished to contributors at cost when ordered in advance.
A table showing cost, with an order slip, is sent with proof.
Manuscripts should be typewritten and carefully revised before submission and should be
sent to the Association of Official Agricultural Chemists, Box 290, Pennsylvania Avenue
Station, Washington, D. C.
Subscription Price: North America and U. S. possessions, $5.00 a volume net, postpaid;
all other countries, $5.50 (27s) net, postpaid.
Claims for copies lost in the mails will not be allowed unless received within thirty days
(domestic) of the date of issue; sixty days (foreign). Claimants must state that the publication
was not delivered at their recorded address. Notice of change of address must be forwarded
at least one week in advance of issue; otherwise publishers will not be responsible for loss.
Address all correspondence to the Association of Official Agricultural Chemists, Box 290,
Pennsylvania Avenue Station, Washington, D. C.
FIRST DAY.
WEDNESDAY—AFTERNOON SESSION.
REPORT ON FERTILIZERS.
By R. N. Brackxetrr (Clemson Agricultural College, Clemson College,
S. C.), Referee.
J. M. Bartlett, Orono, Maine, was designated as Associate Referee on
Boric Acid in Fertilizers and Fertilizer Materials by the Committee on
Recommendations of Referees. As W. H. Ross had been actively and
efficiently working on one phase of this problem, your referee took the
liberty, by the authority he supposed was vested in the general referee,
to add him as an associate referee to cooperate with Bartlett, which
arrangement was accepted.
With regard to the recommendation of the Associate Referee on the
Preparation of Ammonium Citrate Solution the committee strongly
commended the work done but stated that objections to the final adop-
tion of the proposed method as the exclusive official method had been pre-
sented to the committee by several members of the association, it being
contended, among other objections, that the working details of the
method are not sufficiently definite and explicit in certain particulars,
and that it is essential that more definite detailed directions be given
before final adoption of the method as official.
It may also be said that inasmuch as C. S. Robinson had done much
excellent work on the problem of the availability of nitrogen, your
referee took the liberty to request that he act as Associate Referee on
the Availability of Organic Nitrogen and make such recommendations
as seemed to him desirable to modify the present methods of the asso-
ciation and suggest a statement as to limits of accuracy. This work
will be necessary for incorporation in the revised edition of the Methods
of Analysis.
As it seemed to be the general opinion of the members of the asso-
ciation at the last meeting that a considerable amount of work had
already been done by and presented to the association, the Associate
Referee on Potash has prepared a paper which will be presented as a
part of his report, setting forth the present status of the question raised
by H. C. Moore, as to the strength of alcohol to be used in washing the
precipitate in the Lindo-Gladding method. This preliminary review
appeared to be highly desirable, if not absolutely necessary, before
actually taking up the problem and sending out samples for collaborative
work, especially when most laboratories have been working short-handed
375
376 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
and can ill afford to undertake any additional burdens unless they are
shown to be really worth while.
After carefully studying the method offered by Elmer Sherrill, the
associate referee concluded that this method, while no doubt useful as a
factory control method, was not suitable as an official method. There-
fore no collaborative work was advised. Your referee concurs.
You are no doubt aware that F. B. Carpenter presented a paper!
before the Fertilizer. Division of the American Chemical Society at the
Pittsburgh meeting in September, again raising the question as to the
failure of the Lindo-Gladding method to show all the potash in certain
mixed fertilizers, and suggesting that this association again take up this
question and endeavor to make such modifications of the Lindo-Gladding
method as may be necessary to perfect it in this respect. The associate
referee has considered this paper in his report.
In a letter received from A. G. McCall, under date of April 8, the
Associate Referee on Potash Availability recommends that he be re-
lieved from duty, inasmuch as the potash situation does not seem to
warrant any further work on this subject.
Your referee received, through R. W. Balcom, a letter from the United
Chemical and Organic Products Co., asking whether public chemists
could properly use a 1-gram charge in determining the insoluble in
“precipitated pure bone’. A negative reply was given as the recom-
mendation had been read only once, and the method was not, therefore,
official.
The following matters have also been brought to the attention of the
referee:
Insoluble phosphoric acid.—The importance of strictly following the
directions given in the official method for washing the fertilizer before
treating with ammonium citrate solution by H. C. Moore, Armour
Fertilizer Works, Chicago. Some interesting results obtained by W. R.
Austin of Armour’s Nashville plant were submitted. The subject does
not seem to call for any work by the association.
Tron and alumina determination in phosphate rock.—This subject was
brought up before the last annual meeting of the association by some of
the fertilizer chemists, and the question was raised as to the desirability
of incorporating a method in the forthcoming revised edition of the
Methods of Analysis. In April, a letter from the J. H. Pratt Laboratory,
Tampa, Fla., was referred to your referee by R. W. Balcom. It called
attention to the fact that no method was given in the Methods of
Analysis, and asked whether any steps had been taken by the association
toward the adoption of such a method. The question of collaborative
work on this problem was also raised at the last annual meeting of this
1Am. Fertilizer, 1922, 57: 55.
1923] BRACKETT: REPORT ON FERTILIZERS 377
association. Some of the members, including your referee, thought that
sufficient work had already been done on this problem to warrant action
at this meeting. Therefore, a brief paper has been prepared in which an
attempt has been made to gather together all the work done by and
presented to the association on this subject. If the presiding officer
consents, this paper will be presented. The members of the association
can then discuss the matter and come to a decision as to what should be
done about adopting a method or taking up work.
Potash in mized fertilizers.—This has already been referred to in con-
nection with the associate referee’s work on potash. This matter, as
you know, has been brought up before the association several times in
the past, especially by the fertilizer chemists, and perhaps it would be
well to discuss the question briefly and decide whether or not any action
is necessary.
“Basic Phosphate’.—A question of definition and designation was
raised by E. W. Magruder of the F. S. Royster Guano Co., Norfolk,
Va., in reference to mixtures of calcium carbonate and acid phosphate.
This question properly belongs within the jurisdiction of the Committee
on Definitions of Terms and Interpretation of Results, to which it will
be referred.
Authority of the general referees in the appointment of associate referees.—
W. W. Skinner, the secretary, has suggested that this question be brought
before the association inasmuch as there seems to be some misunder-
standing on the part of some of the general referees as to the limits of
their authority in this regard. Permission is requested of the presiding
officer to bring this question up at an appropriate time.
The discussion relating to the authority of the general referee to
appoint associate referees was opened by R. N. Brackett Friday after-
noon, and it will be found in the published proceedings of that day.
SUMMARY OF WORK ON THE DETERMINATION OF IRON
AND ALUMINA IN PHOSPHATE ROCK BY THE ASSOCIA-
TION OF OFFICIAL AGRICULTURAL CHEMISTS.
By R. N. Brackett (Clemson Agricultural College, Clemson
College, S. C.)
The first reference to a method for determining iron and alumina in
phosphates was found in the proceedings of the 8th Annual Convention,
1891, in a paper entitled, ““Proposed Method for the Analysis of Native
Phosphates Containing Iron and Aluminum’’, by L. W. Wilkinson,
Auburn, Ala., in which it was stated: ‘““The discovery in Florida of
native phosphates containing iron and aluminum demands that the
association adopt a method for the analysis of these phosphates”. Then
follows a method which, it is also stated, gave satisfactory results.
378 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
The abstracts relating to analytical work in this volume of the pro-
ceedings also contain the abstract of a paper by R. Jones, “‘Estimation
of Iron and Alumina in Phosphates’!. The method was a modification
of the Glaser method.
No reference to this subject was made in the proceedings of the 9th
Annual Convention, 1892.
In the proceedings of the 10th Annual Convention, 1893, in his report
on phosphoric acid, R. J. J. De Roode says: “The second subject which
was taken up for investigation was the determination of iron and alumina
in phosphates. Now, although I was aware of the fact that this sub-
ject did not come under the duties of the reporter on phosphoric acid, I
felt that, owing to the numerous requests for investigation on this sub-
ject, something ought to be done’. Sample No. 2 (a powdered Florida
phosphate rock) was prepared especially for this purpose, and the results
of the determination of iron and alumina were given. The author says
further: “‘These results admit of no conclusion as regards the best
method, and there is nothing to show which method gives results which
are nearest the truth. In my opinion, the method of Mr. Charles
Glaser’, of the firm of Lehman & Glaser, Baltimore, is a good one.
“Tt is the opinion of some of the members of this association that
the determination of iron and alumina in phosphates is without the
province of the investigations of this association. I, however, am ofa
different opinion, and since this is a subject upon which the greatest
controversies have arisen among chemists, I deem it the duty of the
Association of Official Agricultural Chemists to take up the matter for
exhaustive investigation, and to establish, if possible, a reliable method
for the estimation of iron and alumina in phosphates, to be considered as
an official method in the same light in which our other methods are
official, and I would recommend that a special reporter be appointed next
year for this purpose’. De Roode’s recommendation (7th) was as follows:
“That a special reporter be appointed for next year whose duty it shall
be to institute investigations upon the subject of the determination of
iron and alumina in phosphates”.
The list of reporters for 1893-1894 does not contain any reference to a
special reporter on this subject, because, after a discussion, De Roode’s
7th recommendation was not adopted. De Roode stated: ‘There
seems to be some disagreement among the members of this association
as to whether that is within the province of the work we are doing. I
would like to have that question decided. If it be declared that this
matter is within the scope of our labors, some measures should be taken
which will render it unnecessary for the reporter on phosphoric acid to do
all this work”’.
1Z. angew, Chem., 1891, 4: 3.
Z. anal. Chem., 1892, 31: 382; Pharm. Review, Baltimore, 1892, 1: 185.
1923] BRACKETT: IRON AND ALUMINA IN PHOSPHATE ROCK 379
As a result of the discussion in which Chazel and McDonnell (H. B.)
took part, it was decided that this was not a matter for the association.
The only reference to this subject contained in the proceedings of
the 11th Annual Convention, 1894, was in abstracts of papers.
During the 12th Annual Convention, 1895, in a discussion of a report
on methods of the A. O. A. C. for phosphoric acid, A. A. Persons, Lake
City, Fla. raised the question: ““Would it not be in order to say some-
thing in regard to the estimation of iron and alumina in phosphates?”
He suggested a method. H. A. Huston admitted the desirability and
importance of a method, stating that all methods so far gave varying
results. W. D. Bigelow referred to recent experiments seen at A. A.
A. S. meetings, in which thioacetic acid was used. R. J. Davidson
referred to the method suggested by Wilkinson. No action was taken
by the association.
At the 13th Annual Convention, 1896, the Committee on Recom-
mendations of Reporters recommended “that the methods for iron and
alumina in phosphates be referred to the reporter (on phosphoric acid)
for 1897”’.
At the 14th Annual Convention, 1897, H. B. McDonnell, Reporter on
Phosphoric Acid, gave results reported on the following methods for
iron and alumina in phosphates: acetate, thiosulfate, and Glaser.
Samples sent out were the following: South Carolina rock, Florida rock,
Alabama rock, Pottstown slag, and a solution of chemically pure salts.
Seven or eight collaborated. Comment of referee: ““The results are tceo
few by any of the methods to admit of much comparison or the drawing
of very definite conclusions. There are more results reported on iron
by the permanganate method than by any other, and with a few ex-
ceptions they agree fairly well. This seems to be the best method for
the determination of iron in phosphates. The most promising method
for alumina, in my opinion, will be found to be that of Gladding, potash
method. I would recommend that the work be continued next year’.
A paper by C. W. Lehmann, “Estimation of Iron and Alumina in Min-
eral Phosphates (Iron by Sodium Peroxide, Aluminum as Phosphate)”,
appears in these proceedings. The Committee on Recommendations of
Referees recommended: “In regard to iron and alumina, that methods
for determination of these substances in phosphates be further investi-
gated’. Adopted on motion of M. A. Scovell.
There was no reference to this subject in the proceedings of the 15th
(1898) and 16th (1899) Annual Conventions of the association.
In the proceedings of the 17th Annual Convention, F. G. Runyan
reported that three samples were sent out for iron and alumina in phos-
phates. The methods tried were the modified acetate for combined
iron and aluminum phosphates, phenylhydrazine for aluminum, and
permanganate for iron in separate portions of solution.
380 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
After discussing the results of the collaborative work Runyan said:
“The subject of the determination of iron and alumina in phosphates
is one that, in my opinion, may well receive some attention from the
members of this association during the coming year”’.
In the proceedings of the 18th Annual Convention, 1901, H. K.
Miller, Florida, Referee on Phosphoric Acid, reported that three samples
were sent out for iron and alumina in phosphates, as follows: basic
slag, ground phosphate, and a solution of chemically pure salts; that the
methods used were the acetate and molybdate; and that results were
obtained from eight collaborators. The results were discussed as fol-
lows: “‘As usual few results were reported on iron and alumina, and as
is generally the case, quite varying results have been obtained. It
would evidently be unwise to make any recommendations based on the
results which have been reported on these samples’’.
There was no reference to this subject found in the proceedings of
the 19th (1902), the 20th (1903) and the 21st (1904) Annual Conven-
tions.
At the 22nd Annual Convention, 1905, E. W. Magruder, Referee on
Phosphoric Acid, had no report to present, but recommended that work
be done on the determination of iron and alumina in phosphates, look-
ing to the adoption of an official method. Committee A recommended
that the subject of an accurate determination of iron oxide and alumina
in rock phosphates be examined by the Referee on Phosphoric Acid and
an official method be recommended to the association the following year.
(Motion by T. 8. Gladding referred to the committee.)
At the 23rd Annual Convention, 1906, J. M. McCandless, Associate
Referee on Phosphoric Acid, who had agreed to undertake the investiga-
tion of iron and alumina in phosphates, reported that three prepared
solutions were worked on in his own laboratory. The best results were
obtained by the acetate method by Gladding and the Glaser method.
This report brought out remarks by F. P. Veitch and others on previous
work which had been done on this subject, but Committee A made no
recommendation.
At the 24th Annual Convention, 1907, McCandless again made a
report on this subject. The samples sent out were: No. 1, a synthetic
mixture; No. 2, Tennessee rock. Methods used for alumina: thiosulfate
method modified, Gladding method, Glaser method; for iron, any volu-
metric method preferred. Only two collaborators reported on Sample
No. 1 and four reported on No. 2. During the discussion, W. F. Hand
gave a method which had given good results in his laboratory.
Certain comments by the associate referee and a supplementary
report by F. B. Carpenter on this subject followed. Committee A
made no recommendation apparently, but at the 25th Annual Con-
vention, 1908, McCandless, Referee on Phosphoric Acid, made another
1923] BARTLETT: REPORT ON BORON IN FERTILIZERS 381
report on this subject, which he said was in accordance with a recom-
mendation of the association at its previous convention. He reported
that three samples (Florida rock, Tennessee rock and a synthetic solu-
tion) had been sent out to ten chemists. The methods used were the
Gladding, the Glaser, and a proposed modification of the acetate method.
Six collaborators reported results.
In his remarks McCandless stated: ‘On the whole the results seem to
be encouraging and to show that all three of the methods for which
instructions were sent are capable of giving good results. The referee
would call attention to the fact that this subject has been taken up by
the National Fertilizer Association, and would recommend cooperation
between the next referee and the committee of that association, with a
view to reaching a decision as to what method shall be adopted’.
There was no reference to this subject in the proceedings of the annual
conventions from the 26th to the 37th, inclusive.
As a conclusion of the whole matter, it may be said that the collab-
orative work which has been undertaken by this association from time
to time was done only in a half-hearted way, because the subject of
determining iron and alumina in phosphates has never appealed to the
members as being of any real importance to them. The members of
this association were never called upon to make determinations of iron
and alumina in phosphates in the course of their inspection work. The
interest in this subject was limited to the buyer and seller of phosphate
rocks and in no way concerned the members of this association in their
regulatory work.
Therefore, in presenting this paper, your referee recommends, first,
that the association decide at this meeting whether or not it wishes to
undertake work on this subject; and second that, if so, a special referee
be appointed on this subject.
It was moved that no further work be undertaken at this time in
regard to the determination of iron and alumina in phosphate rock, as
it was considered that this was not properly the work of the association.
The motion was seconded and carried.
REPORT ON BORON IN FERTILIZERS.
By J. M. Bartrert (Agricultural Experiment Station, Orono, Maine),
Associate Referee.
The Referee on Borax in Fertilizers for 1921 recommended that some
modification of the distillation (Bartlett) method! be worked out for
determining water-soluble boron, as the method in its present form gives
not only water-soluble boron but that which is dissolved by weak acids.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 90.
382 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
It is well known that there are several compounds of boron which are
only slightly soluble in water but very soluble in weak acids, and should
any of these compounds occur in fertilizers or fertilizing materials it
would be very important to know whether they are as injurious to
plants as the more soluble compound.
It seemed best, therefore, to experiment with some of these compounds
before suggesting any change in the method since the object desired is
to determine the boron which is injurious to plants rather than water-
soluble boron.
W. H. Ross of the Bureau of Soils very kindly furnished the writer
for this purpose four minerals carrying boron, and some experiments
were carried out in the station greenhouse with bean plants which are
quite susceptible to boron injury.
The minerals used were Colemanite, a hydrated calcium borate,
having the formula CasB;O1u .5H20; Ulexite, also a hydrated mineral
represented by the formula Na Ca B;O,.8H:O; Howlite, a borosilicate
of calcium having a formula of H;Ca2B;SiOi, and a sample of Tour-
malin, said to contain about 10 per cent of boron trioxide. All these
minerals were pulverized fine enough to pass a 60-mesh sieve for analysis
and use in the experiment. They are supposed to be insoluble in water
but when treated with 50 cc. of hot water on the steam bath for 20
minutes about one-third of the boron in the Colemanite, nearly all that
in the Ulexite and about one-third of that in the Howlite was dissolved.
The Tourmalin, of course, was not acted on at all, either by hot water or
weak acid. When one-half cc. of strong hydrochloric acid was added to
the 50 cc. of hot water the first three minerals mentioned were readily
dissolved. The following table shows the amount of boric acid found
by the different methods of treatment.
Amount of boric acid found by the three different methods.
SOLUBLE IN WATER SOLUBLE IN WEAK ACIDS
MINERALS USED =
Modified
Poss-Deemer Method Réss-Deciner Mathod® Bartlett Method
per cent per cent per cent
Colemanite..... 28.48 86.66 86.66
Ulexitews..222<5 69.69 70.29 69.69
Howlite........ 30.30 80.60 73.33
Tourmalin..... 0 0 0)
: *One-half cc. strong hydrochloric acid was added to the 50 cc. of hot water used to dissolve 0.1 gram
of the mineral.
PLAN OF THE EXPERIMENT.
The soil used was from a pasture that had not been cultivated or
fertilized for years. The fertilizer applied was a 5-8-7 goods which
1923] BARTLETT: REPORT ON BORON IN FERTILIZERS 383
was free from boron. Nine-inch pots were employed, three being
allowed for each mineral, and three checks to which only fertilizer was
applied. Borax was applied to three pots for comparison with the other
minerals. The same amount of fertilizer was used in each pot, and the
boron minerals were added in units sufficient to equal 10, 20 and 40
pounds of anhydrous borax to the ton of fertilizer. The fertilizer and
minerals were weighed out separately, but were thoroughly mixed before
being applied to the soil. The fertilizer was also thoroughly mixed with
the earth below where the beans were planted. Four seeds were put
in each pot and nearly all came up at about the same time. They grew
and looked healthy for the first six days, when those containing the
fertilizer carrying the equivalent of 40 pounds anhydrous borax to the
ton began to show very serious borax injury; those carrying 20 pounds
also showed some injury.
The injury at this time was most marked in the pots containing borax
and Ulexite. The plants in the pots carrying 10 pounds of anhydrous
borax to the ton of fertilizer were about as thrifty as those with none,
but the leaves were a little lighter color. At the end of two weeks
more the plants in the pots containing the largest amount of boron
showed extensive injury with all the minerals except the Tourmalin.
The leaves turned yellow and the lower ones died and dropped off. The
plants in the pots with less boron, 20 pounds of anhydrous borax to
the ton of fertilizer, began to show considerable injury, the leaves being
lighter color and dying around the margins, particularly the lower ones.
The only differences noticeable in the plants in pots where the smallest
amount of boron was used (10 pounds of anhydrous borax to the ton of
fertilizer) and those having none, were some yellow spots in the leaves
and some leaves slightly affected around the margins. Throughout the
remainder of the experiment no difference could be detected in amount
of injury to the plants whether the boron was applied in the form of
borax or the less soluble forms of Colemanite, Ulexite or Howlite. The
plants with the largest amount of boron died after reaching the height
of six to eight inches. Those with the next largest amount attained
about two-thirds the size of the check plants and matured a few pods
but showed a good deal of injury. The set grown on the smallest
amount grew nearly as large as the checks but did not develop as many
pods; many of the leaves showed yellow spots and slightly yellow mar-
gins. The pots containing the Tourmalin grew plants as healthy as the
checks; at all times they were good color and showed no boron injury.
RECOMMENDATIONS.
It is recommended—
(1) That as boron compounds not soluble in water but soluble in
weak acids appear to be as injurious to plants as the water-soluble com-
384 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
pounds and the distillation method, as now carried out, determines the
boron in such compounds, it be adopted as an official method in its
present form to determine boron in mixed fertilizers and fertilizer ma-
terials.
(2) That in using the Ross-Deemer! method for the determination of
boron in fertilizer materials known to contain boron compounds not
soluble in water but soluble in weak acids, sufficient hydrochloric acid
be added to make the 50 cc. of water used in the first digestion on the
steam bath to bring the boron into solution, distinctly acid throughout
the digestion. This is recommended for further study.
(3) That the Ross-Deemer method, as given by the referee for 1921,
be adopted as an official method to determine water-soluble boron in
mixed fertilizers and fertilizer materials.
REPORT ON THE PREPARATION OF A NEUTRAL SOLUTION
OF AMMONIUM CITRATE.
By C. S. Roptnson (Agricultural Experiment Station, E. Lansing,
Mich.), Associate Referee.
Three recommendations were made by the associate referee at the
last meeting of the association dealing, respectively, with the definition
of a neutral solution of ammonium citrate, the method for the prepara-
tion of such a solution and the methods for its analysis’. After study-
ing the discussion of the report and consulting by letter with the Chair-
man of Sub-Committee A and with the Referee on Fertilizers it was
decided to limit collaborative work to the last point, t. e., the methods
of analysis of citrate solutions. Changes have been made in the first
two recommendations to conform to suggestions made regarding them.
Before proceeding to an inspection of the results secured in the col-
laborative work the associate referee desires to discuss briefly certain
suggestions that have been made by various members of the association
during the past two years. The question which perhaps comes up most
frequently is that concerning the desirability of controlling the reaction
of ammonium citrate solutions. In other words, do variations in the
reaction of the citrate solutions affect the results obtained in actual
analysis sufficiently to warrant an accurate adjustment of the reagent?
This question has been asked probably at every meeting at which a
report on the subject of neutral ammonium citrate solutions has been
made. But it was definitely brought to the attention of the present
associate referee this year with the suggestion that he secure samples
1 J. Assoc. Official Agr. Chemists, 1922, 5: 327.
2 Thid., 445.
1923] ROBINSON: NEUTRAL SOLUTION OF AMMONIUM CITRATE 385
of solutions actually being used in several laboratories and use them
for analyzing samples of phosphates to settle this point. The suggestion
was not followed out because the writer feels that he has already
answered the question more satisfactorily than could be done in the
manner suggested. A number of years ago he prepared four solutions of
ammonium citrate having reactions pH 6.6, 7.0, 7.4 and 7.8, t. e., vary-
ing from acid to alkaline and including the two “neutral” solutions. A
dozen different materials of varying phosphate content were analyzed by
the usual procedure using these solutions. The results have been reported'.
While variations in the results were observed they were in most cases
small and within the limits of experimental error. Nevertheless, the
fact remains that some differences were noted; hence the possibility
must be confronted of the existence of products sufficiently susceptible
to alkali to be affected by differences in reaction.
A second objection which is frequently made to the accurate adjust-
ment of the reaction of this reagent is that such work is fruitless since
the reaction changes during the determination. The writer also has
considered this point. So far as he is aware there exists only one piece
of experimental evidence supporting the contention. In that work a
current of air was passed through the flask during the digestion to remove
the ammonia liberated. The result naturally followed that ammonia
was lost. A review of the work done in past years will show that this
point received attention in preparing the official method which accord-
ingly prescribes that the flask be “loosely stoppered”’. In the work
of the writer the reactions of the solutions were carefully determined
before and after the analyses, which, as stated, were carried out exactly
as prescribed by the official method except for the reaction of the solu-
tions. It was very definitely shown that with strictly neutral or acid
solutions no change in reaction takes place. Alkaline solutions tend to
become neutral.
In view of these facts it appears advisable to control the reaction of
the reagent with some care. Methods now available make it possible
to do this with the ease and accuracy with which any standard reagent
can be prepared.
As stated in last year’s report, the determination of the composition
of citrate solutions by analysis is influenced by the analytical procedure
used. A study of the more common analytical methods in vogue in
various laboratories was made, and the results, which have been pub-
lished elsewhere2, were made the basis for the collaborative work. This
work consisted in the analysis by five different methods of three samples
of citrate solutions prepared by the associate referee and sent out to
collaborators.
1 Michigan Agr. Expt. Sta. Tech. Bull. 46, 20.
2 J. Ind. Ena. Chem., 1922, 14: 429.
386 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
Solution A was prepared so as to have a ratio of ammonia to citric
acid of 1:4.25 as determined by the formaldehyde method.
Solution B was made to have a pH of 7.0 using the colorimetric method
with phenol red as the indicator, as recommended in last year’s report.
Solution C was neutralized electrometrically and should correspond in
composition to a solution of triammonium citrate.
The methods of analysis were described as follows:
Pipet 50 cc. samples of the solutions submitted into 500 cc. volumetric flasks and
make up to the mark with carbon dioxide-free distilled water. Use these solutions for
analysis.
Methed I.
REAGENTS.
0.25N alkali, 0.5N acid, and 0.1N alkali.
Ammonia.—Transfer 25 cc. samples to distillation flasks, add 40 cc. of 0.25N alkali
to each and distil 45-50 cc. into receiving flasks containing 20 cc. of 0.5N acid. Titrate
back with 0.1N alkali, using cochineal as indicator.
Citric acid.—Wash the residue from the distillation flask into an Erlenmeyer flask and
add a few drops of phenolphthalein solution and sufficient 0.5N acid to decolorize the
solution. Titrate back with 0.1N alkali.
Method II.
REAGENTS.
0.1N alkali and 0.1N acid.
Ammonia.—Transfer 10 cc. samples to distillation flasks, add 40 cc. of 0.1N alkali
and 20 cc. water to each and distil about 50 cc. into receiving flasks containing 50 ce.
of 0.1N acid. Titrate back with 0.1N alkali, using methyl red or cochineal as indi-
cator.
Citric acid.—Wash the residue from the distillation flask into an Erlenmeyer or
other flask suitable for use in titrating and add a few drops of phenolphthalein solution
and sufficient 0.1N acid to decolorize it. Titrate back with 0.1N alkali.
Method IIT.
REAGENTS
0.1N alkali, 0.1N acid, and methyl red indicator.
Ammonia.—Transfer 10 cc. samples to distillation flasks, add 40 ec. of 0.1N alkali
and 200 ce. of water and distil about 150 cc. into receiving flasks containing 50 cc. of
0.1N acid. Titrate back with 0.1N alkali, using methyl red or cochineal as indicator.
Citric acid —Wash the residues from the distillation flask into Erlenmeyer or other
flasks suitable for use in titrating, add a few drops of methyl red solution and sufiicient
0.1N acid to produce a permanent red color. (Just enough methyl red solution should
be used to enable the analyst to detect the pink color. Too much tends to obscure
the final end-point with phenolphthalein.) Boil, add a few drops of phenolphthalein
solution and titrate back with 0.1N alkali to an end-point with this indicator.
1923) ROBINSON: NEUTRAL SOLUTION OF AMMONIUM CITRATE 387
Method IV.
REAGENTS.
0.5N sodium hydroxide and 0.5N sulfuric acid.
Ammonia.—Transfer 50 cc. samples to distillation flasks, dilute with 200 cc. of dis-
tilled water (neutral to phenolphthalein) and add 35 cc. of 0.5N sodium hydroxide
(40 cc. with Solution A). Distil and collect the ammonia in 35 cc. of 0.5N sulfuric
acid.
Citric acid.—Wash the residue from the distillation flask into one suitable for use in
titrating, add a few drops of phenolphthalein and titrate to the disappearance of color
with 0.5 sulfuric acid.
Method V.
REAGENTS.
0.1N alkali, 0.1N acid, and formaldehyde solution, 40%, neutral to phenolphthalein.
Ammonia.—Use results from one of the preceding methods, stating which one.
Citric acid.—Pipet 25 cc. of each citrate solution into 250 cc. volumetric flasks and
dilute to the mark. Transfer 10 cc. to a flask suitable for use in titrating, add 4 ce.
of the formaldehyde solution and titrate the acid liberated, using 0.1N alkali and
phenolphthalein.
Four determinations by each method on each solution were requested with the
intention of using the three agreeing most closely for this report. In the following
table are given the average values and the maximum experimental errors observed.
The following analysts cooperated in the work. The corresponding
numbers are used in the table.
1. C. S. Robinson.
2. 8. L. Bandemer, Michigan Agricultural Experiment Station, E.
Lansing, Mich.
3. E. J. Miller, Michigan Agricultural Experiment Station, E. Lan-
sing, Mich.
4. O. B. Winter, Michigan Agricultural Experiment Station, E. Lan- —
sing, Mich.
5. E. E. Vanatta, University of Missouri, Columbia, Mo.
6. Swift & Co., Union Stock Yards, Chicago, Il.
7. R. D. Caldwell, Armour Fertilizer Works, Atlanta, Ga.
8. R. C. Charlton, 211 E. North Ave., Baltimore, Md.
DISCUSSION.
Ammonia.—The procedures used naturally divide themselves into two
groups: (1) Those involving the distillation of about 50 cc. of liquid
(Methods I and II); and (2) those in which approximately 150 cc. of
distillate were collected (Methods III and IV). The latter group corre-
sponds to the present official method!. Apparently Methods III and
IV give more concordant results. They are somewhat higher than the
1 Assoc. Official Agr. Chemists, Methods, 1920, 6.
388 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
first two, probably because of a more complete washing out of ammonia
from the apparatus by the larger volume of distillate.
Citric acid.—The question which was provocative of the present dis-
cussion was, however, the method of procedure for the determination
of the citric acid. In the work already referred to! it was shown that
Methods III and V checked each other and gave accurate results, while
the other methods gave values which were too high, although Method I
approached closely to the correct ones. These conclusions are sub-
stantiated by the results of the collaborative work. On all three solu-
tions the agreement between Methods III and V is good, while all other
results are higher in value. The conclusion from previous work that the
low results are the correct ones is verified by the figures for the ratio
of ammonia to citric acid on Solution C. This solution was prepared
Collaborative results on the analysis of ammonium citrate solutions.
CITRIC ACID (grams per liter).
ANALYST Meruop I Mersop I1 Mernop III Meruop IV MetHop V
grams | diff. grams | diff. grams | diff. grams | diff.
< 1 226.80 |0.80 ||235.90 |0.90 |/230.90 |0.20 229.00 |0.00
iS 2 230.58 |0.05 |/233.00 |0.64 |/229.45 |0.57 228.40 |0.00
a 3 230.96 |0.00 ||235.46 |0.96 |/230.35 |0.64 228.51 |0.32
a) 4 235.13 10.26 ||241.74 |0.44 |/238.60 |0.51 229.87 |0.00
oF 5 235.33 10.64 |1238.63 |0.96 ||229.76 |0.32 28.40 |0.00
6 230.74 |0.64 |/235.09 |0.95 |/228.68 |0.23 229.20 |0.00
if 231.67 |0.38 ||233.78 |0.32 ||231.54 |0.64 : 234.20 |0.32
8 227.44 10.51*|/229.55 |0.63*|/224.74 |0.00*!/231.36 10.64 |/226.34 |0.64
Average.. .|/231.08 |8.537|/235.39 |9.08 |/230.50 |13.86)/232.46 |9.23 ||229.24 |7.86
1 127.70 |0.70 ||137.00 {0.90 |/128.50 |0.70 ||133.00 {0.00 ||128.40 |0.40
faa) Ds 132.24 |2.57 |/135.00 {0.64 |/130.79 |0.51 ||131.84 |0.00 |/128.11 |0.16
5 3: 127.56 |0.71 |/133.39 |0.96 |/180.53 |0.34 |/132.52 {0.70 ||129.92 |0.00
Ss 4 143.574)/0.13 |/146.20 |0.76 |/130.58 [0.33 |/133.76 |0.00 |/128.70 |0.00
= 5 133.79 |0.52 |1138.74 |0.32 |}127.21 |0.98 |/1386.39 |0.00 |/129.45 |0.32
oa 6 131.43 |1.28 |/1385.42 |0.64*//128.05 |1.30 |/129.98 |0.00 |/128.80 |0.30
7 130.26 |0.77 |/135.90. |0.54 |}181.24 /1.50 |/1380.28 |0.00 ||134.55 |0.64
8 127.96 |2.52 ||128.70 |1.28*|/126.35 |0.64 |/130.03 |3.75 ||127.74 |0.64
Average.. .||130.14 |6.58 ||136.29 |7.50 |/129.16 |4.89 ||132.23 |6.41 ||129.46 |6.81
1 157.86 |0.20 ||165.80 |1.20 |}157.90 |1.50 |}161.05 |0.10 |/158.50 |0.20
Oo 2 161.32 |1.28 |/164.98 |0.98 |/162.02 |0.06 ||162.12 {0.00 |/158.31 |0.20
= 3 159.22 |0.12*||162.75 |0.32 ||162.76 |2.82 ||162.20 |1.00 ||159.69 {0.00
| 4 174.43}/0.39 |/176.171/0.69 ||162.12 |0.19 ||165.09 |0.97 |/158.47 |0.00
a) 5 165.32 |0.24 ||167.44 |0.64*1/157.63 |0.32 ||166.80 |0.64 |/160.98 |0.32
a 6 161.26 |1.03 |/164.55 |0.64 |}158.03 |1.59 |/159.58 |0.45 |/158.78 |0.00
7 162.15 |0.38 |/166.45 |0.00 |/161.65 |0.96 ||161.39 |0.45 |/164.53 |0.00
8 156.92 |0.77 ||158.79 |0.00 |/153.25 |1.29 ||160.29 |0.92 ||157.84 |0.64
Average... ||160.58 |8.40 |/164.39 |8.65 ||159.42 |9.51 ||162.32 |7.22 ||159.64 |6.69
1J. Ind. Eng. Chem., 1922, 14: 429.
1923] ROBINSON: NEUTRAL SOLUTION OF AMMONIUM CITRATE 389
Collaborative resulis on the analysis of ammonium citrate solutions—Continued.
AMMONIA (grams per liter).
ANALYST Mernop I Mertuop II Mernop III Metuop IV
grams | diff. grams | diff. grams | diff. grams | diff.
1 53.88 |0.05 || 53.65 |0.55 || 53.90 |0.00 || 52.87 |0.25
<< He 52.38 |0.04 || 52.73 |0.50 |} 52.88 |0.00 || 53.50 |0.19
a 3 52.72 |0.33 || 52.38 |0.51 || 53.29 |0.00 |} 53.23 |0.09
S 4 53.62 |0.04 || 53.35 |0.18 || 53.30 |0.09 || 53.54 |0.00
= 5 54.55 410.20 || 55.254/0.09 |} 55.311/0.08 || 54.734/0.08
ep) 6 53.51 |0.14 || 53.44 |0.43 || 53.80 |0.26 ||} 53.51 |0.09
a 53.86 |0.07 || 52.27 |0.77 || 53.18 |0.51 || 53.83 |0.17
8 53.47 |0.07 || 53.36 |0.34 || 53.83 {0.00 || 53.94 |0.17
Average...|| 53.35 |1.507|| 53.07 |1.38 || 53.45 |1.02 || 53.49 |1.07
1 34.26 |0.28 || 33.96 |1.18 || 34.37 |0.05 || 33.95 |0.10
= 2 33.45 |0.49 |} 33.16 |0.51 || 33.60 |0.19 || 33.45 |0.00
e 3 33.52 |0.34 || 33.44 |0.09 || 33.52 |0.09 || 33.40 |0.32
ce 4 34.16 |0.13 || 33.87 |0.10 || 34.23 {0.18 || 33.77 |0.21
io a 34.80 {0.08 || 35.14110.07 || 35.491/0.09 || 34.28 |0.08
a 6 34.09 |0.03 || 34.41 |0.34 || 34.41 |0.00 || 33.90 |0.00
7f 34.18 |0.27 || 33.05 |0.59 || 33.39 {0.34 || 34.28 |0.08
8 34.00 |0.14 || 34.13 |0.17 || 34.24 |0.00 || 34.24 |0.00
Average.. .|} 34.06 |1.35 || 33.72 |1.36 || 33.97 |1.02 || 34.16 |0.88
1 42.74 |0.31 || 41.56 |1.20 || 42.33 |0.18 || 42.23 |0.10
iS) 2 41.90 |0.38 || 41.86 |0.00 || 42.35 |0.00 || 39.224/0.18
iS 3 41.99 |0.10 || 41.53 |0.83 || 42.42 |0.17 || 41.81 |0.26
3S + 42.50 |0.21 || 41.84 |0.07 || 42.35 |0.04 || 42.43 10.32
= 5 43.451/0.48 || 43.554/0.09 || 43.411/1.36 || 42.64 |0.08
io) 6 42.27 |0.10 |} 42.53 |0.09 || 42.48 10.17 || 42.29 |0.14
7 42.26 |0.18 || 41.85 |0.34 || 41.99 {0.17 || 42.50 |0.17
8 42.36 |0.06 || 42.59 10.00 || 42.50 |0.17 || 42.59 |0.00
Average...|} 42.29 |0.84 || 41.97 |1.06 || 42.35 |0.51 42.36 |0.83
*Average of two determinations only.
+Maximum difference in grams by different analysts.
tOmitted from average.
by physical-chemical methods involving no analytical procedure, to
have the composition of a solution of triammonium citrate in which the
ratio of ammonia to citric acid should theoretically be 1:3.759. The
figures obtained by Methods III and V approach this ratio much more
closely than those secured by any other method, being 1:3.763 and
1:3.766, respectively, using the average values for ammonia obtained
by Methods III and IV.
THE COMPOSITION OF A NEUTRAL SOLUTION OF AMMONIUM
CITRATE.
In last year’s report the writer recommended “that a neutral solu-
tion of ammonium citrate be considered as one in which the ratio of
390 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
ammonia to anhydrous citric acid is as 1:3.794 +0.02, etc.” The selec-
tion of this figure was based upon the analyses of several carefully neu-
tralized solutions by the formaldehyde titration method, t. e., Method V
of the present report. These solutions were prepared in small quanti-
ties and with great care. Solution B used in this year’s work was pre-
pared by the colorimetric method, recommended last year, and amounted
to about twelve liters. It is interesting to note that the ratio of am-
monia to citric acid in this solution determined from the average figure
obtained by Methods III and V for citric acid and III and IV for am-
monia, representing the average of nearly fifty determinations is 1:3.795.
The limits of agreement with this value greatly exceed those permitted
by the recommendation, varying from 1:3.708 to 1:3.949 when the
extreme average values are used. Although the usual variation was
much lower than this it still embraces a range greater than the recom-
mended one!. The direct determination of the reaction appears, there-
fore, to be much more accurate as well as more simple than the indirect
one of determining the composition of the solution. In view of this
fact the associate referee favors eliminating from the original recom-
mendation the alternative method of adjusting the reaction by analysis.
RECOMMENDATIONS.
It is reeommended—
(1) That a neutral solution of ammonium citrate be considered as
one having a reaction corresponding to a pH of 7.0 +0.2.
(2) That that section of the official methods dealing with the prepara-
tion of neutral solutions of ammonium citrate? be changed to read as
follows:
REAGENTS.
In addition to the reagents described under 4 and 7 prepare ammonium citrate
solutions by the following method:
Ammonium citrate solution—For every liter of solution required dissolve 172.00
grams of anhydrous or 188.13 grams of crystallized citric acid in approximately 700 cc.
of water; nearly neutralize with ammonium hydroxide; cool; measure the volume of
the solution or make it up to a convenient volume, taking care to keep the density
above 1.09; make exactly neutral, testing as follows:
With a pipet transfer 5 cc. of the citrate solution to a test tube (7x% inches is a
convenient size) and dilute to 20 cc. with distilled water. Add from a dropping bottle
5 drops of a solution of phenol red indicator (0.08%), either an alcoholic solution of
the dye or an aqueous solution of its alkali salt being suitable. From a buret run in
dilute ammonia solution until the color approximates that of a standard buffer solution
having a pH of 7.0 contained in a similar test tube and with the same concentration of
indicator. (This solution may be prepared by mixing 50 cc. of 0.2M dihydrogen potas-
sium phosphate solution and 29.63 cc. of 0.2N sodium hydroxide solution and making up
1 The writer is investigating the causes for these errors and will report the results in a paper supple-
menting this report.
2 Assoc. Official Agr. Chemists, Methods, 1920, 4.
4993] PHELPS: REPORT ON NITROGEN [
to 200 cc., as recommended by Clark & Lubs!. Chemicals, especially purified for this pur-
pose, which can be procured from several supply houses, should be used and the standard
solution finally used should not have stood more than a few days unless some means
of checking its reaction are available.) Complete the process by adding the dilute
ammonia solution in small amounts and comparing the colors in a comparator’. From
the amount of ammonia solution required to produce in the sample a color which ex-
actly matches that of the standard, calculate the amount required to neutralize the
rest of the solution.
Add this calculated quantity of ammonia to the original solution and check its reac-
tion against that of the neutral standard, using the technique described above. If the
colors match dilute the solution to a density of 1.09 at 20°C.
REPORT ON NITROGEN.
By I. K. Puerps (Bureau of Chemistry, Washington, D. C.), Associate
Referee on Nitrogen in Fertilizers.
The instructions sent to collaborators for the study of the Devarda
alloy method varied slightly from those sent out last year’. To the
list of reagents was added sodium hydroxide solution—specific gravity
1.453 (42 per cent by weight). No change was made in the directions
headed Determination. Under the heading Experiments, Series I, the
time was changed so that in (A) 1 hour was used, (B) 1} hours, and in
(C) 12 hours; in Series II, 5 grams of potassium nitrate were used in
place of 4 grams. Series III was not changed; Series IV was changed
completely, the following directions being sent:
IV.—Repeat the series of experiments omitting the blanks, using the sample of
sodium nitrate. Retain solution of potassium and sodium nitrate for comparison of
results with the modified Kjeldahl-Gunning-Arnold method by H. C. Moore’.
The following directions were sent for the study of the Moore method:
REAGENTS.
(a) Salicyl-sulfonic acid—40 grams of salicylic acid are made up to 1 liter with
concentrated sulfuric acid.
(b) Sodium thiosulfate (hyposulfile) (hypo).—Commercial photographic, pea size.
(Cc) Potassium or sodium sulfate-—Preferably dry powder.
(d) Mercuric ovide.
(e) Caustic soda.—Dissolve 30 pounds of commercial caustic soda in about 2.5
gallons of water, let settle, and siphon off the clear solution. This strong caustic soda
is practically free from carbonate.
(f) Sodium sulfide—Dissolve 100 grams of fused sodium sulfide in water and dilute
to 1000 cc.
($) Pure granulated, or 20-or 30-mesh zine.—Pure zinc is essential as impure zinc
reacts so actively with the sodium hydroxide that the rapid evolution of hydrogen
1 J. Bact., 1917, 2: 26; W. M. Clarke. The Determination of Hydrogen Ions, (Baltimore), 76.
2 One made from a block of wood as described by Dernby and Avery, J. Exp. Med., 1918, 28: 348, serves
the purpose very well and can be made by any carpenter.
3 J. Assoc. Official Agr. Chemists, 1922, 5: 451.
4 J. Ind. Eng. Chem., 1920, 12: 669.
392 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
carries over by entrainment some free alkali, even when using the Hopkins connecting
bulb. This causes a variable blank. The Davisson bulb will prevent this entrain-
ment.
(h) 0.5N sulfuric acid solution.
(i) 0.2N or 0.1N sodium hydrozide solution.
(j) Sodium alizarin sulfonate—2 grams in 100 cc. of water.
DETERMINATION.
Transfer 0.5 gram NaNO, or KNO; preferably, to a 650 cc. Pyrex Kjeldahl flask;
add 35 cc. salicyl-sulfonic acid, preferably from a dispensing buret, rinsing down the
neck of the flask; warm over low heat or in boiling water or steam bath until reaction
begins, shaking frequently until solution is complete; add 5 grams hypo, heat over low
heat until frothing ceases (about 5 minutes), then add 10 grams sodium or potassium
sulfate, 1 gram mercury, and continue digestion until clear, and for one hour after-
wards, boiling briskly; cool; dilute with water to about 400 cc.; add a small pinch of
20-or 30-mesh zinc (0.1 gram), and 70 to 80 cc. caustic soda in which are dissolved
2 grams fused sodium sulfide. Sulfide may be added previous to adding the zinc and
NaOH. The ammonia is distilled and collected in 0.5N sulfuric or hydrochloric acid.
About 200 to 250 cc. distillates are sufficient, requiring about 44 to 34 hour. Use in
receiving flask a sufficient quantity of 0.5N acid diluted to 75 to 100 cc. with distilled
water and three drops of sodium alizarin sulfonate.
Alternate indicator.—A solution of cochineal is prepared by digesting and frequently
agitating 3 grams of pulverized cochineal in a mixture of 50 cc. of strong alcohol and
200 cc. of distilled water for a day or two at ordinary temperatures. Five cc. of the
filtered solution is employed as an indicator. This cochineal solution will keep in good
condition for use for about two weeks only.
DIRECTIONS FOR EXPERIMENTS COMPARING H. C. MOORE’S METHOD WITH THE DEVARDA
ALLOY METHOD.
Blanks I.—Prepare your reagents and conduct 5 determinations of the nitrogen in
the reagents used, following the directions given. Record the results in Series I as
obtained. (Do not round off the figures, or give averages.)
Series II.—Accurately transfer by means of the same pipet used in the Devarda
alloy work (see Series II under directions for Devarda Alloy Experiments) 25 cc. por-
tions of the potassium nitrate solution used in the experiments using a 650 cc. Kjeldahl
flask; place the flask on a steam or hot water bath and evaporate to dryness, and pro-
ceed according to the directions.
Series II1I.—Treat the solution of Series III, Devarda alloy method, exactly as
Series IT above.
Series IV.—Repeat Series III, above, except that the mercury is to be precipitated
in these experiments with 2 grams of sodium thiosulfate, Na»S.0;+5H.0O, dissolved in
25 cc. of distilled water.
Series IV-A.—Accurately weigh by difference in a glass-stoppered phial, approxi-
mately 0.5 gram of nitrate and transfer to 650 cc. Kjeldahl flask and proceed according
to the directions given for the Moore Method.
Series V.—Repeat Series II, III, IV, IV-A, using the sample of sodium nitrate and
record all results.
SUGGESTIONS.
It is recommended that the digestion be carried out over a free flame
(not a luminous flame). When adding the solution of sodium hydroxide,
1923] PHELPS: REPORT ON NITROGEN 393
it should be allowed to run down the side of the flask so that it collects
beneath the solution already present and is not mixed until the flask is
connected with the condenser when the flask is shaken. Collect the
distillate in a flask containing a measured quantity of standard acid
(hydrochloric or sulfuric), and a sufficient quantity of distilled water to
bring the solution above the glass end of the condenser, using an adapter,
fitted gas tight to the end of the condenser, if desired. The Davisson
scrubber is recommended for the connecting bulb for these determina-
tions. When other forms of connecting bulb are used or any modifica-
tion of the directions given, no matter how slight, please state in your
reply. Record all results.
It has been the experience of the Nitrogen Laboratory of this Bureau
that when free sulfur is present in a Kjeldahl distillation of ammonia,
sodium alizarin sulfonate and methyl red are troublesome indicators
but this is not observed with cochineal. If cochineal, however, is used,
the standard acid and alkali solutions should be restandardized, using
cochineal as an indicator, as in the actual determination of nitrogen.
The collaborators were as follows:
L. D. Haigh, University of Missouri, Columbia, Mo.
W. D. Richardson, Swift & Co., Chicago, IIl.
J. O. Clarke, Bureau of Chemistry, Savannah, Ga.
B. F. Robertson, Clemson Agricultural College, Clemson College, S. C.
Paul Rudnick, Armour and Co., Chicago, II.
Roy E. Neidig, University of Idaho, Moscow, Idaho.
G. A. Hopper, N. D. Agricultural College, Agricultural College, N. D.
. G. J. Noggle, Jarecki Chemical Co., Sandusky, Ohio.
. C. D. Garby, Fixed Nitrogen Research Laboratory, Washington, D. C.
. O. Olsen, Dairy & Feed Commission, St. Paul, Minn.
. D. Caldwell, Armour Fertilizer Works, Atlanta, Ga.
. J. Vollertsen, Morris & Company, Chicago, IIl.
. M. Bible, Read Phosphate Co., Nashville, Tenn.
. W. Kellogg, Department of Agriculture, Harrisburg, Pa.
. J. Patten, Agricultural College, E. Lansing, Mich.
By ni
- He
CON AW wN
Schmelzer, Armour Fertilizer Works, Chicago, II.
Pelot, Picatinny Arsenal, Dover, N. J.
. R. Austin, Tennessee Chemical Co., Nashville, Tenn.
. L. Prince, Experiment Station, New Brunswick, N. J.
20. F. B. Carpenter, Virginia-Carolina Chemical Co., Richmond, Va.
21. W. F. Hand, Mississippi Agricultural and Mechanical College, Agricultural
College, Miss.
22. J. G. Smith, Bureau of Soils, Washington, D. C.
23. J. F. Ellis, Bureau of Chemistry, Washington, D. C.
=
On
PARE PEONBP:
Tables 1, 2 and 3 give the results obtained by the collaborators and
Table 4 gives a summary of these results.
394 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
TABLE
Collaborative resulls on potassium nitrate
SERIES II (0.25 gram).
(Expressed as per
1 Hour 114% Hours 1144 Hours
COLLABORATORS
Highest. | Lowest | Average | Highest Lowest | Average |Highest | Lowest | Average
LS ee
1 13.72 | 13.58 | 13.65 | 13.81 | 13.81 | 13.81 | 13.77 | 13.56 | 13.66
2 13.80 | 13.72 | 13.77 | 13.83 | 13.81 | 13.82 | 13.77 | 13.74 | 13.76
3 13.59 | 13.46 | 13.55 | 13.58 | 13.58 | 13.58 | 13.63 | 13.57 | 13.61
4 13.82 | 13.75 | 13.77 | 13.85 | 13.82 | 13.83 | 13.82 | 13.75 | 13.80
5 13.82 | 18.81 | 13.82 | 13.81 | 13.72 | 13.77 | 13.83 | 13.80 | 13.82
6 13:78") 13.75" 1S-77 WS STE bei ay la Ake fon) Tae
7 13.84 | 13.72 | 13.76 | 13.84 | 13.72 | 13.78 | 13.76 | 13.72 | 13.75
8 13.82 | 13.66 | 13.77 | 13.82 | 13.66 | 13.77 | 13.82 | 18.62 | 13.75
9 13.77 | 18.72 | 13.75 | 13.85 | 13.82 | 13.84 | 13.79 | 13.75 | 13.76
10 13.40 | 13.20 | 13.33 | 13.40 | 13.04 | 13.28 | 13.60 | 13.44 | 13.52
11 13.52 | 18.52 | 13.52 | 13.64 | 13.20 | 13.41 | 13.59 | 13.51 | 13.54
12 13.93 | 13.73 | 18.81 | 13.97 | 13.69 | 13.86 | 13.97 | 13.88 | 13.93
13 13.71 | 13.51 | 13.64 | 13.66 | 13.62 | 13.65 | 13.66 | 13.36 | 13.52
14 13.65 | 13.53 | 13.60 | 13.65 | 13.41 | 13.52 | 13.53 | 13.41 | 13.46
15 13.64 | 13.60 | 18.61 | 13.72 | 13.64 | 13.67 | 13.76 | 13.64 | 13.71
16 13.76 | 13.74 | 18.75 | 18.71 | 13.69 | 13.70 | 13.80 | 13.79 | 13.80
17 13.75 | 13.17 | 18.45 | 13.86 | 12.41 | 13.35 | 13.88 | 13.62 | 13.80
18 13.64 | 13.60 | 13.63 | 13.72 | 13.68 | 13.71 | 13.72 | 13.68 | 13.69
19 13.75 | 13.73 | 13.74 | 13.80 | 13.77 | 13.79 | 13.71 | 13.69 | 13.70
20 13.49 | 13.32 | 13.43 | 13.55 | 13.48 | 13.51 | 13.60 | 13.49 | 13.53
21 13.93 | 13.72 | 13.84 | 13.93 | 13.72 | 13.86 | 13.86 | 13.72 | 13.81
22 13.87 | 13.87 | 13.87 | 13.87 | 13.71 | 13.80 | 13.87 | 13.82 | 13.85
23 13.81 | 18.81 | 13.81 | 13.81 | 13.80 | 13.81 | 13.84 | 13.66 | 13.74
TABLE
Collaborative results on sodium nitrate
SERIES II (0.25 gram).
(Expressed as per
1 Hour 1144 Hours 1144 Hours
COLLABORATORS Peau) ES ea Org eT VT ae
Highest | Lowest | Average | Highest | Lowest | Average |Highest | Lowest | Average
—— ee ey ey Se 8 OO
10 16.20 | 16.00 | 16.09 | 16.08 | 15.76 | 15.95 | 16.20 | 16.20 | 16.20
11 16.24 | 16.20 | 16.23 | 16.32 | 16.20 | 16.26 | 16.23 | 16.07 | 16.16
12 16.67 | 16.60 | 16.64 | 16.60 | 16.57 | 16.58 | 16.60 | 16.51 | 16.56
13 16.30 | 16.18 | 16.19 | 16.28 | 16.04 | 16.15 | 16.28 | 16.04 | 16.19
14 16.11 | 16.01 | 16.05 | 16.27 | 16.17 | 16.23 | 16.21 | 16.11 | 16.15
15 16.32 | 16.28 | 16.29 | 16.24 | 16.24 | 16.24 | 16.56 | 16.28 | 16.37
16 16.38 | 16.34 | 16.35 | 16.39 | 16.36 | 16.37 | 16.44 | 16.41 | 16.43
Lz 16.47 | 15.50 | 16.06 | 16.43 | 16.29 | 16.38 | 16.53 | 14.65 | 15.82
18 16.48 | 16.28 | 16.40 | 16.44 | 16.28 | 16.39 | 16.44 | 16.32 | 16.36
19 16.30 | 16.23 | 16.27 | 16.44 | 16.38 | 16.41 | 16.38 | 16.36 | 16.37
20 16.18 | 15.96 | 16.05 | 16.28 | 16.07 | 16.20 | 16.40 | 16.20 | 16.31
21 16.42 | 16.31 | 16.38 | 16.42 | 16.31 | 16.37 | 16.42 | 16.42 | 16.42
22 16.48 | 16.48 | 16.48 | 16.54 | 16.20 | 16.33 | 16.51 | 16.36 | 16.41
1923] PHELPS: REPORT ON NITROGEN 395
1
by the Devarda method.
SERIES III (0.50 gram).
cent of nitrogen.)
1 Hour 1144 Hours 14% Hours
Highest Lowest Average | Highest Lowest Average Highest Lowest Average
13.79 13.70 13.76 13.79 13.75 13.78 13.74 13.70 13.72
13.83 13.82 13.82 13.84 13.83 13.83 13.83 13.81 13.82
13.37 13.36 13.36 13.51 13.46 13.48 13.51 13.42 13.47
13.85 13.75 13.81 13.85 13.82 13.83 13.82 13.78 13.81
13.91 13.87 13.89 13.83 13.80 13.81 13.86 13.84 13.85
13.90 13.84 13.86 13.90 13.83 13.86 13.91 13.88 13.86
13.86 13.86 13.86 13.82 13.74 13.78 13.92 13.78 13.83
13.77 13.66 13.72 13.82 13.71 13.78 13.82 13.82 13.82
13.81 13.80 13.81 13.81 13.77 13.79 13.82 13.74 13.79
13.54 13.42 13.48 13.52 13.42 13.47 13.48 13.38 13.44
13.70 13.66 13.69 13.70 13.64 13.68 13.59 13.49 13.55
13.91 13.63 13.80 13.94 13.92 13.93 13.94 13.91 13.93
13.77 13.61 13.75 13.68 13.60 13.65 13.72 13.66 13.68
13.80 13.66 13.71 13.80 13.72 13.78 13.77 13.65 13.72
13.74 13.62 13.67 13.74 13.56 13.67 13.76 13.68 13.69
13.78 13.74 13.76 13.81 13.79 13.80 13.80 13.75 13.77
14.18 13.71 13.94 13.96 13.76 13.86 13.92 13.65 13.76
13.66 13.66 13.66 13.70 13.68 13.69 13.70 13.64 13.67
13.66 13.64 13.65 13.85 13.82 13.84 13.83 13.82 13.83
13.70 13.60 13.65 13.50 13.48 13.53 eer re 36 2
13.76 13.72 13.73 13.65 13.62 | 13.63 13.76 13.76 13.76
13.82 13.82 13.82 13.82 13.68 13.77 13.82 13.70 13.77
13.84 13.80 13.82 13.85 13.82 13.82 13.83 13.80 13.82
2
by the Devarda method.
SERIES III (0.50 gram).
cent of nitrogen.)
1 Hour 144 Hours 1% Hours
Highest Lowest Average Highest Lowest Average | Highest Lowest | Average
16.38 16.35 16.37 16.40 16.54 16.37 16.38 16.31 16.35
16.37 16.33 16.34 16.36 16.35 16.36 16.35 16.32 16.33
15.80 15.44 15.56 16.21 15.70 15.95 15.61 15.36 15.53
16.42 16.32 16.37 16.42 16.38 16.39 16.45 16.42 16.43
16.48 16.43 16.46 16.51 16.44 16.48 16.44 16.41 16.42
16.56 16.42 16.48 16.54 16.40 16.49 16.53 16.50 16.51
16.46 16.40 16.42 16.40 16.56 16.39 16.48 16.36 16.41
16.42 16.37 16.40 16.46 16.37 16.43 16.42 16.37 16.40
16.40 16.39 16.40 16.38 16.50 16.35 16.41 16.31 16.37
16.12 16.06 16.10 16.40 15.96 16.16 16.12 16.12 16.12
16.36 16.28 16.31 16.32 16.10 16.23 16.21 16.19 16.20
16.75 16.61 16.67 16.69 16.61 16.66 16.67 16.55 16.62
16.33 16.23 16.26 16.26 16.08 16.14 16.34 16.08 16.17
16.46 16.32 16.41 16.50 16.30 16.43 16.41 16.35 16.38
16.34 16.32 16.33 16.28 15.92 16.15 16.28 16.28 16.28
16.50 16.46 16.48 16.47 16.44 16.46 16.44 16.41 16.43
16.44 16.22 16.33 16.34 16.30 16.31 16.35 15.89 16.11
16.34 16.32 16.33 16.36 16.32 16.35 16.40 16.36 16.38
16.43 16.40 16.42 16.46 16.42 16.44 16.46 16.44 16.45
16.35 16.24 16.30 16.40 16.28 16.33 Pec Sane Eee
16.45 16.21 16.31 16.38 16.34 16.36 16.31 16.31 16.31
16.54 16.40 16.45 16.55 16.49 16.45 16.50 16.34 16.43
16.42 16.35 16.38 16.48 16.44 16.47 16.44 16.39 16.42
396 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
coL-
LABORATORS
Senies II
TABLE
Collaborative results by the
SODIUM NITRATE.
(Expressed as per
Serres III Series IV Series IV-a
High- | Low- | Aver- | High- | Low- | Aver- | High- | Low- | Aver-
est est age est est age est est age
OONIOMTPWHe
—_
a
ve)
—
lor)
S
(7)
—
lor)
iss)
eS)
1. Total average..........
ciel eye le] ew cs. wil eervel.c teil sleie si s)]\ ee) e)-e)s\ [age os) e)f'e| es) ©) je) him (s)) b/s <)h mise ante
2. es @yelito,c. 0 © .e'f, 0) 0s. a ),0) 1) 6) eye le: (ef, © ae! :e 01) oe, 0) (8? ath (a) ete: ) =) 6) ane ee eee eae
TABLE 4.
Summary of collaborative resulis.
2. Average of results me
scrubber
was used.....
3. Average of (2) omitting)
results of Collaborators
3 and 10
Total average
(Expressed as per cent of nitrogen.)
DEVARDA METHOD.
Series IT Serres III
1 Hr. 1144 Hr. | 1% Hr. 1 Hr. 1\% Hr. | 1% Hr.
KNOs.} 13.65 | 13.65 | 13.69 | 13.73 | 13.74 | 13.73
NaNO] 16.29 | 16.31 | 16.31 | 16.33 | 16.34 | 16.30
CNO;.| 13.68 | 13.68 | 13.71 | 13.75 | 13.76 | 13.75
NaNO;| 16.33 | 16.35 | 16.34 | 16.39 | 16.38 | 16.37
H. C. MOORE METHOD.
Serres II | Serres III | Serres IV | Serres [Va
ENO os) © 1d.5¢ 13.68 13.67 13.71
NaNO3.| 16.23 16.03 15.93 |- 16.28
Average, omitting results of vie ays 13.61 13.70 13.68 13.72
Jaborator 10
NaNQ3;.| 16.25 16.03 15.93 16.30
1923] PHELPS: REPORT ON NITROGEN 397
3
H.C. Moore method.
POTASSIUM NITRATE.
cent of nitrogen.)
Series II Series IIT Serres IV Serres IV-a
13.75 | 13.56 | 13.68 | 13.84 | 13.79 | 13.81 | 13.82 | 13.80 | 13.81 | 13.83 tas | 13.9
13.72 | 13.53 | 13.64 | 13.71 | 13.57 | 13.62 | 13.84 | 13.49 | 13.70 | 13.70 | 13.60 | 13.64
DISCUSSION.
Devarda method.—Under the conditions specified, including the
amounts of nitrate and the forms of apparatus, it is concluded that an
hour is sufficient time for distillation. An extension of the time of dis-
tillation to one hour and a half does not appear to give any positively
detectable difference. This conclusion agrees with the collaborative
results of a year ago in that it indicates that an hour is sufficient time.
Those collaborators using the Davisson scrubber obtain results slightly
higher and nearer the theoretical figure than those using other forms of
apparatus.
The H. C. Moore method.—The results for sodium and potassium
nitrates using 0.25 and 0.5 gram, respectively, are contradictory, the
sodium nitrate giving lower results consistently with 0.5 gram and the
potassium nitrate giving higher results. The substitution of sodium
thiosulfate as a precipitant for mercury apparently gives slightly lower
results. It is doubted if the differences noted above are proved to be
due to the differences in experimentation noted. The comparison of
the results for the dry nitrates and for the nitrates in solution is the
most striking of all the comparisons here made and is believed to be
significant. Sodium nitrate gives decidedly higher results for the dry
398 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
salt. Since this salt is hydroscopic, the inference is drawn that the
freedom from water or, in other words, the concentration of the sul-
furic-salicylic acid mixture is a critical condition in determining the com-
pleteness of the reduction of the nitrate. It is thought that this con-
clusion should be further studied with collaborators next year. It is
possible that the apparent differences mentioned above for sodium and
potassium nitrates in 0.25 and 0.5 gram amounts, and also for thio-
sulfate in place of sulfide may, in fact, be due to adventitious differ-
ences in the concentration of the sulfuric-salicylic acid mixture. Cer-
tainly the results obtained by the collaborators show too wide differ-
ences to be entirely satisfactory. If, however, the method can be made
to give more exact and dependable results, it can be recommended for
use. The technique of the method is so similar to that of the Kjeldahl
method that it appears to be worthy of further study.
Sodium thiosulfate as a precipitate for mercury in the Kjeldahl method.—
Commercial sodium and potassium sulfides are satisfactory in pure
condition for precipitants for mercury in the Kjeldahl method. They
also possess the advantage of cheapness. However, the impurity in
which they are commonly found and their tendency to oxidation pre-
sent conditions which are unfavorable to their use. Sodium thio-
sulfate, on the other hand, is reasonably cheap and presents the ad-
vantage of being relatively stable, both as a salt and in solution.
RECOMMENDATIONS.
It is recommended—
(1) That the referee for 1923 be instructed to study the Devarda
method as applied to the nitrates of commerce, as it is believed that the
collaborative work on pure nitrates has shown with sufficient definite-
ness the conditions which should be used.
(2) That the Moore method for nitrates be studied with collabora-
tors next year.
(3) That the Referee on Nitrogen for 1923 be instructed to study
the use of sodium thiosulfate as a substitute for sodium or potassium
sulfide in precipitating mercury in the Kjeldahl method.
1923] FOY: REPORT ON POTASH 399
REPORT ON POTASH.
DEVELOPMENT OF THE LINDO-GLADDING METHOD AND INVESTIGA-
TION OF OTHER METHODS FOR POTASH DETERMINATION BY
THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS.
By J. T. Foy (Clemson Agricultural College, Clemson College, S. C.);
Associate Referee.
It has long been known that the official Lindo-Gladding method does
not account for 100 per cent of the water-soluble potash, or for all the
potash probably available as plant food, especially in mixtures of acid
phosphate and potash. A method or process which will account for
all of this potash will be welcomed by all, and for the benefit of those
who may further investigate it is believed that a review of the pro-
ceedings of the A. O. A. C. in reference to investigations of methods for
the determination of potash in mixed fertilizers will be helpful. This
report will necessarily be largely a history of the Lindo-Gladding method,
with the changes made since it was brought before the association in
1886.
The first official method adopted corresponds closely with the present
optional method with the following exceptions: hydrochloric acid was
employed along with water in effecting the solution of potash; no oxalic
acid or ammonium oxalate was employed in the precipitation of the
lime; and two separate treatments with ammonium carbonate, accom-
panied by an additional filtration, evaporation and ignition’ were
necessary.
In 1885, H. W. Wiley reported the results of cooperative work carried
out under his direction and as a result the use of hydrochloric acid as a
solvent was discontinued.
The Lindo-Gladding method was compared with the official method
in 1886, and proving quite satisfactory it was used as an alternate
method. It was adopted as official in 1887, the former official method
being made an alternate method.
The association carried on the work of improving the official method
from year to year. A few minor changes were made, such as adding
ammonia to the solution before adding ammonium oxalate, and omitting
the use of sodium chloride just before the addition of platinic chloride.
The accuracy of the Lindo-Gladding method was challenged by
German authorities in 1893 when they made determinations by the
Stassfurt method on samples of mixed fertilizers forwarded by the asso-
ciation, claiming that the sulfuric acid, both free and combined, was
responsible for a considerable share of the assumed errors. In the
1U.S. Div. Chem. Bull. 57: 58.
400 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
Stassfurt method the sulfates were removed and the solution was made
with weak acid, the method as a whole not being applicable to mixed
fertilizers.
In 1893, N. Robinson! found that noticeable losses of potash were
shown by the official method. The chief source of error arose from the
occlusion of potash salts by the heavy precipitates formed by addition
of ammonia and ammonium oxalate, or to some potash forming an
insoluble compound with silica or other substance present. Small
losses were attributed to the alcohol washings and to the solvent action
of ammonium chloride solution on the precipitate. Few analytical
methods give a precipitate absolutely insoluble in the wash liquid.
The present method for potash salts was adopted in 1897; this method
called for direct evaporation of the water solution without addition of
ammonia or ammonia oxalate.
The failure of the Lindo-Gladding method to obtain all the potash
soluble in water, especially from mixtures of acid phosphate and potash
was realized and, in 1900, F. B. Carpenter suggested that the addition
of 5 to 10 grams of ammonium chloride to the weighed sample might
aid in securing solution of all potash present. The association found
that this did increase the potash 0.07 per cent, but the large amount of
ammonia salts left after evaporation with sulfuric acid is a disadvantage,
as it might cause sputtering.
The association investigated the method by C. L. Hare? in which
“milk of lime’’ was substituted as the precipitant for phosphates, iron,
alumina, etc., in place of ammonia and ammonium oxalate, which
eliminated the evaporation to expel ammonia, thus avoiding the probable
loss of potash during evaporation. This method proved to be rapid,
but trouble was encountered in washing the final precipitate due to the
large amount of lime, etc. When organic matter is present the sample
is ignited with dilute sulfuric acid, which was an objection, especially
in States that require the potash to be soluble in water. Further experi-
ments were made in the hope of finding a method that would dissolve
all the potash in mixed fertilizers. The theory was advanced that
sodium salts are occluded before those of potash; consequently sodium
hydrate was used instead of ammonia. This was followed by some work
done by F. B. Carpenter who showed that an average of 0.3 per cent
potash was occluded in the heavy precipitate formed by addition of
ammonia and ammonium oxalate, and that the occlusion was not due
to formation of insoluble potash compounds. It was suggested that
5 ec. of hydrochloric acid be added when making the solution, that it
be neutralized with sodium hydrate, and that powdered ammonium
oxalate be added. The results by this modification were very gratify-
1 J. Am. Chem. Soc., 1894, 16: 364.
2U.S8S. Bur. Chem. Bull. 73: 38.
1923] FOY: REPORT ON POTASH 401
ing, the amount of potash found very nearly approaching the theoretical.
It was recommended that these changes be made in the official method,
but, in 1905, by a vote in which chemists in charge of fertilizer con-
trol were the only qualified voters, the recommendation was lost, due
principally to laws that existed in twenty-seven states which required
the potash to be soluble in water. It was agreed, however, that this
small amount of acid in the water solutions, while not liberating any of
the insoluble forms of potash, would liberate any occluded potash in
the substance which would be available to plant food. The associa-
tion appointed a committee to define “available potash’, but the report
of this committee could not be found in the records.
The volumetric estimation of potash as phosphomolybdate, proposed
by M. G. Donks, was suggested as affording a possible means of re-
covering all the potash in mixtures containing acid phosphate and
potash. The association worked on this method and modifications of
the method for three years and in 1908 recommended that further work
be discontinued for the time being, in order to take up the cobalt-nitrite
volumetric method, as modified by Drushel'. This method gave closer
agreement with the official method than did the phosphomolybdate
method. This work was discontinued in 1910. The gravimetric
cobalt-nitrite method was also tried out.
In 1908 the use of ammonia and ammonium oxalate was employed in
the determination of potash salts. Lower results were reported, which
tended to prove the contention of some that potash is occluded in the
precipitate formed.
One of the most important changes made was the adoption of Brecken-
ridge’s? modification of the official method in 1912, which provided for
the washing of a weighed amount of sample through filter paper with
hot water to a volume of about 200 cc. and in case of mixed fertilizers,
adding 2 cc. of hydrochloric acid and heating to boiling, ammonia and
ammonium oxalate being added and potash determined in the usual way.
In 1917 the addition of 2 cc. of hydrochloric acid was eliminated.
The perchlorate method was first studied in 1912 and, with various
improvements and modifications, including the barium hydroxide pro-
cess and the modification of the De Roode moist combustion perchloric
acid method by Keitt and Shiver’, was before the association continually
until 1920.
Moore and Caldwell‘ have shown that higher results can be obtained
by using stronger alcohol for the first washings in the official method,
owing to a solvent effect of the 80 per cent alcohol or to the presence of
sodium salts in the alcoholic solution. Hazen also finds that stronger
2 tnd ek Ghee. 1909-1: 409, 804.
3 [bid., 1918, 10: 219; 1919, 11: 1049.
4 Tbid., 1920, 12: 1188.
402 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
(90 per cent) alcohol gives higher results!. Robertson and McDonnell,
in 1904, found there was no material difference in results in the use of
95 per cent alcohol and 80 per cent alcohol in washing the precipitate.
This question is still before the association.
The centrifugal method by Sherrill? is now before the association, but
it is the writer’s opinion that this method is not suitable as an official
method. but is applicable where a quick approximate potash determina-
tion is required as in factory control.
This review shows that the Lindo-Gladding method has constantly
been before the association, and such chemists as Wiley, Ross, Car-
penter, Hare, Fraps, Breckenridge, Jarrell and others have contributed
to its improvement and development.
It is today the best method available for potash in mixed fertilizers,
and except for the loss of a small amount of potash due to occlusion,
especially in mixtures of acid phosphate and potash and the probable
loss due to the solubility of the precipitate in 80 per cent alcohol, it
would be above criticism. The loss by occlusion is partly compensated
for by the decreased volume of the supernatant liquid caused by the
heavy precipitate. This error could in some cases be avoided by the
addition of a small amount of hydrochloric acid to the wash water,
especially in mixtures of acid phosphate and potash. This change, of
course, would conflict with the existing laws in some States, which call
for water-soluble potash only. If future results warrant this change,
it is possible that the different State fertilizer boards of control could
have those laws modified to suit the conditions.
RECOMMENDATIONS.
It is recommended—
(1) That investigation of the centrifugal method by Sherrill be dis-
continued.
(2) That a further study of the use of stronger alcohol for first wash-
ings of the precipitate as suggested by Moore and Caldwell be continued.
(3) That the use of weak acid in making the solution in mixtures of
acid phosphate and potash be investigated.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 456.
2 Tbid., 1921, 13: 227.
1923] HUSTON: ALCOHOL USED IN OFFICIAL POTASH METHODS 403
SUMMARY RELATING TO STRENGTH AND KIND OF ALCO-
HOL USED IN OFFICIAL POTASH METHODS, 1884-1921.
By H. A. Huston (Soil and Crop Service of the Potash Syndicate,
42 Broadway, New York, N. Y.).
A. As printed in official or provisional methods.
B. Recommendations by reporter or referee.
C. Suggestion or comment by member of association.
D. Recommendation or comment by other chemists.
1884.
A—Atlanta Meeting, May: 95 per cent alcohol.
A—Philadelphia Meeting, September: strong alcohol (80-95 per cent),
more alcohol.
1885.
A—85 per cent alcohol followed by 5 cc. of ether.
C—W. C. Stubbs! stated he used 95 per cent alcohol + 1% its volume
of ether.
D—T. S. Gladding’, in the proposed Lindo-Gladding method, used
for superphosphates alcohol and ammonium chloride solution, followed
by chemically pure alcohol.
1886.
Bre : superphosphates—alcohol, pure alcohol.
i Oe oene ce and kainite—alcohol, alcohol.
Alternate method—strong alcohol, strong alcohol, 5 cc. of ether.
B—W. J. Gascoyne? recommended alternately strong alcohol, 5 ce.
of ether, ammonium chloride solution, alcohol, 5 cc. of ether.
1887.
“use : superphosphates—alcohol, pure alcohol.
A—Lindo-Gladding ae and kainite—alcohol, alcohol.
Alternate—strong alcohol, strong alcohol.
1888.
A—Same as in 1887.
B—Reporter states New Jersey Station uses 80 per cent alcohol in
Lindo-Gladding method.
1889.
A—Same as in 1887.
1U. S. Bur. Chem. Bull. 7: (1885), 25.
2 Tbid., 40.
3 Tbid., 12: (1886), 51.
404 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
1890.
A—Lindo-Gladding—same as in 1887.
Alternate—strong alcohol.
1891.
A—Lindo-Gladding—same as in 1887.
Alternate—80 per cent alcohol, strong alcohol, 5 cc. of ether.
1892.
A—Same as in 1891.
1893.
A—Same as in 1891.
1894.
A—Use of ether struck out; otherwise same as in 1891.
1895.
A—AIll alcohol to be 80 per cent.
B—H. J. Wheeler! recommended 80 per cent alcohol for all. Adopted.
C—F. P. Veitch? suggested one strength alcohol instead of 80 per
cent and ordinary alcohol.
1896-1901.
A—80 per cent alcohol.
1902.
A—80 per cent alcohol.
D—G. W. Lehmann? reports comparison of 95 per cent alcohol with
80 per cent followed by ammonium chloride solution, the latter giving
low results.
1903.
A—80 per cent alcohol.
C—C. C. McDonnell‘ used 95 per cent alcohol for final washing on
official samples.
1904.
A—80 per cent alcohol.
C—J. W. Kellogg® says he had difficulty in dissolving sodium chloro-
platinate (NazPt C1.) in 80 per cent alcohol.
1U.S. Bur. Chem. Bull. 47: (1895), 23.
2 [bid., 18.
8 fhid., 73: (1902), 33.
4 [bid., 81: (1903), 127.
5 Tbid., 90: (1905), 111.
49233) HUSTON: ALCOHOL USED IN OFFICIAL POTASH METHODS 405
1905-1910,
A—80 per cent alcohol.
1911.
No report.
1912.
A—80 per cent alcohol.
C—C. Beatty! compared “‘denatured.’ alcohol with ordinary alcohol.
No difference.
1913.
A—80 per cent alcohol.
B—Reporter states results using “denatured alcohol commercial”’ are
comparable with ethyl alcohol, when used in same strength, and asks for
trial of it.
1914.
A—80 per cent alcohol, sp. gr. 0.8645-15/15. This is 80 per cent by
volume. Denatured alcohol, Formula 1, may also be used after dilution
with water to make 80 per cent by volume.
B—Recommended denatured alcohol as under A.
C—HE. E. Vanatta? reports losses in 3 washings with 80 per cent alco-
hol—50 cc. portions—1.8 to 6.2 milligrams. A. L. Gibson’ reports very
little difference between 80% denatured and 80% ethyl] alcohol.
1915.
A—80 per cent by volume.
C—P. L. Hibbard! thinks alcoho! stronger than 80 per cent should be
used.
1916-1919.
A—80 per cent by volume.
1920.
A—80 per cent by volume.
B—No report in proceedings.
D—Caldwell & Moore® presented paper on varying the strength of
alcohol in Lindo-Gladding method. It would seem that the results
reported, which overran the theory, might be accounted for by in-
sufficient washing (only 3 times) before using the ammonium chloride
solution.
1 U.S. Bur. Chem. Bull. 162: (1913), 20.
ae uae Official Agr. Chemists, 1914, 1: 407.
4 Thid., 1917,
5 J. Ind. Eng. ifaed 1920, 12: 1188.
406 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
1921.
A—80 per cent by volume.
B—Recommendation of the previous year that strength of alcohol
be studied, repeated.
C—William Hazen! compared 80, 90, and 95 per cent alcohol. Recom-
mended that 90 per cent be used for first, and 80 per cent for final wash-
ing.
Solubility of K2PtCl, in Alcohol.
Soluble in 42,500 parts absolute alcohol (Precht)?.
Archibald, Wilcox and Buckley? give results of extensive experiments,
from which it is seen that 100 grams of saturated solution of K.PtCl,
in ethyl alcohol, 70 per cent by weight, contain 0.0128 gram; 80 per
cent—0.0085 gram; 90 per cent—0.0025 gram; and 100 per cent—
0.0009 gram.
Peligot* gives 80 per cent—0.05 gram; 90 per cent—0.02 gram.
Solubility of K2PtCls and NazPtCl, in Alcohol.
Bulletin 43° states:
One liter of 90 per cent alcohol contains 0.03 gram K.PtCl, and one liter of 60 per
cent alcohol dissolves 110 grams Na»PtCl.; one liter 95 per cent alcohol dissolves 22
grams Na2PtCl..
Precht (Comey)* NazPtCl, more soluble in absolute alcohol than in
95 per cent alcohol. Saturated solution in absolute alcohol contains
11.90 per cent; in 95 per cent alcohol, 6.34 per cent.
Solubility of Ammonium Chloride in Ethyl Alcohol (Comey).
One hundred parts, sp. gr. 0.872 (75.35 per cent by volume), dissolves
4.75 parts; 100 parts, sp. gr. 0.834 (88.55 per cent by volume), dissolves
1.5 parts; 100 absolute dissolves 0.62 parts at 19. Ten cc. of mixed
alcohols containing 10.40 per cent methyl and 89.60 per cent ethyl
alcohol dissolve 0.0658 gram of NH,Cl.
MgPtCl,+6H:0 solution in absolute alcohol.
BaPtCl,+6H.O. Decomposed by alcohol.
MgCl,+6H.O much more soluble in strong than in dilute alcohol.
MgS0O.+7H:,0 100 parts absolute alcohol dissolve 1.3 parts at 0.
Hubbard’ published an extended article on potash determination,
1 J. Assoc. Official Agr. Cee: 1922, 5: 456.
2 Z. anal. Chem., 1879, 509.
LIP ie ier "Soc. to08, 30: 747.
‘ Ibid.,
5U.S. Ben Chem. Bull. 43: (1894), 229.
6 Comey-Hahn, a Dictionary of . hemical Solubilities—Imorganic, 2nd ed. 1921.
7 J. Ind. Eng. Chem.., 1917, 9: 50
1923] GORDON: AVAILABILITY OF POTASH IN MIXED FERTILIZERS 407
with bibliography. He shows that K2PtCl, is about four times as
soluble in 80 per cent alcohol as in 95 per cent. He states that only a
slight excess of platinum solution (not enough to form Na2PtCl,) should
be used, because of the slow solubility of Na2PtC1, in alcohol.
No report on potash availability was made by the associate referee.
AVAILABILITY OF POTASH IN MIXED FERTILIZERS.
By N. E. Gorpon (Chemistry Department, University of Maryland,
College Park, Md.).
The paper, “The Determination of Potash in Mixed Fertilizers’,
by F. B. Carpenter, given before the American Chemical Society at
Pittsburgh, September 5-8, 1922, prompted the writer to make this
report. After giving the history of the development of the potash
determination in mixed fertilizers, Carpenter! points out the necessity
of finding some method in the analysis of mixed fertilizers that will
show the same amount of potash derived from the salts readily soluble
in water as was employed in the formula. He says in part: ““The cause
of low results has never been explained, but in the investigation of the
writer, a part of the potash seemed to be occluded or retained in the pre-
cipitate which results from the addition of ammonia and ammonium
oxalate’. He says further: ““The low results in some cases may be
accounted for by some slight fixation of the potash, but if such were the
case, it is not strongly held and in all probability is available for plants”’.
No work with this particular problem in mind has been done, but the
investigations on colloids during the past two years at the University of
Maryland would indicate that Carpenter’s assumptions are partly cor-
rect. Two points may well be discussed: (1) The cause of the low results
in determining the potash in mixed fertilizers; and (2) the availability
of the unrecovered potash.
THE CAUSE OF LOW RESULTS.
The low results in mixed fertilizers might be due to the colloids of
ferric oxide and alumina. When the rock phosphate is treated with
sulfuric acid the iron and aluminum are partially converted into soluble
compounds, as can be shown by testing the filtrate in the potash determi-
nations. At the high temperature at which this treatment is carried
out these compounds rapidly undergo hydrolysis, forming gels of
alumina and iron oxide; silica gel also is undoubtedly formed. The
alumina and iron oxide gels act as fairly strong adsorbents for potassium
salts as the following table shows:
1 Science, 1922, 56: 695; Am. Fertilizer, 1922, $7: 55.
408 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
TABLE 1.
Adsorption of potassium from 0.1N solutions by hydrogels.
GEL USED POTASSIUM ADSORBED PER GRAM OF GEL
K4S0,4 KH-PO, KNO;
mg. mg.
Silica Aw eases 0.42 0.05 None
Alnamingy fc see 9.2 74.3 None
Ferric oxide........ 4.0 107.2 None
It is noted that ferric oxide and alumina take up an appreciable amount
of the potassium while the amount taken up by the silica may be neg-
lected. Therefore, if either of the last two gels is present in the rock
phosphate it is reasonable to suppose that a certain amount of potas-
sium may be adsorbed.
Whether or not all this potassium can be washed out of the gel is
questionable. Leaching out the phosphate has been tried, and it was
found that when about six liters of water had run through, only one-
half to one-third of the phosphate had been washed out, and the rate at
which it was being leached at this time was almost unappreciable (0.3
milligram in 50 ce. filtrate).
TABLE 2.
Amount of phosphate radical left in the gels after washing with 6000 cc. of water.
PO, IN ALUMINA GEL PO, IN IRON GEL
gram gram
Before washing........... 0.3142 0.5788
After WASHING ie. cece erc 0.2308 0.2688
The potassium in the residue was not determined, but it is believed
from results of later pot experiments that it was present in a quantity
equivalent to that of phosphorus.
AVAILABILITY OF UNDETERMINED POTASH.
That unrecovered potash in mixed fertilizers may be available for
plant use is indicated by the following pot experiment. The hydrogels
of iron and alumina were allowed to attain maximum adsorption in a
solution of potassium acid phosphate. They were then subjected to
leaching with water until there was scarcely any reaction obtainable in
the filtrate for the phosphate radical (used because of its delicacy).
Portions of the gels showed on analysis a composition similar to that
given in Table 2. These gels were then mixed with sand which was free
from both potassium and phosphate. Sweet potato seedlings were
planted in the mixtures. After these plants had been allowed to grow
1923] TURNER: VOLUMETRIC DETERMINATION OF PHOSPHORUS 409
for eight weeks, they were analyzed for potassium and checked with a
control plant. The gains in potassium are shown in Column 3 of Table 3.
Column 4 gives the percentage of the total potassium used by the plant
in eight weeks, while Column 2 gives the gain in weight.
TABLE 3.
Availability of unrecovered potash.
INCREASE IN INCREASE OF POTASSIUM
GEL USED WEIGHT OF POTASSIUM TAKEN FROM
PLANT IN PLANT THE GEL
per cent per cent per cent
1 Ii Tile calls Oba een aes en 263 129 63.3
Alama yes POR es 2s 227 150 71.0
These results show that if mixed fertilizers contain colloids of ferric
oxide and alumina, it is possible for the potash determinations to be
low, and still for the unrecovered potash to be available for plant use.
No report on precipitated phosphates was made by the associate
referee.
THE VOLUMETRIC DETERMINATION OF PHOSPHORUS.
By W. A. Turner (Bureau of Animal Industry, Beltsville, Md.).
Experiments conducted to test the reliability of the Pemberton volu-
metric method for phosphorus have given results uniformly higher
(about 8 per cent) than those obtained by the gravimetric method.
These experiments were conducted on a solution of purified sodium
phosphate and on samples of blood, plasma and urine. These results
would correspond to a composition for ammonium phosphomolybdate
such as that given by Hundeshagen?, (NH;); POs-12 MoO;-2HNOs,
and are in agreement with results obtained by recent investigators
(Marchand’, Vogel‘). It is not thought, however, that the formula of
Hundeshagen represents the true composition of the precipitate. It is
thought, rather, that the precipitate consists of an acid ammonium
phosphomolybdate, (NH.)2 HPO, .12M0O; or NHsH2PO.. 12Mo00Os,
together with a certain amount of occluded molybdic acid (Baxter*), the
combined effect of which will account for the 8 per cent error observed.
The error is constant and on this basis a new factor can be calculated
which may be applied with very satisfactory results.
1 Abstract of a paper presented before the meeting of the American Chemical Society in September,
ag y The eel ea ait be published later in the Journal of the American Chemical Society.
3 Chem. Abstracts, 1919, 13: 9722: 1921, 15: sanee S. African J. Sct., 1918-19, 15: 357.
4 J. Soc. Chem. Ind., (Trans.), 1922, 41: 12
5 Am. Chem. J., 1902, 28: 298; Baxter and ‘Griffin, Am. Chem. J., 1905, 34: 204.
410 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
A NEW FERTILIZER SAMPLING TUBE.
By L. D. Haicu (University of Missouri, Columbia, Mo.).
The Association of Official Agricultural Chemists, at the meeting of
November, 1919, recommended certain directions to be followed in
obtaining a sample of fertilizer for analysis. Among these is the recom-
mendation that a sampler be used which removes a core from the bag
from top to bottom.
Of samplers of this type, perhaps the Indiana double-tube sampler is
best known. This consists of two tubes, one inside the other. The
wall on one side of the two tubes is cut away to form a long groove-like
opening through which the tube is filled after insertion in the sack. By
turning the inside tube to one side the opening is closed. The closed
sampler is inserted into the sack; it is then opened with the openings
upward. After shaking the sack to fill the tube, the sampler is closed,
withdrawn, and emptied.
sy eo
Slotted Tube
Core Red,
Recently a sampler was described by J. W. Kellogg! of the Pennsyl-
vania Department of Agriculture. This sampler removes a core by
boring down into the sack, the lower end being open so that the fertilizer
enters as the sampler is inserted. A number of openings along the side
assist in removing the sample from the tube after withdrawal. When
not in use this sampler can be separated into two parts by unscrewing
a joint near the center, placed in an ordinary suit case and carried from
place to place. The writer has not actually worked with this sampler
but from experience certain difficulties with its use might be anticipated.
Among these is the probability that contents of the sack will enter at
the side openings as well as at the end, both when being pushed into,
and withdrawn from, the sack.
In a recent number of this Journal’, the writer published a descrip-
tion of the sampler used in the fertilizer inspection work in Missouri,
together with comparison of results of analysis of samples obtained with
this sampler and with the Indiana double-tube sampler. In this article
it was stated an effort was being made in Missouri to adapt the idea of
the double-tube sampler to the Missouri sampler. As a result of differ-
1J. Ind. Eng. Chem., 1922, 14: 631.
2 J. Assoc. Official Agr. Chemists, 1921, 4: 597.
1993| HAIGH: A NEW FERTILIZER SAMPLING TUBE 411
ent trials a new form of sampler is now in use which is free from the
mechanical difficulties of the double-tube sampler and which obtains,
with equal efficiency, a representative sample from the sack from top
to bottom.
This new sampler consists of two parts: (1) A brass tube 301% inches
long and approximately 11-32 inches inside diameter and 1% inch out-
side diameter; (2) a solid brass rod fitting into the brass tube as perfectly
as possible and yet sliding in and out with slight pressure.
One end of the tube is fitted with a piece of solid-brass rod ground to
a point; the other end has a cylindrical wooden handle 3 inches long and
134 inches in diameter. Three longitudinal slots, 14 inch in width
lying end-to-end along the tube, permit the material in the sack to enter
during the operation of drawing the sample. The length of the brass
tube from the end of the handle to the solid pointed end is 32 inches.
The solid-brass core-rod is also provided with a handle; this is a solid-
brass cylinder, 11% inches long and 1% inches in diameter. The length
of the core-rod (approximately 311% inches over all) is such that when
inserted in position in the tube the lower end rests upon the solid-brass
point of the brass tube, while the handle of the rod is still 1/16 inch from
the handle end of the brass tube. In using the sampler the core-rod is
placed in the tube; the point of the tube is then inserted into the top of
the sack and the sampler, groove down, is pushed in by exerting pressure
on the solid brass handle of the core-rod. If the sampler can not readily
be pushed in by hand, it may be driven in by blows with a block of wood
or mallet. The core-rod is now withdrawn completely from the tube
without twisting, and the tube is rotated in the sack 180 degrees, or
until the groove faces upwards. By tapping on the sack above the
sampler the tube is readily filled with a part of the contents of the sack.
The tube is now withdrawn, the operator holding a finger over the groove
to push away any fertilizer which has piled upon the groove above the
edges. The contents of the tube are turned out on a sheet of paper,
after which the tube is held vertically and tapped a few times to remove
all particles from the inside. The core-rod is now replaced and the
sampler is ready for the next sack.
The contents of this tube are such that after ten sacks have been
sampled the material obtained from the tube amounts to one pound or
more. This is transferred to a suitable container for transportation to
the laboratory.
As mentioned in the previous article, the double-tube sampler is sub-
ject to some difficulties in practice. The attempt to rotate the two tubes,
one inside the other while inserted in a sack of fertilizer, causes fine
material to work into the space between the tubes which at times become
immovable before the sampler is opened wide. If, however, the tube
opens without much difficulty, it is often impossible to close it after
412 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
filling. In the sampler just described—the center rod being withdrawn
longitudinally—the fine material does not work into the space between
the tube and the rod.
The experience of the writer tends to prove that with a sampler closed
longitudinally it is immaterial whether the tube is closed on the side
when withdrawn from the sack. If the tube has been filled before
withdrawing, no more material can enter by rubbing against the side
because there is no‘other opening from which material can be pushed
out by this pressure from the sides. (This, in the writer’s opinion, con-
stitutes a serious defect in the tube described by Kellogg.) It is obvious,
however, that when an open sampler is inserted into a sack, some ma-
terial will enter the sampler before it is in its final position. It seems
necessary, therefore, for best results, that the sampler be closed when
inserted. This suggests at once that the double-tube sampler may be
altered by substituting a solid rod for the inner tube. The rod may
then be withdrawn when the operator is ready to fill the tube.
The core-rod adds considerable rigidity to the sampling tube, and
since the pressure is exerted upon the solid pointed end, the tube is
dragged rather than pushed into the sack, thus preventing any tendency
to bend the sampling tube out of shape.
H. S. Bailey: For several years the American Oil Chemists Society
has been distributing to its members and others interested samples of
cottonseed and other feed meals for collaborative analysis. This work
originally called the “‘check meal work’’ of the society is now known as
the Smalley Foundation, in honor of the late Dr. F. N. Smalley who
gave so generously of his time to make it a success.
This year 30 samples, at the rate of one each week, are being dis-
tributed to approximately 75 collaborators. 'These samples are analyzed
for moisture, gasoline soluble material and ammonia, and the results
are reported to H. C. Moore, Chief Chemist of the Armour Fertilizer
Works, Chicago. Mr. Moore compiles the results and calculates what
is known as the ‘‘accepted average” for percentage of oil and ammonia
on each sample every week and sends a printed report to each analyst.
The accepted average is not the arithmetical average but a weighted
mean of all results except those obviously incorrect.
This checking up every week of the 75 or more laboratories interested
in the analysis of feeds and fertilizers has, in the last four years, resulted
in a marked improvement in the agreement of results. A silver cup and
several certificates of accuracy are awarded every year to those making
the highest standing throughout the season. This competitive feature
is not the aim of the work; it is merely to add interest.
While the samples cost the members of the Oil Chemists Society
$15 a year they are available to all official laboratories without charge,
1923] HAIGH: A NEW FERTILIZER SAMPLING TUBE 413
the only requirement being that those accepting the samples make at
least one of the determinations, oil or ammonia, each week and report
their results to the chairman. Since petroleum ether instead of ethyl
ether is recognized as the official solvent by the American Oil Chemists
Society some of the State chemists who are already availing themselves
of the samples report only moisture and ammonia. ‘There is no required
procedure for the determination of ammonia but the majority of the
analysts use the mercury method.
On Sample No. 7 of this year’s series which contained 6.72 per cent of
ammonia, according to the accepted average, the seven State and experi-
ment station chemists who reported varied from this average +0.03
per cent, —0.15 per cent, —0.04 per cent, +0.06 per cent, —0.02 per
cent, 0.00 per cent, and —0.02 per cent. On this same sample seven
laboratories of one of the large oil companies deviated from the average
value by —0.01 per cent, 0.00 per cent, —0.02 per cent, —0.01 per cent,
—0.00 per cent, —0.03 per cent, and +0.06 per cent.
As a concrete example of the value of these samples to the individual,
the progressive increase in accuracy of a chemist in one State laboratory
may be cited. On Sample No. 1 this chemist was 0.11 per cent low on
ammonia; on Sample No. 2, 0.19 per cent low; on Sample No. 3, 0.36
per cent low; on Sample No. 4, 0.18 per cent low; on Sample No. 5,
0.39 per cent high; on Sample No. 6, 0.04 per cent low; on Sample No. 7,
0.15 per cent low; on Sample No. 8, 0.06 per cent low; and on Sample
No. 9, 0.05 per cent high.
While the names of the chemists are not reported with their results,
merely their assigned numbers being given, each collaborator is sup-
plied with a key to these numbers and so can check himself with any
other collaborator as well as with the accepted average. The results
are not published in any journal nor are they intended for general in-
formation, but obviously among the collaborators the standing of any
one laboratory is to some extent judged by the accuracy of its reported
figures.
Either H. C. Moore or I will be very glad to see that sets of these
samples are sent to any State or Federal laboratory that cares to have
them and is willing to have its results printed with those of the other
collaborators.
414 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
REPORT ON INORGANIC PLANT CONSTITUENTS.
By A. J. Parren (Michigan Experiment Station, E. Lansing, Mich.),
Referee.
In carrying out the work under this subject for the past year, the plan
of preceding years has been followed. The determination of sulfur
and phosphorus in seeds has been handled by the associate referee, W. L.
Latshaw, Manhattan, Kansas, and the work on the determination of
iron and aluminium, calcium and magnesium has been conducted by
the referee.
Owing to the wide difference in character between the ash of seeds and
roughage materials, such as hays and straws, a tendency to adopt differ-
ent methods for the two classes of materials has developed. This has
resulted naturally, since methods adapted to the latter class of materials
may not be adapted to the former; at least this is true as far as the present
official methods for iron and aluminium, calcium and magnesium are
concerned. However, if the future collaborative work on these methods
bears out the conclusions drawn from the results obtained this year, one
set of methods will serve for both classes of materials.
It is suggested, therefore, that the incoming referee make a study of
the entire chapter on Inorganic Plant Constituents in the Book of Methods
before another general revision is made, with a view to deleting any
unnecessary methods.
REPORT ON SULFUR AND PHOSPHORUS IN THE SEEDS OF
PLANTS.
By W. L. Latsuaw (Agricultural Experiment Station, Manhattan’
Kans.), Associate Referee.
The object of the work for 1922 was to secure a satisfactory method
for the oxidation and preparation of solutions from plant material,
including the seeds of plants, for the determination of sulfur; also to
secure a method whereby the filtrate from the sulfur determination could
be used for the determination of phosphorus.
Samples of cottonseed meal, soybean meal and mustardseed meal
were used. Three different procedures for oxidation and solution were
tried as follows:
Procedure I —Bomb method.
Procedure Il —Magnesium nitrate method.
Procedure I11—Official method.
The details of these procedures are as follows:
1923| LATSHAW: SULFUR AND PHOSPHORUS IN SEEDS OF PLANTS 415
SULFUR.
PROCEDURE I.
The description of the apparatus, reagent, and details of oxidation
and solution have been published!.
PROCEDURE II.
REAGENT.
Magnesium nitrate solution.—Dissolve 320 grams of calcined magnesia in nitric acid,
avoiding an excess of the latter; add a little calcined magnesia in excess; boil filter from
the excess of magnesia, iron, etc., and dilute to 2 liters.
PREPARATION OF SOLUTION.
Weigh a 1-gram sample of the seed under examination (ground to pass a }-mm. sieve)
into a 250 cc. low-form pyrezr beaker. Add 7.5 cc. of magnesium nitrate solution, taking
care that all the material is brought in contact with the solution, and heat on an electric
hot plate (at full heat 180°C.) until no further action takes place. Transfer the beaker
while hot to an electric muffle and allow it to remain at low heat (muffle must not show
any red) until the charge is thoroughly oxidized. No black particles should remain.
(Sometimes it may be necessary to break up the charge and again return to the muffle.)
Remove the beaker from the muffle and allow to cool. Add water, then hydrochloric
acid in slight excess. Bring the solution to a boil and filter. The filtrate is now ready
for the determination of sulfur.
The filtrate from the determination of sulfur is used for the estimation of phos-
phorus.
Note.—Reasonable care should be exercised in handling the hot pyrex beakers from the muffle and the
cooler ones going into the muffle.
PROCEDURE III.
Prepare the solution according to the official method?. Also filter and determine
sulfur as herein directed. The filtrate from the determination of sulfur may be dis-
carded.
PHOSPHORUS.
PREPARATION OF SOLUTION.
Prepare according to the official method*, using a 1-gram sample for the determi-
nation, as outlined under 9, (a), page 3.
DETERMINATION OF SULFUR.
Make up the solutions from the several oxidations to 200 cc., keeping the acidity
to from 1-2% with hydrochloric acid (at no time having more than 2% acid). Bring
the solution to a boil and add with constant stirring 10 cc. of barium chloride solu-
tion (1-9). Keep the solution on a hot plate at or near the boiling point for 5 hours
(care being exercised to keep the solution as close to its original volume as possible)
and then allow to stand overnight. Decant the liquid into a weighed Gooch, pre-
viously heated. Treat the precipitate with 15-20 cc. of boiling water, transfer to the
filter, empty and rinse out the suction flask. Wash precipitate free from chlorides
with boiling water. Dry, ignite and weigh as barium sulfate.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 469.
cee aca Agr. Chemists, Methods, 1920, 20.
id.,
416 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
DETERMINATION OF PHOSPHORUS.
Proceed according to the official method!. Evaporate the filtrate from the determi-
nation of sulfur to 75 cc. if used for the determination of phosphorus.
Collaboralive resulls on the determination of sulfur and phosphorus using three different
methods, expressed as per cent.
Sulfur.
COTTONSEED MEAL SOYBEAN MEAL MUSTARDSEED MEAL
II-MAG- nope II-MAG- awe II-MAG- ae
COLLABORATOR BOMB = NESIUM opFycraL | 1BOMB NESIUM orpicraL| BOMB NESIUM orFicIAL
METHOD NITRATE ypq7yqOp | METHOD NITRATE yerHop | METHOD NITRATE yrryHop
METHOD METHOD METHOD
A. J. Patten, 0.49 0.54 0.50 0.37 0.43 0.41 0.87, 0.89 0.85
EK. Lansing, 0.50 0.54 0.45 0.34 0.42 0.40 0.89 0.89 0.83
Mich. 0.52 0.52 0.45 ae MONON shea ae tt eane fe Ne el a
bisa 3, TICE Wyio’e. 4%
Average... 0.50 0.53 0.47 0.36 0.43 0.41 0.88 0.89 0.84
O. B. Winter, 0.55 0.55 0.55 0.43 0.45 0.438 0.89 0.91 0.88
E. Lansing, 0.55 0.59 0.56 0.42 0.50 0.44 0:92), 0.90, » 0:89
Mich. whaysie yl sera ee Faehe she s+ sien RSvhaleae eee
0.57
Average... 0.55 0.57 0.56 0.43 046 0.44 0.91-",0.31" "089
R. N. Loomis, 0.59 0.44 0.49 0.44 0.37 0.37 0.80 0.82 0.85
Manhattan, 0.56 0.46 0.50 0.38 0.36 0.36 0.81 0.82 0.85
Kans. 0.60 0.45 0.50 0.42 0.39 .0.38 0.81 0.82 0.83
0.54 0.51 0.50 0.43 O37 0.41 0.89 0.83 0.87
0.50 0.49 0.52 O43, OG 7) is a
Oe OO vate!
Average... 0.55 0.47 0.50 0.43 0.37 0.38 0.86 0.83 0.85
J. F. Merrill, 0.46 0.49 0.56 0.35 045 0.37 0.83 0.85 0.84
Manhattan, 0.46 0.49 0.53 0.36 0.36 0.42 0.87 0.85 0.85
Kans. 0.47 0.49 0.61 0.34 0.37 0.35 0.83 0.86 0.88
0.44 0.47 0.58 0:83 70:30) GOAT 0.82 0.85 0.97
0.48 0.49 0.57 0.35 0.37 0.46 euler
Average... 0.46 0.49 0.55 0.35 0.38 0.41 0.84 0.85 0.91
W.L.Latshaw, 0.53 0.48 0.53 0.38 0.35 0.40 0.88 0.87 0.90
Manhattan, 0.55 0.49 0.50 0.41 0.36 0.43 0.86 0.87 0.88
Kans. 0.49 0.50 0.44 O39" O37 039 0.84 0.86 0.87
0.46 0.49 0.52 0:35 0:38" 10:85 0.87 0.86 0.85
0.51 ee Lee OSs 4 Hein Geewsih O85 dere Skee
Average... 0.51 0.49 0.50 OST) OLS nO sao 0.86 0.87 0.88
William Ma-
ther, Colleges oii ip OAQien sgn BOS thoi) aoe shee: KOLSE
Park, Md. ene (NOL RNs: Baten MN Hay! Aaa ee ee eal OES
AVETAZe ny nea 0.46 oe ae tats 0.35 Aeite WOKEN 0.86
1 Assoc. Official Agr. Chemists, Methods, 1920, 3, par. 9.
1923] LATSHAW: SULFUR AND PHOSPHORUS IN SEEDS OF PLANTS 417
Phosphorus.
COTTONSEED MEAL SOYBEAN MEAL MUSTARDSEED MEAL
TI-MAG- yy II-MAG- ee MI-MAG- yyy
COLLABORATOR 1—~BOMB NESIUM or¢picrat | BOMB NESIUM oppycrat | BOMB NESIUM opFicraL
METHOD NITRATE ypryHop | METHOD NITRATE yyp7HOp | METHOD NITRATE yeTHOD
METHOD METHOD METHOD
R. N. Loomis. 0.90 0.91 0.84 0.50 048 0.54 LOS eu 1.14
0.87 0.88 0.84 0:50 (0H8 0:55 1.09 i Pali ill
0:89) | (0:8%.5 (0:91 0:50 0.52 0.538 1:09.) 080) “T8h7/
0.89 0.91 0.91 0.538 0.55 0155 4 ts 1.15
0.90 0.92 0.91 0.50 0.53 0.58 ALAS 1.15
0.89 0.93 ees 0:52, 0.55 ~—s 0.55 1.16 aehes 1.13
Average... 0.89 0.90 0.88 OL O52) 90:55 Ueva! ital 1.14
J.F. Merrill. 0.82 0.85 0.94 0.44 0.45 £0.53 06) 07> ELS
Osi, -OSl Oss 0.46 0.45 #&£0.54 TOSS EOS 1.20
OMS). 10:88) EOL 0.63 0.49 0.56 £08 110) us
O76.) O87) 5 S110 0.56 0.50 £0.54 97 Oe lel
0.73 0.88 1.06 0.56 0.50 0.54 96 1:09" 1216
Average... 0.78 0.86 1.00 0.53 0.48 0.54 1:02) 08" ses
W.L.Latshaw. 0.89 0.91 0.91 O54. O55 0:53 LADe, VASE “e4
0.89 0.91 0.91 0:58 0.55 0.53 1.12 12) era
O89) 0:90) ee O52 sODGy .3.2) igi} 1.12 ares
0.87 0.90 ey (0a: 1.11 1.12
0.89 0.90 0.538 0.55 LAO Ry Lt2
Average... 0.89 0.90 0.91 0.538 0.55 0.53 ie la | 1.12 1.14
DISCUSSION.
The results of the work on the different procedures show very little
difference in the percentage of sulfur found. Agreeing that the results are
practically uniform the next thing to consider is ease of manipulation.
It is well known to analysts who have used the present official method
that it is a long and tedious procedure—one that gives the inexperienced
analyst no end of trouble; it requires the use of expensive chemicals and
a source of heat free from sulfur. In the case of the bomb method, the
matter of sulfur-free heat is eliminated, but the expensive chemicals and
apparatus must be contended with.
The magnesium nitrate method is extremely simple, requiring a small
amount of inexpensive chemicals and the use of an electric hot plate and
muffle furnace—appliances that are in use in practically all laboratories
today. This procedure presents the further advantage in that the fil-
trate from the sulfur determination can be successfully used for the
determination of phosphorus. The simplicity of procedure and the elim-
ination of a large amount of sodium salts are important factors and
should aid in securing more uniform results.
418 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
TOTAL SULFUR AND PHOSPHORUS.
Magnesium nitrate method.
(Applicable for plant material including seeds.)
Reagent and procedure are the same as for sulfur, page 415.
The filtrate from the barium sulfate is used for the determination of phosphorus.
RECOMMENDATIONS.
It is recommended—
(1) That the magnesium nitrate method for the determination of
sulfur and phosphorus in plant materials including the seeds of plants, as
outlined, be adopted as a tentative method.
(2) That the magnesium nitrate method take the place of the present
official method.
REPORT ON THE DETERMINATION OF IRON AND ALUMIN-
IUM, CALCIUM AND MAGNESIUM IN THE ASH OF SEEDS.
By A. J. Patten (Michigan Experiment Station, E. Lansing, Mich.),
Associate Referee.
The work this year has been directed, more especially, to the determi-
nation of iron and aluminium, as the methods that have been on trial
for several years for the determination of calcium and magnesium have
given very satisfactory results.
In view of the fact that the ash of seeds contains a large percentage of
phosphoric acid, the basic acetate method and its various modifications
for the separation of iron and aluminium as phosphates were considered,
but it was found that either the details of the methods had not been
sufficiently worked out or they were so complicated as to be unsatis-
factory.
Solutions of ferric, aluminic and calcium phosphate in hydrochloric
acid were then prepared and the range of hydrogen ion concentration
in which they are precipitated in the presence of ammonium acetate
was determined. An amount of each solution corresponding to 0.5
gram of the phosphate was drawn off into a beaker, 25 cc. of a 25 percent
solution of ammonium acetate added, and the pH of the solution deter-
mined electrometrically. One-tenth normal ammonium hydroxide was
then added in 1 cc. portions, the resulting pH being measured after each
addition until the precipitation of the phosphate seemed complete. The
curves obtained from plotting these results are shown in Fig. 1. The
initial acidity varied with the solutions of the different phosphates.
From these curves it will be observed that the ferric phosphate alone
is precipitated when the reaction of the solution shows a pH of approxi-
1923] IRON, ALUMINIUM, CALCIUM AND MAGNESIUM IN ASH OF SEEDS 419
mately 2, and that the aluminic phosphate is precipitated at a pH of
between 3 and 3.5, but that the calcium phosphate does not begin to
precipitate until the pH of the solution approaches 7 and is completed
at about pH 7.8. When all three phosphates were present in the same
solution the ferric and aluminic phosphates seemed to be precipitated at
90
8.0
Coe
“ Prec
AN)
Z0 =
g
O Cloudy
6.0
wy
00
~)
5.0 NUS
Ox
OS
x
Q
&
4.0
Q
Prec
Toudy
30 S
2.9 Prec.
Cloudy
10
pH 0.0
ia} 22 go 40. 50 60
ce. NH, OY
Fic. 1.—Results showing pH values at which ferric, aluminic and calcium phosphates were precipitated.
420 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
very nearly pH 2, while the calcium phosphate seemed to remain in
solution until the solution showed a reading of approximately pH 7.
Therefore, the range between the precipitation of ferric and aluminic
phosphates and calcium phosphate in the presence of ammonium acetate
seems sufficiently great to permit of their separation without much diffi-
culty if the reaction of the solution is properly controlled.
In the actual determination of the phosphates it is sufficient to adjust
the reaction of the solution to the desired pH reading, colorimetrically,
using thymol blue indicator before adding the ammonium acetate. A
number of trials were made using known quantities of the various phos-
phates to determine the reliability of the method and in nearly every
case theoretical results were obtained.
It was then decided to test the methods on actual ash solutions, pre-
pared from the following seeds: Rosen Rye, Red Rock Wheat, Wolver-
ine Oats, Robust Beans and Two-Row Barley.
The results obtained are shown in Table 1.
TABLE 1.
Resulls obtained from ash solutions prepared from various seeds.
FePO,
SiOz + Mns304 CaO MgO P205
AIPO,
percent percent per cent percent percent per cent
RosenvRVOu ds oe he eee ae 1.47 2.45 0.26 3.68 11.99 44.17
Red: Rock;Wheat 4.9... foo 4522" 1.45 2502 0.36 3.13 13.46 47.45
Wolverine Oats............... 28.00 2.00 0.25 4.15 8.16 31.88
Robust Beans. ween eee 0.56 2.08 0.15 5.45 6.82 26.47
Two-Row Barley .6.52)6 525225004 1.34 1.32 0.18 2.46 13.32 40.31
After thoroughly testing the proposed methods two synthetic solu-
tions were prepared, one to represent the ash of seeds (No. 1) and the
other to represent the ash of hays and straws (No. 2).
SOLUTION No. 1 SOLUTION NO. 2
Grams in 1000 ce. Grams in 1000 cc.
CaO Ie .: 0.682 3.580
MO suai: 1.992 1.256
KePOg es. 0.672 0.579
AIPOM eee 0.543 0.457
MinsOg: aes 0.040 0.040
KO Meanie 5.026 5.640
INaSOWS Sore 0.340 0.500
PaO peneioniins 7.611 1.240
A sample of each solution, in quantities of 100 cc., and a copy of the
following methods of analysis were sent out to 10 laboratories:
Transfer each sample to a 200 cc. volume flask, carefully rinsing the stopper and
bottle into the flask. Make to volume and take 50 cc. for analysis according to the
following methods:
1923| IRON, ALUMINIUM, CALCIUM AND MAGNESIUM IN ASH OF SEEDS 421
Iron and Aluminium.
Add four drops of thymol blue indicator and then dilute ammonium hydroxide,
stirring vigorously, until the color just changes from pink to yellow. (At this point
the solution should have only a faint cloudiness.) Add, while stirring, 25 cc. of a
25% solution of ammonium acetate. Heat to 70°-80°C., maintain at this temperature
for about 30 minutes, allow to stand until the precipitate has settled and filter. Wash
thoroughly with hot 5% ammonium nitrate solution, ignite and weigh as FePO,+ AIPO,,.
Manganese.
Heat to boiling the filtrate and washings from the preceding determination. Add
10-15 ce. of bromine water and continue boiling until the manganese separates as the
brown oxide. If the oxidation does not take place readily add more bromine water
and continue boiling until the precipitation has been completed. Place on the hot
plate for 15 or 20 minutes. Filter and wash with hot water. Dry, ignite and weigh
as Mn;0,.
Calcium.
Concentrate the filtrate and washings from the preceding determination to 150-200 cc.
Add 10 ce. of 0.5N hydrochloric acid and 10 cc. of 2.5% oxalic acid. Boil the solution,
add with constant stirring 15 cc. of a saturated solution of ammonium oxalate, and
continue to heat until the precipitate becomes granular. Allow to stand 4-12 hours.
Filter, wash with hot water until free from chlorides, ignite, heat over a blast lamp and
weigh as CaO. If preferred the precipitate of calcium oxalate, after washing, may be
dissolved in hot dilute sulfuric acid (1-5) and titrated with 0.1N potassium permanga-
nate solution.
Magnesium.
To the combined filtrate and washings from the calcium determination, add 15 cc.
of strong nitric acid and evaporate to dryness. Take up with dilute hydrochloric acid
and make to a volume of about 100 cc. Add 1-2 grams of di-sodium hydrogen phos-
phate, or enough to precipitate all the magnesium. When cold, make slightly alkaline
with ammonium hydroxide, stirring constantly. Add 5-10 cc. of ammonium hydroxide
TABLE 2.
Collaborative results obtained from synthetic solutions representing the ash from seeds
(Solution No. 1) and from straws and hays (Solution No. 2).
FePO,+ AIPO,4 Mn304 CaO MgO
ANALYST ee SE TN eee eee | Se NE ee Se
Solution | Solution | Solution | Solution | Solution | Solution | Solution | Solution
No. 1 No. 2 No. 1 No. 2 No. 1 No. 2 No. 1 No. :
1 39.6* | 32.4* 0.9 eff 15.0 87.5 49.8 30.8
7 32.0 25.9 Pee 2 19.1 90.8 49.7 30.7
3 Solr |a0a% DE? 3.0 Papell 97 .9* 56/1* 42.6*
4 30.7 26.0 Ait 0.6 Wie 91.1 50.4 SZ
5 32.0 26.1 eG 1.4 16.1 91.8 50.8 32.1
6 o2:0 25.9 2:2, Qe 17.9 90.3 50.6 See
a By 26.9 2.5 Poets 18.5 90.7 50.5 31.8
8 31.0 29.0 1.0 1.9 17.1 90.3 49.3 31.5
Average Sled, 26.1 2.0 1.8 VES 90.4 50.2 32.0
IEHCOrY 03:6). 30.5 25.8 1.0 1.0 LEAL 89.5 49.8 .31.4
* Omitted from average.
422 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
in excess and allow to stand about 12 hours. Filter, wash with a solution of 2.5 per
cent ammonium hydroxide until free from chlorides, ignite, heat over a blast lamp
and weigh as magnesium pyrophosphate. Calculate to MgO.
Reports were received from 8 laboratories. The results, expressed in milligrams
per 25 cc. of the original solution, are given in Table 2.
DISCUSSION.
The results are unusually good with the exception of those for iron
and aluminium by Analyst No. 1 and those by Analyst No. 3.
High results for iron and aluminium may be obtained if the neutral-
ization of the solutions with ammonium hydroxide is carried too far, in
which case some calcium may be carried down. In the case of Analyst
No. 1 it seems probable that this is what happened as in both samples
the results for calcium are below the theoretical amounts. Concerning
the results by Analyst No. 3 it is difficult to understand why those for
calcium and magnesium should also be high unless the precipitates
were not ignited to constant weight.
The results obtained for manganese varied greatly but it was not
expected that this method would be reliable for such small quantities.
The colorimetric method for manganese! which has already been adopted
as official should be used where an accurate determination is desired.
No attempt was made to determine the iron and aluminium separately
as the well-known method of fusing with potassium hydrogen sulfate
has already been thoroughly tested and adopted as official?.
RECOMMENDATION.
It is recommended—
That the methods for iron, aluminium, calcium and magnesium as
given in this report be further studied with a view to their adoption
as tentative methods.
REPORT ON DAIRY PRODUCTS.
By Junius Hortvetr (State Dairy and Food Commission, St. Paul,
Minn.), Referee.
No collaborative work has been conducted by the referee during the
past year. The results of investigations made during 1919, 1920 and
1921 are deemed sufficiently conclusive to place the cryoscopic method
of examination of milk on a substantial basis. A large number of au-
thentic samples of milk obtained from individual cows and herds have
already been subjected to careful tests, and the natural range of freezing-
1 J. Assoc. Official Agr. Chemists, 1921, 4: 393.
2 Assoc. Official Agr. Chemists, Methods, 1920, 16, par. 6; 29, par. 43.
1923] HORTVET: REPORT ON DAIRY PRODUCTS 423
point depressions has been reasonably substantiated by the experience
of a number of collaborators. The actual limits of reliability of freezing-
point results have been amply illustrated in the reports presented by
the referee during the past two years. Valuable assistance has been
rendered by the associate referee in the investigation of samples obtained
under abnormal conditions as well as normal samples taken from indi-
vidual cows and herds. The results of further work conducted along
lines suggested in connection with the report of a year ago will be pre-
sented by the associate referee. For the purpose of presenting the
cryoscopic method in final form for action on the part of the association
the text has been carefully revised and rewritten, care being taken that
no essential details of the method, as presented in the report of a year
ago, were altered. The description of the method is grouped under
headings as follows:
1. Apparatus:
(a) The Cryoscope.
(b) The Thermometer.
2. Standardization of the Thermometer:
A method of testing the thermometer scale followed by an
explanation of the use of a correction factor to be applied to the
observed freezing-point depression.
3. Cryoscopic Procedure:
The following text is descriptive of the procedure for the col-
lection of milk samples for chemical analysis and of the cryo-
scopic method for the examination of milk and is submitted as
a final report on this subject:
COLLECTION OF SAMPLES FOR CHEMICAL ANALYSIS.
Each sample shall consist of at least one quart.
Bottled milk may be sampled by the collection of one or more bottles
as prepared for sale.
Bulk milk must be thoroughly mixed before the sample is withdrawn.
This is best accomplished by pouring the milk from one vessel into
another three or four times. Where this is impossible, the milk should
be thoroughly and vigorously stirred for at least half a minute with a
suitable appliance long enough to reach to the bottom of the container.
If cream has formed on the milk, the mixing must be continued until all
cream is detached from the sides of the vessel and evenly emulsified
throughout the liquid. The sample should be withdrawn into clean, dry,
air-tight glass jars and if transported by mail,express or otherwise,the sample
bottles should be completely filled, tightly stoppered and properly sealed
424 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
and marked for identification. The samples should be kept in a cool
place (2°-5°C.) but not allowed to freeze until ready for examination.
Immediately before withdrawing portions for the analytical determina-
tions, the sample should invariably be poured into a clean empty vessel
and back in order to insure a homogeneous mixture.
THE CRYOSCOPIC EXAMINATION OF MILK.
1 APPARATUS.
(a) The Cryoscope.—A description of the cryoscope has been published".
The apparatus should be set up as carefully and correctly as possible.
All connections should be sufficiently tight to avoid escape of ether
vapors. Care should be taken to avoid breakage of the Dewar flask.
The perforated loop at the lower end of the metal inlet tube should be
adjusted to a position about 3 cm. above the bottom of the flask. The
rubber tube connecting the air-drying tube with the air-inlet tube should
be extended so as to cover the metal tube as far as the top surface of
the cork. When removing the upper section of the cryoscope withdraw
the glass tube which is inserted in the cork stopper at the top of the air-
drying device.
The bulb of the control thermometer should extend to a position about
three-fourths of the distance from the surface of the 400 cc. ether level
to the bottom. When the thermometer has been properly inserted in
the cork it should remain in position unless for a special reason it may be
necessary to withdraw it.
Prepare a glass ether-level gage of suitable length for inserting to
within a short distance above the bottom of the flask. Insert over the
upper end of the gage tube a short section of rubber tubing for the pur-
pose of preventing breakage of the vacuum flask when the tube is in-
serted into the ether. The lower end of the tube should be provided
with file marks indicating various ether levels, viz., 200 cc., 300 cc.,
400 cc., etc.
Place a plug of cotton in the funnel tube (preferably a narrow short-
stemmed thistle tube) for the purpose of separating impurities which
may be presence in the ether when being poured into the cryoscope.
Pour into the air-drying tube only sufficient concentrated sulfuric acid
to just cover the perforations in the small bulb near the bottom of the
tube. Do not allow the sulfuric acid to rise to a level near the per-
forations at the shoulder of the mantle.
The stirrer and freezing starter should both move freely in the metal
tubes provided for them in the rubber stopper which holds the standard
thermometer.
1 J. Ind. Eng. Chem. 1921, 13: 198; J. Assoc. Official Agr. Chemists, 1921, 5: 173.
1923] HORTVET: REPORT ON DAIRY PRODUCTS 425
Keep the freezing starter in contact with a small block of ice for some
minutes before applying it, as directed in the procedure 3.
Adjust the pump and regulate the pressure in such a manner that air
will be forced through the apparatus at a fairly rapid rate, avoiding
splashing or excessive foaming of the sulfuric acid. When all adjust-
ments are properly made and a free passage of air is maintained through
the apparatus it is possible to lower the temperature of the ether bath
from approximately +20°C. to 0°C. in from 5 to 10 minutes. When
the cooling action appears to be retarded the sulfuric acid must be re-
moved from the drying tube and a fresh supply poured in.
The ether drain tube on the left side of the cryoscope should carry
off the vapor into the sink. No marked odor of ether should be notice-
able at the top portion of the tube. When the cryoscope is not in use
place a plug of cotton in the top of the drain tube in order to check loss
of ether by evaporation. Remove the cotton when the apparatus is
in use.
The glass tube at the back portion of the cryoscope stand is intended
for holding the thermometer when it is removed from the freezing test-
tube. Place a pad of cork or rubber at the bottom of the tube to serve
as a rest for the thermometer bulb.
(b) The Thermometer—Examine the thermometer very carefully,
using a lens if necessary, in order to determine whether any defects exist
in the glass or in the mercury thread. Dislodge any particle of mercury
which may be adhering to the inner surface of the expansion space at
the top of the stem. Also dislodge any gas bubble which may be notice-
able in the bulb or which may form a separation at any part of the mer-
cury thread. When the thermometer is brought into proper condition
for use make standardization tests according to directions given under 2.
Keep the thermometer always in an upright position. In removing
from the stopper or reinserting do not turn the thermometer to an in-
verted position and avoid a horizontal position as much as possible.
When the thermometer has been properly adjusted and carefully tested
it should be handled at all times with great care.
Test the thermometer at frequent intervals, once a week or as often
as may be necessary, in order to keep an accurate record of any changes
which may occur. Determine the true 0-position and the depression
produced by a standard sucrose solution often enough to be certain at
all times regarding the reliability of results.
(c) The Control Thermometer.—Test the control thermometer in a
bath of melting crushed ice for the purpose of determining whether the
0-mark on the scale is correct. The scale graduations should be ac-
curate to within 0.1°C.
426 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
2 STANDARDIZATION OF THE THERMOMETER.
Make freezing-point determinations on the following:
(a) Recently boiled distilled water.
(b) 7 grams sucrose solution—Dissolve 7 grams of pure sucrose in
pure water and make the solution up to a volume of exactly 100 cc. at
20°C:
(c) 10 grams sucrose solution.—Dissolve 10 grams of pure sucrose in
pure water and make ‘the solution up to a volume of exactly 100 cc.
at 20°C.
A sample of pure sucrose may be obtained by application to the Direc-
tor of the Bureau of Standards, Department of Commerce, Washington,
DG.
Make three freezing-point determinations on the distilled water and
on each of the sucrose solutions according to the procedure described in
3 and tabulate the results in the following form:
7 Grams Sucrose SOLUTION 10 Grams Sucrose SoLuTIoN
FREEZING- ae
POINT
OBSERVATIONS aiuvaks Observed Freezing-Point Observed Freezing-Point
Exgering Point Depression S-W _ Freezing Point Depression S-W
(-S) (Algebraic) (-S) (Algebraic)
Ist
2nd
3rd
+V\W
Averages XXXXXX XXXXXXX
Express the results as degrees freezing-point depression below the
average of the observed freezing points obtained on the sample of pure
water (+ W), which may be above (+) or below (—) the 0-mark on the
scale. Obtam each freezing-point depression of the sucrose solutions by
the algebraic subtraction of the average of the freezing-point readings of
pure water (+W) from each observed freezing point.
Omit adventitious results, t. e., results which are in marked disagree-
ment with other results obtained by carefully following instructions.
Apply the average of the freezing-point depressions obtained on the
standard sucrose solutions for the purpose of correcting the thermometer
readings obtained on samples of milk in the manner illustrated in the
report of the referee for 1921}.
3 CRYOSCOPIC PROCEDURE.
Insert the funnel-tube into the vertical portion of the T-tube at one
side of the apparatus and pour in 400 cc. of ether previously cooled to
1 J. Assoc. Official Agr. Chemists, 1922, 5: 477.
1923] HORTVET: REPORT ON DAIRY PRODUCTS 427
10°C. or lower. Close the vertical tube by means of the small cork and
connect the pressure pump to the inlet tube of the air-drying attach-
ment. Adjust the pump so as to pass air through the apparatus at a
moderate rate, as may be judged by the agitation of the sulfuric acid in
the drying tube. Continuous vaporization of the ether will cause a
lowering of the temperature in the flask from ordinary room tempera-
ture to 0°C. in from 5 to 10 minutes. Continue the temperature lower-
ing until the control thermometer registers near —3°C. At this stage,
by lowering the gage tube into the ether bath, then closing the top by
means of the forefinger and raising to a suitable height, an estimate can
be made as to the amount of ether necessary to pour in for the purpose
of restoring the 400 cc. volume. When the volume of ether has been
adjusted to 400 cc. an additional 10 to 15 ce. is sufficient on an average
for each succeeding determination. Pour into the freezing test-tube 30
to 35 cc. of boiled distilled water, cooled to 10°C. or lower, or enough to
fairly submerge the thermometer bulb. Insert the thermometer to-
gether with the stirrer and lower the test-tube into the larger tube. A
small quantity of alcohol, sufficient to fill the lower space between the
two test-tubes, will serve to complete the conducting medium between
the freezing bath and the liquid to be tested. Keep the stirrer in steady
up-and-down motion at a rate of approximately one stroke each two or
three seconds, or even at a slower rate, providing the cooling proceeds
satisfactorily. Maintain passage of air through the apparatus until the
temperature of the cooling-bath reaches —2.5°C., at which time the top
of the mercury thread in the thermometer usually recedes to a position
in the neighborhood of the freezing point of water. Maintain the
temperature of the cooling-bath at —2.5° and continue the manip-
ulation of the stirrer, until a super-cooling of sample 1.0° to 1.2° is ob-
served. Asarule, at this time the liquid will begin to freeze, as will
be noted by the rapid rise of the mercury. Manipulate the stirrer
slowly and carefully three or four times as the mercury column approaches
its highest point. By means of a suitable light-weight cork mallet tap
the upper end of the thermometer cautiously a number of times until
the top of the mercury remains stationary a couple of minutes. Taking
necessary precautions to avoid parallax, observe the exact reading on
the thermometer scale and estimate to 0.001°C. When the observation
has been satisfactorily completed make a duplicate determination, then
remove the thermometer and stirrer and empty the water from the
freezing tube. Rinse out the tube with about 25 cc. of the sample of
milk, cooled to 10°C. or lower, measure into the tube 30 to 35 cc. of the
milk, or enough to fairly submerge the thermometer bulb, and insert
the tube into the apparatus. Maintain the temperature of the cooling-
bath at 2.5° below the probable freezing point of the sample. Make
the determination on the milk following the same procedure as that
428 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
employed in determining the freezing point of water. As arule, however,
it is necessary to start the freezing action in the sample of milk by in-
serting the freezing starter, in the open end of which has been wedged a
fragment of ice, at the time when the mercury column has receded to
1.0°—1.2° below the probable freezing point. A rapid rise of the mer-
cury results almost immediately. Manipulate the stirrer slowly and
carefully two or three times while the mercury approaches its highest
point. Complete the adjustment of the mercury column in the same
manner as in the preceding determination; then, avoiding parallax,
observe the exact reading on the thermometer scale and estimate to
0.001°. The algebraic difference between the average of the readings
obtained on the water and the reading obtained on the sample of milk
represents the freezing-point depression of the milk. Apply necessary
correction to the result in the manner illustrated under 2.
To deduce the percentage of added water from the determined freezing-
point depression, use Winter’s table! or the scale accompanying the
cryoscope. The percentage of added water (W) may also be calculated
as follows:
100 (T-T’)
a
T =the average freezing point of normal milk (—0.550°C.); and
T’ =the observed freezing point on a given sample.
W=
, in which
Make freezing-point determinations only on samples of milk which
are fairly sweet or fresh, i. e., samples which show an acidity test of not
appreciably more than 0.01 per cent above 0.15 per cent (expressed in
terms of lactic acid). Make the acidity determination according to
the following method:
Measure out 17.6 cc. of the milk, using a 17.6 cc. Babcock pipet, dilute with an equal
volume of water (free from carbon dioxide), washing out the pipet with the same, add
0.5 cc. of phenolphthalein indicator, and titrate with 0.1N sodium hydroxide. The
number of ec. of 0.1N sodium hydroxide required to neutralize the sample of milk
divided by 20 gives the percentage of lactic acid.
A minimum freezing-point depression of —0.530°C. and a maximum
of —0.566°C. for milk from normal individual cows and a minimum of
—0.530°C. and a maximum of —0.562°C. for milk from normal herds
is substantiated by collaborative work carried out in various parts of
the country on approximately 300 samples. Owing to these observed
natural variations it is advisable to adopt a tolerance figure in passing
judgment on market samples. A tolerance of 3 per cent may be de-
ducted from results for added water calculated on the basis of an average
freezing-point depression of —0.550°. A thorough investigation of the
1 Chem. News, 1914, 110: 283.
1923] BAILEY: CRYOSCOPY OF MILK 429
cryoscopic properties of authentic samples in a given locality may
justify a smaller, but scarcely a larger, tolerance figure. Owing to the
narrow variations actually found among market milks of genuine charac-
ter, it is not necessary in practice to deduct the tolerance figure from
results showing added water in amounts above 3 per cent.
RECOMMENDATION.
It is hereby recommended—
That the cryoscopic method for the examination of milk be adopted
as an official method of this association.
No report on moisture in cheese was made by the referee. See page 437.
CRYOSCOPY OF MILK.
By E. M. Bairey (Agricultural Experiment Station, New Haven,
Conn.), Associate Referee.
In the report of the associate referee for 1921 the three following topics
were suggested for further study: the correction of freezing point to be
made for increased acidity; the effect of pathological conditions of the
animals upon the freezing-point depression of milk; and corroboration,
if possible, of certain abnormal freezing points reported at that time.
The work this year has been confined to consideration of these sub-
jects.
INFLUENCE OF ACIDITY UPON FREEZING-POINT DEPRESSION OF MILK.
The cause of the acidity which fresh milk shows toward phenolphthal-
ein has been the subject of much investigation. Carbon dioxide, acid
salts and casein, separately or in various combinations, generally have
been regarded as responsible for the so-called apparent acidity of normal
milk in a fresh condition. To accept the careful studies of Van Slyke
and his co-workers, however, the acidity of fresh milk is due to the
presence of acid phosphates'; the acidity decreases with increasing
carbon dioxide content?; and casein is combined with calcium as a.calcilum
caseinate which is neutral to phenolphthalein. As milk ages another
type of acidity appears, due chiefly to bacterial decomposition of lactose
with the formation of lactic acid. Examination of samples of milk,
under induced souring, taken at intervals up to 96 hours showed that the
figures representing increases of the acidity in the milk were almost
identical with those representing the determined amounts of lactic acid’.
In these experiments the degree of acidity was determined by titration
1 Van Slyke and Bosworth, New York Agr. Exp. hie Tech. Bull. 37, 1914.
2 Van Slyke and Baker, J. Biol. Chem., 1919, 40,
3 Van Slyke and Bosworth, New York Agr. Exp. Bee Tech. Bull. 48, 1916.
430 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
with 0.1N alkali, using phenolphthalein as an indicator, but first removing
calcium by means of neutral potassium oxalate to avoid the error other-
wise introduced by the hydrolysis of dicalcium phosphate during titra-
tion. The results obtained in this way are about one-half as great as
those obtained by the usual method of titration.
In applying the freezing-point test as a means of detecting added
water in milk the question of the influence of acidity has been raised.
Without other complicating factors it would be expected that the mere
increase in amount of lactic acid would result in a corresponding increase
in freezing-point depression. Keister! has studied this point, and
additional data have been obtained by the associate referee during the
past year. The combined data are given in Table 1. Acidity is the
result of spontaneous souring in these trials, and it has been determined
and expressed according to the uniform plan followed in work reported
last year”.
A study of the results in Table 1 shows that the effect of increased
acidity upon freezing-point depression is an additive factor, and that the
magnitude of the increased depression closely approximates 0.003°C.
for each 0.01 per cent increase in acidity. If we may broadly assume
acidities less than 0.25 per cent due to normal variations in fresh milk
and figures in excess of that amount due to lactic acid, then with this
distinction in mind, closer examination of the results shows that there is
greater uniformity in depression increments per unit of acidity in the
lactic acid stage than obtains in the stage of apparent acidity. The data
on acidity intervals within the range of apparent or normal acidity are
chiefly furnished by the figures quoted from Keister’s tabulation; but in
any case it is recognized that measurements within this restricted range,
especially when acidity determinations are made by means of titration,
are necessarily attended with greater opportunities for experimental
error. The practical deduction to be drawn from these data is that a
correction for acidity ought to be made in the observed freezing-point
depression when it is required to examine milk which is sensibly sour.
The numerical definition of this point in terms of acidity will obviously
vary in different samples. Steuart’? observed that the acidity of fresh
milk from individual cows varied from 0.10 to 0.21 per cent, and that of
commercial mixed milk varied from 0.16 to 0.20 per cent. McNerney!
noted practically the same limits, and they are further substantiated by
the figures contained in the report of the associate referee last year’.
Sommer and Hart®, however, cite an instance of fresh herd milk with an
acidity of 0.257 per cent which was not sour as judged by the evidence
1 J. Ind. Eng. Chem., 1917, 9: 862.
2 J. Assoc. Official Agr. Gna 1922, 5: 471.
3 J. Dairy Sci., 1920, 3:
4 Tbid., 227.
5 J. Assoc. Official aes are, 1922, 5: 484.
6 J. Dairy Sci., 1921,
1923] BAILEY: CRYOSCOPY OF MILK 431
of smell or taste. In general, it would appear that acidities in excess of
0.20 or 0.25 per cent result from fermentation and will represent milk
which is sour or near the “turning” point. No correction of freezing
point is recommended for acidity within the normal range for fresh
milk—that is to say, milk showing an acidity not exceeding 0.25 per cent.
FREEZING POINT OF MILK FROM TUBERCULAR COWS.
Milk from individual cows in a herd consisting of six Jerseys was
examined. The first series of samples was taken three days after all
TABLE 1.
Influence of acidity upon the freezing-point depression of milk.
INCREASE
DESCRIPTION INCREASE INCREASE IN F.-P.
ae ieee 1922) en eae | oe eee roe,
INCREASE IN
ACIDITY
per cent —0°C. per cent 2G. °C.”
18169 | Pasteurized {11-16 | 0.130 OPS SOVAD RRS See TR er ee ess
11-17 | 0.130 Oss0 AL. Se Mae le
11-18 | 0.460 0.627 0.330 0.097 0.0029
Average (bas/ed on t\otal increjases)..... . 0.330 0.097 0.0029
21667 | Market...... 2-3 0.215 CORY OCO GL. || 9°: pane een | Scores AA TLE it Bee
2-4 0.335 0.600 0.120 0.040 0.0033
2-5 0.405 0.623 0.070 0.023 0.0033
2-6 0.510 0.653 0.105 0.030 0.0029
2-7 0.580 0.672 0.070 0.019 0.0027
PSV CRERE Sie. |o cisnache | 6s als. SIRS Shee 0.365 0.112 0.0031
21668 | Market...... 2-3 0.205 OSS Or TR shoe AE PL AUN aeons
2-4 0.300 0.584 0.095 0.034 0.0036
2-5 0.400 0.620 0.100 0.036 0.0036
2-6 0.535 0.656 0.135 0.036 0.0027
2-7 0.600 0.673 0.065 0.017 0.0026
IA CTADE ist los: SSG Nomen eTATS Wate tc pet eee 0.395 0.123 0.0031
18706 | Raw.........| 2-6 0.140 TESST) Mt ee ANH le SMB Neal ial | Ua Abe. 3 3
2-7 0.140 OR SOR re lets Aria satiate
TSVO7 | Raw.........| 2-0 0.150 O: SAD ene Or en Skee ser nT ne eee ae
2-11 | 0.250 0.570 0.100 0.030 0.0030
2-14 | 0.550 0.660 0.300 0.090 0.0030
PRMICRAME Sots lore. cre lis see ee ae eta ae eee 0.400 0.120 0.0030
US 708; WRawensc....)). 2-8 0.150 Oe aR | DR Ieee eh | | Mehencayaat
2-11 | 0.220 0.567 0.070 0.026 0.0037
SB. |ARER eee mig ner 2-15 | 0.145 ORE (0) Abel Uni. eel me mad | iallcaa kt lle did bs
2-16 | 0.150 0.530 0.005 O:000 Rely wee ee
2-17 | 0.225 0.555 0.075 0.025 0.0033
2-18 | 0.415 0.613 0.190 0.058 0.0031
INVERHRE Ce Ooi hc. [Lee a ateele oemerr sate 0.270 0.083 0.0031
1S 734 RAW i222 20 3 oe 2-16 | 0.150 A Doce rot Si seecs ay sum fale cle Rape rt ea baal
2-18 | 0.310 0.590 0.160 0.049 0.0031
432 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
Tas Le 1—Continued.
Influence of acidity upon the freezing-point depression of milk.
(From Keister’s Table ITT)*
INCREASE
DESCRIPTION INCREASE INCREASE IN F.-P.
~y on DATE cryracy. FREEZING = pe Se DEPRESSION
SAMPLE 1922 POINT ACIDITY DEPRESSION | PER 0.01%
INCREASE IN
ACIDITY
per cent —°C. per cent Of °G;
Ll Pasteurized...|......| 0.15 EFAS REY Gees nai heme ere mn |e eee
oe, Ae 0.18 0.548 0.03 0.003 0.0010
pear ets 0.42 0.637 0.24 0.089 0.0037
IAVETAPC) Noe Cee ne sale edema cate 0.27 0.092 0.0034
2’ | Pasteurized...|......} 0.15 (051019 aa Taree tenured ee Vy Hats NL
Bea bes 0.18 0.548 0.03 0.009 0.0030
seer! 0.34 0.602 0.16 0.054 0.0034
AV CF ARE js) erate li we ih A ea ecto ete 0.19 0.063 0.0033
3 | Pasteurized...|......| 0.18 ASG 18] eis ho sien lla ea oe ea ae
Meee OO" 8 0.21 0.515 0.0 0.019 0.0063
EAC AES 0.24 0.522 0.03 0.007 0.0023
Ae tee 0.27 0.536 0.03 0.014 0.0047
Avera gess< | .|.<< Btoiate + X.<:cca|eeetaa team 0.09 0.040 0.0044
4°) || Pasteunzedsenlee nmol Oslo O35 52 se) hed Sek) Se ee ae
MBAR 0.17 0.555 0.02 0.003 0.0015
bre Ce 0.20 0.558 0.03 0.003 0.0010
AL he 0.46 0.636 0.26 0.078 0.0030
AWeEragebth cli iio metal etc eto ctleterie sole euaikes 0.31 0.084 0.0027
5 | Pasteurized...}......| 0.16 Oa? 1 AO er on EPR Pe MTs nels yl Pas Gl
epee Ea 0.18 0.546 0.02 0.005 0.0025
Ree 0.22 0.564 0.04 0.018 0.0045
AOR Oe Ua OUR kik ch a Oe 0.06 0.023 0.0038
*J. Ind. Eng. Chem., 1917, 9: 864.
the animals had been subjected to the tuberculin test. The second
series was taken about one week after the first.
The data presented last year showed that freezing points of milk from
tubercular reactors or cows otherwise abnormal physically were generally
within the limits for normal milk. The few exceptions noted were in
the direction of decreased depressions.
In the case of the herd examined this year no figures outside the limits
suggested a year ago for normal milk were obtained.
It is further noted in the work of Van Slyke and Baker! that a number
of instances of garget did not cause the milk to show abnormal freezing-
point depression.
1 New York Agr. Expt. Sta. Tech. Bull. 71, 1919.
1923] BAILEY: CRYOSCOPY OF MILK 433
TABLE 2.
Freezing point of milk from tubercular cows.
HERD cow No. DATE SPECIFIC SOLIDS FAT SOLIDS acipity | FREEZING
1922 GRAVITY NOT FAT POINT
per cent per cent per cent per cent -0°C
M. 1 3-21 A. M.| 1.0325 13.54 4.5 9.04 0.14 0.544
Non- P. M.| 1.0323 13.49 4.5 8.99 0.13 0.549
reactor |3-27 A. M.| 1.0309 13.02 4.4 8.62 0.13 0.539
P. M.| 1.0317 13.12 4.3 8.82 0.12 0.546
2 3-21 A. M.} 1.0333 13.62 4.4 9.22 0.14 0.543
Reactor P.M.) 1.0323 13:37 4.4 8.97 0.14 0.539
3-27 A. M.} 1.0323 13.22 4.3 8.92 0.13 0.546
P. M.| 1.0326 13.57 4.5 9.07 0.13 0.539
3 3-21 A. M.} 1.0338 13.63 4.3 9.33 0.15 0.550
Reactor P. M.} 1.0333 14.10 4.8 9.30 0.14 0.549
3-27 A. M.| 1.0327 13.47 4.4 9.07 0.13 0.544
P. M.| 1.0327 13.47 4.4 9.07 0.13 0.540
4 3-21 A. M.} 1.0343 15.08 5.4 9.68 0.14 0.550
Reactor P. M.| 1.0345 15.00 a0 9.70 0.15 0.549
3-27 A. M.) 1.0323 14.08 5.0 9.08 0.13 0.540
P. M.| 1.0336 14.66 5.2 9.46 0.14 0.544
5 3-21 A. M.| 1.0333 14.46 5.1 9.36 0.17 0.548
Non- P. M.| 1.0335 15.00 5.5 9.50 0.16 0.549
reactor |3-27 A. M.| 1.0330 14.76 5.4 9.36 0.17 0.559
P. M.| 1.0331 15.02 5.6 9.42 0.17 0.545
3-21 A. M.| 1.0335 14.27 4.9 9.37 0.17 0.562
Reactor P. M.| 1.0326 14.05 4.9 9.15 0.16 0.553
3-27 A. M.} 1.0318 14.09 Hall 8.99 0.16 0.554
P. M.| 1.0332 13.84 4.6 9.24 0.16 0.549
ABNORMAL SAMPLES.
In the report of 1921 eleven freezing points which were distinctly
outside the tentative limits suggested were noted with the reservation
that they required further corroboration. Ten of these results that
exceeded the maximum depression limit of —0.566°C. ranged from
—0.570° to —0.580°C.; one was outside the minimum limit of —0.530°C.
All these results were obtained on milk from individual cows of one
herd, and this herd was studied further this year. Forty samples from
nineteen individual cows of the herd and two samples of the mixed milk
of the herd were examined, with the result that only one freezing point
outside the tentative limits was observed, and that exceeded the maxi-
mum by a negligible amount, viz., 0.002°. The summaries for acidity
and freezing-point depression are as follows:
In connection with this particular phase of the subject, H. C. Lyth-
goe cited a number of instances of abnormal milks which came to his
attention during the past year. Since these milks were abnormal in
other respects than freezing-point depression they do not essentially
434 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
affect the writer’s conclusions with reference to the freezing-point range
of milk from normal individual cows in the sense of the term “‘normal’’,
as contemplated and reported last year.
TABLE 3.
Summaries for acidity and freezing-point depression.
ACIDITY FREEZING POINT
Individual cows:
per cenl -0°C.
Maximum.... 0.15 0.568
Minimum... . 0.10 0.532
Average.... 0.13 0.547
Herd:
Average... 0.14 0.554
By way of general comment on the cryoscopic method, Mr. Lythgoe
expressed the opinion that the serum refraction and sour serum ash
considered together are as efficient as the freezing point as a means of
detecting added water, but he agreed that the freezing-point depression
is a factor which is less variable than any other single determination
ordinarily made in the examination of milk.
CONCLUSION.
The value of the cryoscopic method as an adjunct to present methods
for detecting added water in milk is fully demonstrated by data covering
a period of more than two years. Its use may be optional when present
methods furnish conclusive evidence; but, in the experience of the
majority of collaborators, its unique value is shown in those cases where
the evidence of present methods is conflicting or inconclusive. The
tentative limits for normal milk may have to be modified; but since the
value of this, or any similar method, is lessened as the limits of normal
variation are widened, it is believed that the limiting values as defined
in the report of last year should remain until there is further evidence
that they should be modified. It should be emphasized that in all
exceptional cases recourse may be had to the examination of authentic
milk from the particular source in question, and the decision made on
the basis of the evidence so obtained.
Collaborators who contributed to the work this year are R. E. Andrew,
Connecticut Experiment Station, New Haven, and S. H. Hall, State
Board of Health, Boston... H. C. Lythgoe, chief of the Boston labora-
tory, submitted data and criticism.
1923] KEISTER: METHODS FOR FAT IN MALTED AND DRIED MILK 435
METHODS FOR FAT IN MALTED MILK AND DRIED MILK.
By J. T. Kerster (Bureau of Chemistry, Washington, D. C.), Associate
Referee.
The work during the past year has been a continuation of the work
along the same line reported at the 1921 meeting’, viz., a comparative
study of the “neutral” procedure in which the ammonia is omitted
in the regular Roese-Gottlieb method with one modification. This
modification consists in preparing a 15 or 20 per cent water solution of
the sample for the fat determination, instead of weighing out about
one gram of the powder. f
The proposed method is described as follows:
PREPARATION OF SAMPLE.
Weigh out 15 grams of the well-mixed sample and 85 grams of distilled water; warm
the water slightly and mix the water and malted milk with a glass rod to assist in getting
all lumps in solution. Cool the solution to room temperature, agitate and weigh out
accurately about 10 grams into a small cylinder; then transfer to a Rohrig tube or
similar apparatus.
DETERMINATION.
Add 10 cc. of 95% alcohol, shake thoroughly and proceed as in the official Roese-
Gottlieb method? for milk, condensed milk and ice cream, washing out the cylinder
with portions of the ether. Make two extractions using 25 cc. of each ether, then a
third extraction using 15 cc. of each ether, transferring the third extract to a separate
flask. The third extraction usually yields less than 1 mg. of fat. Small amounts of
non-fatty material are sometimes dissolved in the extraction process (almost always
in the case of malted milk substitutes), correction for which should be made by dis-
solving out the fat with petroleum ether, drying the insoluble residue and weighing.
In connection with the majority of the samples which were not true
malted milk, some difficulty was encountered in carrying out the neutral
process, in that a more or less heavy precipitation or coagulation took
place on adding the alcohol, which condition probably accounts in some
measure for the non-fatty residue accompanying the fat in some samples.
This condition was particularly noticeable in the case of Samples Nos.
4,10 and 12. There was also a tendency toward a settling out or par-
tial separation of the solids in the case of solutions of malted milk sub-
stitutes, which difficulty necessitated extra precaution in weighing out
samples. These difficulties were, however, not experienced with samples
of genuine malted milk. It will also be noted that practically all the
malted milk substitutes yield a very small percentage of fat, and no
appreciable differences are noted between results obtained by the neu-
tral and alkaline methods of extraction.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 507.
2 Assoc. Official Agr. Chemists, Methods, 1920, 227.
436 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
In the case of true malted milks, a 15 per cent solution was found to
give very satisfactory results, but in the case of samples of lower fat
content a 20 per cent solution was used with apparent advantage. In
trials made with solutions of true malted milk, the amount of fat
obtained by a third extraction indicated that a 15 per cent solution was
preferable.
The results appear to be very satisfactory and the neutral process in
the majority of cases yields a higher percentage of fat than the regular
Roese-Gottlieb procedure. In this connection it should be stated that
in the few cases where the above statement does not hold the product
was a compound and not a true malted milk.
Results of fat determinations in malted milk.
(Calculated to a water-free basis.)
FAT BY FAT BY
SAMPLE NEUTRAL ROESE- REMARKS
NO. PROCEDURE GOTTLIEB
METHOD
per cent per cent
1C 9.64 9.48 15% solution used.
9.67 9.366
1D 9.44 9.27 15% solution used.
9.52 9.36
1E 8.87 8.74 20% solution used.
8.96 8.85
1A 8.547 8.38 20% solution used.
8.558 8.44
2 8.36 SiWAty, ile cieah woclle, omer Rael aaah racy has Cees a eile eae agen Sea ee
8.305 8.23
3 11.967 11.86 15% solution used. Product labeled “‘A compound
11.946 11.905 of malt and milk’’.
4 1.207 1.069 15% solution used. Product labeled “A compound
1.14 1.08 of malt and milk’’.
5 1.45 1.395 20% solution used. Product said to contain malt,
1.45 1.405 skim milk powder, sugar and salt.
6 1.58 1.429 20% solution used. Product labeled ‘“‘Malted skimmed
abghe 1.437 milk’.
i 11.58 IN 20% solution used.
11.588 W575
8 9.157 9.117 15% solution used.
9.22 9.01
9 6.82 6.79 15% solution used.
6.775 6.84
10 0.646 0.619 | 20% solution used. Product labeled ““A compound
0.69 0.64 of malt, skim milk and cereals’.
11 0.59 0.533 20% solution used. Product labeled ‘““A compound
0.609 0.572 of malt, skim milk and sugar’’.
2 1.799 1.726 20% solution used. Product labeled “Skim milk
1.692 1.716 and malt’’.
13 1.129 IP S55 20% solution used. Product labeled ‘““A compound
122 1.24 of malt, skim milk powder and sugar’.
14 6.74 GiGSO0s | Uwione. Meas GAR RRS els AR tes Yee Rae eee ae
6.69 6.629
1S 4.135 3.898 20% solution used. Product chocolate flavored.
4.16 3.976
16 0.502 0.526 20% solution used. Product labeled ““Compound of
0.569 aii malt and milk’’.
1923] DATA SECURED WITH “TURBIDITY POINT” OF BUTTER FAT 437
RECOMMENDATIONS.
It is reeommended—
(1) That the “neutral” procedure, as outlined, be adopted as a tenta-
tive method for the determination of fat in malted milk.
(2) That a further study be made of the neutral Roese-Gottlieb
method as applied to dried milk products.
MOISTURE IN CHEESE.
A communication received from L. C. Mitchell, Associate Referee,
reads as follows:
“Owing to the large amount of work at this Station your Associate Ref-
eree was unable to carry out the collaborative study, as planned, of the
present tentative method, with the changes as recommended last year,
for the determination of moisture in cheese. It is suggested, however,
that a collaborative study of this method be made during the coming year.”’
RECOMMENDATION.
It is recommended—
That the present tentative method for moisture in cheese, together
with changes proposed in the report of the Associate Referee in 1921,
be subjected to further collaborative study during the coming year.
DATA SECURED WITH THE “TURBIDITY POINT” OF
BUTTER FAT.
By ArMIN SEIDENBERG (Chemical Laboratory, Department of Health,
New York, N. Y.).
Many of the values used in identifying fats and oils are dependent,
not upon properties possessed by the entire substance, but upon some
one constitutent that may be present quantitatively in a comparatively
slight proportion. Thus, in butter fat, the Reichert-Meissl number is
the most characteristic value; but it is dependent upon the presence of
a comparatively small quantity of the total fatty acids present, which
form only a fraction of the complete butter fat. The volatile fatty
acids, upon which the determination of the Reichert-Meissl number
depends, are affected by seasonal variations, changes in feed, and other
factors to a more marked degree than is the case with other constituents
of butter fat. On the other hand, the addition of many foreign fats
usually affects all the components of butter fat equally.
The “turbidity point” of butter fat, described by the writer in pre-
438 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
vious papers!, is dependent upon the solubility relationship of the
glycerides to each other and to the particular solvents used. It takes
into account to some extent properties possessed by all the main con-
stituents of butter fat.
The turbidity point serves to indicate the presence of quantities of
certain foreign fats that can not be detected by other values. Some
examples of this in work on experimental mixtures made up in the labora-
tory were given in one of the previous papers’. Similar results were
also secured on suspected cream samples submitted for analysis.
In order to secure the fat in these creams for examination, a somewhat
simplified procedure was devised. After allowing the creams to sour
by natural fermentation, about 200 grams were thrown upon a large
filter and 25-30 cc. of water were added. After being allowed to drain
from 12 to 24 hours, or until the residue had a fairly firm consistency,
the filter paper was peeled off and the residue transferred to a small
beaker. The room temperature during the draining of the creams
should not be much above 20°C. as otherwise the lower-melting-point
glycerides of the fat melt and are absorbed by the paper. For this
reason, also, the residue should not remain on the filter paper after the
water has passed off. The beaker containing the cream residue was
placed in an oven at a temperature of 90-100°C., care being taken not
to use a temperature that would produce charring. Gradually the fat
separated out and, after repeated stirring in order to mix the sample
and to permit any water present to evaporate, the fat was poured off
through a funnel containing a small wad of absorbent cotton. It was
then ready for chemical examination. This method yields an entirely
representative sample of fat, but of course it is not quantitative.
The turbidity point was determined on the fat secured in this way
from over 1000 samples of cream. The majority of these samples did
not give any evidence of adulteration by any of the values determined
on them, the turbidity point as well as the other values being normal.
In a considerable proportion of other samples, however, evidence of
adulteration was indicated either by the turbidity point alone, the other
values being normal, or it was definitely confirmed by the turbidity
point in cases where other evidence was inconclusive.
In Table 1 certain of these results have been selected as typical of
those cases in which the usual values are all practically normal, although
the turbidity point is 12 to 26 points beyond the limits of 48 to 64,
established for a pure butter fat. There is no doubt that the presence
of a foreign fat in these cases can be considered as clearly established by
the results obtained by the turbidity point even though not substantiated
by any of the other values.
1 J. Ind. Eng. Chem., 1918, 10: 617; J. Assoc. Official Agr. Chemists, 1922, 5: 512.
2 J. Ind. Eng. Chem., 1918, 10: 617.
1923] DATA SECURED WITH “TURBIDITY POINT’ OF BUTTER FAT 439
TABLE 1.
Typical cases where the turbidity point establishes adulteration which escapes detection
by other tests.
SAMPLE NO, REICHERT-MEISSL POLENSKE REFRACTIVE INDEX TURBIDITY
NO. NO. AT 25°C. POINT
1 23.0 1.9 1.4623 36
2 27.8 2.2 1.4615 36
3 28.1 1 Bs 1.4588 34
4+ 29.3 1.9 1.4583 36
5 22.8 1.6 1.4594 90
In Table 2 the results obtained by the usual values are near the bor-
der line of the established limits, and they deviate very little from ex-
treme variations noted on unadulterated butter fat. The turbidity point
in these instances, however, is 16 to 19 points beyond the established
limits, and the presence of a foreign fat can be considered as decisively
established on the basis of the evidence supplied by it. In cases such as
these the turbidity point affords a valuable and in some instances, neces-
sary confirmation to the evidence supplied by the other values.
TABLE 2.
Results showing adulteration by turbidity point where other constants are not entirely
conclusive.
SAMPLE NO. REICHERT-MEISSL POLENSKE REFRACTIVE INDEX TURBIDITY
NO. NO. AT 25°C. POINT
1 21.9 5.6 1.4575 32
2 23.0 5.2 1.4582 30
3 18.7 3.9 1.4567 30
4 20.3 5.4 1.4583 31
5 17.0 4.2 1.4580 29
In the experience of the writer, it is not possible to add to butter fat
any considerable quantity of the more common natural fats or oils,
with perhaps one exception, without producing a mixture in which their
presence would be indicated by the turbidity point even though not
indicated by any of the other values. It may, however, be possible by
carefully controlled addition of certain artificial fats or mixtures to destroy
the evidence of adulteration supplied by the turbidity point. Other
values may or may not in these instances serve to indicate adulteration.
The turbidity point referred to in this paper occurs when certain of
the least soluble glycerides are thrown out of solution. It would
seem that additional information could be obtained by developing
another turbidity point which would serve to throw these glycerides out
of solution coming next in the order of solubility. This could be accom-
plished either by filtering off the precipitate obtained by the first tur-
bidity pomt and running another turbidity point after the addition of
alcohol containing water and of ether, or otherwise by doing this directly
440 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
on the original fat after redissolving the precipitate by raising the
temperature.
From some experimental work undertaken by the writer but not yet
concluded it would seem possible in this way to develop a second and,
if necessary, a third turbidity point by which the presence of any foreign
fat, natural or artificial, could be established with complete certainty.
REPORT ON FATS AND OILS.
By G. S. Jamieson (Bureau of Chemistry, Washington, D. C.), Referee.
In accordance with Recommendations 1 and 2 (1921 report!) the
referee communicated with the American Society for Testing Materials
in regard to the preparation of the Wijs solution in order to secure uni-
formity in methods authorized by this society and the A. O. A. C. It
was found that the American Society for Testing Materials had not yet
adopted the Wijs method, but experimental work under the direction
of the Linseed Oil Committee is being conducted at the present time
with a view to adopting this method ultimately. This society is using
the same method for the preparation of the Wijs solution as that given
under the official procedure of this association’. Investigation has
shown that the method of preparing the Wijs solution in general use in
this country and abroad (by iodine and chlorine gas in an acetic acid
solution) is identical with that given under the official method. This
method of preparation, given in many works on the analysis of oils,
was adopted April 14, 1919, in the Report of the Committee on Analysis
of Commercial Fats and Oils of the Division of Industrial Chemists
and Chemical Engineers of the American Chemical Society’.
The chairman of the Linseed Oil Committee of the American Society
for Testing Materials stated that it was his opinion, based upon investiga-
tions of other chemists, that the alternative method for the preparation
of the Wijs solution using iodine and iodine trichloride in an acetic acid
solution was not so satisfactory as the solution made from iodine and
chlorine gas. In this connection it is interesting to note that in the
1918 Report on the Tentative Standard Methods for the Sampling and
Analysis of Commercial Fats and Oils‘ by the Committee of the Ameri-
can Chemical Society mentioned above, the iodine trichloride method of
preparing the Wijs solution was given, while in the 1919 report of this
committee, which was adopted as official, the original method for the
preparation of this solution was substituted without any comment in
the notes and remarks. However, this change showed that the use of
iodine trichloride was not satisfactory.
1 J. Assoc. Official Agr. Chemists, 1922, 5: 512.
2 Assoc. Official Agr. Chemists, Methods, 1920, 245.
3 J. Ind. Eng. Chem., 1919, 11: 1161.
4 Ibid., 1918, 10: 315.
1923] JAMIESON: REPORT ON FATS AND OILS 44]
During the years 1918 and 1919 the Bureau of Standards made an
investigation of the Wijs method in which solutions prepared by both
methods were employed, and it was found that the solutions made with
iodine and iodine trichloride were not satisfactory because they gave
lower results than those obtained with the solutions prepared from iodine
and chlorine gas. It is not surprising that the use of iodine trichloride
proved unsatisfactory in view of its unstable nature, and this accounts
for the fact that it can not be readily purchased in a pure condition.
Soon after the manufacture of iodine trichloride it begins to decompose
into iodic acid, iodine, etc. Therefore it is recommended that this alter-
native method for the preparation of the Wijs solution be not adopted,
and further that a statement be inserted in the A. O. A. C. official
Wijs method calling attention to the undesirability of using iodine
trichloride for the Wijs solution on account of its unstable character.
Under Recommendation 3 (1921 report), that further study of the
Hanus method be made as to the length of time of absorption (contact
of Hanus solution with oil), a series of experiments was made by W. F.
Baughman in the Bureau of Chemistry, and the results given in Table 1
show conclusively that no advantage is gained by allowing the Hanus
solution to react with an oil for 45 minutes instead of 30 minutes as
stated in the official method. In view of the results obtained it is not
considered necessary to undertake collaborative work.
TABLE 1.
Iodine numbers by Hanus method.
OIL 14 HOUR ABSORPTION 34 HOUR ABSORPTION
REC os see Macrae) etctea te lore sho aya « & 178.5 LAF etS
Sara. 1S BE Oe ee ee eee 128.7 129.5
Cottonseedes es shew SPP Ss 113.8 113.4
AViishareesceds® 257.5 4; sadevdci- 109.1 109.3
TEES HOO Los Sees ® oa: 6 aoa chs) < 66.7 67.5
As directed, the referee conferred with the American Society for
Testing Materials in regard to the preparation of the Hanus solution
and found that the A. O. A. C. official method is employed.
In accordance with Recommendation 4 (1921 report) further study
was made on the detection of sesame oil in olive oil, special attention
being given to those olive oils of African and Spanish origin which them-
selves give a crimson color with the sesame oil reagents. The referee
recommended last year that the testing of the liquid or unsaturated
acids of these oils be added to the present official methods because they
give no color. Since then two rapid methods for the removal of the
color not due to sesame oil have been found. Consequently, this year
it is recommended that the testing of the liquid acids for sesame oil be
not added to the official methods.
442 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
The first method studied was that of Prax', which is based on shaking
the olive oil with 10 per cent alcoholic ammonia, heating until the am-
monia and alcohol are removed, and then applying the usual test. The
reports of the collaborators were very satisfactory. However, in view
of the fact that the referee’s attention subsequently was directed to a
modification of the Villavecchia method, which is even simpler than the
Prax procedure, none of the results obtained with the Prax method will
be given in this report.
The modification referred to was devised or accidentally discovered
many years ago in the Bureau of Chemistry by L. M. Tolman and was
called to the attention of the referee by C. 8S. Brinton. The test is made
according to the official Villavecchia method, and the color is allowed to
develop for 10 minutes before the test solution is shaken with 10 cc. of
water. Any color not due to sesame oil disappears at once. Since it
was found that when the Baudouin reagent (sugar + hydrochloric
acid) was used, the color not due to sesame oil did not completely dis-
appear after shaking with water and further that in many cases the color
due to sesame oil faded very fast, it is recommended that the Tolman
modification be used only with the Villavecchia reagent (furfural and
alcohol).
SAMPLES SENT TO COLLABORATORS.
Five samples of olive oils labeled A, B, C, D, and E were sent to the
collaborators. Sample A was a Spanish oil which gave a crimson color
with the reagents. Sample B was a mixture of 75 per cent of Spanish
oil (A) and 25 per cent of California oil (C). This mixture when first
made gave a light crimson color when tested, but after standing several
weeks it failed to give the color. Sample C was a California olive oil
which gave no color with the reagents. Sample D was California oil
(C) containing 5 per cent of sesame oil, while Sample E was Spanish
oil (A) with a like amount of sesame oil. In view of the satisfactory
results obtained on applying the modified Villavecchia method to these
samples, and of the fact that this method has been successfully used by
a number of chemists for many years, it is recommended that no further
study be made, and that it be made an official method.
Table 2 gives the results obtained and reported by the collaborators.
DISCUSSION.
Although Sample B contained a large amount of Spanish olive oil
(75 per cent) and gave at first a pale crimson color with the sesame oil
reagents, after standing for two weeks it was found that it did not give
any color; this accounts for most of the tests of B being negative.
1 Ann. fals., 1921, 14: 270.
1923] JAMIESON: REPORT ON FATS AND OILS 443
TABLE 2.
Collaborative results obtained on five oils using four different tests.
OIL VILLAVECCHIA TOLMAN BAUDOUIN TOLMAN
ANSEXSE: TEST MODIFICATION TEST MODIFICATION
L. W. Ferris, A Positive Negative
Southern Cotton Oil Co.,; B Negative Negative
Savannah, Ga. (& Negative Negative
D Positive (strong) Positive (strong)
E Positive (strong) Positive (strong)
H. S. Bailey, A Positive (faint) Negative Positive (medium) | Faint pink color
Southern Cotton Oil Co.,| B Negative Negative Very faint pink Negative
Savannah, Ga. Cc Negative Negative Negative Negative
D Positive (strong) Positive (medium) | Positive (strong) Positive (faint)
1D; Positive (strong) Positive (strong) Positive (strong) Positive (faint)
H. P. Strack, A Positive (medium) | Negative Positive (medium) | Faint pink
Southern Cotton Oil Co.,) B Very faint pink Negative Very faint pink Negative
Savannah, Ga. Cc Very faint pink Negative Negative Negative
D Positive (strong) Positive (medium) | Positive (strong) Positive (faint)
E Positive (strong) Positive (medium) | Positive (strong) Positive (faint)
J.T. Parsons, A Positive Negative Positive Faint pink color
H. J. Heinz Co., B Negative Negative Negative Negative
Pittsburgh, Pa. C Negative Negative Negative Negative
D Positive (strong) Positive (strong) Positive Positive
E Positive (strong) Positive (strong) Positive Positive
R. M. Hann, A Positive (crimson) | Negative
Bureau of Chemistry, B Faint crimson Negative
Washington, D. C. Cc Negative Negative
D Positive (strong) Positive (strong)
E Positive (strong) Positive (strong)
A. L. Mehring, A Positive Negative
Bureau of Animal Indus-| B Negative Negative
try, Washington, D. C. G Negative Negative
D Positive (strong) Positive
E Positive (strong) Positive
G. S. Jamieson. A Positive (crimson) | Negative
B Pale crimson Negative
Cc Negative Negative
D Positive (strong) Positive (strong)
E Positive (strong) Positive (strong)
R. H. Kerr, A Positive Faint pink
Bureau of Animal Indus-| B Negative Negative
try, Washington, D. C Cc Negative Negative
D Positive (strong) Positive
E Positive (strong) Positive
J. B. Martin, A Positive Faint pink
Bureau of Animal Indus-| B Negative Negative
try, Washington, D. C. (e Negative Negative
D Positive (strong) Positive
E Positive (strong) Positive
D. G. Sorber, A Positive Faint pink
Bureau of Animal Indus-| B Negative Negative
try, Washington, D. C Cc Negative Negative
D Positive (strong) Positive
E Positive (strong) Positive
Since it was recommended that a more comprehensive description be
prepared in connection with the tests for sesame oil, the following is
offered for consideration:
10 minutes.
SESAME OIL.
Baudouin Test.—Official.
Dissolve 0.1 gram of finely powdered sugar in 10 ce. of hydrochloric acid (sp. gr. 1.2),
add 10 cc. of the oil to be tested, shake thoroughly for 1 minute and allow to stand for
In the presence of even a very small admixture of sesame oil, the aqueous
444 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
solution is colored crimson. It should be observed that some olive oils, especially
those of African or Spanish origin, give pink or crimson colors which can be readily
differentiated from the color due to sesame oil by applying the following modification
of the Villavecchia method:
Villavecchia Test.
Add 2 ce. of furfural to 100 cc. of 95 per cent alcohol by volume and mix thoroughly
0.1 ce. of this solution with 10 cc. of hydrochloric acid (sp. gr. 1.2) and 10 ce. of the oil
to be tested by shaking them together for 14 of a minute. Allow mixture to stand
10 minutes, observe color, add 10 cc. of water, shake and again observe color. If the
crimson color disappears, sesame oil is not present.
_ Norr.—As furfural gives a violet tint with hydrochloric acid, it is necessary to use the very dilute solu-
ion specified above.
FUTURE WORK.
THE DETERMINATION OF UNSAPONIFIABLE MATTER.
The Fat and Oil Committee of the American Chemical Society re-
quested the referee to call attention to the fact that the association’s
official method for unsaponifiable residue which was adopted years ago
was not found satisfactory by the committee. The reason why it is men-
tioned at this time is that the A. O. A. C. methods are recognized abroad,
and a number of referee chemists have stated that they are using the
methods which, with this one exception, would be recognized as suitable
for commercial referee work. It was stated that the method given in
the last report of the Committee on Standard Methods for the Sampling
and Analysis of Commercial Fats and Oils', based on several years’
study and a large amount of cooperative work, was found to give very
desirable results. Since the determination of unsaponifiable matter is
very important commercially, it was requested by the committee that
this association take up again the study of this determination.
The attention of the referee was called by R. Hertwig and T. O. Kel-
lems to an important omission in the description of the official method
for the preparation of the Hanus solution’, which is liable to cause some
chemists to make serious errors in the preparation and standardization
of this solution.
The method should be corrected as follows:
The sentence beginning “Add 3 cc. of bromine to 200 ce. of acetic acid, etc.”’, should
read ‘‘Add 3 cc. of bromine to 200 cc. of acetic acid and titrate 5 cc. of the solution
against the N/10 sodium thiosulfate, adding 10 cc. of potassium iodide solution (15%)
before titrating’.
RECOMMENDATIONS.
It is recommended—
(1) That the alternative method for the preparation of the Wijs
solution (iodine trichloride method) be not adopted, and further that a
1 J. Ind. Eng. Chem., 1919, 11: 1161.
2 Assoc. Official Agr. Chemists Methods, 1920, 244, par. (a).
1923] BAILEY: REPORT ON BAKING POWDER 445
statement be inserted in the A. O. A. C. official Wijs method! calling
attention to the undesirability of using iodine trichloride for the Wijs
solution on account of its unstable character.
(2) That the method for the preparation of the Hanus solution be
corrected as specified in this report, but that no other change be made
in the official Hanus method.
(3) That the modified Villavecchia test be made official. It is recom-
mended also that the description of the Baudouin and modified Villa-
vecchia tests be changed to read as given in this report.
(4) That further work be done on the determination of the unsaponi-
fiable matter.
H. S. Bailey: It is apparently difficult to obtain hydrochloric acid
which has a specific gravity of 1.20, as recommended in the present
official method for the detection of sesame oil in olive oil.
It has been found that acid with a specific gravity of 1.18 is just as
satisfactory as the stronger acid in this test, and therefore it is suggested
that when the present method is rewritten hydrochloric acid of 1.18
specific gravity be specified.
It was recommended by Committee B that a study be made of
the Baudouin and Villavecchia tests using hydrochloric acid of varying
specific gravity.
REPORT ON BAKING POWDER.
By L. H. Bartey (Bureau of Chemistry, Washington, D. C.), Referee.
The work on baking powder for 1922 was followed along the lines
recommended by Committee C at the 1921 meeting. Collaborative
work was done on the electrolytic determination of lead, the neutralizing
value of mono-calcium phosphate, the volumetric determination of car-
bon dioxide and the determination of fluorine.
The samples sent to the collaborators were prepared through the
courtesy of J. R. Chittick, Jaques Manufacturing Co., Chicago, IIL;
E. W. Thornton, R. B. Davis Co., Hoboken, N. J.; and Augustus H.
Fiske, Rumford Chemical Works, Providence, R. I.
DETERMINATION OF LEAD BY THE ELECTROLYTIC METHOD.
Directions:
(1) Use the Corper-Bryan method as published.
(2) Use your own method, giving with your report the details of the
method used.
1 Assoc. Official Agr. Chemists, Methods, 1920, 245.
2 J. Assoc. Official Agr. Chemists, 1920, 4: 221.
446 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
Samples for the determination of lead were sent to 10 analysts who had
agreed to work along this line, but results were received from only two
of them, and these results are so widely apart that they are worthless.
It is possible that in the case of one analyst a mistake was made in placing
the decimal point. The following are the results submitted:
TABLE 1.
Electrolytic determination of lead.
BRYAN-CORPER ANALYST’S
ENE DEAS METHOD METHOD
parts per million parts per million
Augustus H. Fiske 4.1 6.6
Oo: 8.0
PNVEEALO 26s cle icid 4 aera 4.7 7.3
J. K. Morton, Bureau of Chemistry, Washington, 57.69
DE Ge 62.80
58.90
IAN ETALC | Neiseite re ee 59.80
More work should be done with this method or with modifications of
it before taking any action as to its adoption.
NEUTRALIZING STRENGTH OF MONO-CALCIUM PHOSPHATE.
The use of different indicators and combinations of indicators was
studied by Ruth Buchanan of the Food Control Laboratory of the
Bureau of Chemistry, but the subject was not submitted to collaborative
study. Her report on this subject follows:
In the study of the use of different indicators the following method was employed:
0.84 gram of the phosphate was weighed and put into a 250 cc. beaker; 125 cc. of
distilled water and a definite amount of a standard indicator solution were added.
The solution was titrated with 0.5N nitric acid until the proper end-point was obtained,
and then boiled for 1 minute. The titration was continued where necessary to regain
the correct end-point. The total reading multiplied by 5, equals the neutralizing
value in terms of parts sodium bicarbonate per 100 parts of phosphate.
The indicators used were:
(1) Phenolphthalein 0.5% alcoholic solution
(2) Thymolphthalein 0.04% alcoholic solution
(3) Thymol Blue 0.04% solution.
(4) Methyl Red 0.02% alcoholic solution.
These indicators were suggested by an article by J. L. Lizius'.
A starch-filled phosphate was used in this work.
The results obtained are given in Tables 2, 3, and 4.
1 Analyst, 1921, 46: 355.
1923] BAILEY: REPORT ON BAKING POWDER 447
TABLE 2.
Titration.
cotp 0.5N HOT 0.5N NEUTRALIZING
SODIUM HYDROXIDE SODIUM HYDROXIDE VALUE
ce cc
1 cc. Phenolphthalein 8.9 8.9 44.5
1 cc. Thymolphthalein 9.75 10.2 51.0
0.25 ec. Phenolphthalein 9.2 9.2 46.0
0.75 cc. Thymolphthalein
0.5 ec. Phenolphthalein 9.1 9.1 45.5
0.5 cc. Thymolphthalein
0.4 cc. Phenolphthalein 9.02 9.02 45.10
0.6 cc. Thymolphthalein
1 cc. Phenolphthalein 9.05 9.05 45,25
3 cc. Thymolphthalein
0.75 cc. Phenolphthalein 8.95 8.95 44.75
0.25 cc. Thymolphthalein
0.6 cc. Phenolphthalein 8.95 8.95 44.75
0.4 ec. Thymolphthalein
3 cc. Phenolphthalein 8.60 8.60 43.00
1"cc. Thymolphthalein
All the above combinations work well.
TABLE 3.
Titration.
coLp 0.5N HOT 0.5N NEUTRALIZING
SODIUM SODIUM VALUE REMARKS
HYDROXIDE HYDROXIDE
cc. cc.
1 cc. Methyl Red 1 | 4.4 22.0 End-point fair.
Ls cc. Thymol Blue 9.7 9.7 48.5 End-point good.
d
0.25 cc. Methyl Red 9.3 9.7 48.5 Orange color to start, yel-
0.75 cc. Thymol Blue low with 3 cc. alkali,
blue with 9.3 cc. alkali.
t ae combination of methyl red and thymol blue is no better than thymol blue by
itself.
TABLF 4.
Titration.
coLtp 0.5N HoT 0.5N NEUTRALIZING
SODIUM SODIUM VALUE
HYDROXIDE HYDROXIDE
cc. cc.
0.5 cc. Thymol Blue, 1 drop Methyl
ANC eyelets csielsed Matos scene 9.7 9.7 48.5
Pee. Methyl Orange)... i.e 0.1 0.1 0.5
Methyl orange gives too low results. A combination of methyl orange and thymol
blue is no better than thymol blue by itself.
448 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
CONCLUSIONS.
(1) Of all the indicators employed, the combination of phenolphthalein and thymol-
phthalein is preferred. The best proportion probably is half and half. The end-point
obtained by the use of both indicators is a little more distinct than that obtained by
the use of either one alone.
(2) The indicator should be made up with accuracy, and the amount should be
measured by means of a pipet graduated in tenths of a cc.
Collaborative study was made of the neutralizing value of mono-
calcium phosphate by using two methods sent out by the referee as
follows:
NEUTRALIZING VALUE OF MONO-CALCIUM PHOSPHATE.
Method I.
Weigh 0.84 gram of phosphate into a 3A casserole.
Add 25 cc. of water and stir a moment.
Add exactly 90 cc. of 0.1N sodium hydroxide.
Bring to boil and boil for 1 minute.
Add 1 drop of phenolphthalein (1% solution).
Titrate while still boiling hot with 0.2 hydrochloric acid.
End-point when pink color due to indicator has all but disappeared and does not
return in one minute.
CALCULATION.
90 —2 (ce. standard hydrochloric acid used) = neutralizing strength of 100 parts
of phosphate in terms of bicarbonate of soda.
Method II.
Weigh 0.84 gram of mono-calcium phosphate into a 150 cc. beaker.
Add 25 cc. of water and 10-15 drops of phenolphthalein (1% solution).
Titrate with 0.5N sodium hydroxide to a faint pink, then heat to boiling, boil 1
minute and titrate while hot to faint pink again.
(Add bulk of alkali rapidly with vigorous stirring.)
CALCULATION.
Total buret reading X 5 = neutralizing strength of 100 parts of phosphate in terms
of bicarbonate.
These methods are so different that the results obtained were noticeably
lower in one case than in the other. The collaborators were asked to
make up baking powders with the sample of phosphate sent them by
adding the amount of bicarbonate of soda indicated by their determi-
nations and then make biscuits with these baking powders and report
upon the character of the biscuits made.
Table 5 gives the average results of the collaborators using the two
methods suggested.
DISCUSSION.
The analysts in commenting upon the biscuits made as directed were
in agreement that there was not a great difference but that those made as
indicated by Method II were whiter in color than those made according
1923] BAILEY: REPORT ON BAKING POWDER 449
TABLE 5.
Neutralizing value of mono-calcium phosphate.
ANALYST METHOD I METHOD II RUMFORD
METHOD*
per cent per cent per cent
Augustus H. Fiske 82.20 72.00 71.40
W. G. Warning, Provident Chemical Works,
St. Louis, Mo. 79.90 73.00
A. L. Foscue, Piedmont Electric Chemical Co..,
Mt. Holly, N. C. 81.675 79.50
R. Leone Rutledge, Bureau of Chemistry,
Washington, D. C. 81.09 71,25
Ruth Buchanan 79.74 TORS
*Similar to Method II.
to the proportions given in Method I. On the other hand, there was
no evidence of undecomposed bicarbonate of soda in the biscuits made
according to results obtained by Method I.
Experiments made in the Food Control Laboratory of the Bureau of
Chemistry showed that a greater proportion of phosphate than indicated
by Method ITI did not increase the whiteness of the biscuits, while a
greater proportion of bicarbonate of soda than indicated by Method I
did give a yellow biscuit, the color of which became more intense with
increasing amounts of soda.
It is the opinion of the referee that the results obtained by Method II
are more nearly in accord with those that are actually obtained in
baking than are the results by Method I, and that those obtained by
Method I are too high for exact neutrality in baked goods although
they are not so high but that these figures may be used in making up
baking powder that will produce biscuits which do not give evidence of
containing an excessive amount of soda. Quite a range may exist,
therefore, within which a value may be taken as the neutralizing value
and used satisfactorily in calculating the proportions to be employed in
making a baking powder. Nevertheless it would be desirable to have
one method only for getting the neutralizing value, and this should
represent as nearly as possible the reaction actually obtained in baking.
For this reason Method II is suggested as the more desirable method.
FLUORINE IN BAKING POWDER.
This phase of the subject was handled by J. K. Morton, the associate
referee, and a report will be made by him.
VOLUMETRIC METHODS FOR THE DETERMINATION OF CARBON
DIOXIDE.
Two methods for the volumetric determination of carbon dioxide in
baking powders were studied. Descriptions of these methods were fur-
450 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
nished by the firms originating them. They have been used for a num-
ber of years for routine control work and this year were submitted to
collaborative study. The methods are as follows:
A simple and rapid volumetric method for the estimation of carbon dioxide
in baking powder.
(Submitted by R. B. Davis Co., Hoboken, N. J.)
The apparatus consists of a Schiff nitrometer (Eimer & Amend No. 4750) graduated
to 100 ce. in 1/5 ec. with the adapter tube (B) sealed off about one inch from the nitrom-
eter tube. A leveling bulb (D) is attached to the nitrometer tube at C by means of
heavy rubber tubing (E), of sufficient length to allow the leveling bulb to be raised to
the top of the nitrometer tube.
To the top of the nitrometer tube above the stop-cock (F), which should be left open
at all times, is attached another piece of heavy rubber tubing, the other end of which is
attached to a piece of strong glass tubing of about 76 inch inside diameter passing
through a No. 9 rubber stopper (G).
The rest of the apparatus consists of (1) a heavy glass bottle cap (the same as used
for covering stoppers) of 154 inches diameter and having a capacity of about 50 cc.
and (2) a flat-bottomed glass cylinder (J), having an inside diameter of +4 inch and
height of 11% inches, with a 5 cc. graduation marked about i's inch from the top. (This
cylinder may be made by cutting off a flat-bottomed test tube of 1% inch diameter,
1 inches from bottom of the tube.)
The nitrometer tube should be filled with mercury, care being taken that air bubbles
are expelled. The leveling bulb should be about half filled with mercury when the
bulb is raised to the top of the nitrometer tube. The apparatus should be supported
on a ring stand having a heavy base by two strong clamps.
DETERMINATIONS.
0.5 gram of the well-mixed sample is introduced into the bottom of the glass bottle
cap (H). 5 cc. of hydrochloric acid (sp. gr. 1.127) is placed in the cylinder (J), which
should be absolutely dry on the outside, and the cylinder lowered into the bottom of
the bottle cap (H) by holding it against the side of the bottle cap by the index finger.
The bottle cap is then connected with the rubber stopper (G), care being taken not to
overturn or shake out any of the acid on the sample of baking powder. (The leveling
bulb should be near the top of the nitrometer tube when this connection is made.)
The level of the mercury in the leveling bulb and in the nitrometer tube is then
adjusted so that the levels are exactly the same and the reading taken. Then holding
the cup (H) in the right hand and the leveling bulb in the left, shake the cup, over-
turning the acid on the sample. The level of the mercury in the nitrometer tube will
fall. Lower the leveling bulb with the left hand, keeping the levels of the mercury
in the bulb and in the tube as nearly the same as possible during the entire evolution
of the gas.
Shake the cup (H) thoroughly in order to be sure that all the baking powder has
been decomposed, adjust the levels of the mercury in the leveling bulb and in the nitrom-
eter tube by moving the leveling bulb up and down an inch or so until the levels are
again exactly the same, and take the reading. Note temperature and pressure.
The per cent of carbon dioxide is calculated as follows:
Example: Volume of gas liberated...............6... 35.0 ce.
PeMperavure! Weyl clear eee tone ate ee 29°C.
Barometers Mase Ma eR Een oe On 760 mm.
451
REPORT ON BAKING POWDER
BAILEY
1923]
—ABSORPTION APPARATUS FoR Davis METHOD
1
Fia.
452 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
From Table 6, absorption of carbon dioxide in 5 ce. of hydrochloric acid (sp. gr.
1.127) is 5.16 ce.
Therefore, total evolution of gas is 35.0+5.16 cc. =40.16 ce.
From Table 7, weight of 1 cc. of carbon dioxide (in milligrams) at 29°C. and 760 mm.
pressure = 1.7101.
1.7101 X 40.16 =0.0686 gram.
0.0686 X2 X 100 —0.25! = 13.47% carbon dioxide.
756
1.8399
1.8318
1.8233
1.8150
1.8065
1.7981
1.7895
1.7309
1.7722
1.7634
1.7546
1.7456
1.7365
1.7274
1.7184
1.7094
1.7016
1.6920
2 4.17
2 3
2.00 2.16
LGieealid
4.33
31
5.10
45
5.28
59
5.47
73
30
5.09
44
5.27
58
5.45
72
5.65 5.66
86 87
5.85 5.86
100
6.04
758
1.8448
1.8367
1.8292
1.8199
1.8114
1.8030
1.7943
1.7857
1.7770
1.7682
1.7593
1.7503
1.7412
1.7321
1.7231
1.7142
1.7054
1.6967
TABLES TO BE USED WITH THE DAVIS METHOD.
4
2.31
18
4.48
32
5.11
46
5.30
60
5.48
74
5.68
88
5.87
5
760
1.8498
1.8417
1.8331
1.8248
1.8162
1.8078
1.7992
1.7906
1.7818
1.7730
1.7641
1.7551
1.7460
1.7368
1.7278
1.7189
1.7101
1.7014
6
20
4.79
34
5.14
48
5.32
62
5.51
76
5.71
90
5.90
762
1.8548
1.8466
1.8381
1.8297
1.8211
1.8127
1.8040
1.7954
1.7866
1.7778
1.7689
1.7598
1.7507
1.7416
1.7325
1.7232
1.7148
1.7051
TABLE 6.
Baking powder absorption of carbon dioxide in 5 cc. of hydrochloric acid, sp. gr. 1.127.
7 8
2.47 2.62 2.78 2.93
19
4.61
33
5.13
47
5.31
61
5.50
75
5.69
89
5.89
21
4.95
35
5.16
49
5.34
63
5.52
77
5.72
91
5.92
22
4.97
36
5.17
50
5.39
64
5.54
78
5.73
92
5.93
9
3.09
23
4.98
37
5.18
51
5.36
65
5.59
79
5.75
93
5.94
‘TABLE 7.
Weight of a cc. of carbon dioxide in milligrams.
(Millimeter on barometer.)
764
1.8597
1.8515
1.8430
1.8346
1.8260
1.8175
1.8089
1.8002
1.7914
1.7326
1.7737
1.7647
1.7554
1.7463
1.7372
1.7283
1.7199
1.7107
766
1.8647
1.8565
1.8479
1.8395
1.8308
1.8233
1.8137
1.8050
1.7962
1.7874
1.7784
1.7694
1.7602
1.7510
1.7419
1.7330
1.7241
1.7153
10
3.24
24
5.00
11
25
5.03
39
5.21
53
5.38
67
5.58
81
5.78
95
5.97
38
5.20
52
5.37
66
5.57
80
5.76
94
5.9
768
1.8697
1.8614
1.8528
1.8444
1.8357
1.8282
1.8185
1.8099
1.8012
1.7922
1.7882
1.7741
1.7649
1.7557
1.7466
1.7378
1.7298
1.7190
12
3.40 3.55 3.71
26
5.04
40
5.23
54
5.40
68
5.59
82
5.79
96
5.99
770
1.8748
1.8663
1.8577
1.8492
1.8406
1.8330
1.8234
1.8147
1.8060
1.7970
1.7880
1.7788
1.7697
1.7605
1.7513
1.7427
1.7345
1.7246
13 14
3.86
28
5.06
42
5.25
56
5.42
70
5.62
84
5.82
98
6.02
27
5.06
41
5.24
55
5.41
69
5.61
83
5.80
oF
6.00
772
1.8798
1.8713
1.8626
1.8541
1.8454
1.8379
1.8282
1.8195
1.8108
1.8018
1.7928
1.7836
1.7744
1.7652
1.7660
1.7474
1.7382
1.7293
Evolved
Absorbed
Evolved
Absorbed
Evolved
Absorbed
Evolved
Absorbed
Evolved
Absorbed
Evolved
Absorbed
Evolved
Absorbed
Evolved
Absorbed
774
1.8848
1.8763
1.8675
1.8590
1.8503
1.8427
1.8331
1.8243
1.8156
1.8066
1.7975
1.7884
1.7791
1.7699
1.7707
1.7517
1.7429
1.7339
Norts.—A correction factor must be determined for each apparatus. 0.25 will be found to be about right.
1923] BAILEY: REPORT ON BAKING POWDER 453
A volumetric method and apparatus for determining the carbon dioxide conient cf baking
powder.
(Submitted by J. Raymond Chittick.)
DETERMINATION.
The determination is carried out in an apparatus by treating a factor weight of the
baking powder, or the residue therefrom, with dilute sulfuric acid and measuring the
volume of the evolved carbon dioxide.
APPARATUS.
The apparatus consists of a decomposition
flask connected by means of a glass T-tube,
provided with a stop-cock, to a gas measuring
tube, which in turn is connected to a leveling
bulb. The composition flask—a 250 cc. Py-
rex wide-mouth extraction flask—is fitted
with a two-hole rubber stopper to allow for
connection with the gas-measuring tube by
means of glass and rubber tubing and for
the insertion of the tip of a buret. The buret
has a capacity of 25 cc. and is graduated in
cubic centimeters at 200°C., numbering each
5 cc. The tip of the buret is extra long, bent
in order to pass through the rubber stopper.
The gas-measuring tube is graduated in cubic
centimeters at 20°C., numbering each 10 ce.,
the zero mark being placed at a volume of
25 cc. below the top marking to allow for
graduating upward from 0 to 25 cc. and
downward from 0 to 200 ce.
A rubber connection is made between
the glass tube leading from the decomposition
flask and the T-tube extensions of the gas-
measuring tube to permit the rotation of the
decomposition flask. The gas-measuring tube
is connected by means of rubber tubing with
a leveling bulb. The bulb has a capacity of
about 300 cc. A saturated solution of sodium
chloride is prepared to which a small amount
of sodium bicarbonate is added. The whole
is then rendered slightly acid with sulfuric
acid. This solution is used in the gas meas-
uring tube and leveling bulb and seldom
needs to be replaced.
REAGENT.
Dilute sulfuric acid, sp. gr. 1.14 (approxi-
mately one volume of concentrated acid to
five volumes of water). This solution is used
= Fic. 2.—ABsSORPTION APPARATUS FOR
in the 25 GC. buret. Cxuittick MeErtruop.
454 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
PREPARATION OF SAMPLE.
Remove the entire sample from the package, pass through a 40-mesh sieve and mix
thoroughly.
DETERMINATION.
Thermometric and barometric readings, preferably expressed in degrees Centigrade
and in millimeters of mercury, are essential. The factor weight of the baking powder
to be used in the determination is dependent upon the existing atmospheric conditions.
After both temperature and pressure of the air in the room are determined, reference
is made to Parr’s table! for the density of carbon dioxide, and the weight of one liter
of carbon dioxide under like conditions is taken as the factor weight.
For example: Pressure = 746 mm.; temperature = 22°C.; one cc. of CO: weighs
1.7390 mg. or one liter weighs 1.7390 grams; therefore, 1.7390 grams is the factor weight
of baking powder to be taken for analysis.
TOTAL CARBON DIOXIDE.
The factor weight of baking powder is placed in the dry decomposition flask and
connection made to the apparatus by means of a rubber stopper. The T-tube stop-
cock is opened and, by means of the leveling bulb, the salt solution is brought to a
graduation above the zero mark equal in volume to the amount of acid to be used in
the decomposition. (For example, if 10 cc. of acid are to be used, the solution is leveled
at the 10 cc. graduation above the zero mark.)
A minute is allowed to insure equalization of the temperature and pressure within
the apparatus with that in the room.
The stop-cock is closed. The leveling bulb is lowered somewhat, diminishing the
pressure within the apparatus, and 10 cc. of dilute acid are slowly run into the decom-
position flask. The salt solution should at all times during the decomposition be kept
at a lower level than that in the gas-measuring tube to prevent the liberated carbon
dioxide from escaping through the acid buret into the air. The decomposition flask
is well rotated to secure intimate contact of materials, then allowed to remain at rest
for 5 minutes.
The pressure is equalized by means of the leveling bulb and the volume of the evolved
gas is read. Divide the number of cc. by 10 to obtain the per cent of total carbon
dioxide by weight.
RESIDUAL CARBON DIOXIDE.
The factor weight of baking powder is placed in the decomposition flask; 20 cc. of
water are added and allowed to stand 20 minutes. Place the flask in a metal drying
cell surrounded by boiling water and heat, with occasional shaking, for 20 minutes.
To complete the reaction, heat quickly to boiling and boil for a minute. Cool to room
temperature, then connect flask to the apparatus and determine the carbon dioxide
present, by treating with 10 cc. of dilute acid as described under total carbon dioxide.
AVAILABLE CARBON DIOXIDE.
Subtract the residual carbon dioxide from the total.
Unfortunately the different analysts did not have both types of
volumetric apparatus, but some of them compared the results obtained
with one apparatus with those obtained by some other method in use
in the laboratory and in general got concordant results.
1 Van Nostrand’s Chemical Annual, Olsen, Fourth Issue, 1918, 100.
1923] BAILEY: REPORT ON BAKING POWDER 455
Two samples for the determination of carbon dioxide were submitted.
One of them contained theoretically 16.197 per cent and the other one
13.09 per cent of carbon dioxide. The collaborative results are given
in Table 8.
These results are very encouraging and indicate that volumetric
methods should be checked against the absorption methods which are
now Official.
TABLE 8.
Volumetric determinations of carbon dioride*.
ANALYST CHITTICK METHOD DAVIS METHOD ROBINSON METHOD | RUMFORD METHOD
No. 1 No. 2 No.1 No.2 No» iy) (Nor 2 No.1 No. 2
per cent per cent | per cent per cent | per cent per cent | per cent per cent
G. D. Richards, 16:15" 12:97
Jaques Mfg. Co. 16.15 12.81
Chicago, II). 16.13 12.90
16.14 12.95
16.16 12.86
16.16 12.93
Average...... 16.15 12.90
J. R. Chittick 16:12 138.05
16.17 13.05
eet 13:05 Bei
Average...... 16.15 18.05
C. J. Preston, 16.10 12.93
Jaques Mfg. Co., 16.15 12.95
Chicago, Ill. 16.10 12.85
16.10 12.99
au 12.93
Average...... 16.11 12.93
Ruth Buchanan 1G: O1SAS') Looe.) Tee
16.15 13.13 ace oA
16.24 13.138 ties leo
16.20 13.13 Sacer see
16.14 —— © cee p LOG
16.14 Ay.13.13 coins 8 1303
AGL Aye, Spork sieht SLOG
G23: Wee: fee 13:06
G23 os sre we ae sere dalale SRY 8
—— —— |Average 13.04 | ——- ——— | —— ——
Average..-... 16.19
O. B. Winter, Michi- .... paid 16.44 13.46
gan Agricultural suber sade bpl6:30) pls 40o hae. eagk: S cua 5 ae
College, E. Lan- ri Dy ae 16.28 13.46 estan eye lilo bs ©
sing, Mich. en ae a ei
Average...... ied Bt] Ot e torae
*Sample No. 1 contained theoretically 16.197% and Sample No. 2, 13.09% of carbon dioxide.
456 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
TABLE 8—Continued.
Volumetric determinations of carbon dioxide*.
a
ANALYST CHITTICK METHOD DAVIS METHOD ROBINSON METHOD |RUMFORD METHOD
No. 1 No. 2 No.1 No.2 No: 1) Nox No.1 No.2
per cent percent | percent percent | per cent percent | percent percent
L. J. Hendryx, Mich- .... dees baes a One) Se
igan Agricultural ate So Ne LOSZOW AZ OF:
College, E. Lan- ae Boe 16.00 13.20
sing, Mich. Arete Jo. | GIS 13.20
Pe eee 16.20 13.14
16.20 12.84
.s.+ | ==, 18.00
Average| 16.20 12.84
Re Se ane
13.14
13.14
13.08
Average 13.04
C. S. Robinson, at hee COR 5. tee Gy LO 12.00
Michigan Agricul- ae ae Bek i Bl alae) ) apy
tural College, E. AS es io a owes Wy 1645 oe LAG
Lansing, Mich. aha Sar Batak eh 16.12 13.03
ee Sera 16.05 13.00
wee. | —— 138.06
Average] 16.09 12.89
Sete Le eD
12.71
12.78
13.05
12.88
Average 12.87
Augustus H. Fiske RAD SUES 3c. Ns Gr a a Sle Ea P ocarg,felail Une ae een
hee tami Mi | a2) AS Wee lt RP abel met ote Aid| ia! | cal a hb! lol
16.26 13.31 Sai Or Say a Se eee
16.59 eee eee | —
W612 ay BBE vee! ONS OG Ee yee
1633S 7 Ses setae en ae «fins
16.63.
16.49
16.41
Average} 16.47
*Sample No. 1 contained theoretically 16.197 % and Sample No. 2, 13.09 % of carbon dioxide.
RECOMMENDATIONS.
It is recommended—
(1) That the electrolytic method for the determination of lead be
further studied.
(2) That Method II for determining the neutralizing value of mono-
calcium phosphate as collaboratively studied in 1922 be made a tenta-
tive method.
1923] MORTON: REPORT ON FLUORIDES IN BAKING POWDER 457
(3) That the accuracy of the volumetric methods for the determina-
tion of carbon dioxide be compared with the official absorption methods
before they are recommended as tentative methods.
REPORT ON FLUORIDES IN BAKING POWDER.
By J. K. Morton (Bureau of Chemistry, Washington, D. C.), Associate
Referee.
The report of the associate referee in 1921 pointed out that the Wag-
ner-Ross method for the determination of fluorides as published! did
not give the degree of accuracy desired when applied to baking powder.
Some changes were suggested in the manipulation and apparatus which
resulted in a higher and more consistent recovery of fluorine. Inthe absence
of any published detailed instructions as to the procedure in determining
fluorine in baking powder a detailed method was submitted for approval.
The report of Subcommittee C recommended that the Wagner-Ross
method for fluorine in baking powder be submitted to further study.
In accordance with this recommendation samples of baking powder
were prepared for collaborative work.
These samples, together with a copy of the Wagner-Ross method and
a statement of the experience of the associate referee with this method,
setting forth the changes suggested in the report of the associate referee
for 1921, were sent to those who had agreed to collaborate in this work.
Directions were also given for the preparation of a carbon-free ash.
The collaborators were directed to carry out the determination as
follows:
Ash 20 grams of baking powder in a muffle furnace. Place the ash, together with
1 gram of quartz flour and 5 grams of anhydrous copper sulfate, in the digestion flask.
Thoroughly mix the contents of the flask. Connect the flask in its position in the
train. Pour 50 cc. of special sulfuric acid into the 50 cc. Erlenmeyer flask and place
it in its position in the train. Start the air very slowly, tilting the digestion flask
sufficiently to allow the first portion of the acid to flow into the trap and form a seal.
Regulate the flow of air to give just enough headway to prevent any back pressure.
Apply heat to the digestion flask slowly, allowing the mixture to come to boiling in
not less than two hours. Shake the flask occasionally during the heating. Boil for
ten minutes, remove the flame and allow the air to pass through for thirty minutes
longer. Disconnect the delivery tube with the absorption flask and transfer the con-
tents to a 750 cc. Erlenmeyer. Dilute with water to 250 cc., bring to boiling for 10
minutes, cool slightly under running water and titrate with 0.1N alkali, using phenol-
phthalein as indicator.
The following table gives a record of the results submitted by the col-
laborators on the determination of fluorine in baking powder:
1 J. Ind. Eng. Chem., 1917, 9: 1116.
458 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
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1923] MORTON: REPORT ON FLUORIDES IN BAKING POWDER 459
DISCUSSION AND COMMENTS.
W. E. Stokes of the Royal Baking Powder Company introduced a
modification in the manipulation of the method and the calculation of
fluorine. He disregarded the production of sulfate in the absorption
flask but determined the amount as barium sulfate and corrected accord-
ingly. By a number of control determinations he established a factor
of 1.117 for fluorine. His results are very good comparatively, but
they are a trifle high.
A. H. Fiske of the Rumford Chemical Company commented on the
difficulty of securing a suitable ash by simple ignition and leaching
with water. In ashing the material he used a 40 per cent solution of
magnesium nitrate. Milk of lime was added to each sample before
ignition to be sure there was sufficient base present to prevent the
volatilization of fluorine.
L. D. Mathias of the Victor Chemical Company mentioned the diffi-
culty of securing a suitable ash and the importance of a source of con-
stant air pressure. He suggested the use of compressed carbon dioxide
because of its general availability, as a carrier for the gases evolved.
The use of magnesium nitrate in ashing the material was given a
thorough trial by the associate referee with most excellent results.
Duplicate determinations were made on all the collaborative samples
with the results reported in the table. The advantage of the use of
magnesium nitrate to ash the material was at once apparent. Where
carbon is present, the sulfur dioxide evolved by the decomposition of
the sulfuric acid is not retained in the chromic sulfuric acid wash solu-
tion, except in very slight amounts, but passes on into the absorption
tube, introducing a source of error. The addition of magnesium nitrate
to the ash and the re-ignition of the material completely destroys the
carbon remaining and yields a carbon-free ash. The presence of nitrates
in the digestion flask gives rise to nitrous fumes. In passing through
the chromic-sulfuric acid wash solutions these are completely absorbed.
Repeated tests were made to detect their presence in the absorption
tube without success.
The addition of any neutralizing agent to a phosphate or alum-
phosphate baking powder before ignition has not been found necessary.
The material is prepared to be neutral or slightly alkaline. An excess
of alkalinity is to be avoided.
Any inert gas such as air, carbon dioxide or nitrogen, the pressure
of which can be carefully controlled to give a uniform flow, can be used
in this determination.
The results obtained by the different analysts are not concordant.
Some show excellent agreement, but the fluctuations on the whole
460 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
are too great. This may be explained by the fact that each of the
collaborators introduced modifications of the method.
The results obtained by the associate referee and W. E. Stokes clearly
indicate that this method can be applied successfully to the determi-
nation of fluorine in baking powder, with a recovery of approximately
90 per cent of the fluorine in the sample.
The following procedure is recommended for the preparaiion of a
baking powder for the determination of fluorine:
Take 20 grams of baking powder in a porcelain evaporating dish. Place it in a
muffle furnace at low heat and allow the volatile organic matter to burn off as com-
pletely as possible without allowing the furnace to come to the point where any redness
is discernible, about 400°C. The resulting ash will be quite dark. Remove and allow
to cool. Powder it again and add 10 cc. of a 50% solution of magnesium nitrate. (Be
sure that the ash is thoroughly saturated without excess of the solution.) Drive off
the excess of moisture in an oven and reheat in the muffle as before.
RECOMMENDATION.
It is recommended that the Wagner-Ross method as applied to the
determination of fluorine in baking powder be submitted for further
study.
DRUG SECTION.
REPORT ON DRUGS.
By G. W. Hoover (Food and Drug Inspection Station, Transportation
Building, Chicago, Iil.), Referee.
Your referee on drugs has no elaborate report to make. It may be
stated that the work on the various subjects has been conducted by the
associate referees according to the plan initiated several years ago.
Some important investigations are completed with this year’s report,
and attention will be given to a few new subjects. It has been impos-
sible to secure the assistance of as many associate referees as desired
during the past year; however, considering the work as a whole, very
satisfactory progress has been made. The associate referees deserve
much credit for the excellent reports that will be presented on the various
subjects at this meeting, and your referee is grateful to them and others
who have manifested an interest by giving suggestions and assistance
in the drug work for the association.
1923] HOOVER: ANALYSIS OF ARSPHENAMINE AND NEOARSPHENAMINE 461
REPORT ON METHODS OF QUALITATIVE AND QUANTITA-
TIVE ANALYSIS OF ARSPHENAMINE (SALVARSAN) AND
NEOARSPHENAMINE (NEOSALVARSAN).
By G. W. Hoover and C. K. Griycart (U.S. Food and Drug Inspection
Station, Transportation Building, Chicago, Ill.), Associate Referees.
The collaborative work on methods of analysis of arsphenamine and
neoarsphenamine was continued this year in accordance with the recom-
mendations approved by the association at the 1921 meeting.
Samples consisting of ampules of arsphenamine and neoarsphenamine
of American manufacture and labeled with the serial numbers pertain-
ing to the respective batches were forwarded to the collaborators. The
directions submitted for the qualitative tests and the quantitative
method, marked “Method No. 1”, were substantially the same as
adopted as tentative at the last meeting?. The directions for the quanti-
tative method suggested by Engelhardt and Grantham, designated as
“Method No. 2”, were also submitted for study.
The following directions for conducting the work were sent to col-
Jaborators:
Qualitative tests for Arsphenamine (Salvarsan).
3,3’ —diamino—4,4’ —dihydroxy—arsenobenzene dihy-
drochloride corresponding to 31.57% arsenic.
HCl].NH.OH.C,H;.As : As.CsH;.0H.NH:2.HCl + 2H,0.
PHYSICAL PROPERTIES.
Arsphenamine is a pale yellow powder, unstable in moist air. It is soluble in water,
1 to 5 parts, methyl alcohol 1 to 3 parts, and only slightly soluble in ether. The aqueous
solution is greenish yellow, and it reacts strongly acid to litmus. The moisture con-
tent is not more than 7.6% when dried in an atmosphere of hydrogen at 105°C.
CHEMICAL PROPERTIES.
An aqueous solution of arsphenamine (1 to 100) yields no precipitate with dilute
mineral acids, with the exception of sulfuric acid (distinction from neoarsphenamine).
The addition of sodium hydroxide T. S. yields a precipitate which is soluble in excess
of the reagent.
Heated with alkaline solution of potassium permanganate, ammonia is liberated.
Mayer’s reagent produces a heavy orange-yellow precipitate.
Ferric chloride solution produces a brownish violet color, turning turbid.
Silver nitrate solution added drop by drop produces a dark red precipitate, changing
to black.
Reinsch test is positive.
Hydrogen sulfide produces no precipitate even after addition of hydrochloric acid
and warming.
lJ. Assoc. Official Agr. Chemists, 1922, 5: 529.
2 Ibid., 526.
462 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
Qualitative Tests for Neoarsphenamine (Neosalvarsan).
Sodium 3,3’ —diamino 4,4’ —dihydroxy —arseno-
benzene-methylene —sulphoxylate.
NH.OH.C,H;.As : As.CsH;.0H.NH (CH,O) OSNa.
Mixed with inert inorganic salts.
PHYSICAL PROPERTIES.
Neoarsphenamine is a lemon-yellow powder, unstable in moist air, turning to a
reddish brown color. It is readily soluble in water but only slightly soluble in alcohol
or ether. The aqueous solution is neutral to litmus. On exposure to air the solution
rapidly becomes dark brown.
CHEMICAL PROPERTIES.
A freshly prepared aqueous solution of neoarsphenamine (1 to 100) yields a tardy
precipitate on addition of dilute mineral acids (distinction from arsphenamine).
The addition of 10% sodium hydroxide solution produces no precipitate (distinc-
tion from arsphenamine).
Solution of alkali carbonates produces no precipitate (distinction from arsphena-
mine).
Mayer’s reagent produces no precipitate until the solution is acidified with dilute
hydrochloric acid (distinction from arsphenamine, which yields a precipitate directly).
Ferric chloride solution produces a violet color, turning to dark red.
Silver nitrate solution produces a yellow color, quickly forming a black precipitate
on heating.
If 5 cc. of dilute hydrochloric acid is added and the mixture heated, the irritating
odor of sulfur dioxide will be evolved (distinction from arsphenamine).
METHOD No. 1.
Quantitative Determination of Arsenic in Arsphenamine and Neoarsphenamine.
REAGENTS.
(a) 3% hydrogen peroxide solution.
(0) Oxalic acid solulion.—Dissolve 1 gram in 100 cc. of water.
(C) C. P. potassium iodide.
(d) C. P. potassium permanganate (finely ground).
(@) Potassium permanganate solution.—Dissolve 1 gram in 100 cc. of water.
(f) 0.1N sodium thiosulfate solution.
(&) Sulfurie acid solution —10% by volume.
DETERMINATION.
Mix 0.2 gram sample with 5 cc. of 10% sulfuric acid in a 500 cc. Erlenmeyer flask,
fitted with a ground-glass stopper. (A blank is conducted, using the reagents under
the same conditions, and the amount of 0.1N sodium thiosulfate consumed is deducted.)
Add 1 gram of finely powdered potassium permanganate in small portions, mix thor-
oughly and allow to stand for 10 minutes. Add 10 cc. of concentrated sulfuric acid in
2 cc. portions. Shake thoroughly after each addition. Allow to digest 10 minutes,
rotating the flask frequently during this period. Add 5 cc. of hydrogen peroxide solu-
tion, and continue adding this solution drop by drop until the brown precipitate dis-
appears. To remove excess of peroxide, add 25 cc. of water, boil gently for 10 minutes
and carefully add a few drops of a 1% solution of potassium permanganate until the
1923] HOOVER: ANALYSIS OF ARSPHENAMINE AND NEOARSPHENAMINE 463
pink color is just permanent. To remove excess of permanganate, add a drop or two
of oxalic acid solution. Dilute with 50 cc. of water. When the solution is cool, add
2 grams of potassium iodide, stopper flask tightly and let stand for 1 hour in a cool
place. Titrate the liberated iodine with 0.1N sodium thiosulfate, omitting the use of
starch indicator.
1 cc. of 0.1N sodium thiosulfate is equivalent to 0.00375 gram of arsenic.
The arsenic content of arsphenamine should not be below 30 or above 32%.
The arsenic content of neoarsphenamine should not be below 18 or above 20%.
METHOD No. 2.
(Applicable for assaying organically combined arsenic products.)
Proceed with the directions under “Determination”, Method No. 1, using the same
reagents but omitting the blank and including ‘‘add 2 grams of potassium iodide’’.
Let the solution stand for 1 hour.
ADDITIONAL REAGENTS.
Sodium sulfite solution.— Dissolve 2 grams in 100 cc. of water.
Sodium hydrozide solution, (1 to 1).
C. P. sodium bicarbonate.
0.1N iodine solution.
DETERMINATION.
Add from a buret, avoiding excess, the sodium sulfite solution to decolorize the
liberated iodine. Add sodium hydroxide solution until slightly alkaline to litmus
paper and render slightly acid with concentrated hydrochloric acid. Place the flask
in cold water until the solution is thoroughly cooled; add 5 grams of sodium bicar-
bonate and titrate with 0.1N iodine solution.
1 ce. of 0.1N iodine solution is equivalent to 0.00375 gram of arsenic.
The results shown in the table were reported by the following col-
laborators: H. Engelhardt and R. I. Grantham, Sharp and Dohme,
Baltimore, Md.; G. W. Raiziss, University of Pennsylvania, Phila-
delphia, Pa.; C. G. Remsburg, U. S. Public Health Service, Hygienic
Laboratory, Washington, D. C.; and C. K. Glycart.
Results of determination of arsenic in arsphenamine and neoarsphenamine.
Mertuop No. 1. Meruop No. 2.
COLLABORATOR
Arsphenamine Neoarsphena- | Arsphenamine Neoarsphena-
mine mine
Sample A-1 Sample N-2 Sample A-1 Sample N-2
per cent per cent per cent per cent
Ei Bnvelhiardt. : Ms. 23.5 'S 31.4 18.6 31.4 19.5
REG Grantham) s) 2..404.055 . 33.0 19.5 Sik? 19.4
Wis RAIZASS 5 5.85 es hates ses 31.19 18.68 31.28 18.48
Mixer FREMSDUEE. . os. 0s 0 31.31 18.99 30.47 18.47
31.41 19.07 30.56 18.47
18.56
eee Giycart. cs. oc le wes ol 19.28 30.38 19.23
31.38 19.18 30.56 18.85
It appears that Method No. 1 has been considered generally satis-
factory for the purpose of estimating the arsenic content of arsphena-
464 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
mine and neoarsphenamine. Method No. 2 yields equally good results,
as shown by comparison of the reports. Since it is based on the direct
titration of the active constituent, that is, the arsenious acid, and no
blank is required, this method should be given further consideration.
COMMENTS BY COLLABORATORS.
G. W. Raiziss.—It is our impression, however, that the method of
Drs. Engelhardt and Grantham requires more work than the original
method.
H. Engelhardt.—The results obtained by Method No. 1 are not as
concordant as could be desired, but this is due to a varying blank test as
already pointed out in our letter of May 12, 1921.
RECOMMENDATIONS.
It is recommended—
(1) That the qualitative tests and the quantitative method, No. 1,
submitted for the examination of arsphenamine and neoarsphenamine
be adopted as official methods.
(2) That the quantitative method, designated ““Method No. 2” be
adopted as a tentative method with the view to further study for final
adoption.
(3) That during the next year the associate referee study and devise
methods to determine the ratio of arsenic to nitrogen in arsphenamine
and neoarsphenamine.
No report on the determination of alcohol in drug preparations was
made by the associate referee.
No report on the determination of chloroform in drug preparations
was made by the associate referee.
No report on analytical methods for the determination of silver in
silver proteinates was made by the associate referee.
No report on the determination of camphor in pills and tablets by
the alcohol distillation method was made by the associate referee.
No report on the distillation method for the estimation of santalol
in santal oil was made by the associate referee.
1923] CLARKE: REPORT ON TURPENTINE 465
REPORT ON TURPENTINE.
By J. O. Cuarxe! (U. S. Food and Drug Inspection Station, Savannah,
Ga.), Associate Referee.
A study of two methods of polymerization begun last year was con-
tinued. Samples were sent to several collaborators, but no reports
were received. The samples were pure gum turpentine containing
known amounts of kerosene, as shown in the table.
The fuming sulfuric acid? and the sulfuric-nitric acid? methods were
used on all the samples.
Results of polymerization of pure turpentine with known amounts of mineral oil.
FUMING SULFURIC ACID SULFURIC-NITRIC ACID
as MINERAL OIL
Taare Residue Refractive Index Residue Refractive Index
20°C. 20°C.
per cent per cent per cent
A 0 1.2 1.5015 0 —
1. 1.5010 0 _
B* 0.5 2.0 1.4847 0.5 1.4477
1.6 1.4853 0.2 1.4377
(Or 1.0 2.4 1.4713 0.8 1.4395
2.4 1.4716 0.9 1.4857
D* 2.0 3.2 1.4869 1.4 1.4496
32 1.4829 1.0 1.4889
E 2.5 3.2 1.4720 1.8 1.4345
3.2 1.4666 1.9 1.4356
F 5.0 5.6 1.4587 4.0 1.4354
5.6 1.4562 4.1 1.4347
|
*Determinations by L. A. Salinger, U. S. Food and Drug Inspection Station, Savannah, Ga.
Both methods appear to give good results. Neither can be considered
as strictly quantitative for the determination of mineral oil, but either
gives an approximation of the amount present. When the amount of
residue is considered in connection with its refractive index either method
can be relied on to detect comparatively small amounts of mineral oil.
On the particular sample of turpentine used in this work as little as
0.5 per cent was easily detected.
RECOMMENDATIONS.
It is recommended—
(1) That the fuming sulfuric acid method be adopted as tentative in
the following slightly modified form:
1 Presented by W. L. Heath.
2 Assoc. Official Agr. Chemists, Methods, 1920, 306.
3 J. Assoc. Official Agr. Chemists, 1922, 5: 552.
466 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
POLY MERIZATION.—TENTATIVE.
REAGENTS.
Fuming sulfuric acid—Mix about 140 grams of concentrated sulfuric acid with
sufficient liquid, fuming sulfuric acid (about 100 grams), to obtain an acid containing
slightly more than 83.38 per cent of sulfur trioxide. Determine the exact strength of
this mixture and also of the concentrated acid as follows: Weigh out a suitable amount
of acid in a bulb, having a capillary tube in the lower end and a tube with a stop-cock
in the upper end, fitted with a platinum wire for suspending on a balance. (The bulb
is filled with the aid of a slight vacuum, and the lower end of the capillary is emptied
by closing the stop-cock simultaneously with the withdrawal of the capillary from the
acid, after which it is wiped off, first with a wet and then with a dry piece of cloth.)
Run the acid into cold water, make up to volume and titrate an aliquot of the solu-
tion against standard alkali. Calculate the sulfur trioxide content of the acid and add
sufficient concentrated sulfuric acid to make it exactly 82.38 per cent of sulfur trioxide.
The acid must be carefully protected against absorption of water from the air.
Concentrated sulfuric acid.—Specific gravity 1.84.
DETERMINATION.
Place 20 cc. of the sulfuric acid in a graduated, narrow-necked, Babcock flask; stop-
per, place in ice water and cool. Add slowly 5 cc. of the turpentine. Mix the con-
tents gradually, cool from time to time and do not allow the temperature to rise above
60°C. When the mixture no longer warms on shaking, agitate thoroughly, place in a
water bath and heat to 60-65°C. for about 10 minutes, keeping the contents of the
flask thoroughly mixed by vigorous shaking 5 or 6 times. Cool to room temperature
and fill the flask with concentrated sulfuric acid until the unpolymerized oil rises into
the graduated neck. Centrifuge 4-5 minutes at about 1200 revolutions per minute,
or allow to stand for 12 hours. Read the unpolymerized residue, notice its consistency
and color and determine its refractive index.
(2) That the sulfuric-nitric acid method in the form published in
The Journal be adopted as tentative.
(3) That the method of Grotlisch and Smith! for the determination
of coal tar oils in turpentine be studied.
A NEW SEDIMENTATION TUBE AND ITS USE IN DETER-
MINING THE CLEANLINESS OF DRUGS AND SPICES.
By Arno VieEHOEVER (Bureau of Chemistry, Washington, D. C.),
Associate Referee on Crude Drugs.
The cleanliness of crude drugs is a question closely related to volume
weight determination, as discussed in previous reports of the Associate
Referee on Medicinal Plants?.
The work of 1922 followed along the line of obtaining an easy and
rapid method of determining the cleanliness of crude drugs. In the
1 J. Ind. Eng. Chem., 1921, 13: 791.
2 J. Assoc. Official Agr. Chemists, 1920, 4: 149; 1921, 4: 409; 1921, 5: 155; 1922, 5: 553.
’
1923] VIEHOEVER: A NEW SEDIMENTATION TUBE
Fic. 1.—SEDIMENTATION TUBE.
A—Small tube containing approximately 30 cc. B—Tube containing approximately 200 ce.
port for centrifuging.
467
468 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
determination of total and acid-insoluble ash the attempt was made to
ascertain the amount of foreign inorganic matter (dirt, sand, etc.)
present. It was felt that a simpler method might be devised, by which
the amount of inorganic matter could be determined.
In a publica-
tion, entitled “‘Acid-Insoluble Ash Standards for Crude Drugs’, atten-
tion was called to the work on pennyroyal and the separation of excessive
A—Large tube.
foil to prevent cup (B) from adhering to rubber (R).
SEDIGENTSTION TUBE CROSS
SECTION SAOWS1NS :
A- LARGE TUBE.
B-SMALL CUP.
C- CAPILLARY KOO WITHA
RUBBER TUBINE (R) Ont
ENO OF ROO.
T- TINFOUL 79 PRESENT CUP
(EB) FROD BONERING FO
RUBBER (®&).
P- FLANT TISSUE.
S- SEDIMENT.
Fig. 2.—Skertca ILLustratinG SEDIMENTATION TUBE.
B—Small cup.
C—Capillary rod with rubber tubing (R) on end of rod.
P—Plant tissue.
S—Sediment.
1 Ewing, C. O., and Viehoever, Arno. Acid-Insoluble Standards for Crude Drugs.
Assoc., 1919, 8: 725.
J. Am.
T—Tin-
Pharm
4
1923] VIEHOEVER: A NEW SEDIMENTATION TUBE 469
sand by means of carbon tetrachloride. The amount of sand found, as
acid-insoluble ash, was 27.9 per cent, while a similar amount, 26.7 per
cent, was obtained by separation with carbon tetrachloride.
Carbon tetrachloride has a specific gravity of 1.6, and, as far as the
writer’s experiments have gone, it appears to separate the plant tissue
from adhering inorganic matter quite satisfactorily. Should generally
useful results be obtained by the separation method, the work of ascer-
taining the degree of purity of a given drug would be greatly facilitated.
After preliminary experiments with various apparatus, the tubes A
and B, illustrated in Fig. 1, were used.
PROCEDURE.
After the sedimentation tube (Fig. 2) is assembled, with the glass rod (C) removed,
place the finely powdered drug—or the whole material, if of uniform size—in a tube
containing sufficient carbon tetrachloride to permit floating and stir vigorously, so that
the plant material will come in close contact with the liquid. The settling of the im-
purities can be effected either by means of the centrifuge or by setting the tube aside
for 1 to 2 hours. Carefully insert the rod (C), with the rubber tubing (R) on the end,
in the base of the large tube (A). This will permit the removal of the small cup (B),
which contains the sand and dirt, without disturbing the contents in the tube (A).
Decant the liquid from the residue and dry in the small cup (B) to constant weight at
100°C.
The size of the tube depends, of course, on the nature and amount of
the material to be examined. In the examination of crude drugs and
spices one or two grams are used with the small tube (A, Fig. 1), which
holds about 30 cc. For larger amounts of solid material or liquids con-
taining sediments! a larger tube, such as is illustrated by B (Fig. 1),
holding about 200 cc., will prove satisfactory. A support (C, Fig. 1),
devised by H. A. Lepper of the Bureau of Chemistry, will be found
helpful in holding the cup in the centrifuge apparatus. Thus the cup
is fixed firmly in place, both by a tin-foil-covered rubber band and by a
rubber stopper fitted in the center of the wooden block.
WORK OF COLLABORATORS.
The efficiency of the sedimentation tube is proved by the results
obtained, as given in Table 1.
The results show that checks can readily be obtained.
In order to establish the usefulness of the apparatus in the examina-
tion of crude drugs and spices, the following experiments were made:
WHOLE DRUGS (SPICES).
Whole cumin, found by J. F. Clevenger, Bureau of Chemistry, to
yield, upon ashing, 8.4 per cent total ash and 1.1 per cent acid-insoluble
1 Tankard, Brit. Food J., 1922, 24:51, suggests the use of a similar apparatus with ground joints, to
determine the sediment in milk. This apparatus can not be centrifuged.
470 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
ash, was shaken with carbon tetrachloride. The residue of 4 grams of
fruits amounted to 0.035 gram and 0.038 gram, respectively, or 0.91
per cent residue as an average. It consisted mainly of small pebbles
and dirt, the presence of which could thus be readily demonstrated.
TABLE 1.
Collaborative results showing efficiency of separation method.
AMOUNT ASH OF
COLLABORATOR MATERIAL OF CHECK RESIDUE CHECK
per cent per cent per cent per cent
0.41 0.40 0.18 0.18
0.45 0.44 0.21 0.20
0.56 0.52 0.26 0.26
0.54 0.60 0.33 0.31
0.33 0.34 0.13 0.13
0.26 0.30 0.14 0.13
0.32 0.27 0.15 0.14
0.30 0.28 0.12 0.12
H. A. Lepper, Bureau of 0.50 0.49 0.31 0.33
Chemistry, Washington, Tea 0.28 0.29 0.17 0.16
D.C. 0.28 0.28 0.16 0.16
0.18 0.19 0.09 0.10
0.30 0.29 0.17 0.18
0.34 0.33 0.13 0.13
0.19 0.22 0.12 0.12
0.45 0.41 0.27 0.27
0.54 0.58 0.29 0.32
0.39 0.36 0.22 0.20
0.26 0.28 0.12 0.13
0.25 0.26 0.16 0.14
Veratrum 0.3 Ge
3.4 3.2
Veratrum, rhizome 1.9 1.8
2.8 2.8
Ruth G. Capen, Bureau of || Veratrum, roots 3.1 3.6
Chemistry, Washington, 11.9 9.4
D. C. Hydrastis 6.7 6.8
2.4 2.4
Geranium 4.5 4.5
Aconite (mother) iL 1:3
Menispermum 0.4 0.4
Mandrake 0.3 0.2
POWDERED DRUGS.
Material, together with the small sedimentation tubes and a detailed
outline of the procedure, with the suggestion to use 1 or 2 grams of
material, was submitted to collaborators. It was suggested that the
total and acid-insoluble ash of the material be determined according to
the following outline:
Method for total ash.
Ignite 2 grams of the dry, ground drug, placed in a tared crucible and thoroughly
moistened with alcohol, and incinerate the residue at a heat not to exceed dull red-
\
1923] VIEHOEVER: A NEW SEDIMENTATION TUBE A471
ness, to constant weight. If a carbon-free ash can not be obtained in this way, mois-
ten the charred mass with alcohol. Allow the alcohol to burn off in the open and in-
cinerate, repeating the alcohol treatment if necessary to obtain a white or nearly white
ash.
Method for acid-insoluble ash.
Boil the ash obtained by the method for total ash with 25 cc. of 10% hydrochloric
acid for 5 minutes. Collect the insoluble matter on a Gooch crucible or an ashless
filter and wash with hot water, ignite at a heat not to exceed dull redness, and weigh.
The collaborative results are shown in Table 2.
TABLE 2.
Collaborative results on cleanliness of crude drugs and spices.
RESIDUE AFTER
ASH SEPARATION
WITH CARBON
COLLABORATOR PRODUCT tae
Acid- After After
Total | insolu- | stand- | centri-
ble ing fuging
per cent | per cent | per cent | per cent
Geranium.) .:.. 3. ot eeeee Thre 3.0 4.5 ghey
Hydrastis:..: ....'. 1 2c 11.8 7.6 6.8 8.7
FV drastis),) vac ccke eee 5.8 1.8 0.8 1.4
Aconite (mother)............ 5.9 1.3 1 1.0
|Marjoram, fine powder... ... «| 27.5 HRDBOMG.G ears
Marjoram, coarse powder... .. 11.3 Bs Tix. prea We ashes
Menispermumt,...3.0 rs dhe iss 4.1 0.8 0.4 0.25
Wandrake:. 4 oe cee 3.2 12, 0.4 0.5
Veratrum, roots and rhizomes.| 13.0 9.0 Thee 10.4
Ruth G. Capen. Veratrum, roots and rhizomes.| 19.0 | 15.0 |17.0 | ....
Veratrum, roots and rhizomes.| 12.0 8.0 fed ela.5
Veratrum, roots and rhizomes.| 6.1 3.6 2.8 3.6
Veratrum, roots and rhizomes.| 16.5 | 12.7 | 10.5 16.1
Veratrum, rhizomes.......... So 0.5 0.7 1.0
Veratrum, rhizomes.......... 3.6 2 1.2 125
Veratrum, roots... 25a: serait 6.6 3.2 |, 4.2 4.5
( Veratrami, roots 02>. 2 aes: 9.2 3.7 | 3.4 4.5
Tee WicNanus’ Food '& ety No. 40 powder....... ney ise ee
Drug Inspection Sta- i . ; ; j
Patni ce terial Ga: ides powderedyi) anes. 18 oe 28,
= Veratrum, finesigg. 50 Cee 1B ey 8.8 8.1
ae coe poe Veratrum, ‘course. 92%. isin 4.2 0.9 et
i Sa a Se WW Hydrashis, fine... on). Sona 5.2 1.5 1.2
ington, 1)... Mandrake; ‘coarse. 3.)2: 2. 22. eet 0.3 0.9
*] gram sample.
COMMENTS OF COLLABORATORS.
R. G. Capen.—The acid-insoluble ash in general is higher than the percentage of
residue obtained on standing after separation with carbon tetrachloride.
The residue obtained after centrifuging in general is somewhat greater than that
obtained after standing.
It is believed that this method furnishes a rapid means of obtaining an approximate
result.
472 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
It has been found from experience that the fineness of the powder influences the
amount of the residue obtained. The finer the powder, the more accurate the results,
inasmuch as the separation of plant tissue and dirt is more complete.
J. J. McManus.—In regard to the method for separating dirt by the use of carbon
tetrachloride, you will note that in the case of aletris results will be somewhat mis-
leading. It must be that, in this drug, the dirt is so finely imbedded in the tissues of
the plant that it will not separate and settle. The ash figure in the sediment indicates
that not only does some of the dirt remain in the floating pieces of the tissue, but that
part of the dirt brings down with it considerable organic matter. In this sample of
aletris, which was ground to a No. 40 powder to obtain a better mixture, comparatively
good checks were obtained on duplicate samples. In the separation method it was
found easier to manipulate a one-gram sample of aletris as the amount of dirt separated
from the two-gram sample more than filled the little tube.
In the one determination made on a sample of powdered hydrastis, the results were
not very satisfactory, but it might be that after becoming more familiar with manipu-
lating this method, better separation of the dirt could be obtained. The few experi-
ments made with chenopodium are not listed. They indicated that the separation of dirt
from these small seeds was not so rapid as one would ordinarily expect, and subsequent
treatment of the floated matter would bring down more dirt and also some organic
matter. * * * It was also noted that the residue in the small tube must be allowed
to dry very slowly to prevent sputtering. It does not seem from the very few data
which I have on hand, that the method is sufficiently accurate for general use. It
does seem that it might have possibilities for use in the trade for easily determining the
amounts of dirt in a small number of drugs which are handled continuously. For
instance, a handler of anise or caraway might take a measured amount and quickly
shake it in one of the tubes and allow it to stand for a set period of time and note the
height of the sediment in the tube of standard diameter, and by comparing the results
on the new samples with the results on samples known to pass the standard, could
easily get an idea of the approximate excess of dirt in his sample. The comment on
this would probably be that a tradesman handling continuously a certain line of drugs
would become so familiar with their physical appearance that he could note the dirt
without using this method. However, the method does seem to be a very interesting
one, and I would like to do some more work on it.
Geo. L. Keenan.—The carbon tetrachloride separation method appeared to give
satisfaction for the purpose of separating dirt in powders, the finer the powdered crude
drug, apparently, the more consistent the results obtained. As a rough working method
for the determination of the amount of dirt present in a crude drug which has been
finely ground, it appears from the work done thus far that such a method might be
desirable.
SUMMARY.
(1) Further work should be done to establish more definitely certain
facts, e. g., the influence of fineness of powder in various types of material
upon the final result and the composition of the dirt, separable as resi-
due in carbon tetrachloride, by standing as well as by centrifuging.
(2) The separation method, by means of tetrachloride, is recommended
as a rapid procedure to obtain a definite indication of the degree of purity.
(3) The sedimentation tube described should prove to be a valuable
apparatus, capable of wide application, since it permits of centrifuging
and ready separation of the sediment.
1923] VIEHOEVER: SUBLIMATION OF PLANT AND ANIMAL PRODUCTS 473
SUBLIMATION OF PLANT AND ANIMAL PRODUCTS—
THIRD REPORT.
By Arno VIEHOEVER! (Bureau of Chemistry, Washington, D. C.),
Associate Referee.
The sublimation experiments reported at the 1920 and 1921 meetings?
were continued.
Various apparatus were tried out—those that permit the sublimation
of small quantities only, about 0.1 gram of material (microsublimation),
and those in which both minute as well as larger amounts may be sub-
limed. Figure 1, A to D, shows various types used in the work. Fig-
ure 1, A, represents practically the apparatus of Eder’, with the differ-
ence that it provides for cooling. It is described in greater detail in
the discussion of the collaborative work. Figure 1, B, shows an ap-
paratus of simpler form, in which the ground joints are eliminated, thus
permitting of easy construction in any laboratory. A very simple
apparatus illustrated by Fig. 1, C, represents an Erlenmeyer suction
flask in which a test tube, filled with water, is introduced. It is possible,
of course, to provide for the circulation of water, as shown in the other
apparatus.
A specially constructed sublimation flask, devised by the writer, is
shown in Fig. 1, D. This apparatus, as well as various modifications
shown in the sketches (Fig. 2), has proved very satisfactory. The
flask should be made of Pyrex or Jena glass, in order to withstand
marked differences in temperature to which the flask, especially the
constricted area, is subjected during the experiments. It can be made
by a glassblower at small cost. It permits of the ready sublimation of
quantities of material within the general range needed in analytical
work.
The lower bulb-like part of the apparatus is heated in a suitable
bath. At present cottonseed oil is used, since it has been found very
satisfactory at temperatures up to 225°C. and over. The oil is placed
in a metal crucible. Uniform heat is supplied by an electrically heated
shell‘, which is preferred to an open flame. This shell is prepared from
long-fibered asbestos and plaster of Paris, moulded around the crucible
and wired; it gives a wide range of heat. Figure 1, F, shows this heater
with rheostat. The available means to provide heat, e. g., gas, or another
bath (sulfuric acid, glycerin or sand), can also be used instead of the
one suggested. The flask is inserted into the bath to approximately
the middle of the constricted neck.
1 Presented by J. F. Clevenger.
2 J. Assoc. Official Agr. Chemists, 1921, 4: 414; 1922, 5: 557.
3 Eder, Robert. Uber die Mikrosublimation von Alkaloiden im luftverdiinnten Raum, Schweiz.
Wochschr., 1913, 51: 228, 241, 253.
4 Constructed by J. F. Clevenger, Bureau of Chemistry, Washington, D. C.
474 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
Fic. 1.—SuBLIMATION APPARATUS.
A, B—Microsublimation apparatus adapted to vacuum and cooling. C—Suction flask adapted to
sublimation. _D—Sublimation flask for micro- and macrosublimation. E—Oil bath (cottonseed).
F—Heating shell.
Sketches 1 and 2 (Fig. 2) provide for outside cooling by means of
either a waterjacket or a copper coil with running water, and Sketch
1923] VIEHOEVER: SUBLIMATION OF PLANT AND ANIMAL PRODUCTS 475
3 provides for inside cooling. The distinct ridge in the upper neck
end, visible in all the sketches, together with the downward curved
bottom of the inner condenser, Sketch 3, prevents such liquid-con-
densation products as water, fat, etc., which may be formed during the
heating, from dropping back into the original material.
The ridge may be covered with a cover-glass, to receive small amounts
of sublimate for microscopic examination, or with a porous diaphragm
(platinum gauze), or a perforated disk (?@ inch in diameter), which
prevents the dropping back of the sublimate to the original material.
The neck-like constriction permits of the insertion of a stopper.
Sketch 3 (Fig. 2), shows the inner walls of the neck, ground to make
a good joint, with a glass stopper at the end of the glass rod, introduced
after sublimation. A rubber stopper fastened to a rod will usually do
as well, especially if protected from the ready attack of organic solvents
by tin-foil. This stopper separates the sublimate from the original
material. Thus, the cylindrical part of the apparatus, containing part
or the whole of the sublimate, can be readily washed out with liquids
suitable to dissolve and remove this sublimate. A small notch in the
wall of the opening will, of course, facilitate this removal.
The following approximate dimensions may assist in the construction
of a suitable apparatus.
PARTS DIAMETER HEIGHT APPROXIMATE
CAPACITY
Sublimation flask iy) i NTI AO 150 ce.
Bulb 6.3 cm. (greatest) 3.8 cm. 62 ce.
Constriction 1.9 cm. 1.6 cm. 2-3 ce.
Cylinder 4.2 cm. (outer) 9.5 cm. 85. cc.
SESE (TNMESE) UMM NAN tl. Nea Niet!
COLLABORATIVE WORK.
The collaborative work was carried out by Ruth G. Capen, Bureau
of Chemistry, Washington, D. C.; P. B. Clark, Food and Drug Inspec-
tion Station, San Francisco, Calif.; and C. K. Glycart, Food and Drug
Inspection Station, Chicago, Ill. Joseph F. Clevenger collaborated in
the improvement of the apparatus. Samples of Mylabris (Chinese
flies), containing cantharidin; Artemisia cina (wormseed), containing
santonin; and Ilex cassine (Cassine), containing caffeine, were sub-
mitted to these workers, together with one apparatus for the sublima-
tion of small quantities of material, and another for the observation of
the melting and subliming points of crystals under the microscope.
MICROSUBLIMATION APPARATUS.
This apparatus (Fig. 1, A) is adapted to qualitative sublimation of
plant products. It consists primarily of two pieces fitted together with
a ground joint. The smaller piece has a narrowed extension in which
the material to be sublimed is placed. On the shoulders of this piece
476 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
re ol
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SUBLIVIATION -FLASTE .
Fic. 2 —MoprFications ror OuTsipE AND INsipE Coo.ina.
1923] V\EHOEVER: SUBLIMATION OF PLANT AND ANIMAL PRODUCTS 477
a round cover-slip, approximately 18 mm. in diameter, is placed to
receive the sublimate. The larger piece is provided with a tube having
a three-way stop-cock through which a vacuum is applied. The upper
portion is provided with an opening through which a water-cooling
device may be introduced.
PROCEDURE.
After assembling, heat the substance in the apparatus by immersing the narrow
extension of the smaller piece into a heated bath of cottonseed oil. A medium flame
is used for sublimation, and the temperature is usually not increased beyond 10°C. of
the melting point of the substance to be sublimed. The temperature is determined
by placing the bulb of the thermometer directly in the oil bath. The time of heating
varies from less than one hour to several hours, depending upon the ease of sublima-
tion—the higher the vacuum the more effective the sublimation.
Fic. 3.—MiICROMELTING-POINT APPARATUS.
A—Heating block carrying object slide. _B—Cover enclosing slide in heating chamber. C—Rheostat
for temperature control
MICROMELTING-POINT APPARATUS.
This apparatus is adapted for the observation, under the microscope,
of the melting point or temperature of sublimation of crystalline sub-
stances. It was devised by B. J. Howard of the Microchemical Labora-
tory, Bureau of Chemistry, and consists of the following parts:
The lower section, consisting of a block of metal with a triangular extension, is
modified to take care of the object slide. The extension is heated by means of an
478 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
alcohol or gas flame. On the end opposite the extension a hole is provided for the
insertion of a thermometer. Another hole in the middle of the block permits observa-
tion of the object by transmitted light. An upper section, serving mainly as a cover,
fits tightly over the lower part of the block. The outer surfaces of the apparatus,
with the exception of the triangular extension which is to be heated, are covered with
asbestos board glued ‘to the metal surface with sodium silicate. The apparatus is
placed upon. the stage of the microscope, and observations are made directly, while
the apparatus is being heated.
An improvement of this apparatus by Clevenger! provides for heating with elec-
tricity (Fig. 3). By this means better control and temperatures as high as 400°C.,
and over, are obtained.
PROCEDURE.
The melting point can usually be determined by observing the temperature at which
the crystals lose the ability to polarize light. Thus far the simple apparatus has readily
permitted the observation of melting points up to 200°C., or slightly over.
The sublimate heated in the melting-point apparatus may partially sublime on the
small cover-slip located in the upper portion of the apparatus. The sublimation point
is not sharply outlined. It represents the temperatures at which the crystals become
visibly smaller through sublimation and finally disappear. The heating of the sub-
stance in narrow capillary tubes placed in the apparatus under the microscope, will,
as J. F. Clevenger has shown in the case of cantharidin, retard sublimation, and thus
permit the observation of the melting point.
The important factors in sublimation are temperature of the bath,
air pressure, time of heating and melting, as well as subliming points of
the substance under examination. For the identification of crystals
obtained it is desirable, in addition to the properties enumerated above,
to determine as many optical and chemical reactions as possible.
REMARKS SUBMITTED IN CONNECTION WITH PROCEDURE.
Caffeine.—Characteristic crystals are obtained by treating the sub-
limate with aqueous chloral hydrate solution (5+3), or mercuric bi-
chloride solution (0.1 per cent).
Cantharidin.—If the insect material is moistened with hydrochloric
acid alcohol (1+9) before it is heated, larger amounts of cantharidin
are obtained. Characteristic crystals are secured by treating the sub-
limate thus obtained with barium hydroxide solution (about 5 per cent).
Santonin.—The sublimate is usually deposited on the cover-glass in
droplets, which, upon standing, especially at a temperature of about
100°C., develop into large crystals. The formation of crystals may be
hastened by treating the sublimate with ether.
The following results were obtained:
1 The detailed construction will be discussed in a subsequent publication.
1923] VIEHOEVER: SUBLIMATION OF PLANT AND ANIMAL PRODUCTS 479
Sublimation of plant and animal products.
TEMPERA- TIME SUBLIMA-
MATERIAL iia AIR on MELTING on CRYSTAL SUBSTANCE
USED San PRESSURE nr POINT Baan FORM OBTAINED
ct Bs hours Sc: °G.
Ulex vomitoria (Ait.) _| 130-140 | 100-3mm. Ye a ya, eae 135f Needles Caffeine*
130-150 | Normal at- SENT hae ae 133 Needles Caffeinet
mospheric
Mylabris cichorii§ 110-120 | 760-3mm. A PAIR. sh Me 100-110t¢ | Plates Cantharidin*
(Fab.) 120 Normal at- Vat OS eC han 109 Plates Cantharidint
mospheric
Artemisia cina(Berg.)|_ 135-170 | 20-3mm. 4-1 165-170 | 155-160t | Plates and needles} Santonin*
170 Reduced 1 168 173 Close plates Santoninj
pressure**
*Determinations made by R. G. Capen.
{Determinations made by C. K. Glycart. i
Determined from resublimation of crystals at normal air pressure obtained with the micromelting-point
apparatus.
§Treated with hydrochloric acid.
**Not determined. No manometer available.
COMMENTS OF COLLABORATORS.
P. B. Clark.—A number of difficulties were encountered in the use of
the microsublimation apparatus so a little different form of apparatus
was devised (Fig. 4). The sample of wormseed was the only one used,
but several things were noted in trying to obtain a crystalline sublimate
which would also apply to a number of other drugs. In the first trial
the time, temperature and pressure given in Dr. Viehoever’s letter was
used, and it was found that a large quantity of oil (probably both vola-
tile and fixed) was deposited on the cover-slip with the santonin, and the
santonin failed to crystallize. The apparatus was then charged with a
fresh sample of santonica, a 6-inch vacuum maintained and a fresh
cover-slip was placed in the apparatus for every 10° rise in temperature,
starting with 90°C., each cover-slip being held in the apparatus about
45 minutes. No crystals were obtained until a temperature of 150° to
160° was reached, although all but the first two cover-slips gave a posi-
tive test for santonin. This experiment was repeated several times,
the temperature being raised as high as 200°C., and chemical tests showed
that santonin was still being sublimed at 200°C.
In the light of the foregoing experiment it does not seem as though
this method would be very reliable for determining melting points, as
the purity of the sublimate would be doubtful owing to the presence of
fixed and volatile oils and the probability of some destructive distillation
taking place. The sublimate on the cover-slip might, however, be used
for making short tests for active principles in drugs where absolute
purity would not be necessary to make a test.
C. K. Glycart.—The qualitative tests performed according to direc-
tions were entirely satisfactory with the following reagents:
480 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
Caffeine Mercuric chloride Fine needles
Cantharidin Barium hydroxide Large and small crystals
solution
Santonin Furfural-sulfuric Purple, changing to
acid dark opaque solution
The hydriodic acid test was not performed as this acid was not avail-
able. The droplets of cantharidin required time to crystallize.
The determinations are easily performed by use of the apparatus
supplied, and the methods should prove to be of great value.
“WATER /NLET
COVER SLIP
~— CARO LOARO COKER
- LEVEL oF O11. BATH
ELECTRIC PERCOARTOR
£ HEATING ELEMENT
TEMPERATURE OF Off @ATM
CONTROLLED BY PNEOSTIT.
Fic. 4.—MicrosuBiimaTIon APPARATUS (AFTER CLARK).
1923] HORTVET: SUBLIMATION AS AN ANALYTICAL PROCEDURE 481
SUMMARY.
The experimental work on the improvement of sublimation apparatus
led to the construction of a sublimation flask. This is an inexpensive
apparatus, which permits of the sublimation of minute as well as fair-
sized quantities of material.
The task of definitely identifying the sublimate resulted in a notable
improvement of an apparatus permitting the observation of the melting
and subliming points under the microscope.
The collaborative work has produced valuable suggestions in the im-
provement of the apparatus and has demonstrated the fact that sub-
limation carried out by various workers under like conditions will yield
like results.
RECOMMENDATIONS.
It is recommended—
(1) That the work on the sublimation of plant and animal products,
as well as any other materials representing or yielding sublimable con-
‘stituents, be continued.
(2) That in this work the improved apparatus, or any other apparatus
or modifications available in the course of the work, be used.
(3) That the methods for the isolation and identification of canthari-
din, caffeine and santonin be adopted as tentative methods.
SUBLIMATION AS AN ANALYTICAL PROCEDURE.
By Jutius Hortver(State Dairy and Food Commission, St. Paul, Minn.).
On the subject of sublimation as commonly practised in the laboratory,
Gorup-Besanez! commented in 1855 as follows: ‘The sublimation of
organic bodies is an operation which must often be used for their puri-
fication. In such cases the amount of material at hand is limited, and
the losses entailed by recrystallisation, decolorisation and similar opera-
tions are so considerable that it seems very desirable to reduce these
losses to a minimum in order that the thorough examination of such
bodies may be facilitated”’.
The process of sublimation has, in recent years, found increased
serviceability as a laboratory operation. Though not frequently ap-
plicable in the analysis of inorganic substances, the process has been
found to be of considerable importance in the examination of a large
number of organic compounds and mixtures. Approximately 150
sublimable substances—20 inorganic and 130 organic—are listed in
Olsen’s Manual (1922). There are also many compounds not included
in the Manual that are known to be susceptible to sublimation under
modified conditions.
1 Ann., 1855, 93: 265.
482 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
GENERAL AND QUALITATIVE.
Sublimation is often very serviceable in the separation and _ purifica-
tion of substances. As well-known illustrations may be given: the
separation of pyrogallic acid, benzoic acid, oxalic acid, salicylic acid,
vanillin, etc., from crude material or impurities; the separation of
strychnine, morphine, cocaine, santonin, and other active principles
from crude drugs; the separation of caffeine from coffee and tea, gen-
tisin from gentian root, and cantharidin from the dried insect, can-
tharides. Pure oxalic acid and benzoic acid are readily prepared in a
high state of purity by sublimation for use in making standard solutions.
By means of sublimation a distinction can often be made between
genuine tea leaves and tea substitutes, between genuine Levant worm-
seed and the domestic variety, and also in many instances between
standard and exhausted drugs.
The method is serviceable in many cases for the purpose of affording
an indication regarding the best course to be pursued in a chemical
analysis, and it may also serve as a useful sorting-out test in the pre-
liminary examination of a great variety of substances. It has been
shown! that a large number of alkaloids which formerly were not found
to be sublimable under ordinary conditions are, on the other hand,
rendered sublimable in vacuum, as for example, hyoscyamin, papaverine
and narcotine. In the case of such alkaloids as strychnine, morphine
and cinchonine beautiful crystalline sublimates are obtained. By
means of rapid sublimation under vacuum, definite crystalline deposits
are formed in the case of substances with high vapor pressure, as caffeine,
theobromine and cantharidin. The crystal formations are constant and
characteristic for definite alkaloids, although in some cases they exhibit
unusual behavior. Cantharidin is readily separated from the male or
female insect, or from the eggs, by moistening the finely divided material
with strong hydrochloric acid, followed by sublimation, and evapora-
tion of any condensed acid by exposing the sublimaie over unslaked
lime (Fig. 1).
In addition to their vesicating properties, melting-point and polarizing
action upon light, the crystals may be identified by their behavior
with baryta water.
QUANTITATIVE APPLICATIONS.
A number of quantitative methods are improved and materially
shortened by resorting to sublimation. In many instances the process
may be applied directly to the properly prepared material; in other
cases previous extraction, using a suitable solvent, may be resorted to,
then the impure residue subjected to sublimation for the purpose of
1 Eder R., Schweiz. Wochschr., 1913, 51: 228, 241, 253.
1923] HORTVET: SUBLIMATION AS AN ANALYTICAL PROCEDURE 483
obtaining the compound in a condition of greater purity. As illustra-
tions may be given: the separation of benzoic acid, salicylic acid, sac-
charin, etc., from residues obtained by extracting food products with
ether and other solvents. Sublimation applied to the residue after
evaporating the chloroform from an extract obtained from catsup
yielded 0.086 per cent benzoic acid, which, calculated to sodium ben-
zoate, gave 1.101 per cent. The sample of catsup was represented on
the label to contain 0.10 per cent of sodium benzoate. The modified
Stahlschmidt method applied to a sample of ground coffee yielded 1.32
per cent caffeine. By direct sublimation of the same coffee, using a
l-gram sample, there was recovered 1.92 per cent caffeine plus impuri-
ties. The material was washed out from the sublimator by means of
chloroform, the solvent evaporated, and the residue mixed with inert
material (sand) and subjected to repeated sublimation, with the result
that 1.26 per cent pure caffeine was obtained. This result was checked
by means of the nitrogen determination according to official method!.
Another sample of coffee subjected to the same procedure, but under
changed conditions, yielded 1.39 per cent caffeine on first sublimation
and on second sublimation, 1.35 per cent. A number of trials carried
out on known mixtures of active material mixed with inert material
(sand) yielded results as follows:
Santonines 52.3 sis ee 0.100 gram, yielded 0.0988 gram.
AMA EOI 2.2 5): 5.23 . EQS. 0.052 gram, yielded 0.0513 gram.
Benzoic acid .74 Pe oS ee 0.141 gram, yielded 0.1400 gram.
Fig.2
CANTHARIDIN ARSENIC TRIOXIDE.
The camphor sublimation was conducted under ordinary atmospheric
pressure. The above are only a few preliminary trials. Investigations
1 Assoc. Official Agr. Chemists, Methods, 1920, 270, par. 15.
484 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
are to be continued so as to cover a considerable variety of food products,
pharmaceutical preparations and drugs.
MICROSUBLIMATION.
By means of a suitable apparatus, characteristic sublimates can be
obtained from very small amounts of material. It is possible in many
cases, for purposes of identification’, to isolate from a complex mixture or
from a crude drug, substances in definite crystalline form. Investiga-
tions have demonstrated the applicability of microsublimation in vacuum
as a valuable analytical method and as a means of identifying poisonous
plant-base forms, also its usefulness in connection with microchemical
reactions as a valuable method in forensic chemistry. The microscopic
appearance of a sublimate will frequently give valuable confirmatory
evidence, or will suggest the course that should be followed in carrying
out a systematic investigation of a substance submitted for analysis.
The work of Eder? and others has demonstrated the advantage of carry-
ing out sublimation tests under reduced atmospheric pressure and by
means of carefully controlled methods of heating.
Among results obtained by Eder on various alkaloids sublimed under
pressures ranging around 10 millimeters are the following:
Cocaine) nese between 75 and 90° Chenine?:.... 3 ./)<: between 130 and 148°
Atropine........between 100 and 130° Narcetine:..'..... between 146 and 156°
Codeme!ii2caa-e between 93 and 110° Brucine so] ee between 158 and 175°
Solanine: . 4524. 2: between 158 and 184°
The following results were obtained in the laboratory of the Minne-
sota Dairy and Food Department on various substances sublimed under
reduced pressures varying from 23 to 25 millimeters:
Initial Sublimation Temperatures.
Oy eumra Ua AL aia, ule © vay) Mtoe ee hot whee 53° Menthol. 2): se eae ase eee 41°
Bema MEI 260.5 ive Meee) oe, 47° Resercine') 52:4. 5 56a 65°
A BIPEIE alice shenst on le peas te al ations 80° Phenolphthalein..............- 134°
Salicyhe GIG. 93) 4) cca o's sins 64° Santonin . ... ./:4.cse eee 127°
Oxalic acids... isd cee is sto 110° Hexamethylene-tetramine...... 90°
Cama. o)2 ea cere.) oes 37° Cantharidim, 2 45):.22tae saree 93°
Further practical applications of microsublimation were made with
strychnine and arsenic. A sample of strychnine alkaloid weighing
less than 0.001 gram was sublimed on a microscope slide, and charac-
teristic crystalline deposits were obtained. Arsenic trioxide mixed with
chopped meat in proportion approximating one part in 100,000 was sub-
jected to the Reinsch test. The copper-foil was cut up into small pieces
and packed into the narrow base of a glass capsule placed inside the
sublimator, the capsule covered with a microscope slide, the apparatus
1 Viehoever, Arno, J. Assoc. Official Agr. Chemists, 1921, 4: 414; 1922, 5; 557.
2 Schweiz. Wochschr., 1913, 51: 228, 241, 253.
1923] HORTVET: SUBLIMATION AS AN ANALYTICAL PROCEDURE 485
connected with a vacuum pump and the heating conducted cautiously
until a deposit was observed on the slide. On examining the deposit under
the microscope characteristic octahedral crystals were identified. (Fig. 2.)
For the purpose of further verification the deposit was subjected to
solubility tests with various reagents. A similar process may be applied
to crude drugs or to vegetable powders to obtain sublimates in a con-
dition exhibiting characteristic features of any volatile crystalline
principle which they may contain. The appearance of a sublimate
may, in certain instances, vary somewhat according to the rate of sub-
limation, amount of moisture and other factors. It may, however, be
pointed out that it is possible, by means of a suitable contrivance, to
remove moisture from the inside of the apparatus prior to adjusting
temperature and vacuum conditions necessary for the sublimation.
Having once obtained a sublimed deposit on a microscope slide great
possibilities are available in the line of microchemical precipitates for
the purpose of identifying various substances. In many instances the
microscopic structure of a precipitate is a reliable method of distinguish-
ing between two or more closely allied substances.
THE SUBLIMATOR.
In order to meet the requirements incidental
to the various operations involved in sublima-
tion processes, a new model sublimator has
been designed to serve all the purposes which
have been fulfilled, to a greater or less degree,
by a number of well-known laboratory devices.
The construction of the sublimator involves
the following features:
(1) The sublimation cell, consisting of an
upper and a lower glass section tightly joined
by means of accurately ground surfaces.
(2) Sublimation chamber (upper section),
containing the cooling bulb placed centrally
so as to receive the deposit of sublimed
material.
(3) The sublimation cup (lower section)
constructed for the purpose of holding various
receptacles containing material to be sub-
jected to sublimation.
(4) A porous diaphragm, fitted between the
upper and lower section, serves—
(a) to allow the complete passage of the
= subliming material from the lower chamber
Fic. 3.—Hortvet SuBLIMATOR. into the upper, and
WONIWA
486 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
(b) to prevent the sublimed material from
falling back from the surface of the bulb into
the cup.
For all general uses, a 100-mesh platinum
gauze diaphragm is most satisfactory. A
diaphragm of porous material other than
platinum must be used in sublimation work
with compounds destructive to platinum.
(5) Glass dishes, provided of various ca-
pacities and shapes suitable for different pur-
poses. An adjustable spring support rests on
the bottom of the cup and serves to fit the
dishes in suitable position beneath the dia-
phragm. For microsublimation, a glass cap-
sule with narrow base portion rests in a verti-
cal position in the central hole of the spring
support. A microscope slide placed in the
upper section rests on the ground edge at the
top of the capsule when the upper and lower
sections are joined. After being removed from
the subliming cell, the slide is placed in a
specially constructed glass holder which fits on the microscope stage and
thus permits examination in the usual manner.
(6) The bulb tube, sealed vertically at the top of the subliming cell
serves for connection with the vacuum pump, thus permitting the ad-
justment of pressure to any degree desired. After disconnecting the
rubber tubing from the upper section and detaching the base section or
cup, the subliming chamber is turned to an inverted position (without
the removal of the diaphragm); the sublimed material is then removed
by means of a suitable solvent and washed out through the bulb tube
into a beaker or crystallizing dish.
Fic. 4.—SuBLIMATION CELL.
(7) The heater, consisting of an adjustable copper cup constructed in
two sections so as to permit adjustment of depth. The cup is sup-
ported on a cylindrical sheet-metal stand at the base of which is placed
a small gas burner. The depth of the heating cup is varied by lowering
or raising the supporting rods which are riveted to the inner section.
The adjustable cup serves the purpose of varying the temperature con-
ditions to meet the requirements of the experiment in hand. A metal
rod rests vertically on the upper surface of the heater and is provided
with a clip for the purpose of supporting a thermometer to be used for
temperature control. A loop at the upper end of the rod is for the
purpose of holding the pressure-tubing which connects the bulb-tube at
the top of the sublimator with the vacuum pump.
1923] HORTVET: SUBLIMATION AS AN ANALYTICAL PROCEDURE 487
THE USE OF THE SUBLIMATOR.
The heating cup is placed on the sheet-metal support and rigidly
secured in position by tightening the set-screws. A suitable heating
bath is provided by means of a one-inch depth of clean, dry sand placed
in the bottom of the cup. Care is taken that no sand grains are per-
mitted to lodge in the space between the two cup sections and thus
interfere with, or effectually prevent, the up-and-down movement of
the inner section. The cup is adjusted to a depth of about three inches
and set in position by means of the thumb-screws provided at the top
of the posts.
The properly prepared and dried substance to be subjected to sub-
limation is mixed with a suitable amount of inert material—as pure
ignited sand of about 40 mesh or powdered magnesia—the well-mixed
material placed in one of the glass dishes suitable for the purpose and
the dish placed in the subliming cup, resting centrally on the spring
support. It is desirable that the dish be filled with material to near
the top edge, thus bringing the surface of the contents close to the
diaphragm. The diaphragm is placed in position on the glass pro-
jections, a thin film of vaseline or other suitable material is spread on
the ground-glass surfaces of the upper and lower sections, and then by
a firm though gentle pressure accompanied by a turning movement the
two parts are tightly fitted together. When the spring support and
dish are properly placed in the cup the top edge of the dish will be in
close contact with the lower ground surfaces of the projections. The
subliming cell is lowered into the heater and gently pressed down into
the sand-bath so as to bring the sand well around the widened portion
of the base, and the heater cup is lowered to its full depth. By means
of rubber tubing the apparatus is connected with the water tap in such
a manner as to afford a slow stream of cold water through the cooling
bulb. The bulb-tube at the top is connected with the vacuum pump
by means of pressure-tubing passed through the metal loop above. A
vacuum gage (preferably a mercury manometer) is connected in posi-
tion between the pump and the sublimator. When using a water
pump, a trap is placed between the pressure gage and the pump, in
order to prevent a sudden back-flow of water in the direction of the
apparatus. For efficient heating in general sublimation operations, such
as the purification of substances and quantitative separations, the
cup is adjusted to its full depth, thus submerging the sublimation
chamber to approximately two-thirds of its height. For microsublima-
tions and for operations requiring the application of heat only to the
base portion, the heater is adjusted to a shallow depth of about two
and one-half inches. When all connections are properly made and
tested and adjustments correctly arranged, the gas burner is placed
488 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
on the base beneath the heating cup and the flame adjusted to a small
size, hardly exceeding one inch in height or even lower. Great caution
should be exercised in the adjustment of the flame in order to prevent
overheating or too rapid heating of the apparatus. The thermometer
is supported in the clip and lowered until the bulb is fairly covered in
the sand-bath.
The sublimation process is clearly observable with the aid of an
electric light bulb placed near the apparatus, and a fair judgment is
thereby obtained as to the progress of the experiment. When the
material appears to be completely deposited on the condensing bulb,
the pump is shut off, the vacuum carefully released, and the water
inflow tube disconnected and closed by means of a rubber cap; the out-
flow tube is then disconnected and closed in the same manner. The
flame is turned off, the cell removed from the heater, allowed time to
cool, and the base portion detached. After the subliming chamber is
turned to an inverted position, without removal of the diaphragm which
falls loose into the space between the bulb and the outer shell, the
deposit on the bulb is washed through the bulb-tube into a crystallizing
dish by means of a suitable solvent (ether, chloroform, or other fluid).
The dissolved sublimate may be passed through a funnel, or through a
filter if deemed necessary in order to separate insoluble impurities.
After evaporation of the solvent the dish and contents are placed in a
desiccator for a short time and weighed. The weight of the sublimed
deposit can also be obtained direct by draining the water from the
bulb, removing the remaining traces of water by means of successive
small portions of alcohol and ether followed by passage of a current of
dry air, drying in a desiccator and weighing. The material may be
subjected to further examination by separating a small portion from
the condenser bulb or from the crystallizing dish and submitting it to
the procedure described by Chamot!. Further purification of the
material may be effected by repeating the sublimation in the manner
described. The heating is conducted gradually, beginning at a low
temperature, and controlled so as to diminish the impurities in the
sublimate. For microsublimation where only a very small quantity of
sublimable substance may be present, the material is placed in the
narrow base portion of the subliming capsule supported in the circular
opening at the center of the spring support. The specially made glass
slide is inserted so as to rest on the projections at the base of the sub-
liming chamber and the cup section connected, thereby resting the
slide across the top of the capsule. The apparatus is then placed in the
heating cup adjusted to a depth of about two and one-half inches.
Connections with the water stream and vacuum pump are made in the
1 Elementary Chemical Microscopy, 1916, 288-292.
1923] VIEHOEVER: DOMESTIC SOURCES OF CANTHARIDIN 489
usual manner, and the heating is conducted gradually by means of a
low flame. With the aid of a suitable light, and a magnifier if neces-
sary, the appearance of the deposited material on the slide may easily
be observed. When the sublimation appears to be completed the cup
section is disconnected and the slide is removed and placed in the special
glass holder for examination under suitable power without the use of a
cover-glass. Further observations and tests on the sublimed deposit
may be carried out following the procedure described by Chamot.
Observations have been conducted for the purpose of determining the
relation of the observed temperature in the air-bath to the actual tem-
perature in the sublimator. At a bath temperature approaching 100°C.,
after approximately one-half hour heating, there is substantially no
difference between the observed and the actual temperature inside the
sublimator cup. A number of tests have shown that the temperature
inside the cup is only a trifle lower than the observed temperature of the
heating bath.
DOMESTIC SOURCES OF CANTHARIDIN.
I. Macrobasis albida Say.
By ARrNo VIEHOEVER and RutH G. Capen (Bureau of Chemistry,
Washington, D. C.).
Cantharidin is the blistering principle occurring in certain beetles. The
official source is limited to Cantharis vesicatoria (Linné) De Geer, Spanish
or Russian flies. Another recognized source for cantharidin is My-
labris cichorit Fab., so-called Chinese flies. None of these forms occur
in this country; consequently, material containing cantharidin, or
cantharidin itself, is imported. In spite of the fact that blister beetles
are known to occur in the United States, no domestic sources have, to
the knowledge of the writers, been examined, either qualitatively or
quantitatively, for the presence of cantharidin. The price of the ma-
terial yielding cantharidin is comparatively high, Russian cantharides
being quoted at $3.25 per pound, while Chinese flies are $1.10 per pound!.
Cantharidin, which the United States Pharmacopceia Revision Com-
mittee contemplates making official, is not quoted in the open American
market.
For these various reasons it seemed justifiable to make a survey of
the domestic sources. This paper describes work done with one of the
species of beetles, Macrobasis albida Say. (see Fig. 1), found to contain
cantharidin.
1 Drug and Chemical Markets, October 25, 1922.
490 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
F «. 1.—Macrobasis Albida Say. After Chittenden
ORIGIN AND NATURE OF THE MATERIAL.
Material for the work was obtained through the kindness of F. H.
Chittenden, Truck Crop Insect Investigations, Bureau of Entomology.
The species Macrobasis albida Say., the “‘two-spotted blister beetle’,
belongs to the family Meloidae. It compares very well in size with
the European Cantharis vesicatoria. It is gray, yellowish or brownish,
unicolorous, or with markings. The prothorax usually has two longi-
tudinal black stripes; the elytra are usually concolorous, sometimes with
sub-marginal black stripes. The basal points of the antennae are brown.
This variety of beetle occurs abundantly in Texas, Kansas and adjoin-
ing states. Macrobasis albida and closely related species feed on legumes
and other plants that root deeply, devouring the petals and pollen of the
flowers. Irish potatoes and sugar beet plants are completely defoliated
by the beetles}.
ISOLATION OF CANTHARIDIN.
The beetles were carefully dried at a temperature not exceeding 70°C.
Cantharidin was readily sublimed from very small amounts of the
powdered material. Even larger amounts were obtained when the
1 Milliken, F. B., U.S. Dept. Agr., Bull. 967, 1922, 2, 3, 5.
1923] VIEHOEVER: DOMESTIC SOURCES OF CANTHARIDIN 491
powder, before sublimation, was moistened with chloroform containing
sufficient hydrochloric acid (10 per cent) to render it distinctly acid.
The material was sublimed in a small apparatus! which was heated in an
oil bath at temperatures from 110° to 120°C. A partial vacuum and a
cooling device was used. Cantharidin was deposited on the cover slip
in pure white plates, sometimes with a small amount of fat, which was
readily removed with petroleum ether.
CHARACTERISTICS OF CANTHARIDIN.
Cantharidin has a melting point of 210°C., but sublimes as low as
100°. It forms a white substance which crystallizes in large plates.
OPTICAL PROPERTIES”,
Angle of extinction = parallel.
Indexes—1.505 1.54.
SOLUBILITIES.
Soluble in 30,000 parts cold water 3, °.
Soluble in 15,000 parts hot water %, °.
Soluble in 8,000 parts 1 per cent sulfuric acid’.
Soluble in 2,500 parts carbon tetrachloride‘.
Soluble in 900 parts ether’.
Soluble in 833 parts 45 per cent formic acid‘.
Soluble in 800 parts absolute alcohol’.
Soluble in 715 parts 10 per cent acetic acid‘.
Soluble in 500 parts benzol?.
Soluble in 65 parts chloroform, 5.
Soluble in 38 parts acetone’.
Soluble in 245 parts 75 per cent acetone’.
Soluble in 625 parts 50 per cent acetone‘.
Soluble in 5,000 parts 25 per cent acetone’.
Selinite Test.
This test was carried out according to the method of Klein®. Con-
centrated sulfuric acid and a trace of sodium seljnite added to the alco-
holic cantharidine solution gave a slight purple color. Upon heating,
the coloration gradually increased and changed to blackish, which,
upon addition of alcohol, turned to a dark purple color.
Quantitative Experiments.
Dubois’? method was used, extracting both the free, and free and
combined cantharidin. The method is as follows:
1 Viehoever, Arno., J. Assoc. Official Agr. Chemists, 1922, 5: 557.
2 Determined by TF. Clevenger, Pharmacognosy Laboratory, Bureau of Chemistry, Washington, D. C.
3 Rosenthaler, L., Der Nachweis organischer Verbindungen, 1914, 834.
4 Seidell, A., Solubilities of Inorganic and Organic Compounds, 1919, 226.
6 Schmidt, Ernst., Lehrbuch der Pharmaceutischen Chemie (Organische Chemie), II, Part IT, 1911, 1926.
§ J. Ind. Eng. Chem., 1910, 2: 389.
7 Am. J. Pharm., 1920, 92: 157.
492 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VJ, No. 4
To 10 grams of dried powder passing through a 40-mesh sieve add 30 cc. of chloro-
form and allow to stand overnight. Then shake at short intervals during 2 or 3 hours.
Filter and wash with 70 cc. of chloroform and evaporate the filtrate on water bath.
Treat the residue with 5 cc. of carbon bisulfide and transfer to tared filter paper. Wash
with 10 cc. of carbon bisulfide and dry at 60°C. Weigh material. Add 0.010 gram for
solvent action. This should give free cantharidin. To obtain combined as well as
free cantharidin follow the same procedure, except add 2 cc. of concentrated hydro-
chloric acid to the original chloroform.
The results obtained by this method are as follows:
per cent per cent
Pree cantharidginy: oii. Soe eee ene 1.04 0.85
0.80 0.67
Free cantharidin and cantharidin salts......... 3.92 3.83
4.21
DISTRIBUTION OF CANTHARIDIN.
Female beetles are considered to be more valuable as a source of
cantharidin than the male!. Various experiments have been made by
subliming material consisting of different parts of the beetles. The
eggs were found to be very rich in the active principle. The heads
contained a smaller amount and the wings none. Macrobasis albida,
yielding over 1 per cent free cantharidin and from 4 to 5 per cent free
and combined cantharidin?, contains as large, if not larger amounts of
cantharidin than do the other varieties. Cantharis vesicatoria yields
less than 1 per cent’, and Mylabris chicorii from 0.426 to 1.362 per cent,
or on an average 1.2 per cent‘.
SIGNIFICANCE OF FINDINGS.
The fact that the beetles occur abundantly in various middle western
states and that they contain cantharidin far in excess of the minimum
requirements of the U. S. Pharmacopeeia, namely, 0.6 per cent, very
strongly suggests their commercial value.
SUMMARY.
The beetle, Macrobasis albida Say, abundant in Texas and Kansas,
was found to contain cantharidin.
The amounts of free cantharidin varied from 0.6 to 1 per cent; of
cantharidin and cantharidine salts from 4 to 5 per cent.
The eggs were found to contain large amounts; the heads, very small
amounts; and the wings, no cantharidin.
Macrobasis albida, American blister beetles or American blister flies,
represent a possible domestic commercial source of cantharidin.
1Sanders, Wm. Proc. Amer. Pharm. Assoc., 1876, 24: 509.
2? Determined by Ruth G. Capen.
8 Juritz,C. F. S. African J. Industries, 1919, 2: 470.
4 Ewe, Geo. E. J. Am. Pharm. Assoc., 1920, 9: 260.
1923] SPENCER: DETERMINATION OF ACETIC ANHYDRIDE 493
QUANTITATIVE DETERMINATION OF ACETIC
ANHYDRIDE’.
By G. C. Spencer (Analytical Reagent Investigations Laboratory,
Bureau of Chemistry, Washington, D. C.).
Previous methods are briefly reviewed. The proposed method is
based upon the reaction of acetic anhydride and aniline dissolved in cold
chloroform. An equivalent amount of acetanilide forms. Attempts
made to separate and weigh acetanilide proved unsatisfactory. The
acetanilide is hydrolyzed by sulfuric acid and the resulting aniline sul-
fate is titrated with bromate-bromide solution.
The methods that have been proposed for the quantitative estimation
of acetic anhydride may be grouped under three heads: (1) Direct
titration; (2) extraction with a solvent; (3) separation of .a derivative
which may be weighed or titrated.
(1) The United States Pharmacopeeia (9th edition, page 522) directs
that 10 cc. (‘mils’) of acetic anhydride be accurately weighed and
made up to 100 cc. with water. Ten cc. of this solution are titrated
with normal alkali. Not less than 19.3 cc. are required to neutralize
1 gram of acetic anhydride. The U. S. P. requirement therefore indi-—
cates 90 per cent or more of the anhydride.
A method given in Beilstein’s? recommends boiling a weighed quantity
of acetic anhydride with an excess of normal sodium hydroxide and
titrating back with 0.1N acetic acid. Expressed as acetic acid, each
per cent of acidity in excess of 100 corresponds to 5.67 per cent of acetic
anhydride.
(2) The one method found in the literature that depends upon ex-
traction with a solvent is that proposed by Wolgast’. Exactly 25 ce.
of water are shaken with a solution of 25 cc. acetic anhydride in 30 ce.
of benzene for 15 seconds and allowed to separate. The acetic anhydride
remains dissolved in the benzene while the acetic acid is dissolved by
the water. The increase in the volume of the water layer in cubic
centimeters multiplied by 4 gives the percentage of acetic acid in the
sample.
It may be explained here that acetic anhydride does not react as
readily with water as do the anhydrides of many inorganic acids.
(3) The literature describes two procedures based upon the formation
of a derivative such as acetanilide. One of these is stated by its origi-
1 Presented at the 64th meeting of the American Chemical Society, Pittsburgh, Pa., Sept. 4-8, 1923.
2 Handbuch der organischen Chemie, 1920, vol. IT, 169.
3 Svensk Kem. Tid.. 1920, 32: 10.
494 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
nators to be applicable only to high concentrations of anhydride in
acetic acid, and the other is recommended only for low concentrations
in the same acid.
The first is the method of Menschutkin and Wasilieff!. It is recom-
mended by them for solutions containing over 60 per cent of anhydride
in acetic acid. The sample is treated with aniline, which reacts with
the anhydride to form aniline acetate and acetanilide in molecular pro-
portions, and with the free acetic acid to form aniline acetate. The
total aniline acetate is titrated directly with standard barium hydroxide
solution, using phenolphthalein as an indicator. The results have been
found by the writer to be satisfactory.
The second of these methods has been published by Edwards and
Orton’, who state that it is applicable only to low percentages of an-
hydride in acetic acid. The anhydride is caused to react with 2, 4—
dichloroaniline at 16°C. This reaction forms equivalent quantities of
dichloroacetanilide and dichloroaniline acetate. An unstable chlorine
derivative is made by treating the dichloroacetanilide with bleaching
powder solution. This compound reacts with potassium iodide to
liberate an equivalent amount of iodine which is titrated with sodium
thiosulfate solution. The writer’s experience with this method leads to
the belief that while it may be accurate in the hands of experienced
workers, it nevertheless involves a number of reactions and requires the
use of large volumes of solution.
The writer’s experience with the preceding methods has been un-
satisfactory, except as noted.
H. E. Buc, formerly of the Bureau of Chemistry, suggested tenta-
tively that acetic anhydride be assayed by dissolving in ether a weighed
quantity of the sample, adding an excess of aniline to form acetanilide
and aniline acetate, extracting the acetanilide with chloroform, evap-
orating the solvent, drying, and weighing. From this weight the
amount of acetic anhydride is calculated. This procedure served as a
basis of the method about to be proposed.
EXPERIMENTAL WORK.
Blanks on chloroform and aniline alone.—1.5 cc. of aniline was dissolved
in 15 ce. of chloroform, and the solution was transferred to a Squibb
separatory funnel with 10 cc. more of chloroform. Ten cc. of 10 per
cent sulfuric acid and 15 cc. of water were added, the mixture was
shaken well, and the liquids were allowed to separate. The chloroform
layer was drawn into a second separatory funnel containing 15 cc. of
water. After shaking, the chloroform layer was allowed to separate
1J. Russ. Phys. Chem. Soc., 1896, 24: 190.
2 J. Chem. Soc., 1911, 99: 1181.
1923] SPENCER: DETERMINATION OF ACETIC ANHYDRIDE 495
and was then drawn into a 200 cc. Erlenmeyer flask through a small
dry filter. The aqueous residues in the two funnels were further ex-
tracted in succession, first with 10 cc. and then with 7 cc. of chloroform.
These extracts were drawn into the Erlenmeyer flask. Ten cc. of 10
per cent sulfuric acid were added, and the flask was placed on a steam
bath at moderate temperature until the chloroform had been expelled
and the acid solution reduced to 4 or 5 cc. Ten cc. of water were added,
and the evaporation was repeated. The practice here described may
reasonably be questioned. In fact, it has since been abandoned, but,
so far as the writer observed, no frothing or spurting occurred in this
case. To the residue in the flask were added 60 cc. of water and 5 cc.
of concentrated hydrochloric acid. This solution was titrated with
half-normal potassium bromate-bromide solution. The results shown
in the table indicate that some of the aniline in the form of sulfate was.
taken up by the chloroform, since no acetic anhydride or even acetic
acid was present to form any acetanilide. Small amounts of tribromo-
aniline were observed as a flocculent precipitate after the titration.
Blanks on glacial acetic acid.—To 1.5 ce. of aniline, dissolved in 15 ce.
of chloroform was added 0.3-0.8 gram of glacial acetic acid, and the
solution was allowed to stand for 1 hour. The determination was
carried out as already described. The results are given in the table as
the apparent equivalent content of acetic anhydride in the acetic acid.
It is uncertain whether a small amount of acetic anhydride is actually
present in glacial acetic acid, or whether the action of the acetic acid on
aniline is sufficient to form a small amount of acetanilide at low tem-
peratures in dilute solutions.
As shown in the table, “‘edible’’ acetic acid (that made from calcium
carbide) shows an apparent anhydride content lower than in commercial
c. p. acetic acid. The effects of small amounts of water and of alcohol
on the reaction showed that these did not appreciably affect the results.
The blank on 90 per cent acetic acid was fairly comparable with that
obtained on glacial acetic acid. The results have been corrected by
subtracting the values for the chloroform and aniline blank in each case.
REAGENTS.
(a) Sulfuric acid, 10 per cent.
(b) Aniline, freshly redistilled.
(c) Chloroform, U.S. P.
(d) Potassium bromate-bromide solution.—Either dissolve appropriate quantities of
the two salts in water or make up as follows: Dissolve 28 grams of potassium hydroxide
in 300-400 cc. of water and from a buret in a hood add slowly and with stirring 13.3 cc.
(40 grams) of bromine. Warm the mixture gently until the bromine has completely
dissolved, then raise the temperature to the boiling point. Continue to boil for 5-10
minutes and if necessary add a little more potassium hydroxide to take up the last of
the bromine. After cooling, make up to 1 liter. Standardize this solution as follows:
496 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
Weigh 0.3 gram of recrystallized acetanilide into a 200 cc. Erlenmeyer flask and add
10 cc. of 10 per cent sulfuric acid. In the same manner as directed in the next para-
graph, proceed with the hydrolysis and titration. Ascertain the acetic anhydride fac-
tor by dividing the acetanilide weight (in grams) by the volume of bromate-bromide
(in cubic centimeters) and multiplying this quotient by 0.7555. A solution thus pre-
pared is approximately half-normal.
DETERMINATION.
Weigh 0.3-0.4 gram of the acetic anhydride sample in a small glass capsule, fitted
with a well-ground glass stopper. Add the capsule containing the charge to a cooled
mixture of 15 cc. chloroform and 1 cc. of aniline contained in a 100 cc. glass-stoppered
Erlenmeyer flask. The capsule is most conveniently opened by holding it in the neck
of the inclined flask, removing the stopper, and allowing both parts to slide into the
chloroform. Stopper the flask immediately, mix thoroughly, and leave the flask in the
refrigerator for not less than 1 hour.
Rinse the chloroform solution of the charge into a 125 cc. Squibb separatory funnel
containing 15 cc. of 10 per cent sulfuric acid and 15 cc. of water, using 10 cc. more of
chloroform. Shake well and allow to separate. Draw the chloroform layer into a
second separatory funnel containing 15 cc. of water. Shake this mixture, and after
the layers have separated draw the chloroform into a 200 cc. Erlenmeyer flask through
a small dry filter. To the first separatory funnel add 10 cc. of chloroform. Shake
well and draw the lower layer into the second separatory funnel, shake, and pass the
chloroform into the Erlenmeyer flask through the same filter. Repeat the extractions
with 7 cc. of chloroform. Evaporate or distil cautiously the greater part of the chloro-
form from the combined extracts and drive off the remainder of the solvent by a gentle
air blast.
Add 10 cc. of 10 per cent sulfuric acid to the crystals in the Erlenmeyer flask. Allow
it to evaporate slowly on the steam bath until the volume is reduced about one-half.
Add 10 cc. of water and repeat the evaporation. Care must be used to insure complete
hydrolysis of the acetanilide, but the acid must not become so concentrated that it
will decompose the aniline sulfate. Take up with 60 cc. of water, add 5 cc. of con-
centrated hydrochloric acid, and titrate the solution with the potassium bromate-
bromide solution. The liberated bromine reacts with the aniline sulfate to form
s-tribromo-aniline which separates as a white flocculent solid. The end-point is the
yellow tinge that appears in the solution as soon as the bromine is in excess and must
be approached very carefully.
1 cc. 0.56N KBrO;—KBr = 0.008505 gram acetic anhydride.
Greater accuracy is attained by using fifth-normal potassium bromate-bromide
solution when only small amounts of acetic anhydride are present.
The reactions are expressed as follows:
2 C.HsNH2+(CH;CO),0 =C,H;NHCOCH;+C.Hs NH; O2 C2 Hs.
C,-H;NHCOCH;+H.20+3 H.SO,=CsHsNH2 4 H2SO.+CH;CO2H.
C.-H;sNH: 4} H.SO.,+6 Br=C,H2Br; NH2 } H:SO,+3 H Br.
The table summarizes the collaborative work of five chemists. Sam-
ples 11 to 29 are the same commercial acetic anhydride. The mean of
all these results is 90.78 per cent.
Two of the collaborators were inexperienced in the method, and two
others only slightly experienced.
1923] SPENCER: DETERMINATION OF ACETIC ANHYDRIDE 497
The nature of acetic anhydride and the difficulties attending its
preparation in a state of absolute purity render the confirmation of any
analytical method more or less uncertain.
Analytical Results.
(1 cc. 0.5N. K BrO;—K Br solution =0.008505 gram acetic anhydride.)
SAMPLE WEIGHT 0.5N
NO. MATERIAL EXAMINED TAKEN STANDARD ACETIC ANHYDRIDE
SOLUTION
gram ce. gram per cent
1 Blank oni aniline sy i'w) jig) Wi ihc bay aye oay 0.26 O.002Z2 0 ib) ieiweine
2 Blank on aniline"! 9%). PA ae cee 0.25 O.CO2ZTZ HOR Te
3 Glacial acetic acid 0.4045 0.30 0.00255 0.63
4 Glacial acetic acid 0.3598 0.34 0.00289 0.80
5 3 and 4 reduced to 0.2646 0.13 0.00110 0.41
6 90 per cent acid strength 0.2742 0.11 0.00093 0.33
7 ““Edible”’ acetic acid 0.3103 0.07 0.00059 0.13
8 “Edible” acetic acid 0.3366 0.04 0.00034 0.10
9 4 per cent solution in 0.5262 2.36 0.02007 3.81
10 glacial acetic acid 0.5742 2.46 0.02092 3.64
11 Commercial acetic anhydride 0.4772 50.48 0.4293 89.97
12 Commercial acetic anhydride 0.4145 44.27 0.3765 90.84
13 Commercial acetic anhydride 0.4021 42.05 0.3576 88.94
14 Commercial acetic anhydride 0.2976 31.67 0.2693 90.51
15 Commercial acetic anhydride 0.3644 39.03 0.3319 91.08*
16 Commercial acetic anhydride 0.3494 37.29 0.3171 90.75*
17 Commercial acetic anhydride 0.5105 55.08 0.4684 91.757
18 Commercial acetic anhydride 0.5620 61.09 0.5196 92.45T
19 Commercial acetic anhydride 0.4480 47.64 0.4052 90.447
20 Commercial acetic anhydride 0.5417 58.51 0.4976 91.867
21 Commercial acetic anhydride 0.3705 39.53 0.3362 90.74t
22 Commercial acetic anhydride 0.3136 33.52 0.2851 90.91t
23 Commercial acetic anhydride 0.3610 38.58 0.3281 90.89t
24 Commercial acetic anhydride 0.3579 38.58 0.3281 91.78t
25 Commercial acetic anhydride 0.3626 38.86 0.3305 91.15§
26 Commercial acetic anhydride 0.4268 44.99 0.3826 89.64§
27 Commercial acetic anhydride 0.3496 37.20 0.3164 90.50§
28 Commercial acetic anhydride 0.3650 38.75 0.3295 90.29§
29 Commercial acetic anhydride 0.3118 33.13 0.2817 90.37§
*Results by W. F. Baughman.
tResults by J. K. Morton.
tResults by R. M. Hann.
§Results by J. I. Palmore.
SUMMARY.
A volumetric method for determining acetic anhydride which applies
equally well so far as experience shows to high and low concentrations
in acetic acid is described.
The estimation is readily effected without using unusual or expensive
chemicals or apparatus.
The results obtained indicate for the method an accuracy within one
per cent.
498 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
CONTRIBUTED PAPERS.
THE EFFECT PRODUCED UPON THE FAT OF HOGS BY
FEEDING FISH MEAL.
By James B. Martin (Bureau of Animal Industry, Washington, D. C.).
Fish meal! is a commercial product obtained by cooking, pressing and
drying wholesome, undecomposed, raw fish material, under sanitary
conditions. Its principal constituents are protein and fat. Feeding
experiments have shown it to be a valuable supplementary feeding stuff
and have failed to confirm the assumption that the feeding of fish meal
of good quality as a supplementary feed in connection with other feeds
imparts a fishy taint to the meat of the hogs or to the lard rendered
from their fat.
Frank G. Ashbrook?, of the Bureau of Animal Industry, conducted
experiments at the Experimental Farm of the Bureau at Beltsville,
Maryland, to determine, first, the comparative values of fish meal and
tankage as supplements in a ration for growing and fattening pigs; and
second, the value of dried pressed potato in a ration for fattening hogs
when supplemented by feeds rich in protein.
Under the first experiment, the feeding period was divided into two
parts: (1) a growing period; and (2) a finishing period. During the
first period the pigs were divided into two lots of eight and four and fed
on the following rations:
Lot 1 ration: 4 parts corn meal, 4 parts middlings, 1 part tankage.
Lot 2 ration: 4 parts corn meal, 4 parts middlings, 1 part fish meal.
During the second period the pigs were divided into 3 lots of four and
fed on the following rations:
Lot 3 ration: 4 parts corn meal, 4 parts middlings, 1 part fish meal.
Lot 4 ration: 9 parts corn meal, 1 part fish meal.
Lot 5 ration: 9 parts corn meal, 1 part tankage.
Under the second experiment, the pigs were divided into four lots of
three pigs each and fed on the following rations:
Lot 1 ration: 6 parts corn meal, 1 part tankage.
Lot 2 ration: 6 parts dried pressed potato, 1 part tankage.
Lot 3 ration: 6 parts dried pressed potato, 1 part linseed oil meal (old process).
Lot 4 ration: 6 parts dried pressed potato, 1 part fish meal.
1U. S. Dept. Agr. Bull. 378.
2 [bid., 610.
1923] MARTIN: EFFECT ON HOGS OF FEEDING FISH MEAL 499
The analysis of the fish meal was as follows:
per cent
Wiaternnr dr diiets wept to a tet men at Lee 6.36
1 eRe ARNE NR eee 2s Pie a. AG EY AA Re 15.34
Proteins (Nex<6:25) ean ee cite cae Deol
ASHE Nace than acne eR rN MAES RE eM eh ieee. acl are 16.52
Undetermined’) oye ee ER ee yh 4.47
The results of these experiments showed conclusively that fish meal is
a very effective supplement to a grain ration for pigs, that it is superior
to tankage in all comparisons, that it is an outstanding protein supple-
ment to feed along with potatoes, and that where it can be obtained
conveniently at a reasonable price it is of considerable value in hog
feeding. In addition, pigs relish it and maintain a thrifty growth.
These experiments also showed that fish meal does not impart a fishy
flavor to the meat or lard if it is fed in proper proportions with other
feeds. At the conclusion of both these experiments the fresh pork from
one of the hogs was eaten by individuals who were ignorant of the feed
that the hogs had been given. Lard was also rendered from both the
trimmings and the carcass, and observations were made. In no case
was the meat reported as having a fishy odor or taste, neither was it
evident in the rendering of the lard.
Four samples of the lard rendered from hogs fed on fish meal were
sent to the Meat Inspection Laboratory for chemical examination and
came under the observation of the writer. The lard was very white
in color and had an agreeable taste and normal odor; no fishy odor or
flavor could be distinguished. Approximately 50 grams of this lard and
50 grams of a normal prime steam lard were heated simultaneously over
a Bunsen burner to a temperature of 176°C., and up to this temperature
neither sample gave any evidence of a foreign or an offensive odor.
Heating was discontinued at this point as both samples began to smoke
and give off the characteristic acrid fumes of overheated fat. The regu-
lar laboratory methods for testing a lard chemically for its identifica-
tion were next applied to both lards, and the following results, which
are practically identical, were obtained:
LARD FROM HOGS FED PRIME STEAM
ON FISH MEAL LARD
OTe) I ta eae INEM se Cerur gL TT. tela White White
Bae efi U8 Ah. a3! Fes pies» Seve hate acai es Me Negative Negative
TEEMCCHL OPECE LACIE. che. «) eo connie sre cane eee 0.11 0.17
Nerve Nou 6 Se Tia iis DORI Cae tees eS Pe 62.86 63.15
Melting point of stearine crystals............... 64°C, 64.2° C,
The samples were then tested for the presence of glycerides of the
characteristic fatty acids of fish oils. Fish and marine animal oils differ
from other fats in that they contain glycerides of certain highly un-
saturated acids which have the property of forming insoluble brom-
500 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
addition compounds. This property is the basis of a sensitive method
for the detection of fish oils in animal and vegetable oils. The lard was
first tested by the official method! for the detection of fish and marine
animal oils in animal and vegetable fats. This test consists in dissolving
a portion of the suspected fat in a mixture of chloroform and glacial
acetic acid, adding an excess of bromine and allowing to stand for a
brief period of time in boiling water. Vegetable and animal fats remain
clear, but if fish fat is present there is a precipitate due to the formation
of the insoluble brom-addition compounds. When tested by this
method a small but distinct and unmistakable precipitate was observed
in each sample.
The samples were further examined for the presence of clupanodonic
acid. This acid, C;;H.;COOH, has been isolated from fish and marine
animal fats by several observers and is the characteristic acid of those
fats. It is capable of taking up eight atoms of bromine, thereby forming
octo-brom stearic acid. The latter compound is insoluble in ether and
other organic solvents. It may he readily separated from the brom-
addition products of the other unsaturated acids, all of which are soluble
in warm ether. When separated, it may be distinguished by the fact
that it does not have a definite melting point but decomposes at temper-
atures of 200°C., or thereabout, without melting.
The fatty acids were prepared by the following method:
Approximately 100 grams of the lard were mixed with 200 cc. of alcohol distilled over
sodium hydroxide in a large Erienmeyer flask and let stand on the steam bath until
the boiling point was nearly reached. At the same time 30 grams of potassium hydroxide
were dissolved in water, mixed with 150 cc. of alcohol, placed on the steam bath and
heated nearly to the boiling point. When the contents of each flask were nearly at
the boiling point the alcoholic potash was added to the flask containing the fat. Sapon-
ification was immediate and complete. The soap solution was evaporated to dryness and
dissolved in 400 cc. of water. The fatty acids were then set free by adding an excess
of sulfuric acid in 5% solution and washed four times with distilled water, 300 cc.
being used for each washing. They were next dissolved in 500 cc. of a mixture of
glacial acetic acid and ether in equal parts, and a solution of bromine in glacial acetic
acid was added until the color of the bromine persisted. This action was carried out
at a temperature ranging from 5 to 8°C. The solution was held in a refrigerator at
a temperature of not over 12°C. for 18 hours. A white precipitate of powdery or sandy
character was formed. The clear supernatant liquid was then decanted off and the
precipitate washed with ether and dried.
The precipitate was hard, brittle and rather easily broken up to a
fine white or gray powder, having the appearance of fine white sand.
It was insoluble in all organic solvents tried. When determination of
its melting point was attempted it decomposed at 186°C. As a check,
a portion of the prime steam lard used for comparison, as well as several
other samples of lard, was saponified, and the fatty acids were bromi-
1 Assoc. Official Agr. Chemisls, Methods, 1920, 256
1923] MARTIN: EFFECT ON HOGS OF FEEDING FISH MEAL 501
nated in the same way. No precipitate of brominated acids insoluble
in cold ether was obtained.
The percentage of bromine in the precipitate was next determined. A
weighed portion was placed in an ignition tube with approximately four
times its weight of a mixture consisting of equal parts of calcium oxide,
sodium carbonate and potassium nitrate and cautiously ignited until
the substance decomposed. The temperature was then raised until the
carbon was all burned off, leaving a white mass in the tube. The tube
was shattered by dropping it while still hot into a beaker containing
water, and the mass was dissolved in dilute nitric acid and filtered.
Bromine was determined in the filtrate in the usual way. The results
of the first test showed 62.94 and 62.59 per cent bromine in duplicate
samples. This percentage is considerably below the theoretical per-
centage of bromine in octo-brom stearic acid, which is 69.84 per
cent. As the fatty acid had been allowed to stand overnight on the
steam bath, it appeared probable that there had been oxidation of a
portion of the clupanodonic acid. The experiment was, therefore,
repeated, the fatty acids being brominated as soon as prepared. Dupli-
cate determinations of bromine in the precipitate yielded 68.8 and 67.9
per cent of bromine. While the percentage of bromine found does not
agree exactly with the theoretical, it is believed that the discrepancy is
due to the possible presence of small amounts of impurities in the pre-
cipitate, and that the bulk of the precipitate consisted of octo-brom
stearic acid derived from the clupanodonic acid present in the fat.
Quantitative determination of brominated acids in one experiment gave
a yield of 0.15 per cent, corresponding to 0.045 per cent of clupanodonic
acid in the lard.
SUMMARY AND CONCLUSIONS.
The fat of hogs fed on fish meal has been found identical with normal
fat in its physical aspects and ordinary chemical characteristics.
The fat of hogs fed on fish meal has been found to contain a small
proportion of the glyceride of clupanodonic acid.
Clupanodonic acid has been identified by the preparation of insoluble
octo-brom stearic acid having the known properties of that substance
and containing nearly the theoretical percentage of bromine.
502 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
NUT MARGARINES.
By J. T. Keister (Food Control Laboratory, Bureau of Chemistry
Washington, D. C.).
INTRODUCTION.
According to Clayton', Hoffman? first suggested the use of nut oils in
the manufacture of margarine. A patent was issued to Meinert and
Jeserich? for the manufacture of this product exclusively from vegetable
oils, and in 1896 the use of coconut oil, which has become the chief
constituent of this product, was patented by Ruffin‘.
From a purely scientific standpoint, several important advances have
been made in margarine manufacture since the invention of the French
chemist, Mége-Mourie, in 1869. First may be mentioned the use of
cultures of lactic acid organisms for souring the milk used in churning
the fats to impart a butter flavor to the product; second, the introduc-
tion of vegetable oils and fats, leading to the class of products known as
nut margarines, which class is the subject of this paper. A third im-
provement was the introduction of the hardened (hydrogenated) oils,
the use of which assists in regulating the melting point of the margarine
fat, thereby producing a product more resistant to temperature con-
ditions than would be the case without such hydrogenation. It may be
stated, therefore, that the entire process of the manufacture of nut
margarine is based upon scientific principles.
RAPID GROWTH OF THE NUT MARGARINE INDUSTRY.
The manufacture of nut margarine appears to have begun in this
country early in the year 1917. The first figures available’, for the
month of February, show a total production of 608,330 pounds, and for
the entire year, a total production of approximately 22,000,000 pounds,
which represented about 23 per cent of the total margarine produced.
The production for the month of February alone, in 1918, was over
9,500,000 pounds, about 25 per cent of the total production, and nearly
16 times greater than the production in the same month in 1917.
In September, 1919, the production of nut margarine is shown to have
been about 28 per cent of the animal variety (oleomargarine); for the
month of October it had increased to about 73 per cent; for the month
of December the production of the two products was almost equal in
amount; and in May, 1920, statistics show that the production of vege-
table or nut variety exceeded that of the animal variety, being 20,972,644
and 19,962,711 pounds, respectively.
iMargarine, 1920
ene. ag 3867, "1880.
&’ Amer. Food. Hid +018, 13: 207.
1923] KEISTER: NUT MARGARINES 503
The number of factories producing nut margarine in the United
States increased from three in April, 19171, to over 60 in December,
19207.
REASONS FOR THIS INVESTIGATION.
Nut margarine being a comparatively new food product, it was neces-
sary to secure information as to its manufacture and composition, also
to determine whether the present analytical methods used for butter
were adequate and applicable to this product, and to develop and apply
new methods where necessary.
A sufficient number of factory inspections were made to get a general
knowledge of the materials used, the methods of treatment and the
processes followed in the manufacture of the margarine. All samples
were collected by the writer in Washington, where many different brands
of the product are on sale.
MATERIALS USED AND PROCESS OF MANUFACTURE.
Different kinds of oil and either skimmed or whole milk form the basis
for the manufacture of this product in the United States. The principal
oils used are coconut and peanut oils which have been properly refined
and deodorized. Other vegetable oils, such as cottonseed and sesame,
have been found present in small quantities.
In order to obtain a margarine which has the desired consistency
(softening and melting points), various proportions of hydrogenated and
untreated oils are employed. The proportions used depend not only on
the degree of hydrogenation of the hardened fat, but also upon the
season of the year. It is customary during the warm weather to pre-
pare margarine which contains a somewhat larger quantity of hardened
fat. Pickard*® estimates that the amount of untreated oil used varies
from 5 to 25 per cent.
Whole or skimmed milk, ripened to 0.6 to 0.7 per cent lactic acid, is
added, and the mixture, at a temperature of about 68°F., is put into
large barrel-shaped revolving churns or mixers. The essential element
in preparing the cultured milk is temperature control; the heat should
not be raised so high as to change the physical properties and flavor of
the milk, nor should it be too low for proper bacterial growth. Accord-
ing to Pickard, “the fundamental principle of the churning operation is
to form an emulsion of the milk with the oil in order that the utmost.
degree of contact of the two may be brought about * * *so that the
effect of the one upon the other is at a maximum. The temperature of
the liquid must be closely watched, and the operation stopped at the
1 The a S. Bur. Markets, April 3, 1920.
2 Tbid., January 15, 19
3 Amer. Food J., 1918, 13: 16.
504 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
time when the emulsion is most perfect”. From the mixers the
emulsion flows through a pipe to the floor below and is deposited in a
thin film upon the surface of hollow revolving cylinders, which are chilled
by the circulation of cold brine through them. By the proper applica-
tion of scraping knives to the surface of the cylinders, the solidified
emulsion is scraped off directly into tempering trucks. These trucks,
containing the fat, are stored in a cool room for 24 hours while the
product “‘ripens”’; this process is claimed to give the finished article the
proper flavor. The product then goes to a machine where water is
worked out and the salt added and worked in, as in the case of butter.
From the worker the product is placed in trucks, and from these it is
transferred by means of wooden scoops to a hopper which leads to the
moulding or printing machines. The margarine comes from the moulds
in a continuous flat block from which one-pound—or larger—prints are
cut by wires; it is then packed in cartons either by hand or by machinery.
Weights are occasionally checked up to insure full weight.
METHOD OF ANALYSIS.
As seen from the attached table, water was determined both by the
official method!, and by Patrick’s “rapid beaker” method’, withslight mod-
ifications. The latter method consists in weighing out accurately about
5 grams of the prepared sample into a dry aluminum or silica beaker,
driving off the moisture by heating over a burner (low flame), using a
wire beaker holder, revolving gently and removing from flame, if neces-
sary, to avoid loss by sputtering. When the sample ceases to foam and
the curd assumes a light-brown color, it is removed from the source of
heat; the beaker is cooled in cold water, and all moisture adhering is
carefully wiped off; the sample is weighed, and from the loss in weight
the percentage of moisture in the sample is calculated. It will be noted
from the results recorded in the table that checks in fairly good agree-
ment with the official method were obtained in most cases by this method.
It should be stated that the principal difficulty in determining moisture
in nut margarine is in obtaining a uniform sample; this appears to be
more difficult than in the case of butter.
Fat was determined by the official (indirect) method’. Casein and
salt were also determined by the A. O. A. C. methods‘, the volumetric
silver nitrate method being used, with potassium chromate as indicator.
EXAMINATION OF THE FAT.
The following methods were used: for refractive index, free fatty
acids, Reichert-Meiss! number, Polenske number and saponification
1 Assoc. Official Agr. Chemists, Methods, 1920, 232.
2 J. Am. Chem. Soc., 1907, 29: 1126.
3 Assoc. Official Agr. Chemists, Methods, 1920, 232.
4 Ibid., 233.
1923] KEISTER: NUT MARGARINES 505
number, the regular official methods', the Leffman and Beam method
being applied for the Reichert-Meissl! number; for the iodine number,
the Wijs procedure?, with approximately one gram of the sample; for
the melting point of the fats, the capillary tube method?, as recommended
by the Committee on Analysis of Commercial Fats and Oils of the
Division of Industrial Chemists and Chemical Engineers of the American
Chemical Society; for cottonseed oil the official Halphen test*; for
sesame oil, the Baudouin and Villavecchia tests‘; and for peanut oil,
Bellier’s qualitative test®.
Bellier’s method is essentially as follows:
Saponify 1 gram of the oil with 5 cc. of alcoholic potash solution (4.25 grams of po-
tassium hydroxide, purified by alcohol and containing about 87% of potassium hydroxide,
dissolved in 70% alcohol and made up to 50 cc.) by gentle heat until clear. Add
1.5 ce. of an acetic acid solution of such strength that the 1.5 cc. will exactly neutralize
the 5 cc. of alcoholic potash solution. Cool in water at 18°C. for at least 30 minutes,
with occasional shaking. To the solution in the tube, add 50 cc. of 70% alcohol con-
taining 1 cc. of concentrated hydrochloric acid per 100 cc., mix the whole and place in
water at 18°C. {[f peanut oil is present in amounts of 5%, or more, a distinct pre-
cipitate is formed, the volume of precipitate increasing with the percentage of oil present.
The question of determining peanut oil quantitatively was given
considerable attention, and some results were obtained and reported on
the last eight samples as shown in the tabulation. This work was based
upon the work of Bellier’, as modified by M. Mansfield’, Adler? and
Evers®. The method:
Weigh 5 grams of sample into a flask, saponify with 25 cc. of alcoholic potash (80
grams of potassium hydroxide dissolved in 80 cc. of water and diluted to 1000 cc. with
90°%, alcohol) by heating under a reflux condenser for 5 minutes. To the hot soap, add
7.5 cc. of acetic acid (1 volume of glacial acetic acid to 2 volumes of water) and 100 ce.
of 70% alcoho! containing 1 cc. of concentrated hydrochloric acid per 100 cc.; cool to
12°-14°C. for 1 hour. Filter and wash with 70% alcohol containing 1 cc. of concen-
trated hydrochloric acid at a temperature of 17°-19°C., breaking up the precipitate
occasionally with a platinum rod; continue the washing until the filtrate gives no tur-
bidity with water (the washings being measured). Dissolve the precipitate according
to its bulk in 25-70 cc. of hot 90% alcchol and cool to a temperature of 15° to 20°C.
If crystals appear in any quantity allow to stand at this temperature from 1 to 3
hours; filter and wash with a measured quantity of 90% alcohol (about one-half the
volume used for crystallization) and finally with 50 cc. of 70% alcohcl. Wash the
crystals with warm ether into a weighed flask; evaporate off the ether, dry at 100°C.,
and weigh. In case no crystallization is effected with 90% alcohol reduce the strength
to 70%. Correction is made for the solubility of the mixed fatty acids in 70% alcohol,
depending upon the volume used for washing and also upon the weight of the fatty
1 Assoc. Official Agr. Chemists, Methods, 1920, 241-250.
2 Tbid., 245.
3 J. Ind. Eng. Chem., 1919, 11: 1165.
4 Assoc. Official Agr. Chemists, Methods, 1920, 253-254.
5 Bolton and Revis. Fatty Foods, 31.
6 Ann. Chim. anal., 1899, 4:4.
7 Die Untersuchung der Nahrungs-Und Genussmittel., 2nd ed., 1905, 57.
8 Zeit.-Nahr. Genussm., 1912, 23: 676.
9 Analyst, 1912, 37: 487.
506 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
acids obtained. Evers used the factor 20 for fatty acids having a melting point of
72°C. and 22 for a melting point of 73° to convert to percentage of peanut oil.
Bellier!, in his work with pure peanut oil, found the factor 23.8 to
give nearer a 100 per cent recovery. The experience of the writer
would indicate that this factor of 23.8 is preferable, and it was used in
calculating the results here reported. It is evident, however, that due
to the impurity of the mixed fatty acids obtained, and also to natural
variations in the content of arachidic and lignoceric acids present in
oils from different sources and methods of treatment, no factor that may
be selected would in every case give 100 per cent recovery.
Since the work on peanut oil reported in this paper was done, an im-
proved method for the determination of peanut oil has been reported in
a paper by Thomas and Chai-Lan Yu’, entitled ““The Determination of
the Mixture of Arachidic and Lignoceric Acids in Peanut Oil by Means
of Magnesium Soaps’.
DISCUSSION OF RESULTS.
When this work was begun, judging from the experience of others, it
was thought that difficulty would be met in determining accurately the
percentage of water in nut margarine, owing principally to the presence
of large quantities of coconut oil. The experience of the writer has
shown this not to be the case, provided the sample is reasonably fresh.
Further work upon the method for the quantitative determination of
peanut oil seems essential in case it is necessary to determine the pro-
portion of the different oils present. By determining the percentage of
peanut oil present by Evers’ method the percentage of coconut oil could
be obtained by difference, provided the oils used consisted only of co-
conut and peanut, which seems to be the usual practice at present.
From a review of the tabulated results, considerable variation in com-
position and proportion of the fats used is noted, as is indicated by a
comparatively wide range in the refractive index and also in the melting
point and iodine number of the fats, the two latter figures being an index
of the degree of hydrogenation and proportion of hydrogenated oil used.
Considerable variation in the Polenske number is also noted; this number
is an index of the amount of coconut (or palm oil) present.
It is interesting to note that Sample No. 4311 gave a strong test for
sesame oil, while another sample of this brand was examined for this
oil with negative results.
It will be noted also that large quantities of cottonseed oil were found
to be present in two samples and small amounts in four other samples.
In several other cases a slight color was obtained which, no doubt, was
due to cottonseed oil introduced by contamination from the machinery
1 Ann. Chim. anal., 1899, 4: 4.
2 J. Am. Chem. Soc., 1923, 45: 113.
507
NUT MARGARINES
KEISTER
1923]
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508 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
used for refining different oils in the same plant. It is not believed,
however, that as much as 5 per cent could originate from this source.
As cottonseed oil is not derived from nuts, its presence in nut mar-
garine in excess of a small amount that may be due to a contamination
from refining machinery would appear to constitute adulteration.
SUMMARY.
1. Analyses, including the examination of the fat, are given of 15
samples, representing 15 different brands of nut margarine.
2. Special care is necessary in the preparation of the sample in order
to obtain concordant moisture results.
3. The results show considerable variation in composition and pro-
portion of the fats used, as revealed by wide ranges in certain physical
and chemical characteristics.
4. The official methods for water, fat, curd, and salt were found
applicable to this product.
5. Results on peanut oil by Evers’ modification of Bellier’s method
indicate that this method can, with experience, be made to give results
that are approximately quantitative when applied to nut margarine.
DETERMINATION OF FAT IN ALIMENTARY PASTE, FLOUR
AND DRIED EGG.
By R. Hertwic (U. 8. Food and Drug Inspection Station, San Fran-
cisco, Calif.).
It is a recognized fact that the determination of fat in alimentary
pastes and egg noodles by the direct extraction of the sample with dry
ethyl ether! gives results considerably less than those for the combined
fat of the ingredients entering into the product?. The same is true of
bread’. Apparently the ether does not penetrate the hard glutenous
particles sufficiently to extract all the fat. Unbroken plant cells may
also prevent complete extraction. Disintegration of the sample with
an acid and heat hydrolyzes the proteins and starch, disrupts the cell
walls and liberates the fat so as to allow its easy extraction. In order
to extract the fat from these products more completely, a method has
been developed and designated an “‘acid digestion method”. Groszfeld‘
applied the same principle of inversion for determining fat in bakery
products.
1 Assoc. Official Agr. Chemists, Methods, 1920, 72.
2Z. Nahr. Genussm., 1913, 25: 717.
8 Leach, Food Inspection and Analysis, 1920, 341.
4 Z. Nahr. Genussm., 1917, 34: 490.
1923] HERTWIG: FAT IN PASTE, FLOUR AND DRIED EGG 509
Method for the determination of fat in alimentary paste, flour and dried egq.
Place 2 grams of ground sample in a 50 cc. beaker, add 2 cc. of 95 per cent alcohol,
and stir so as to moisten all particles. Add 10 cc. of hydrochloric acid (sp. gr. 1.125)
mix well, immerse the beaker in a water bath held at about 65°C., and stir at frequent
intervals for 15-25 minutes, or until the proteins and starch are sufficiently hydrolyzed
to form a clear solution. Add 10 cc. of 95 per cent alcohol and cool. Transfer the
mixture to a Rohrig tube or a Mojonnier fat extraction tube; rinse out the beaker with
25 cc. of washed ethyl ether, in three portions, and shake well. Add 25 cc. of redistilled
petroleum ether (b. p. below 60°C.) and mix well. From here proceed as directed under
the official Roese-Gottlieb method for fat in milk!. re-extracting twice more with 15 ce.
of each ether.
The moistening of the sample with alcohol prevents lumping on
addition of the acid. The method, as described, is adapted to flour,
alimentary pastes, and dried egg powder. It is believed that it is also
applicable to bread and bakery products.
Results obtained by the acid digestion method and by the official
direct method of fat extraction are shown in Table 1. The figures
given are averages of duplicate determinations.
TABLE 1.
Results of determination of fat by direct extraction and acid digestion methods.
FAT
SAMPLE MATERIAL
Direct Extraction Acid Digesiion
per cent per cent
A INoodles, (7.7% eee solids..4. 2.14 act 3.91 4.84
B Noodles, 4.7% yolk solids........... 3.34 4.33
(e Noodles, 4.4% egg solids............ 2.10 Belfi
D Noodles, 4.5% yolk solids........... 2.81 4.24
E DCIMOLINAM TS ek cela ayo ohare 1.37 1.86
F LOU TARE tate ET) 5A, Ae NRE 1:20 1.73
G LTTE CT eR Se rt IBN rae 1.22 1.93
H SETHOMMANT i et eee ero ee: 1.10 1.86
I DriediwWihoie Begs Ak ee 36.74 42.39
The fat extracted by the proposed method is perfectly clear when
warm and dissolves in chloroform to a clear solution, leaving no residue.
The fat extracted by this method from two egg noodles was found to
contain much less lipin-phosphoric acid than the actual amount present,
as determined by hot alcohol extraction or other methods®. The lipins
of the wheat and egg are apparently more or less destroyed by the
vigorous acid treatment. The method therefore determines those fats
and fat-like substances which withstand the acid digestion.
The noodles used in these determinations (Table 1) were made up
under the direct supervision of the writer or other representatives of
1 Assoc. Official Agr. Chemists, Methods, 1920, 227.
2Z. Nahr. Genussm., #6+3-260-224. (goo, Hee}
510 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. VI, No. 4
the Bureau of Chemistry. From the formulas of three noodles (Sam-
ples B, C and D) and the analyses of the flour and eggs used in them,
the theoretical fat content by the acid digestion method can be com-
puted. Table 2 shows the calculated fat content and that actually
recovered by the proposed method on the moisture-free basis.
TABLE 2.
Results showing fat content.
FAT
SAMPLE MATERIAL Bg oe eS eS RECOVERY
Calculated Found
per cent per cent per cent
B Yolk Noodle... . 5.05 4.93 ,
C Whole Egg Noodle 4.31 4.26 98.8
D Yolk Noodle.... Lay 4 4.79 93.6
The data in Table 2 indicate that the acid digestion method recovers
practically all the fat from noodles that is contained in their component
materials, as determined by the same method. This method, therefore,
should be found very useful in calculating the egg content of noodles
from their fat content after the average percentages of fat in flour and
eggs, by the proposed method, have been established.
The lipin-phosphoric acid content of noodles, commonly used to com-
pute the amount of egg present, is believed to diminish during storage’.
Some constitutent which does not thus change would be more depend-
able for this purpose. The fatty substances determined by the acid
digestion method very probably remain unaltered during storage. The
egg content of noodles should therefore be calculated from the fat by
this method to corroborate that calculated from the lipin-phosphoric
acid.
1Z. Nahr. Genussm.,
Hats 4.
Igid, 25: 77.
INDEX TO VOLUME VI.
PROCEEDINGS OF THE SECOND AND THIRD DAYS OF THE THIRTY-
SEVENTH ANNUAL CONVENTION, 1921, AND OF THE THIRD DAY
AND PART OF THE FIRST DAY OF THE THIRTY-EIGHTH
ANNUAL CONVENTION, 1922.
PAGE
Acetic anhydride, quantitative determination, paper by Spencer................ 493
Address
byaVertchs Presidents 70/002 220 Ske oy USS Ce) eae ARN he) SPR 223
by, Wallace, Secretary. of Agriculiaré:, 5). és). sds cec 0s «s nncwce sd sane 90, 251
Be Wwaley, Honorary President... .... 43.542 cc danse cnt eee ee 51
Alcohol in beer, limits of accuracy in determination of small amounts, reeommenda-
HONSHO VE GommMiIteee Gis.so1s.565.0.6 Ne tic get fe eee Le See aE aye 147
Alcohol tables, results of vote on uniform temperature...................+-0065 283
Alcohol used in official potash methods, summary of strength and kind, paper by
ROGUE 853 Ler ia.b 5 S503 2s Sec ds OMS Soe MOBS ee Se baa eae Ca Meats 403
Alimentary paste, flour and dried egg, fat determination, paper by Hertwig....... 508
Alsberg
election to honbrary life membership. ;, -... 5. asc 0/6 lus > iss so oe wn cee ee 172
report
of Secretary-Treasurer from November 15, 1920 to June 21, 1921...... 158
on publications from November 18, 1920 to June 18, 1921............. 162
anenietients tO COnStitUtion: . ...2. 52:54. 550622 4oe 5254 cok DORM ee eeeetene: 253
American Oil Chemists Society, remarks on collaborative work by H. 8S. Bailey... 412
American Public Health Association, joint publication on milk methods, resolution. 240
American Society for Testing Materials, committee to cooperate with, report,
AbREReS Lesh cs a Pelle e's SEE IF OY cE ne eee ah eli 124, 255
Amino acids in globulin-albumin fraction of beef flesh report by Moulton........ 86
Ammonium citrate, preparation of neutral solution
recommendations by Robinson. :25.522 54. aac sooo ode cote eee ail ae creer 390
REPRE L IO VAR ODINSON:: 3) s&s 5514.5. 20k 5 hace Reo uate ok sa Delete See cle ats aenens 384
Analysis of licorice root and licorice extract, paper by Houseman............... 191
EMILE CEPOEL, CEH 442. 5 oh. sje. ote ae perineal a ae eared 107
Aromatic amino compounds, use of sodium-alpha-naphthol-2-sulfonate for the
spectrophotometric estimation, paper by Mathewson.....................45. 16
Arsenic in foods
reconnmcnaations by Elam. . .02.2 2. . s/c sas aletmeleie oie! “lo Sinisa els ciel eie e Ra eee 34
Eeportby Tann:,. 2... 25564'..28 Baa, BARTER DRE ae ae ert ante 31
Arsphenamine (salvarsan) and neoarsphenamine (neosalvarsan) qualitative and
quantitative methods
recommendations by Hoover and Glycart ..........00.2.0 cee e eee e et ece 464
report by Hoover and. Glycart sj. sii bus ges ok Wats een he Se een to eee 461
Ash in cane sirup and molasses
fecorimendations: by, Brewster in) ya th ad clk cies ate aire alae <i sale. aiaialatels 369
EENOEG Wy Brewster's 6 o:soog, 2 scenes seis Sm ecg aes Lana otal ean ayia nan at aia aa 365
O12 INDEX TO VOLUME VI
PAGE
Associate referees, authority of referee to appoint. .................0 0.0 ce cuee 377
Associate referees, officers, committees and referees tor year ending November,
DO ee Lr nt kas tuks cet ite meh ese PMBE a Re eb al GR sat tel a antes Rahs SNR als ted au ie EAU St ee a 209
Auditing committee
appointment ‘and persormel ss (0 oo. oA Mh ee a 373
1 st 0,0] bf TROP aS Pole ire any CE eRe Rn ERENT IEE «PICT Sore LR Gta a PRIM neater ciscae 168, 303
Availability of potash in mixed fertilizers, paper by Gordon. ................... 407
Babcock test for milk, reading the fat column, paper by Hoyt.................. 354
Bailey, G\E report, cereal foods: so) £ very i ieee) ls at neice 9 alba 60
Baileys Mi reports CLyOSCOpyrob milk): <. aci PRUe neta hee clue Ruatao aisha tenn as 429
Bailey, H. S., remarks on collaborative work of American Oil Chemists Society. ... 412
Bailey, 'L. H:, report on Baking ypowder,. 312 tit ineu dye achive Weeer aie siskehoa partitions ik 445
Bailey and Johnson, paper, studies on wheat flour grades [1I—effect of chlorine
bleaching upon the electrolytic resistance and hydrogen ion concentration.... 63
Baking powder
determination of fluorides
recominen dations byl Mortion s::} fayieiciareods aye al relsieneuanl hey kia t cee ealai ible 460
FEPOLE DM WLORLOR As, 4.5 5, 5.6 CES, 5 ened ela Wing) LEE nae aie tees ae ee 457
recommendations
bynballeyi dé feigk Aacsauetic ts «semamersteteis <2 Seucid eisaces eeoia Rese! Scene tat amy ee 456
by Committee ag more OT en aisle aka tecteetts an pial ne Regt ee 137, 266
report (byiiBaley oo ue an chin etnd BR ela amauta Ao a 445
Baking powders and baking chemicals, changes in methods................ eos
Balcom
report
of Bornd of Tditorsy 05) . 1). adexcuveihs autanl: aiekenienve a one oie ee 119, 241
of Secretary-Treasurer from June 21, 1921 to October 15, 1921.......... 160
on Canied foodsy es Me, Fe PRR ah Sh LEA eh ee ALAS Bll ee 49
on nominating COMMIthee. 4) 5.2!5)0/ey)) Rea dddstia Gler- Baetd cio Ree NE 4 171, 305
on publications
from June 951921) to October, 15 tO2I wands). qk as ee eine ore 164
from October! 1651921 to November 19225.) 2). ns oe cia eee 244
Bartlett, report, boranjini fertilizers?) tag Sh) sacle ak Maoh Oe ee Pee 381
Basic slag, vegetation tests on availability of phosphoric acid, report of committee
Gaskins) hl lace eon DU we kot MR TI K acid aa ag a a 123, 254
Baadouta test for sesame ome oy oe nb ik al a eee ed a ei ee 265
Baughman, report, methods for examination of cacao butter..................-. 101
Beef flesh, amino acids in globulin-albumin fraction, report by Moulton.......... 86
Beers, limits of accuracy in determination of small amounts of alcohol, recom-
mendations: by Committee! Gi, Hosta ee Aes LOT ey eee ee 147
Beverages, non-alcoholic, report by Skinner... ......5.2..6 00:0 ¢s.00.0Heueeeeewe 3
Board of Editors
amendment to: Constitution's) 4:5 0 hae aco ee ak hk ie A te ee 253
report, ‘Daleomny) : vivian + eR Us. Rte, Gage eel? jaaate 119, 241
Boron in fertilizers
recommendations by Bartlett:.16 3.2 ere ee ene ee eee nent 383
report ‘by ‘Bartlett: ,.) 1/554 2.522.080 25 Mer SC ee emer re e eee te ee Oe 381
Brackett-
paper, summary of work on the determination of iron ard alumina in phos-
phate rock by the association, 25 \i\)) Tu as Gy nia oon ba ene Sie one ee RRC eee 377
report On PertWizers 225i \e./-o eae Laks RES wD spel Sale RUC REL RE etal eR 375
INDEX TO VOLUME VI 513
PAGE
Breads. StanGards OCOP PC olan ioe ols cis Settee aa Rik no pala oie 4,6 ie di gies moval ee Mloralal a 295
Brewster, report, determination of ash in cane sirup and molasses.............. 365
Butter
renovated. standards adapted ane italy ote faeiece = cis s) 6o¥ os) fogs 2 vetehe ayelenapehet seers 294
Butter fat, data secured with “turbidity point’’, paper by Seidenberg............ 437
Cacao butter
mothods for exammation /!<), PRUE ee Sa Ei re, ER, 278
recommendationsiby/Baughnian . Asie: Sa eee ee ae a FD 106
report by Baughnivan. 24 seceke okies VM At cebd biel ase ey Se 101
Cacao products
Changes 1m MeEHOUS A o.4 51s eee aN Eee te POs a Ren eae 257
determination of shell, report by Silberberg............ Aner een tag 1 teh 98
recommendations by Committee Gos yen es os 3 he ak aoe Ae ee 150, 278
BLANC ALGSIAM OPED 4 care a sav Ris eA eee otS, 9 coe ea ea eo 294
Cane sirup and molasses, ash determination
Recommendations by; brewstercny 45 eee Gee eke aoe uae At a SOD)
meporbiny Brewster . 0 26:2 hair. aso deck sek gaan eee iol ce eR gee 365
Canned foods
recommendations
yd BalComnisis a, Lt: ise sod OA nee RS En Oe LOL nen a eee 50
byaGommittee Gis..5 25556 se BART WEL EN oar let atta Me med GN JAE t . .146, 274
NEDOE OVE AICOME 4%). ashi eee tse SI REE colar CNUs es awe ares ee eee 49
Canned vegetables. See vegetables, canned.
Cantharidin, domestic sources, paper by Viehoever and Capen.................. 489
Capen and Viehoever, paper, domestic sources of cantharidin................... 489
Cereal foods
Chaneesunumethods ei .0%s4.. kyayols: aap aide MOR oie ar eae ee 236
recommendations
DEANE aye xorioteney 2. 08d) «sak areicgehe. Hoa OLE ees ee Or oe eae: 62
Ip yaGommittee! Gs. bo 3 so. eieia Sic eens Ry ee ora oe eee 147, 274
REDOE Es Vg DAMON s oh 5056, axcicareys sth apc) ia Ro SOREN IG as ee aia ik eee 60
Change in order of publication, announcement................-.0-0.e2eeneenes 229
Cheese, moisture content, recommendations by Mitchell....................... 437
Chemical reagents
recommendations
Wing OAEATIVEG LEG Eo 5/0 i050, cso as, deeuel SPE ep a eeveL Sia hela eee pete ene 137, 266
RR SPEMCET! 2), Sin se eed nc es Sale SUN eat eaters ol ocmep a eee att oe eae 3
REM rL iy Spencer's) sofort, Meee et Pa eee ee nee eae oe de eee 1
Chlorine bleaching, effect upon the electrolytic resistance and hydrogen ion con-
tration of water extracts, paper by Bailey and Johnson...................... 63
Chlorine in bleached and natural flours, quantitative determination, paper by
Pe ae os ad wo che ca e Lig ALR SN SIR, |e aU Rua vk Saale oe te et aera 68
Merke. 0: ©:, report, turpentine. «5 5 pd 1h Ry ecucnery tiacokais briccloaed) aaiabeen: Rite dohesise 465
Skew .. report, metals mi foods.) ha) oss sates osc = ed nee ein eae 28
Cleanliness of drugs and spices, new sedimentation tube for determination, report
BMAP REIONER | 5 )0/5 che ovS 2d oid oe Hae EE BSA ee CeIn ee ene nici aks oe Nee 466
Clemens, paper, determination of crude fiber in prepared mustard............... 205
Coe and Walton, paper, the determination of starch content in the presence of inter-
fering polysaccharides as in impure linseed products..................020000. 850
514 INDEX TO VOLUME VI
PAGE
Coffee
Ghangesiin methods eee vagy NL MI AWON ie tas MU ga La i ro Me ae ag Ml PB V0
recommendations by: Gonmnntte] Gis iin cuatcau sae Duala n cietanie eeiae PT 150, 279
report by Tapper iis enna tee b iiaia ee ha lates gee ayaa ee a SMO a Ne 106
Coloring matter in foods
CHAMBER MMIMETHOUR 8 acd e's alleen alia late re PN alec alta aN Kee nae thn aa oa 116
recommendations) by, Gommittee: Gs. Wei. secu vaemes oleic ele aie sede 144, 272
Committee A on recommendations of referees, report (Ross)................ 127, 258
Committee B on recommendations of referees, report (Lythgoe)............. 133, 262
Committee C on recommendations of referees, report (Doolittle)............. 144, 272
Committee, auditing
appointment and personnels. 2.3) 62 ad aidiats ducing eahcciata tre eae Mele eee eee 373
FE DOUG Ss oe ee yal UU MAN TES CGI a Ae rie RO Un Once aM ee RU RRR a a ee OR eC a 168, 3038
Committee on definitions of terms and interpretation of results on fertilizers
Appointment OF menalpens. 6605). ..caie aici s aialea seede tole a ieobunble we ecu een alte ate Clee 133
PODOTG | GRAASEUIIS) He see ta 2a alg SA add aR ONR Caer ao ee ee 302
Committee on editing methods of analysis, report (Doolittle)................ 113, 229
Committee on nominations, appointment and personnel...................-.... 373
Committee:on nomimations, report, (Balcoom)..):..). 5.05 60 bs eee sce en dine Oa wee 171
Committee on recommendations of referees, report (Doolittle)............... 125, 256
Committee on resolutions
Appointment aad Personne ale ZO A ae eye anaes Neyaueoueecapaneensenaeranens 373
PE PORE os even hare cin Ce. MRR SNAG SA VARA We oe, Ge lpi elteuer ch iN game a 172
Bay VRS ieee aa se HO Ot re a 305
Committee on vegetation tests on the availability of phosphoric acid in basic slag,
report (Chlaskins)iiisse wy UN a TR ae Rae UN Ure ER anc ae Cte e 123
Committee to collaborate in formulating program of World’s Dairy Congress... . . 251
Committee to cooperate with other committees on food definitions, report (Hort-
Ve) Mae A AUS TRL Hl 3 A OU a AT RO DOR Ph boys 169, 292
Committee to cooperate with the American Society for testing materials, report
py Bee Minbar) 70 re Sel Rae Co SCI co RE ESN RAL Ov 124, 255
Committee to cooperate with the United States Pharmacopoeia Revision Com-
MIGCEESS INETODETS eh. eN Pte ete He Te Mn RAC PE re Re een PC 153, 281
Committee to wait upon the Honorary President, appointment and personnel.... 373
Committee to wait upon the Secretary of Agriculture, appointment and personnel. . 373
Committee to wait upon Senator Ladd, appointment and personnel............. 373
Committees, officers, referees, and associate referees for the year ending Novem-
er, LOZ 3.4 w sreicatatslailald/ ee MMe saree MAU aI a abionaTe UM eal AL ls To a a aD 209
Concentrated milk. See milk.
Concord grape, variations during ripening, paper by Noyes, King, and Martsolf.. 197
Condensed milk. See milk.
Condiments. See Spices.
Condiments (other than vinegar and salt) standards adopted................... 296
Condiments and spices, recommendations by Committee C..................08. 277
Constitution amendments nse aie uid a a een ee tena Ree ON eI Cees (staan 253
Contribated papers sine) Nk ek Te ROR RANG AUR UN eR OS ak SE 175, 498
Coppers methods. cds is ce SG aaa cake dalle val eeaiter edah Goat el etetioner atedie ale eavalen ih oi tenons eee ae 307
Crop Protection Institute of the National Research Council, report of representa-
CL VER sid Wsusvastiadiala th enatiatttaiaonit henna abiala’ dala lara eau ale hene eebete vain: anh tna Cetera aan 154, 286
Cropping, effect upon the active potash of soil, paper by Fraps................. 329
INDEX TO VOLUME VI 515
PAGE
Crude fiber
determination in prepared mustard, paper by Clemens..................... 205
FECOMMMETIGS HONS I VA EA Ri caret rain Neate lar aiiAlay oharjetle o's ea ve os laws? a3) mare aogietae 343
report: by; Brapsy ie, eye peel a naan RU came ea Vaat sy crsliosieusia hyena ia tans Sakoba yay dayels taal 333
Cryoscopy of milk
report
by: Bailey cys) fee a RM SRR Ue hse 2 aK ve yaya saree Unie a 429
Dy Ort Ve ioc os Ree ae RNA PIPE. Sao en cu uc E cite eat Gin ae ean 424
Dairy Congress, World’s
ATMOUNICEMIEME «3's 55555)5. Shells cuscie ena Roe epee Ne TcA a ortho e alle Tos fa.rs a) 612 UU aRS NaN eRe toled Vo MSDN oe 250
Committee to collaborate in formulating program...................-.004- 251
Dairy products
elanges/in methods 02)... 220 VGN ON eh 2: AMD near Oh dae Mie ala 236
recommendations
by Gommittee! Be). 66 es ee ee ies ons sie Ree Ee Cane 136, 264
Dy SETORE VOU A esucsickes isles tclicid id eat RN Shae NRA SUEY UG ara ee a ae a 429
JAKE] YON el OR alr Kay of EAS REANIM a NE AS IN ea eee ULs ted elo, 422
Data secured with the “turbidity point” of butter fat, paper by Seidenberg...... 437
Definitions of terms and interpretation of results on fertilizers, report by Com-
“COPS GK (LG (21S 91) | ena Rh TN RUD A i RES an ul 302
Denny, paper, methods for the estimation of small amounts of starch in plant
“STE Sy a eR RPP Ee cee UA ne MOD BLAU Mut beg eh 175
Determination of ash in cane sirup and molasses
Pecominendations by ‘Brewster )...).5 a tae Hees see Bio oe Re neeuee animale ene aoe 369
BEPMIEUAY SFO WSECEY, 55.5) o 20a 4 6: 5:6.5:.5im 5 aheee mete Te eel ee Res eae ese 365
‘Determination of crude fiber in prepared mustard, paper by Clemens............ 205
Determination of moisture in dried fruits
recommendations: by Hilts,..: 0.5.0.6) 2 de eels! ow) a stalnero eae ele Sipe eas 48
MEPORU OY ELS eh 2 ets bic a wxhus we Sia. eter Ge ee ee OTR Sil aL ao SRE AIOE re era 40
Deter mination of pectin in fruits and fruit products
recommendations by Wichmann 2). o.2)3) sesso civists 3-0 9/0: 6\o ule plernjaie Sie alae lagee eras 39
EOL CHIN aAVV AC RRINIEN OND) 702.405, ishe to Vese So saat Men eietietecel one e eaeie Gafeecal/e tela aCaaeIiz ey ae 34
Determination of shell in cacao products, report by Silberberg................... 98
Determination of starch content in the presence of interfering polysaccharides as
in impure linseed products, paper by Walton and Coe....................-4. 350
Development of Lindo-Gladding method and investigation of other methods for
potash determination by the A. O. A. C.
FECOIMIMENUALIONS DY POY: ss. <6 fave, Slaps g Sbarrete esa sl scter ole eae latte eee Ce 402
POOOGE DY) POY! =. 5 2 o's wien, « a5.4, osoferd che 6 cusunioadie auetMeyaielo aon alrevelele”slaual elu lehstalad sence 399
Domestic sources of cantharidin, paper by Viehoever and Capen................ 489
Doolittle, report
of committee on recommendations of referees................00000 0 eee 125, 256
of Committee C on recommendations of referees...................-0-- 144, 272
of committee on editing methods of analysis....................000000- 113, 229
Dried and malted milk, method for the determination of fat
recommendations by. Keister. is) 05) js os/s/dle ele ale otayreie e's ls PR eMaeaN ene eet a 437
RA PORE DY, IK GISBER 0c. 5. 0 == sei a/ a! sighs sl nnel Sere auld a iaval oy ahs ct SRR aes Oe 435
Dried fruits. See Fruits.
Drugs
Ghanges-tt methods). 64)... 4 ON CN ito mea hs ie Wal, bial aaah A Rave ae i ah 118, 288
recommendations by, Committees B! .ierjsa sae eta Val oe Sh eee 138, 266
TEPORt by: HOOVER set's 55h Wa Bias Ee ele laden ellen ae) lla ree 9 ROE ved hha tana 460
516 INDEX TO VOLUME VI
PAGE
Drugs and spices, new sedimentation tube for determining cleanliness, report by
I Atey CoC tgs) ee BU Coa HAN bahay OD MORN i el MOA Res ni dal edonh cb aah Bespoke) dana Wes et 466
Edible vegetable oils and fats, standards adopted...................0 cece ee eee 295
Editing methods of analysis, report by committee (Doolittle)................ 113, 229
Editors
board.ofvamendment to;constitution.. “iso ee ack Gonee ecm Diener an 253
report. of board by'Baleomn ji). jive ued fale ae A ay a sas Se at ee ey eee 119, 241
Effect of cropping upon the active potash of soil, paper by Fraps.............. 329
Effect produced upon the fat of hogs by feeding fish meal, paper by Martin...... 498
Eggs and egg products
changes in methods . 23)... . Oe.0. RSET IE 2S RPT r Ly,
recommendations
by Committees By) j)iec 2. 2! 051) 2 cca a iealaid diadig A alalor po RO ee 137, 266
Diy: Lo ariey)oics sie) tei aii eects Waly eect Sete eh ed ine RT ee 13
TEPOLG Wry: Larne eyo etd ae! o< 3 old scu)die:s wsig aealaliediatal giant) hehe mane MMS REN tat ha 4
Eggs, dried, flour and alimentary paste, fat determination, paper by Pertwig.... 508
Estimation of small amounts of starch in plant tissues, methods, paper by Denny.. 175
Evaporated milk. See Milk.
Extracts, flavoring
recommendations by Committee Gy). 330 5e eh ok gis amie aula 147, 276
SUAHUOLUS AMODLCR IN. ccccuaie cvs, + ce le tis Baal soo os le falleva eve pair oho lalla co] el ales oleae 296
Fat in alimentary paste, flour and dried egg, paper by Hertwig................. 508
Fat in malted and dried milk
recommendation by Keister... . . AN a, Moped PANS | ener Ms 5 gt A aes etic ae 437
report by! Keister: 2/2) 0)0....... ett, i ea AR taba elena na eb 435
Fats and oils
changes in methods......... Wea uniter neat Spi aE Hat tia Le ciemtottblap 3 dP 117, 237
recommendations
by, Committee Bain. sj.:. <4, SAD Har hls pashan an goal enema 802 or an We 136, 265
Biv, DamMiesonhs seis Mac eyahtiarc Sige Stengel Cat Ue cn ste 444
TEPOLE (OY PD AIMESOIL. sine seal Aveta orale eRe Miao Aah goa al eRe NN Saale 440
Fats and vegetable oils, edible standards adopted.... ....... pilabarainacataihoubiintyhi iba) DAC)
Feeding stuffs and foods
recommendations
by Committee B....... Bea AAU ue NSA ose a RMA 2 hehe gs 'yait 262
by Reed: cae. ait SRA BELGE NL ARENT, NaS. di ans cSeTt CaNS 333
TEPOrt, by Reeds aecaee saved! ieaqere eis aa ebeteletens leuhe & Use Melanesia rathayY ue A elated 332
Feeding stuffs and foods. See Foods and feeding stuffs.
Fertilizer definitions and interpretation of results, amendment............. Je eho Qod
Fertilizer sampling tube, new, paper by Haigh...............---5. 000225 c eee 410
Fertilizers—
boron content
recommendations by Bartlett) .))) .0\0 22) 20 ele, ae ER, ak 383
report by: Bartlett.) 0.5.9 2 Oa RE ME PARE ae 381
Changes im) MECHORS | 6.625056) lie shaeare herbie shape! in alias} a) ht baleen LM ane 118, 282
committee on definitions of terms and interpretation of results, appointment... 133
definition of terms and interpretation of results, report of committee (Haskins) 302
mixed, availability of potash, paper by Gordon. .............-0. eee eee 407
recommendation by Committee A, report (Ross)...........0 0000. ee ee es 127, 258
report: by: Brackett. ysis sys -yennfeswete! onpvayes biera}shnbareatetivy ool ips and bo aha OPM W) cht, Or mn 375
INDEX TO VOLUME VI Bie
PAGE
Fiber, crude. See Crude fiber.
Financial report on publications
from June 19, 1921 to October 15, 1921 (Balcom)..... ssh tut dt val ,. 164
from October 16, 1921 to November 1, 1922 (Balcom) .. | .. 244
from November 18, 1920 to June 18, 1921 (Alsberg).... . Be chol MMO.
Secretary-Treasurer
from June 21, 1921 to October 15, 1921 (Balcom)........ Penge ghee wenn ls: 0)
from October 16, 1921 to November 1, 1922 (Skinner)... . ee Mire eae be!
from November 15, 1920 to June 21, 1921 (Alsberg)............ 2h lbs
Fish meal, effect of feeding upon fat of hogs, paper by Martin............. ths 2 2 AOS
Flavor .emeer ale, standards adopted). oo ae soe aas cs sso sii, «alone eel te 294
Flavoring extracts. See Extracts, flavoring.
Flour, alimentary paste and dried egg, fat determination, paper by Hertwig...... 508
Flour, bleached and natural, quantitative determination of chlorine, paper by
RACIAL Sc 8 Ae dU aha aeGua el ol alteemavtiwen thee At MaMa DD i ig kei iio ok SL MR a 68
Fluorides in baking powder
recommendations by Morton ;..:)) 4s ee ee ae ee ae BOP ee 460
EepOrt Dy Morton... a succes safc ot Aitele ee eee e » «NOC OT SS eine ae ee 457
feodieolors, report by. Mathewson )))) besa. BS ee SE A ee 15
Food definitions, report of committee to cooperate with other committees (Hort-
NYE) 95-29 Ae ee Pen oe ly eee menen Lac er rata font) © roi 169, 292
Food preservatives. See Preservatives.
Food preservatives (saccharine). See Preservatives.
Foods and feeding stuffs
EHBURES THANCGOOGS 5.0525 oe Lo. eT ON APSE ey eee eal oe 235
recommendations
by Committee B. . AP eee Ma sie a sis ee aay oe a 133, 262
BAER CGE ee FS Sah al JRE Geek acy gland tee Salles Tie age’ aioe Ie ees a 333
BERLE OU PIRCEG s 3) 00505605 3 45.0 5 5 4) fb ahs AO OR RAO Olea slice Gee ane needs aa 332
Foods, arsenic. See Arsenic in foods.
Foods, canned. See Canned foods.
Foods, cereal. See Cereal foods.
Foods, coloring matters. See Coloring matters in foods.
Foods, metals. See Metals in foods.
Foods, nitrogen content, recommendations by Committee C.................... 280
Foy, report, development of Lindo-Gladding method and investigation of other
methods for potash determination................ CPD ROMLANS RN NE Ae OTA 399
Fraps
paper, effect of cropping upon the active potash of soil........ ae eRe EEA 329
renort,.crude fiber: 3 6/))2:5 4.0002. Se ee Ee gat 333
Fruits
and fruit products
recommendations Dy; Halts)... aap hog apa ey Re UAB CE oan bo TAS
epOnt DY EMRE soa oe oes in cls eMC) gtd a ear d ney id HN em eae ee)
MMERP EST VIMELNOGS 0.5.5... 4/5. Ss ae SEO Re ER ae Na eae ME ett Je ss SOO
determination of pectin
recommendation by Wichmann... 8). 6.y.0..6 5. EE as 39
report. by, Wichmann. » «3 9/4283 344s seis Wc gHias 48 pide Oe ee 34
dried, method for determination of moisture.......................-..0.00- Zhe
recommendations by Committee |G 4136 one en es tonto Gla ae eee oes 145, 273
518 INDEX TO VOLUME VI
PAGE
Fungicides and insecticides
ISHARES UM TROBE 15 15)(5 2h (alee is d\'s ep yo (a and Ne aT MEU tas ira USI AUR ch 114, 233
recommendations
By Goemrmipt eee ihe citi. sik sa shy a) cou8 hevelaal uel ue eNean tal aaa Valet Ura sas 130, 261
Boy: GorenTieaana ik a ole cai to ib dalla os baci aA al a ce eo 319
pas) Soa All ok gi ccs F412 ARMED a a RAP SS A MIN Se Meee 313
Gensler: ‘report: stock Teed adulteration: )) 02h) Rie Te eet ai 345
Ginger ale, Standards WAOPLEGy. oo)... a2) sc\s)s/6:c « upinyat eras d oily enaunvaye Opens a steele tetas 294
Globulin-albumin fraction of beef flesh, amino acid determination, report by Moul- *
Oe Hel a HSIN WAL UaIURltaday ei Vays e's allel ahenate ene lotta edsliawe tay: te eetevemaiate tetel al tret eat eai apa 86
Glycart and Hoover, report on methods of qualitative and quantitative analysis
of arsphenamine (salvarsan) and neoarsphenamine (neosalvarsan)............. 461
Gordon, paper, availability of potash in mixed fertilizers...................0.4. 407
Goré} report} maltose products. hl! FC ANI Ns ene en eee 364
Graham, report, insecticides and fungicides. 27.0) 2 os eee ois vee os ie siecle eicle nse 313
Haigh; paper: a new, fertilizer sampling tube: . .).\.).\. .selaaiabiticiak iaeietenimceneen edema 410
Hann, report, ATSemic, AM TOGS }.)). 6... s/s ih eb 50s base's, a | arms oor ars! co MON 31
Hartwell and Patterson, report of representatives on board of governors of Crop
Protection Institute of National Research Council...................008- 154, 286
Haskins, report of committee on vegetation tests on the availability of phosphoric
geid In basicislag i) Clee ele es 6 Senha si Glue Meme a Cls c ee ea 128, 254
Hertwig
color method for eggs and ege products... 2/15 (ies oleic acacia cee 12
paper, determination of fat in alimentary paste, flour and dried eggs........ 508
Hilts, report, determination of moisture in dried fruits.................020000. 40
Hite;\Bert. Holmes, obituary by Hanson...) )).)2.5 5.6.52 .\52. 2st RE Pek, ee 174
Hogs, effect of feeding fish meal upon fat, paper by Martin...................4. 498
Honorary ‘President’ s addres 50) 005 UM Aa eee 51
Honorary President, committee to wait upon, appointment and personnel....... 373
Hoover, report OR ArUBS 1. )6 boi stein) = asele says) saiarras ales SUS eRe Sa einds Sanaaes see ase 460
Hoover and Glycart, report on methods of qualitative and quantitative analysis
of arsphenamine (salvarsan) and neoarsphenamine (neosalvarsan)............ 461
Hortvet
paper, sublimation as an analytical procedure...............0 eee ee eens
report
of committee to cooperate with other committees on food definitions . .169, 292
OD GOW, PFOGUCES 5.) S01», dn daiaraiatsunud bouaeueckh russe acu eics ual Nee eusiias sikeiee 422
Houseman, paper, analysis of licorice root and licorice extract..............0+6 191
Howard, paper, net micrometer for use in making mold counts.................. 50
Howe, remarks on Crop Protection Institute of National Research Council....... 154
Hoyt, paper, reading the fat column in the Babcock test for milk. .............. 354
Huston, paper, summary relating to strength and kind of alcohol used in official
PROLUIE TACEIOU Ss oj, sia face, se Rrageiars alu. deo el is ih ooh e lege Opa ea Teh eoatty ass ake tetas eae nena 403
Inorganic plant constituents
CHAT WES Wd TAAL TIO, 5) 05) sib) «cays hyson, Miele Mobtoraiiagay a, a2. 0 amen nee arse Mpa sich 233
recommendations of Conamittee Aijipsjs «isa -tyneietntein marentalbyotehahiew Ragen uls 129, 260
report Dy Patben si, 6 << sissy y.scaineiayetsjorn,ooa.e ncn iid aoa a inue wate ans ine ern 414
INDEX TO VOLUME VI 519
PAGE
Insecticides and fungicides
GHANVES IH TMOCNOUS fe ite cine tere eR tate cle Ste isi cat one a wlera ds ate at pekae ahs 114, 233
recommendations
iyn Committee Avy aati ne eae erent ate crise cies cena oeamaretdse a EeOn ae 130, 261
Dry Graliarnys Sse seater Re ee ote to i coer ik ate talaHoge ae een 319
Raporg by? Garaliarnn: |. Penta eh teste Mees 2 0. 0 uete acne anots ae ape ae 313
Iron and aluminium, calcium and magnesium in ash of seeds
RECOMMENGATONS DY Pathe sists Valen eee vik lor ay st eiohel a1 Sis) oy SERENA eee 422
FEDOLU DP atten t'9) cysic cls lacy Maca a alate) Wor ot a ect aaa a 418
[ron and alumina in phosphate rock, summary of work on determination, paper
MOE RCC EG S105 5° 00 i ci 0 Le an Tela os heh aS CME TRS Eee leva cie, b-¥ilo level ee tee tle eae 377
Jablonski, color method for eggs and egg products................:00eeeceeeees 12
mica report On fats and oils...) 2. 0 ales tos a ak uo hue ce lapdiersie tle Stee aie 440
Johnson and Bailey, paper, studies on wheat flour grade Ill—effect of chlorine
bleaching upon the electrolytic resistance of hydrogen ion concentration of water
RTA DS EP eee LOTS 75 os SECS ey ait, ashe ae alte t IAEA Ce ney Sane ESV elec oT aia are re gs CTRL eee een 63
AOURETT EA CLES CUSSION ters tote su ee aes ells MR ney URE Pe ee ee pe a Re 166, 250, 290:
Kebler, report of committee to cooperate with the revision committee of the
Somers SLATS Ee armaCgpoeia | 6.) nae teen aa oie beeing dea ee 152, 281
Keister
eer Ul ARMA ENS 2 oe eee ec ne cata cect cutteis Lote k Mella a deuce ee ee men 502
report on methods for fat in malted milk and dried milk................... 435
King, Martsolf and Noyes, paper, variations in the Concord grape during ripening.. 197
Ladd, Senator, committee to wait upon, appointment and personnel............. 373
Latshaw, report on sulfur and phosphorus in seeds of plants.................... 414
Leather and tanning materials
mecommendavons by Committee A\.).".\))0)6. 0 46 ss tos cee Cae eee 130, 261
UPD CLECEE ee ee Re ee ood ea yaralae cteke eaee a 309
MMT MOTEMCOIED ein cic og linc «etd tie ele ois.6 scale 8) 9) 0 a CRUE ee 106
Licorice root and licorice extract, analysis, paper by Houseman................. 191
Liming materials, report of committee to cooperate with the American Society for
Testing Materials in regard to methods of analysis, MacIntire................ 255
Limits of accuracy in determination of small amounts of alcohol in beer, recom-
PAM OMNAN Te. OMIMILCe Cr. 6) i Poe Ce eee nae eee 147
Panne report cers andiege products. 2) 24) s cleo Ploeg cle sree weer nla es eee 4
Lythgoe, report of Committee B on recommendations of referees............. 138, 262
MaclIntire, report
of committee to cooperate with the American Society for Testing Ma-
CGT Se tee a a la PUT MDA hl RAR pans ee La OO ATLA 124, 255,
CULL Sige se a ale aD Aen Oeb i eA ie boied im iili tlie ltl 320)
DoD, SL STEA Cr a eR AHR Ale aeaey eon Ye lem te aL 2s a 320)
Malted and dried milk, method for determination of fat
PeeMMmeMontions by Keister 10)... 02 11S oar sata pre ovale ia etelaee eh eee 437
MTORR OLCCISTOT (20S 31 004) x4 Sane acel salah daha aE CRM ad SM einen tine Danan NE 435.
Maieceproduets, report-by Gore...) 6 Ee a eee Hee ee veel nee el 364
WMercarnes rut, paper by Keister: .. 4) 4 2 Boer eRe Nt cc nan aen te hy aie ore 502:
Martin, paper, effect produced upon the fat of hogs by feeding fish meal.......... 498
Martsolf, Noyes and King, paper, variations in the Concord grape during ripen-
520 INDEX TO VOLUME VI
PAGE
Mathewson
paper, use of sodium-alpha-naphthol-2-sulfonate for the spectrophotometric
estimation of aromatic amino compounds..................ecececereees 16
report; food Colores yoo.) y a4 tele svdsalied ag ahh Ae cyinla slaos tik Sap a a a ea 15
Meat and meat products
ities dois) 4/0: io eee ern MA AA Arup nce 116, 236
recommendations
Iny Commmiptee Gis cio ese ie 5 08 Seal eoeye ok ake ae ea 148, 276
Bry WWOUGI circ oie acs 2 oe keira eiahae eto nal neta elegans el e Ra 75, 85
Meat proteins, separation of, report by Moulton.................6-00e ee ee eee 72, 76
Members and visitors present, 1922 meeting «.. 2. 6. cic cu cle eaters oisie pele aie dieu 216
Metals in foods
recommendations
Boy. Clear iets syia oA ayes ag pics Re apahs al Geib hea al ae rR ale a ea 31
By Committee © sc gin « «2.42 eye csepdiaer oyna age bane s.t heuer aes 144, 272
report bry Glare oo eed a oie o. <n aces at Mess eae aed ae ey aia Maaco eal ae 28
Methods for examination of cacao butter
recommendations by, Bamghman, o s45 04's 2 vuis, 206,40) skate 41 y's Sai tia rvae erento 106
FOPOLE LY ER AUprER aa eo 5 ts vatgvs, ie eae! oldest os-atel-oue GS Chall gl Sete inten ane canara 101
Methods for the estimation of small amounts of starch in plant tissues, paper by
POCMTNY oe it aie oe Sk aatiate GG tees sR ote Me Oke cia hr oiahs 0 late ose) CR ee et ae ae eh 175
Methods of analysis, report of committee on editing (Doolittle).............. 118, 229
Micrometer, net, for use in making mold counts, paper by Howard.............. 50
Microscopic method for the quantitative determination of rice hulls in rice bran,
FIST DY SUDOELDOR ge 5 oo aaa 5 bine elp aiuabea ics Leper Dla eka naan Le laro\ ck ing ia 71
Milk
condensed, evaporated and concentrated, standards adopted................ 293
cryoscopy of, report, by Batley aii. sii Boas lavavegosdss Mave uate mie eaten 429
malted and dried, method for determination of fat
recommimendavion by) Kester...) 4 eee skosbakeicna ctl less akong nL aien meen 437
Teport Dy Weister yo oo aes ole cee ee ole elk © aris 6 6. >. > foo giana eu eae 435
methods, chemical and bacteriological, joint publication with the American
Public: Health Association ,resolution jis oir cts, se tee spsinlscclinbiye tila ovckehainge ee 240
Mitchell, moisture in cheese, recommendation. .............-2--0+e essere eeeee 437
Moisture in cheese, recommendation by Mitchell....................02-2ee ee es 437
Moisture in dried fruit
MeELtWOM Of GELETMUMALION: 2 oi)s.a:hcaja aise sls or sve) oo amiss treacle ik ahaa 273
TEcCoOMMendation: by MATES! ons cke cccice aieieis\ noee sv ereacueiehe pce snekoa keer Reeds eee Ran te 48
FEWOre DY EMMULES. 2 ec mae, occ Hs es tocirocacdeucwine, socse Gee vaca beet renee kas ae ae 40
Molasses and cane sirup, ash determination
LECOMMENAAONS DY JSreWSter floes ae hte exert eee eee) ciel oe eee 369
Report Dy, BTewster. fice ie So ee ERA Ye RRL a a ues San 365
Mold? counts: uselof net micrometer 2 S23y4oir aoe ele racial oie el oes ees 50
Morton, report on fluorides in baking powder.............. 2.00000 e eee ee eee enes 457
Moulton
paper, amino acids in globulin-albumin fraction of beef flesh................ 86
report
meat and meat, PLOGUCES . 6)).)/5 ales Jo, wyecmiastgrs Ueda jolais yet ayeuaye) Mth Rein pa ey Chelan 72
separation of meat, Proteins... 65)6)6 665 6 84 etapiagy & larch, Sep ee Pe RN Hea 76
Mustard, prepared. See Prepared mustard.
National Research Council, report of representatives on Loard of governors of the
Crop Protection Institute 226
INDEX TO VOLUME VI 521
PAGE
Net micrometer for use in making mold counts, paper by Howard............... 50
New fertilizer sampling tube, paper by Haigh. yey ee) ee ee 410
New sedimentation tube and its use in determining the cleanliness of drugs and
BOCEA EODOEU INT VIFNOCUBE SC aa silts Mt eRaeil oie os so oie diel & shoe cea Bae eh eee 466
Nickel dishes, use of for ashing saccharin products, paper by Whaley............ 370
Nitrogen in foods
recommendations
By MGommrnittee Gai ll ad a Ue Sk i). 5 aa le | it 280
byt Phelpias’ cf 4 terete ols se cyan teak nens above «ith»: aeepae eis tae la cites eomtae 398
EEpOre Dy Phelps nes, Meee ee eae rs ae A Seyatiatdadten aa ieee ayant. aaa 391
Nominating committee, report by Balcoom..................00 002 ce ce eeeee 171, 305
Nominations, committee, appointment and personnel.....................-+-5. 373
Non-alcoholic beverages
recommendations by Coniniwttee Bs oe sok eck is cece us te eeinnee ee Osean 266
iE OTN D\LERPIS) SE 012) ei REA 1 a oil AR 3
Noyes, King and Martsolf, paper, variations in the Concord grape during ripening.. 197
Mutmarrarines, paper by Keister. «25.9%. anastenudaahe do aeranlsricos Gabe ke aiekere 502
Obituary
Gembers Holmesthite, by Hanson... 2. .i4e ac ac ua cviatssausauanacin al seca eee 174
SRS EEZ) WV bein Woll, by Jala: O36. k RRO oe actual hah Sone k ein ae No. 3, 1
Officers, committees, referees and associate referees for the year ending Novem-
BUEN eters AN ig Neu £9 Bid ate svnla dha oases hisave ia RN ele eal ape aeeias tos 2 209
Oils and fats
TLEPOTOES UTA TVS) 1 177 GRR A ee) re aac ey» VL el i 117, 237
recommendations
lon (Crovea han v i A ierciyl Bia Mule Ma NES Mae ae UAlINI Hag tO MOINS D sc) Held roe 136, 265
Linh IS TPrhcs/o 710k le eR en RE Rh LA RRR RMIT DE Sh Mg Ran 444
EE PORNO VR) ANNI CSOT 8) 518) sc alice Ae ccIe oy Shane cates TN pate aps) sia) NAL NE Re eee 440
Paige teport Ol SACCHATING PTOGUCES:. 4. «yaya e boa < 5 «0,8 4+ 0 250092 Mah igs coutenerl ele 363
Patten, report
on determination of iron and aluminium, calcium and magnesium in the ash
OMSCCUS MATAR ETE ee ech OM ene Ue EDN AG) EARN ROBES ICN vate tenet are 418
OnMMEr-anic plarit constituents deisel. ah. Waser. Ws JID 414
Patterson and Hartwell, report of representatives on board of governors of the Crop
Protection Institute of the National Research Council.................... 154, 286
Pash enon a spies arid OLHEr COMGIMENES .:<, See/-\ 6,5: Sucisucieysseieusih, cusohan beta bec see alees 92
Pectin in fruits and fruit products
KE COMMENGATIONS VV ICHMIATION: 5 \5..00). 5c sla serenade oy sleeien scone areolar eel 39
TE TONELD Vi VV CEVA TRIA hey) AIS yas eval a on aeayeieil) sheitel RSMeans celatitey Ok 0k ba Umm an a 34
Pharmacopceia, committee to cooperate with the revision committee, report by
Eel} Ler AVG Re eR OR PPT SBE RT SLE Adu WIN eh ty 281
[F.rieite sl yer toy acy ahd 11Lh ¢0y4s. | A ae ame GR RPO Ee a here Me) Penge cH ili ba: 4 Aho Ma 391
Phosphate rock, summary of work on determination of iron and alumina content,
ah Glen Bs ee sl Col A i nr TOMA r cK eee Co] Mela dele) 377
Phosphoric acid, vegetation tests on availability in basic slag, report of committee
(CHE IG LST TTD) SAN LON SION TU ADS RI OURS EP esa RA TU CNA ESAS 1A URI Sead 8 123, 254
Phosphorus and sulfur in seeds of plants
CECOMMEN GATIONS) DY LiAbSLAsyys eice/s Mile eereilllsi sey sails ileeetetel abate alee sea ar pena Aa 418
BEPOUE Dy LAPSAW ): cje'n jai. 5) 2/8 sii01 eeavslales sealed ede) aeenaiahenseeuel ayaa aahens eneilanin. < ehateahamen 414
522 INDEX TO VOLUME VI
PAGE
Phosphorus, volumetric determination, abstract by Turner..................... 409
Plant and animal products, sublimation
recommendations by VicnGever oa.» 5 ci. on. na) vies fuss bedi in |Get eae a a 481
PEMONT DY VICHDE VEN. fh s.als iis be = aise hls aide ail oy athe Sere ane a eae ae a 473
Plant constituents
inorganic
changes injmetiaods 5). 51) 56551.) eleiataie ace volt ate kepiels akca hele he AGES ee 233
recommendations by Committee Au. i). .)hc aoe cicccceee ee eee 129, 260
TEpOrE by; PRES ih -acect oc nin a shpeiced ua eherans' Devicbol alana ene tenets oe eee ee Deke 414
Polysaccharides, interfering, determination of starch content, as in impure linseed
products,‘ paper by Walton and Coe. «4: 5/02/6247. tik ee eb heen ee eee 350
Potash
active, effect of cropping, paper, by. Fraps oo. de.4/cctassccsarn- nat eee SR 329
determination, development of Lindo-Gladding method and investigation of
other methods by the A. O. A. C., report by Foy...................- 399, 402
in mixed fertilizers, availability, paper by Gordon.......................0. 407
summary of strength and kind of alcohol used in official methods, paper by
ERUISTOM A Fen ete core ss ih i Bie ee CaN RUSE efesis ee eT CET EE te eRe Te 403
Preparation of neutral solution of ammonium citrate
LEcOMMENGgtiOnS'! bysODINSOM ap shies «Liat ae ese ee eee acetone Cee 390
reportyby URODMSONG) A ralie ts a/e:s (ache! othe) a endsecs cea lotea Wein eel b aon eee tee ek eee 384
Prepared mustard, determination of crude fiber, paper by Clemens.............. 205
Preservatives, food (saccharin)
recommendations
by Commnrttes Gane 0 Ee Oe ue oe ella Cae rel eet See 144, 272
By WON eo oa so ais etal eiala trap Wel Les gol int Ck ee eee 15
report by Wolf ese ah kl iasare sf ae ere © opel sid = 4p Paste UE eee sete ere 14
President's address, sy Vewtela je o's) s cian a) hate stonem hic ees bic eibeke chee eee een 223
Publication, announcement of change in order... 2... 0.002 ote pees eee 229
Publications, financial report
from Jnine 19.1921 to October15: 1921) (Balcom)'e). 5. 4. soe ae ee eee 164
from October 16, 1921 to November 1, 1922 (Balcom)..................... 244
from November 18, 1920 to June 18, 1921 (Alsberg)....................... 162
Quantitative determination of acetic anhydride, paper by Spencer............... 493
Quantitative determination of chlorine in bleached and natural flours, paper by
Raskcily sad Sa cea ae YS lad des ee ese ie Ss, Cie nae a eee 68
Rask, paper, quantitative determination of chlorine in bleached and natural flours.. 68
Reading the fat column in the Babcock test for milk, paper by Hoyt............ 54
Reagents, chemical
recommendations
Bey Aor rtie hte BS uel ke 0! aw tic Mia edag eetew wiles Siete ates CR a a ate 137, 266
DY, SET COM Hs hen cid si 5258 ier oily oncld mien ateteselia os ais be cena win Sr abe ed eked Rese 3
PEpOrt DY SMEG. 4 sje 15: ove! torn avqeyyie td exes ONS Soaks ies atee aS in oleae ia Gas ca 1
Recommendations of referees, report
by Gonemittes (Doolittle). sui icc bovine ies 22eeh Wold aaias 125, 256
baijommmnttes A: \ CROSS) 4) <1 tec weathered wed eae aa 127, 258
by Conunittee B (Lythgoe) . 20. \:.......3. ....0s) Relay. keene td ee ea 133, 262
by Committee Ci (Daolittle) iu) i/s ee Ee 144, 272
Reed, report, foods and feeding: stuils. 0). ci sees ne te see la teen eee ener 332
INDEX TO VOLUME VI 523
PAGE
Referees, report
of Committee A on recommendations (Ross) ..........0..0 00000000 ee uee 127, 258
of Committee B on recommendations (Lythgoe)...................00-. 133, 262
of Committee C on recommendations (Doolittle)....................... 144, 272
of Committee on recommendations (Doolittle)..............0...000008. 125, 256
Referees, associate referees, officers and committees for the year ending Novem-
Deh Me co adian. obasouumes ethane ebai hip we bagaatiow abate taihyuth 209
Renovated butter. See Butter.
Feotinious: report of committee, 2... eta ae ils My ook fie c ae Samadles 172, 305
Resolutions committee, appointment and personnel......................2-00-: 373
Rice bran, microscopic method for the quantitative determination of rice hulls,
TPE SLE ASTI Lot oi RR aR PR br Ce ene IRE TEL 71
Robinson, report, preparation of neutral solution of ammonium citrate.......... 384
Ross, report of Committee A on recommendations of referees................ 127, 258
Saccharin, food preservatives
PEE OTMGHCIA GIONS DAVE WK OME «5 3.345). 2 5 out are Al Ha ain Rial oS ct ee nus aes fone ae a ea 15
REPION aly UM OIE cis strap = Se sha Sore dass att betel R he aed, bia ee SRR eer aon Cae 14
Saccharine products
roeommendations by Committee By «(0002/2254 s62s.< 10.0 « «1 stave 135, 263
PRPMSEU EY SUNG occ 512) ses wk 5 esa hcllles SM ah chy dala ayave a tisha ne 363
use of nickel dishes for ashing, paper by Whaley......................2.5- 370
BOREErE Ore, Water.) 2. 10 162M) Se, SMP oe ea ee 307
Salvarsan and neosalvarsan, qualitative and quantitative methods of analysis
recommendations by Hoover and Glycarts. .,.j-....<...- «peach, 09 Kincaid scheint 464
BERBER ON HOOVER ANG GIYVCAEE <2... sn lc Godan» os she Sik Oe a ee 461
peccetary of Agriculture, address by Wallace... ... 22... 2.06 oe snoscus dean en 90, 251
Secretary-Treasurer report
OE IETS ra hace as) eal Aca talarsiesas aoa 'y Sel ondne al cee ee 287
iomyune:2 11921 to, Octobers15:21921 (Balcom) so... oo) eee oe ee 160
from October 16, 1921 to November 1, 1922 (Skinner)..................... 248
from November 15, 1920 to June 21, 1921 (Alsberg).................-.200- 158
Seeds of plants, sulfur and phosphorus determination
See SSHRC 19) ESEMINAR) 3 5 2h2 NESE at cia) 1 xaigao./asain, olay oh eMyaeaas alee 418
Ee ORTHO INACS HAW Owes cc 11Eh tS BS deg the he Se eee) nee Oe Ree ne reer ae 414
Seidenberg, paper, data secured with the “turbidity point” of butter fat ......... 437
Separation of meat proteins
PeeAmmMnenasIGnS: ty Wioulton 0. 66 Se SPE Pe er ee orca oe 85
MOTEL SMT VNC Te Fe eee ea SS ee eS aie heen eer ra ale eat ene eae 76
BRC OMe MELTS Of ANALYSIS) ) o 5 6 eR ees ULE eee tee ones eee 265
Shell in cacao products, determination, report by Silberberg.................... 98
Silberberg
paper, microscopic method for the quantitative determination of rice hulls in
STCER EAN cee eae) Rd.) ae oe eel | a a ea ee 71
report, determination of shell in cacao products...................4200000- 98
Skinner, report
BMESECRCEATDY—MreAaSULClsrs iaic's ss, sr/<iete Oe Re ek sere aie eae PEN RS 248, 287
GHEHON=21CONOHG DEVETARES sis,.(15 sec Nels oe ae ran a ea eS Lee 3
Sodium-alpha-naphthol-2-sulfonate for the spectrophotometric estimation of aro-
matic amino compounds, paper by Mathewson... .............0..0 0.000000. 16
Soil, effect of cropping upon active potash, paper by Fraps..................... 329
524 INDEX TO VOLUME VI
PAGE
Soils
recommendations by Committee Anc)(] ) ery ulate ere thes Bn dg le late 132, 261
report. by Maclatire jo :.0.1).uideie le ..- SET OSH) Die ey dee ean tad 320
Soils, sulfur
recommendations by Macintire. ').'2 2004), POOLS oe Reena te ears 329
report, by .Macintirey. 643 <i. 0).j.<s! saline Jute Teeth: See APSE, crest 320
Spectrophotometric estimation of aromatic amino compounds, use of sodium-alpha-
naphthol-2-sulfonate, paper by Mathewson... ............. 00.0 ee ee eee eeee 16
Spencer
paper, quantitative determination of acetic anhydride ..................... 493
TEPOLL: (CHEMICAL TEAUERER tow eo ae are anal are rece NNR ae Gale peal e ces aaa 1
Spices
recommendations by Committee Coo. ciel e ie souk ae chee soln Gane 149
BUATILATOS ACOPIE EO coho 5 coda: my «a faiin oi cabo for ue a SHB Gke ee lin 2 Spence oe eee ea 296
Spices and drugs, new sedimentation tube for determining cleanliness, report by
VIGEOR VER eho co sli seeps ect Socune onsets valde needed oeuadih i ot etait adn eS ARARet ee Ay ep 466
Spices and other condiments
changes in MethGdss geises oi vaeaies Gee URE MIA sal. ibils wea soko eine Wein eee 237
recommendations
hy ComimiibpeetGe ys ee eerie sia eine inte atte es ene eI 277
by Pal st. sigtes oh Stings 06 so etal BY faim etc SR a cio a ra esrectene gone 97
report by Pare Mice ewes occ uve s sete cae aa ee ele ere ete cheasye ne tee een ohooh megs 92
Standards.faods report Of Gummimittee |! 555 '.'7. she's o/s! tiace etal 2) oie os ne ola hes tua ee 292
Starch content, determination of in the presence of interfering polysaccharides as
in impure linseed products, paper by Walton and Coe...................4055 350
Starch in plant tissues, methods for estimation of small amounts, paper by Denny.. 175
Stock feed adulteration
necommendalions DY AGeNBIEr . 6.6.3 sae se Re misleole Me eae Cale osiaeielee en a alee 350
FEPGNE Dy: GENBIER ST Ai Sela he: weet ee eon costa ab 9 eee eee ae ete 345
Studies on wheat flour grade II1]—effect of chlorine bleaching upon the electrolytic
resistance and hydrogen ion concentration of water extracts, paper by Bailey-
FOUTS oy yee ETRE Se wig we Sig ote ak ie) coesaet ais ele datteyoean adsl) 5 ]o) Stee he 63
Sublimation as an analytical procedure, paper by Hortvet....................-. 481
Sublimation of plant and animal products
recommendations by, ViEOEVER \. 65.1); +. «5 .s7\5 eras, 4)seeieas bs bik =e 481
report by Viehoevery ic. 1006 sais 05,8 recs ro) \s) sis hee bot ane aaa ae ne 473
Sulfur and phosphorus in the seeds of plants
recommendations by Latshaw 2. 2... «65.2 +, «weiss sis 4, aaeetleee ere OE 418
report) by Gatshiaws 22.77.05. 0s ciec sec c so sles ain oi) ohaiahatenstone Ahepaparela eka paral 414
Sulfur in soils
recommendations by, MacIntire, 3... ccc) 3.0 tai oS ek he ne Der ee ee 329
réport- by Macintie sy iitarey SOON’, a, SRN Pe shoe eer 320
Summary of work on the determination of iron and alumina in phosphate rock, paper
byobbracketts, 6512 55 Sivas Ss Sadgies acca aes camels meyere ete Arete Sie tea a 377
Summary relating to strength and kind of alcohol used in official potash methods,
PAPEL DY TMVStOH 6. sy7 cine cic oe ning weed salere aisles eee Ran Moe a Se Ce 403
Tanning materials and leather
recommendations by Committee Ascii sii lo!) aya. steve tiga Sistan oe WO eRe 130, 261
report. by Neitclas:.:. Ssantewn debed Mncreheg, ottaldiieyere & SN UREA ER UR be ee 309
INDEX TO VOLUME VI 525
PAGE
Tea
CMANIEER IT MELHORS aon. TN states oe ee CENA OPPS OPTI, Fa 117, 237
method for. determination of water extract... 0.022.006.0200. e. le... 280
recommendations
by Andre weer natees ite Aeon ee ee Stee eee, 7 ERE 5 ee eee 111
Dg CORGIOLCE: ras 4 co REE et ee ee ee ee 150, 279
FADOEL DV ANIGKE Wes a 216} Oe SE) ER TR gee 107
Treasurer, report
LOW AS [sd 161 1c pear OS 5 ne al MR RIAA Ah EN Oo MMT Ae Si 2 287
from June 21, 1921 to’ October 15, 1921: (Balcom)® ............. 27252229. 160
from November 15, 1920 to June 21, 1921 (Alsberg)....................... 158
“Turbidity point’’ of butter fat, data, paper by Seidenberg...................... 437
Turner, abstract, volumetric determination of phosphorus...................... 469
Turpentine
FECOMMENCALIONS) Wy! Glarkeson eur: area NCES 1c. tas edhe ete bis a ane Reet 465
BETO UAC AT KOA role) For ees Scns GRE TT SRE reais fy oy svele Shas ae eA Ree Chae 465
United States Pharmacopceia revision committee, report of representative (Kebler). 152
Use of nickel dishes for ashing saccharine products, paper by Whaley........... 370
Use of sodium-alpha-naphtha-2-sulfonate for the spectrophotometric estimation
PAR MIALIC AMINO (CONIPOUMGS 26:2 3) ax! Sages eis ate ae a2 5 & Gye: oie epee eo 16
Van Norman, announcement of World’s Dairy Show...................0000065 250
Variations in the Concord grape during ripening, paper by Noyes, King and Mart:
ECS Ft PGS oi Shas Suara es «OME S Sa eee is DB ete acd oie 197
Weetable oils and fats;-edible; standards adopted... 5..-.....-.:+-..--sseecne ee 295
Mecerables. cannedchanges,inimethods:.-- een eee ok eee eee 235
Vegetation tests on the availability of phosphoric acid in basic slag, report by com-
PPET eee (1S ETS) A ea ee em RE etme Ad a ht et yn cnc 123, 254
Veitch
PRP EH I AG OTERS 5.215, 2) a0 0k «nisin 3,3 SR ee gen ho ee Se eee 223
FepOLtannime materialsiand leather esse oe eee Cee 309
Viehoever, report
new sedimentation tube and its use in determining the cleanliness of drugs
TG Gy CCEA SS SS eo ee ee PRE Teste OSES CP Och MCISE MRIS Cin'd Oo pia eo OU 0 ic 466
manimation of, plant-and animal products’.; 25... <.<..6<322 soe - ease 473
Viehoever and Capen, paper, domestic sources of cantharidin..................- 489
Ser eH TeSt LOR SCSAINE ONE: / 22/4 20. Be ae Cet oreo © Le eo arene oe ale ee 265
Vinegars, recommendations by Committee C.....................0-0000 08: 147, 275
Wisitors.and members present, 1922 meeting: <2... <<: oii. 6... Seles hoes eee te 216
Volumetric determination of phosphorus, abstract by Turner................... 409
Winllaces secretary of Agriculture, address)s- en an seins o: cleeieiae es oe eee 90, 251
Walton and Coe, paper, determination of starch content in the presence of inter-
fering polysaccharides as in impure linseed products...................--.--. 350
Water
recommendations
bey CoommannrG bee A: os. ss. 8S srg aeons pies cele aie ema ee eee 129, 260
RAS ee ee NLT CAPE ESSE rh Rime rr i etm 309
ETL Lh ahs | | he ne ierre enh otek yaa eh reer ERNE city cr > rie Al ° 307
Water extracts, effect of chlorine bleaching upon the electrolytic resistance and
hydrogen ion concentration—studies on wheat flour grades, paper by Bailey
ERTNEMAD COEDELSOND 5 vos sh ois cs eonss Siticie are Hoe eG SIE AS I Ie re BOLE hea 63
Waterss changes Im MethOUS is 5/5 5 Voces ee ee eet EO roe OE see 118, 233
526 INDEX TO VOLUME VI
Whaley, paper, use of nickel dishes for ashing saccharine products.............. 370
Wheat flour grades, studies, I[{I—effect of chlorine bleaching upon the electro-
lytic resistance and hydrogen ion concentration of water extracts, paper by
Baile y/anid Johnsen oo 2 55 cea) es + ain ai's syse oe leliev ese = > ale. SOUR) 6 jn ESPEN eR eae mete 63
Wichmann, report, determination of pectin in fruit and fruit products........... 34
Wiley: Honorary President; address’... 5.435.465 dyes es 023 oad ee eee Bik
Wolf, report, preservatives (saccharin). .)...\:< bys :)s s+ ps Pea lols a eee 14
Woll; Fritz) Wilhelm, obituary by Taffa.ccasi:. i). oss lein wiales ¢ ene = oe ee ne No. 3, i
World’s Dairy Congress
ANNOUNCEMIENE |) se se.o'2 «yo, 4.05:5. 3 Cisne ets obey Ae ate eeu nee: ie eeeere denen 250
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