bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Calculation of Gas Chromatographic Peaks in Pesticide Residue Analyses
Authors: Gaul Jean A
Published: February 2020

Comparison of five methods for calculating gas chromatographic peaks (disc integration, triangulation, peak height × width at half height, Rt × peak height, and peak height) shows no significant difference in the calculated results when aldrin, heptachlor epoxide, and dieldrin are injected into a gas chromatograph equipped with electron capture detector.

Problems are associated with the calculation of toxaphene, chlordane, DDT, and BHC The author makes suggestions for calculating these four residues when present individually and in combinations with other pesticides. Use of the last fovir toxaphene peaks compares favorably with results obtained by vising the entire toxaphene curve. A method for calculating DDT in the presence of toxaphene, based on the construction of “parallel lines”, gives 89–100% of the DDT in the presence of 1–10 parts of toxaphene. Results for chlordane obtained by adding heights of individual chlordane peaks are shown to be close to results obtained with an integrator. When electron capture detection is used for determining the α, β, γ, and δ-isomers of BHC, the response of the β-isomer is fovmd to be approximately 50% less than response of the other isomers, thus pointing up the need for use of individual BHC isomers for electron capture gas-liquid chromatography quantitation.
Collaborative Test of a Microbiological Assay for Low Chlortetracycline Concentrations In Final Feeds
Authors: Abbey Anthony
Published: February 2020

Commercial poultry, cattle, and swine feeds, containing low levels of chlortetracycline (CTC) activity (5, 10, and 20 ppm CTC), were assayed collaboratively in eight laboratories by compensating CTC standard curves prepared with diluent from sodium hypochlorite-inactivated animal feed extracts. The coefficients of variation for poultry, cattle, and swine feeds, individually, were 20, 13, and 10%, respectively. The combined data from those laboratories on both poultry and cattle feeds yielded a coefficient of variation of 12%, while the combined data from those laboratories assaying poultry and swine feeds gave a coefficient of variation of 15%. The inactivation of CTC in animal feed extracts by sodium hypochlorite plus heat appears to be operative in all eight laboratories.
Determination of Acetaminophen in Combination with Other Drugs
Authors: Levine Joseph , Hohmann John R
Published: February 2020

Acetaminophen can be separated from acidic, basic, and neutral solutions on a sodium carbonate-sodium bicarbonate column. Salicylamides and barbiturates are eluted in chloroform; acetaminophen is eluted in ether and measured spectrophotometrically.
Dilution Method for Mold Count of Catsup
Authors: Wildman John D
Published: February 2020

The method of diluting catsup with an equal volume of stabilizer solution previous to the application of the official method for mold count has been tried by twelve different analysts in eleven District laboratories of the Food and Drug Administration. The analysts were in general agreement that the dilution method was easier and more accurate than the official method. The method, with the exception of the method of preparation of stabilizer solution, is recommended for adoption as official, first action.
Gas Chromatography of Unsaponifiable Matter. IV. Aliphatic Alcohols, Tocopherols, and Triterpenoid Alcohols in Butter and Vegetable Oils
Authors: Eisner Jerome , Iverson John L , Firestone David
Published: February 2020

The unsaponifiable matter of butterfat, castor oil, cocoa butter fat, corn, cottonseed, linseed, milo maize, peanut, rice bran, safflower, soybean, and tung oils was fractionated on a Florisil column and the third fraction (tocopherols, high molecular weight alcohols, and triterpenoid alcohols) was gas chromatographed. This fraction showed three homologous series, tentatively identified as normal, iso- and/or anteiso-, and multiple branched chain alcohols. Each sample was examined before and after hydrogenation with Adams catalyst. Gas chromatograms from most of the oils displayed characteristic patterns which could be used to identify individual oils.
Improved Cleanup Method for Determination of Biphenyl in Citrus Fruits and in Biphenyl-impregnated Kraft Papers by Thin Layer Chromatography
Authors: Norman Shirley , Rygg G L , Wells A W
Published: February 2020

A simple, rapid, and efficient method has been developed for determining biphenyl in citrus fruit and in biphenyl-impregnated kraft papers. Biphenyl is separated from citrus tissue by steam distillation and from biphenyl-impregnated papers by solution in iso-octane. Plastic sheets coated with silica gel, to which a polyvinyl alcohol binder and a fluorescent indicator have been added, are used for cleanup by thin layer chromatography (TLC). The TLC spots are extracted and measured spectrophotometrically at 248 m/µ. Recoveries of added biphenyl ranged from 92 to 98%. The new method is simple and brief; it is more accurate than cleanup by oxidative degradation since the variable background is practically eliminated. The new method is easier and faster than the silicic acid chromatostrip technique, and is just as accurate.
Determination of Oxidative Metabolites of Dimethoate and Thimet in Soil by Emission Spectroscopic Gas Chromatography
Authors: Bache C A , Lisk D J
Published: February 2020

The conversion of dimethoate to its oxygen analog and the production of oxidative metabolites of Thimet in soil has been shown by using emission spectroscopic gas chromatography for their determination. Preparative thin layer chromatography was vised for prior separation of Thimet oxidation products. The sulfoxide and sulfone of Thimet were the major determinable products.
Automated Elution-Filtration Analysis of Anticholinesterase Organophosphorus Compounds on Thin Layer Chromatographic Scrapings
Authors: Ott Daniel E , Gunther Francis A
Published: February 2020

An automated analysis system for anticholinesterase organophosphorus compounds has been modified to include an automated elution-filtration technique for analysis of these compounds after thin layer chromatography. The entire method offers specificity previously unobtainable by automated anticholinesterase methods and is rapid when combined with a multiple spotter apparatus for thin layer chromatography.

The present method has been used to determine parathion residues in fortified canned peaches down to a level of 0.1 ppm.
Synthetic Organic Colors in Oils
Authors: Jones F B
Published: February 2020

A fast and simple method was developed for the separation and identification of micro amounts of 11 oil-soluble synthetic organic colors. The colors under study were D&C Red Nos. 17, 18, and 35; D&C Green No. 6; D&C Violet No. 2 ; D&C Yellow No. 11; Ext. D&C Blue No. 5; Ext. D&C Orange No. 4; Ext. D&C Red No. 14; and Ext. D&C Yellow Nos. 9 and 10. Results of the collaborative study were good, and the method is recommended for adoption as official, first action.
Estimation and Identification of Turpentine in Multi-Component Mixtures: Identification of Pure Turpentine
Authors: Saxton Wilbur L
Published: February 2020

Turpentine is separated from multi-component products by steam distillation, quantitatively determined by a titrimetric bromination, and identified by gas chromatography of the brominated product. The method is satisfactory for each of the three types of turpentine produced in the U.S. but does not distinguish among them. Twenty-five samples of turpentine, representing the three main types, obtained from various sources, were assayed by the proposed method to determine range of titration value and the mean titration value. Recovery of turpentine from three products containing known added amounts were 83, 100, and 104%. The 25 samples of turpentine and 10 samples of commercial products known to contain turpentine all gave similar gas chromatographic curves. Curves show that a combination of peaks lying between 0.5 and 0.85 retention time (relative to aldrin) can be used to identify turpentine.
Factors Affecting the Precision of Moisture Measurement in Grain and Related Crops
Authors: Hunt W Haward , Neustadt M H
Published: February 2020

Moisture content is one of the most important factors affecting the quality of grain. Many types and makes of moisturemeasuring devices have been tested to establish a practical method of moisture measurement. Oven methods, used as standards to calibrate these devices, are empirical. Factors affecting the precision of moisture determinations by oven methods are discussed in detail. Since the relationship between moisture content and electrical properties may vary considerably at times, factors affecting the accuracy of electrical moisture meters are also discussed.
Analysis of Dairy Products for Chlorinated Insecticide Residues by Thin Layer Chromatography
Authors: Moats William A
Published: February 2020

Butterfat and milk samples were analyzed for chlorinated insecticides by thin layer chromatography (TLC) on aluminum oxide or silica gel plates containing a small amount of silver nitrate. The adsorbent was washed with distilled water before preparing the plates. A one-step cleanup on a partially inactivated Florisil column was performed prior to TLC analysis. For color development, the TLC plates were sprayed lightly with hydrogen peroxide to suppress possible interference from fat and then steamed before exposure to ultraviolet light to accelerate and intensify the color reaction. Rf values for a number of solvent systems on aluminum oxide and silica gel plates are given. With this procedure, 0.05 μg or less of insecticide can be detected in a 0.4 g butterfat sample or the extract from 10 ml milk.
Chemical Assay and Isolation of Chick Edema Factor in Biological Materials
Authors: Campbell T C , Friedman L
Published: February 2020

In the chemical assay for the chick edema factor (CEF) in biological material, the unsaponifiable matter containing the CEF is recovered from the saponification mixture and is cleaned up by column (alumina adsorption) and thin layer (silica gel adsorption) procedures. The final extract is analyzed on an electron capture gas chromatograph, and the chromatogram peaks are compared to a known standard. Recovery is good, and the approximate limit of detection is 0.2 ppb. Two CEF components that have been isolated as crystalline materials correspond to Peaks 4a and 7 of previously isolated material. The UV absorption maximum for the crystalline material is 242 mμ.
A Gas-Liquid Chromatographic Method for the Determination of Cyclohexylamine Sulfamate Salts in Animal Excreta
Authors: Derse Philip H , Daun Robert J
Published: February 2020

A relatively rapid, quantitative method for the determination of cyclamates in urine and feces is reported here. Rats maintained at various levels of cyclamate for 20 weeks excrete percentages of cyclamate based on the levels fed, either as the sodium or calcium salt; less sodium cyclamate is excreted than calcium cyclamate and most of the salt is excreted in the feces. Preliminary work indicates that with certain modifications, the method can be applied to the analysis of cyclamate in animal tissue at the level of a few parts per million.
Determination of Unsaponifiable Residues in Milk
Authors: Teague Robert T , Joe Frank L
Published: February 2020

Unsaponifiable residues are determined in milk samples by the following procedure: oily drug bases and fats are extracted with iso-octane (rather than the usual mixed ether solvents) in an alkaline alcohol-acetone mixture; this extract is concentrated and the fatty constituents are saponified with KOH. The unsaponifiable matter is then re-extracted with iso-octane and the residual soaps and extraneous constituents are removed by water washing and column chromatography. Mineral oil added at levels of 12–404 ppm to milk samples was quantitatively recovered, with an average value of 98%. Unsaponifiable matter in market milk was also determined; results demonstrated good precision between duplicate analyses. Milk-out studies were performed to determine the rate of diffusion and dissipation of infused formulations.
Determination of Secondary and Minor Plant Nutrients in
Fertilizers by Atomic Absorption Spectrophotometry:Third Collaborative Study
Authors: Mcbride C H
Published: February 2020

The atomic absorption procedure, 2.086— 2.091, was studied further and expanded to include Ca, Na, and K. Examination of 7 samples by 19 collaborators resulted in between-laboratory precision of 4—7% in the range of concentrations of agronomic interest for Cu, Fe, Mg, Mn, and Zn. The method is recommended for adoption as official, first action for Ca. Further study of the method for K and Na is recommended.
Mechanisms of Sampler Bias
Authors: Baker W L , Gehrke C W , Krause G F
Published: February 2020

Possible mechanisms of sampler bias on dry mixed fertilizers were evaluated in an effort to develop better official sampling instruments and procedures. Three lots of dry mixed fertilizer (about 1 ton each) with known physical and chemical composition were prepared in the laboratory. Twelve vertical and 12 horizontal cores, arranged in a latin square sampling pattern, were secured from each lot with 3 triers: the AOAC double tube trier, a double tube compartmented trier, and an experimental double half-tube trier wherein the core was encompassed in place rather than being required to flow into a compartment as with conventional triers. Individual cores were analyzed physically and chemically. Only marginally significant differences were found between cores on the basis of tube opening size. The experimental double half-tube trier was less selective to particle shape than either the compartmented or AOAC triers, but differences were not statistically significant. All triers produced more representative samples from vertical cores than from horizontal cores. Cores drawn at a 60—75° angle from horizontal were not consistently different from vertical cores. Results of chemical analysis confirmed the sieve analysis findings quite closely. Horizontal cores secured with the experimental double half-tube trier confirmed that the bias observed in horizontal cores was due to downward drifting of small particles when the core area was disturbed by sampler insertion. Cores secured with the sample-retaining face upward contained an excess of fines, while cores secured with the sample-retaining face to the side or downward more nearly resembled vertical cores in composition.
Arsenious Oxide, Potassium Bromide-Bromate, and Iodine
Standard Solutions
Authors: Moore Richard A
Published: February 2020

Official Methods of Analysis was reviewed for these two standard solutions to eliminate all unnecessary duplication of instructions in preparation and standardization
Sweep Co-Distillation Cleanup of Milk for Determination of
Organophosphate and Chlorinated Hydrocarbon Pesticides
Authors: Watts Randall R , Storherr Robert W
Published: February 2020

A rapid extraction and sweep co-distillation cleanup procedure is described for organopliospbate and chlorinated pesticide residues in milk. Ethyl acetate and methanol are used as the extracting and the coagulating solvents, respectively. The extraction apparatus includes a graduated cylindrical separatory funnel which expedites sample handling. A suitable aliquot of the extract is concentrated in a Kuderna-Danish concentrator, sweep co-distilled for 30 min to remove the fat, and determined by GLC with the thermionic detector. Milk samples were fortified, on a whole milk basis, prior to extraction with three different pesticide standard solutions. The pesticide solutions contained as follows: (2) diazinon, methyl parathion, malathion, parathion, and Trithion; (2) Thimet, ronnel, ethion, Imidan, and Cuthion; and (3) lindane, heptachlor, aldrin, heptachlor epoxide, dieldrin, endrin, and p,p'-DDT. Average recoveries of these pesticides were generally 90+%. Sensitivity of 0.01 ppm was readily obtainable for pesticides such as parathion
Field Weathering of Toxaphene and Chlordane
Authors: Klein A K , Link J D
Published: February 2020

Both toxaphene and chlordane are rapidly lost on kale and presumably on other vegetables by weathering. Only trace amounts remain from an initial heavy application after 28 days. During this period the composition of the pesticides changes. With toxaphene, even at low levels, the remaining components appear to be organic chlorine compounds. The revised colorimetric method for toxaphene gives satisfactory results and supplements gas chromatography when the toxaphene level is not lower than 10 ppm or perhaps 5 ppm. The colorimetric method is not applicable at levels of 1 ppm or less. Large amounts of DDT interfere with the proper evaluation of the toxaphene by gas chromatography. Chlordane interferes seriously in both methods
Extraction of Chlorinated Pesticide Residues from Nonfatty
Samples of Low Moisture Content
Authors: Bertuzzi Patricia F , Kamps Laverne , Miles Corbin I , Burke Jerry A
Published: February 2020

A study using samples with field-incurred residues of chlorinated pesticides showed that acetonitrile alone is not effective for extracting the pesticide residue from samples containing about 10% moisture. Investigation of a variety of solvents resvilted in the choice of 35% water/acetonitrile as the most effective extractant. Other variables of the extraction studied were sample size, extractant volume, sample grinding, and blending time. The extraction system chosen compared well with an exhaustive extraction technique previously demonstrated to completely remove residues of chlorinated pesticides. Results are given for the extraction of field-incurred residues of five pesticides from three commodities. A procedure for extracting "dry" samples is outlined
Analysis of Dursban in Livestock Dips and Sprays
Authors: Czech Fred P
Published: February 2020

Chemical and spectrophotometric procedures for Dursban in emulsifiable concentrates, dips, sprays, and hair and hide extracts are compared. Infrared spectrophotometric methods are more rapid, simple, free from interference, and specific than the UV or sodium biphenyl methods.
Metabolism of DDT and Some Other Chlorinated Organic Compounds by Aerobacter aerogenes
Authors: Mendel J L , Klein A K , Chen J T , Walton Mae S
Published: February 2020

The micro-organism, Aerobacter aerogenes, reductively dechlorinates o,p'-DDT to o,p'-DDD. The yield is constant for a constant 24-hour incubation period. This metabolic pathway appears to be rather specific for the DDT's, since Perthane is not produced from l,l,l-trichloro-2,2-bis(pethylphenyl) ethane even after long incubation with A. aerogenes. In general, incubation of methoxychlor with the bacterium results in loss of the pesticide: its olefin and the reductively dechlorinated pesticide [ (l,l-dichloro-2,2-bis (p-methoxyphenyl) ethane] are sometimes produced but only after long term incubation. A. aerogenes does not effect the conversion of aldrin to dieldrin.
Determination of Starch and Soluble Carbohydrates. II. Collaborative Study of Starch Determination in Cereal Grains and Cereal Products
Authors: Friedemann Theodore E , Witt Norman F
Published: February 2020

The method of Friedemann, Witt, and Neighbors for starch in cereal foods was studied collaboratively on 12 samples by 8 laboratories. Results were compared with those obtained in the Associate Referee's Laboratory and were generally somewhat lower, probably because of inexperience with the method. The method is recommended for adoption as official, first action.
Persistence of Sevin Residues on Some Vegetable Crops After Various Harvest Times
Authors: Elessawi Makarem Ahmed , El-Refai Abdel Rahman
Published: February 2020

Chemical analysis of edible portions of untreated okra, cowpeas, tomato, and eggplant gave relatively low values for apparent Sevin. These crops were planted on experimental plots ( 4 X 4 meters), treated with multiple application of Sevin at the rate of 0.34% technical Sevin (60 g 8 5 % wettable powder/15 L water), and grown vinder simulated commercial practices. The Sevin residues were far below the tolerance level two hours after the final application. Higher initial and more persistent residues were found on okra and cowpeas than on tomato and eggplant crops. Maximum Sevin residues on okra, cowpeas, tomato, and eggplant were 3.2, 5.03, 1.88, and 1.88 ppm, respectively, 3 hours after the last application; these residues declined within 8 days to below 0.05 ppm in all vegetables
Correlation of Fatty Acid Structure With Preferential Order of Urea Complex Formation
Authors: Iverson John L , Weik R W
Published: February 2020

The selective order in which methyl esters of fatty acids form urea complexes was correlated with the fatty acid structure. Detailed information about the preferential order in which inclusion compounds are formed was obtained by fractionating complex oils (e.g., butter, lanolin, cod liver). The preferential order was correlated with GLC retention times, and the detection of trace amounts of fatty acids (<0.1%) was possible. Urea adductability values (UAV) are proposed as a useful means of expressing preferential order of the formation of inclusion compounds
Detection of Solvents by Infrared Spectrophotometry
Authors: Schwartzman George , Sullivan Daniel , Sarnoff Evelyn
Published: February 2020

The solvent used in the recrystallization of a solid may be determined by use of the IR spectrum and gas cell. Recrystallized powders retain a minute amount of solvent which is not detectable in a KBr disk of the powder, but is detectable when a gas cell is vised. The following solvents were examined by this method: acetone, benzene, n-butanol, tert-butanol, carbon tetrachloride, chloroform, ethanol, ethyl acetate, ethyl ether, isopropyl alcohol, methanol, n-propanol, trichloroethylene, toluene.
Validation Study of a Method for Pesticide Residues in Foods and Animal Feeds
Authors: Wells Clyde E
Published: February 2020

Eighteen laboratories of the Food and Drug Administration tested a multi-pesticide residue method using 65 pesticides and 80 food and animal feed products. Recoveries of 32 pesticides averaged between 80 and 110%; 20 additional pesticides were recovered with some degree of success; and 13 of the pesticides tested were not recovered. The method tested is based on the AOAC procedure which involves extraction of the pesticides with acetonitrile, partition into petroleum ether, cleanup on a Florisil column, and gas-liquid chromatography. Recoveries were essentially independent of the type of product. Of the products tested, only carrots, parsnips, onions, and lettuce exhibited serious interference when the electron capture detector was used
Spectrophotometry Determination of Temik® Residues in Citrus
Authors: Meagher W R , Hendrickson R , SHIVELY B G
Published: February 2020

An improved spectrophotometric method for determining Temik residues in citrus has been developed by using an acetone extraction followed by a Florisil column cleanup to remove interfering svibstances. The method also determines the sulfone and sulfoxide metabolites of Temik and Temik oxime, but it does not differentiate between parent compound and/or its metabolites. An overall average recovery of 98.5 ± 2.2 % was obtained on samples fortified at levels of 0.002-0.200 ppm. As little as 0.0006 ppm Temik, based on a 500 g fruit sample, covdd be determined
Identification of Antibiotics in Pharmaceutical Preparations. I. Identification of Penicillin Types
Authors: Weiss Peter J , Taliaferro Brenda , Huckins Robert , Chastonay Richard
Published: February 2020

Methods for the rapid confirmatory identification of various penicillin types in pharmaceutical preparations are presented. Ultraviolet absorption spectra are useful after simple purification, and thin layer chromatography is applicable in some cases. A method based on differential distribution between chloroform and buffer phases, using solutions prepared for routine potency assays, can also be used
False-Positive Coagulase Reactions in the Characterization of Microorganisms Isolated from Foods
Authors: Litkenhous Claudia J , Baer Edward F , Gilden Mildred M , Bromer Marcia B
Published: February 2020

From 3578 cultures tested for coagulase production, 66 suspected false-positive coagulase cultures were selected on the basis of delayed clotting time (3—4 hr). Coagulase production by these cultures was compared, using citrated rabbit plasma and citrated rabbit plasma containing heparin. Twentynine of these cultures were also tested, using plasma containing EDTA. Results indicate that either EDTA or heparin should be used in conjunction with citrated plasma to eliminate false-positive reactions, or, if citrated plasma is used, that all delayed positives (3—4 hr) be considered suspect and additional confirmatory tests be performed
Extraction and Estimation of Polycyclic Aromatic
Hydrocarbons in Total Diet Composites
Authors: Howard John W , Fazio Thomas , White Richard H , Klimeck Barbara A
Published: February 2020

A general method for polycyclic aromatic hydrocarbons and a specific procedure for benzo(a)pyrene in various total diet composites (dairy products; oils, fats, and shortenings; beverages; meat, fish, and poultry; and root vegetables) have been developed. Recoveries ranged from 75 to 100% at the 2 ppb level. Pyrene and fluoranthene were found to be present in all of the total diet samples analyzed. Trace quantities of benzo ( a ) pyrene, benzo(k)- fluoranthene, benzo ( b ) fluoranthene, and other hydrocarbons were isolated from various lots of the oils, fats, and shortenings composites.
Comparison of Optical Emission and Atomic Absorption
Methods for the Analyses of Plant Tissues
Authors: Brech Frederick
Published: February 2020

Practical farmers are now realizing the value of plant tissue assays for trace metals and many laboratories offer services for such analyses by optical emission spectroscopy. The newer technique of atomic absorption could also be used, but not as many elements can be detected because the dynamic range of concentration for some elements is limited and the analyses take longer. A study of these limitations was made in order to improve the applicability of the atomic absorption method; Al, Si, and Mo can now be measured by this method.
A New Direct Colorimetric Method for Determining
Aldehydes in Alcoholic Beverages
Authors: Owades Joseph L , Dono Joseph M
Published: February 2020

A direct, colorimetric method for determining aliphatic aldehydes in alcoholic beverages has been developed. Free acetaldehyde and acetaldehyde bound to bisulfite and to alcohol (acetal) can be determined on separate aliquots. 3-Methyl-2-benzothiazolinone hydrazone hydrochloride reacts with the aldehydes to form a highly colored compound which is measured spectrophotometrically. The average recovery of acetaldehyde added to various wines and distilled liquors was about 98% ; levels of about 30—175 ppm were detected
Efficiency Parameters of Gas Chromatography Columns
Used in Pesticide Residue Analysis
Authors: Bostwick David C , Giuffrida Laura
Published: February 2020

The parameters in the preparation and operation of columns used in the gas chromatography of pesticide residues were studied and effects of varying each were compared. The parameters investigated were column length, diameter, configuration, amount of liquid phase, and solid support mesh size. Experimental conditions have been determined for more efficient columns, as follows: 4—10% liquid phase, 4 mm i.d column, length not less than 6 feet, 100—120 mesh for 6 foot column, 80—100 mesh for 6—12 foot columns
Effects of Chemical Preservatives and Storage on
Constituents Used to Characterize Lemon Juice
Authors: Vandercook Carl E , Guerrero Henry C
Published: February 2020

The effects of sulfur dioxide, sodium benzoate, and potassium sorbate preservatives on the analytical methods for chemically characterizing lemon juice were studied. None of the preservatives had any effects on the analyses for total acidity as citric acid, the l-malic acid, the UV absorbance at the 330 m/x peak (referred to as the total phenolics), or the formol determination of total amino acids (after expelling the S02 by boiling 1 min). The study was continued over storage periods of up to 17 weeks at room temperature and 6 weeks at 30 °C. The constituents measured remained relatively stable except for some small but statistically significant changes that were apparently a function of both the juice and, in the case of the total phenolics, the preservative used. For practical applications, the changes did not affect the multiple regression approach to the chemical characterization of lemon juice
Collaborative Study of "A Versatile Procedure for Assay of
Aflatoxins in Peanut Products," Including Preparatory Separation and Confirmation of Identity
Authors: Eppley R M , Stoloff L , Campbell A D
Published: February 2020

collaborative study of the CB procedure for aflatoxin in peanut products was carried out on naturally contaminated peanut butter and peanut meal and on peanut butter to which known amounts of aflatoxin Bx and Gi were added. Part of the study included preparatory isolation of the aflatoxin Bx fovind in the naturally contaminated samples and confirmation of the identity by both chemical and biological tests. The results from 13 collaborators demonstrate both between- and withinlaboratory precision and accuracy equal to the official, first action procedure; advantages in speed and convenience were noted. The preparatory separation was easily accomplished with clear chemical and biological proof of satisfactory isolation by seven of the nine participants in this phase of the study.
Use of Fish and Whale Insulin as Drugs in Japan
Authors: Nagasawa Kakuma
Published: February 2020

Insulin has been extracted from the Stannius corpuscle or pancreas of marine animals such as whales, tuna, and bonito. These insulins have been purified, characterized, and compared with other insulins for amino acid sequences and for potency.
Analysis of Carbaryl in Formulations
Authors: Broderick E J , Sherman R M , Mack G L
Published: February 2020

Four methods of analysis for carbaryl in mixed formulations were compared. The ultraviolet absorption method is the most sensitive but the least specific becavise of many interferences. The alkaline distillation method is the least sensitive and is subject to interference from several common pesticides. The infrared and near infrared are intermediate in sensitivity and relatively free from interference. The near infrared was the method of choice on the basis of specificity, accuracy, sensitivity, and rapidity.
Separation of Penicillins by Paper and Thin Layer Chromatography
Authors: Hellberg Hans
Published: February 2020

The development of a paper and a thin layer chromatographic method for separating many of the most common penicillins is described. The separation on thin layer plates of the two epimers of phenoxyethyl penicillin (phenethicillin) and phenoxypropyl penicillin (propicillin) as their a-penicilloic esters is also reported.
Fat as a Factor in the Epimerization of Chlortetracycline in Feeds
Authors: Katz Stanley E , Fassbender Carol A
Published: February 2020

Fats were investigated in depth as a contributing factor in the conversion of chlortetracycline to epichlortetracycline in feeds. Fats with a free fatty acid content of 0.4— 100% and iodine values of 0.3—132 from both animal and vegetable sources were studied. An average of 12.5% of the added chlortetracycline potency was converted to epichlortetracycline but neither free fatty acid content nor unsaturation could be shown to be contributory factors to the epimerization reaction. Fats, per se, accelerated the rate of the attainment of equilibrium between chlortetracycline and epichlortetracycline but in themselves did not change the equilibrium point.
Collaborative Study of the Ultraviolet Spectrophotometric Determination of Sulfoxide in Formulations
Authors: Haus Joseph B , Manolev Lazar
Published: February 2020

A spectrophotometric method for the analysis of sulfoxide formulation was studied by six collaborators. The method consists of separating the sulfoxide from other components by column chromatography on silicic acid with three successive eluting solutions: chloroform, 2% acetone in chloroform, and 1 0% acetone in chloroform. Sulfoxide is removed in the last eluate and is determined by UV spectrophotometry. Solvents, emulsifiers, pyrethrins, compounds related to sulfoxide, and other insecticides are separated by the column. Results on standard samples of four formulations showed good agreement between samples and laboratories with the exception of one sample which, because of its complex nature and low sulfoxide content, resulted in poor correlation within and between the laboratories. It is recommended that the method for the assay of sulfoxide formulations be adopted as official, first action.
Determination of Trace Component Distribution in Illicit Spirits by Neutron Activation Analysis (NAA), Atomic Absorption (AA), and Gas-Liquid Chromatography (GLC)
Authors: Hoffman C M , Brunelle R L , Pro M J , Martin G E
Published: February 2020

Trace inorganic constituents of illicit spirits were measured by neutron activation analysis and atomic absorption; organic constituents were determined by gas-liquid chromatography. These identifying components were evaluated statistically, and the data were applied to actual case work. Results also show that the use of multiple techniques increased the probability of matching two or more samples in determinating a common source.
Gas Chromatographic Separation and Quantitative Estimation of Barbiturate Mixtures in Solid Dosage Forms
Authors: Allen John L
Published: February 2020

A gas chromatographic method has been described for the analysis of mixed barbiturates in solid dosage forms. Analysis on a 10% SE-30 column gave good separations for butabarbital, amobarbital, secobarbital, pentobarbital, and/or phenobarbital; amobarbital is not separated adequately from pentobarbital. An internal standard, mephobarbital, is used to minimize injection errors. The method gives both good quantitative and qualitative results on the barbiturates investigated. Two synthetic tablet mixtures were analyzed by this procedure and recoveries were 98—103%. It is recommended that the method be subjected to collaborative study.
Collaborative Study of the Separation and Spectrophotometric Determination of Acetylcarbronial and Bromisovalum
Authors: Look James M
Published: February 2020

The method for Celite column separation and infrared spectrophotometric determination of acetylcarbronial and bromisovalum, reported to the AOAC last year, was studied collaboratively. Nine collaborators made duplicate determinations for each ingredient on a powder from a commercial tablet and a powder prepared by the Associate Referee. Recovery on the authentic powder was 104.7 ± 3.1% for acetylcarbronial and 95.8 ± 2.5% for bromisovalum. The tablet powder assayed 101.1 ± 3 . 1 % of declared acetylcarbronial and 91 ± 3.6% of declared bromisovalum. The Associate Referee recommends that the method be adopted as official, first action
Comparison of Sample Preparation Methods for Phosphorus in Grains and Stock Feeds
Authors: Rash Aaron E
Published: February 2020

The nitric-perchloric acid digestion, 22.070(b) and 22.073, for the determination of phosphorus in grains and stock feeds was compared with three other methods of sample preparation (destruction of organic material) : quinoline molybdate precipitation, perchloric-sulfuric-sodium molybdate digestion, and the plant method. The values obtained by the nitric-perchloric acid method were not in good agreement with those obtained by the other methods studied. Six samples of commercial feeds and one barley sample were analyzed. The barley sample gave very poor recoveries by method 22.073.
Separation of Vitamins D2 and D3 as Isotachysterols D2 and D3 by Gas-Liquid Chromatography
Authors: Sheppard A J , Lacroix Denis E , Prosser A R
Published: February 2020

A method for the quantitative determination of 0.5—20 μg vitamins D2 and D3 by gas-liquid chromatography is described. Vitamins D2 and D3 are completely isomerized to their respective isotachysterol isomers by acetyl chloride as demonstrated by ultraviolet and infrared absorption data. Dihydrotachysterol D2, isotachysterol D2, and isotachysterol D3 are completely resolved with a 3% JXR on 100-120 mesh Gas Chrom Q column packing. Calibration studies show that each compound exhibited a characteristic dose-response plot. Therefore, one isomer cannot be used as a direct internal standard for the quantitative measurement of the other isomer.
Total Nitrogen in Fertilizers
Authors: Rexroad Paul R , Krause Gary F
Published: February 2020

A three-laboratory collaborative study was made of the comprehensive nitrogen method and the new Raney catalyst powder method for total nitrogen in fertilizers. Both methods worked quite well and, with minor modifications, they should provide the basis for a broader collaborative stvidy to provide an official method for total nitrogen in fertilizer applicable to all samples. The limitations of method 2.045 are reviewed and a rephrasing of the official applications of the method is recommended. Further work is recommended toward adoption of a new method and possible deletions or change of status in current official methods.
Sampling Bulk Fertilizers
Authors: Gehrke C W , Baker W L , Krause G F , Russell C H
Published: February 2020

An experimental "D" sampler, which encompasses a core of fertilizer in place, and a powered auger sampler are compared with official compartmented probe and stream samplers on dry mixed fertilizer from three types of blending plants in six states. Standard deviations reflecting variability and precision of the "D" tube indicate performance comparable or superior to the official samplers in both chemical and mechanical analysis. The powered auger compared favorably to the official samplers in chemical analysis, but comparison as to mechanical analysis could not be made because particle size reduction occurred. The official stream sampler failed to secure representative samples from baffle-type mixers when the discharge time was unusually short. Improved indexes of sampling accviracy and precision were secured for all samplers used. It is recommended that sec. 2.001(b), as expanded, be raised to official, final action status.
Extraction Procedures for DDT Residues in Firm Fruits and in Hay: Colorimetric Method
Authors: Wilderman Milton , Shuman Harry
Published: February 2020

The stripping (tumbling) procedure for residue removal is no longer considered adequate for DDT in firm fruits and hay. On the premise that barriers to extraction in fruit tissue do not exceed those in leafy vegetables, the isopropanol:hexane (1 + 2) blending extracting procedure was applied to chopped apple and peach samples with DDT added prior to extraction. Recoveries of 92-97% agreed with previous results by several investigators on vegetable products. Three procedures were compared for effectiveness in the removal of fieldincurred DDT residues from hay: the twostage blending-Soxhlet "exhaustive" procedure of Mumma et al., the 35% water: acetonitrile procedure of Bertuzzi et al., and isopropanol:hexane (1 + 2) extraction following sample hydration. All three procedures gave essentially equal results and the 35% water:acetonitrile procedure is recommended for adoption as official, first action.
Temperature-Dose Relationships with Aflatoxin on the Brine Shrimp, Artemia salina
Authors: Brown R F , Wildman J D , Eppley R M
Published: February 2020

Temperature-dose relationships with aflatoxin B1 were studied, using the brine shrimp, Artemia salina. Increase in temperature resulted in increased sensitivity by the brine shrimp to aflatoxin. Optimum sensitivity occurred at 37.5°C. Positive results were obtained at 0.5 μg aflatoxin B1/ml artificial sea water with a mortality of over 60%. Greater than 90% mortality occurred at dose levels of 1.0 μ/ml and above. The test can be conducted in 24 hours, and highly trained personnel are unnecessary.
Determination of Sulfonamides in Milk
Authors: Houston Stanley F , Umstead John E
Published: February 2020

Sulfonamide residues were determined in milk by first treating the milk with acetone and acetic acid and then purifying and concentrating the sulfonamides on an ion exchange column. This method yields a low control reading, an achievement which has been difficult to obtain by other procedures. This control reading, which shows up as false sulfonamides, can result in erroneous recovery and residue data unless a correction procedure is used. The average recovery is 85%, the sensitivity is 0.1 ppm, and the control milk samples read less than 0.1 ppm
Microcrystalline Identification of Phenothiazine-Type Tranquilizers. I. Development of the Method
Authors: Andres Carolyn X
Published: February 2020

Microcrystalline reactions are described for the identification of twelve related phenothiazine-type compounds with six reagents (1% ammonium reineckate, 5% ammonium thiocyanate, gold chloride, picric acid, platinum bromide, and stannous chloride). The procedure involves the diffusion of a drop of reagent into a drop of a solution of substituted phenothiazine in HC1 ( 1 : 9 9 ) . The resultant crystalline derivatives are described, and photomicrographs are included as an additional identification guide. By the use of these microchemical tests, it is possible to detect and identify microgram quantities of promazine, chlorpromazine, trifiupromazine, mepazine, prochlorperazine, trifluoperazine, methoxypromazine, promethazine, propiomazine, fluphenazine, acetophenazine, and chlorprothixene. The method was successfully applied to ten trade-name drug products. A collaborative study is underway
The Effect of the Route of Administration of Single Doses of
p,Ṕ-DDT on Residues in Adipose and Liver Tissues
Authors: Mccully K A , Mckinley W P , Phillips W E J
Published: February 2020

p,Ṕ-DDT was administered orally, intraperitoneally, and intramuscularly (10 mg/kg body weight) to rats, sheep, chickens, rabbits, and guinea pigs. Animals were killed 5 days after dosing and fat and liver samples removed. All animals except chickens stored a greater concentration of total residues in the fat and livers following intraperitoneal injection than by oral or intramuscular administration. Residues in the fat demonstrated that oral administration of p,Ṕ-DDT resulted in greater conversion of p,Ṕ-DDT to p,Ṕ-DDD than administration by the other routes. Conversion appeared to be greatest in sheep (ruminant) and rabbits (functional cecum). Livers of all treated animals contained p,Ṕ-DDD residues, regardless of the route of administration
Determination of Fluorine in Feeds by the Fluoride Ion Activity Electrode
Authors: Torma Laszlo , Ginther Burton E
Published: February 2020

A specific ion electrode was utilized in the determination of fluorine in feed materials. A National Bureau of Standards rock phosphate standard sample, an AAFCO check feed sample, and commercial feed samples were analyzed by the specific ion electrode method. The results obtained by the developed method were compared with the results of the AOAC fluorine method (24.029—24.035). Comparison shows that the two methods are in very good agreement, but the specific ion electrode method is faster.
Solid State Fluorescence Emission of Aflatoxins on Silica Gel
Authors: Robertson James A , Pons Walter A
Published: February 2020

The solid state fluorescence emission maxima of aflatoxins B1, B2, G1, and G2 on silica gel range from 427 to 455 mµ, with excitation maxima at 368—369 mµ. Both the order and the magnitude of the relative fluorescence intensities of individual aflatoxins are different in solution and in the solid state on silica gel.
Identification and Quantitative Estimation of Aldrin Residues in the Presence of Interfering Materials in Samples of Plant and Animal Origin
Authors: Osadchuck M , Wanless E B
Published: February 2020

Aldrin is converted to dieldrin by epoxidation with m-ehloroperbenzoic acid and, after the removal of epoxidizing agent, the resulting derivative (dieldrin) is measured by GLC. The original amount of aldrin may be calculated from a predetermined per cent yield of dieldrin. Other substances with GLC responses similar to aldrin do not yield derivatives with GLC peaks in the region of dieldrin.
Gas Chromatography of Fusel Oils in Alcoholic Distillates
Authors: Kahn J H , Trent F M , Shipley P A , Vordenberg R A
Published: February 2020

A single gas-liquid chromatographic column is described which will separate all the major fusel oil components rapidly and directly without prior concentration or extraction procedures. Quantitative data obtained using a 1:1 2% 1,2,6-hexanetrio 1:2% glycerol column compare favorably with those of the official AOAC colorimetric fusel oil method. Four additional components may be determined simultaneously and quantitatively.
Collaborative Study of the Kjeldahl Method for Determination of Protein Content of Milk
Authors: Strang D R , Sherbon J W
Published: February 2020

Nitrogen in 12 milk samples was measured in 19 laboratories by the Kjeldahl method. Three of the 19 laboratories were excluded from statistical analysis because the nitrogen values they reported differed markedly from those reported by the remaining 16 laboratories. The average standard deviation for the determinations was 0.012% nitrogen, which is equal to 0.077% protein. Analysis of variance indicated that the error due to the laboratories effect was significant when 16 laboratories were considered. When the laboratories were sorted according to various experience criteria, the variations due to laboratories were significant. When the laboratories were blocked according to catalyst used, the variation among laboratories was not significant.
Thermistor Cryoscopic Determination of the Freezing Point Value of Milk Produced in North America
Authors: Henningson R W
Published: February 2020

A survey of the freezing point value of 660 milk samples, known to contain no added water, taken from dairying areas in 22 States and 4 Canadian Provinces was conducted during late spring of 1968. The data collected were subjected to analysis of variance and simple linear regression statistical procedures and tested for significant relationships and differences at the 5 and 1% levels. The mean freezing point value for all samples was estimated as —0.5404°C with a standard error of 0.0003°C and a standard deviation of —0.00676°C. Thirty-five (5.3%) of 660 samples yielded freezing point values of —0.530°C or higher; twenty-five (3.8%) yielded a freezing point value of —0.551°C or lower. Significant differences were found among mean freezing point values for States and for breeds.
Method for Extraction of Light Filth from Flours by Defatting and a Mineral Oil Flotation
Authors: Thrasher Joel J
Published: February 2020

AOAC methods 36.027 and 36.028 are only suitable for flours of low bran content. With these methods, fdter papers usually contain excessive amounts of plant debris and recoveries are low and varied. A new method has been developed that results in reproducible recoveries and cleaner filter papers. This method is applicable to flours with a wider range and a higher level of bran content.