bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas-Liquid Chromatographic Determination of N-Nitrosodimethylamine in Ham
Authors: Fiddler Walter , Doerr Robert C , Ertel John R , Wasserman Aaron E 
Published: February 2020

Abstract
A method is described for the gas chromatographic determination of N-nitrosodimethylamine in ham. The use of a commercial rubidium sulfate alkali flame ionization detector for nitrogen-containing compounds permits a simple cleanup procedure and a rapid analysis. This method consists of digesting the ham sample with methanolic KOH, distillation from aqueous alkali, washing the distillate with hexane, acidification and extraction of the aqueous layer with methylene chloride, and washing the extracts with base prior to concentration. The sensitivity of the method is 25 ppb; the average recoveries at this level range from 73 to 100%. Ten hams including 4 varieties were analyzed and found to contain less than 1 ppb apparent N-nitrosodimethylamine.
Identification of Amphetamines and Related Sympathomimetic Amines
Authors: Warren R J , Begosh P P , Zarembo J E 
Published: February 2020

Abstract
The IR, UV, and NMR spectral data as well as the pKa′ values of a series of 18 phenylpropyl amines are presented and discussed. The series includes the amphetamines and many of the commercially available phenylpropyl amines being used in the field of medicine as sympathomimetic agents. These data provide a basis for rapid identification of samples from biological, forensic, and medical research.
Identification and Determination of Sugars in Some Fruit Juices
Authors: Stepak Y , Lifshitz A 
Published: February 2020

Abstract
The sugars α-glucose, β-glucose, fructose, galactose, and sucrose were identified in the juice of Israel orange, grapefruit, and lemon by gas-liquid chromatographic methods. Rhamnose, xylose, and trehalose were also identified but only tentatively. The amounts of glucose and fructose before and after hydrolysis were measured in 88 samples of citrus juice by enzymatic methods. The concentration of glucose found was in all cases very near that of fructose. In other fruit juices (e.g., pear) the concentration of fructose was found to be higher than that of glucose. The ratio fructose:glucose cannot therefore be used as a criterion for purity in orange and grapefruit juices but may serve as a useful tool to detect addition of sucrose to other fruit juices.
Determination of Fill of Beer Containers
Authors: Schoeneman Robert L , Dyer Randolph H , Earl Elaine M , Greenfield Michael S 
Published: February 2020

Abstract
Since the tax on beer is based on volume, the Internal Revenue Service suggests that beer containers be filled as nearly as possible to the quantity shown on the label, with substantially as much underfill as overfill in each lot. However, the philosophy of weights and measures officials in protecting the consumer is that the beer container should always contain at least as much as the quantity shown on the label, with very little tolerance for underfills. These different attitudes illustrate the need for establishing reasonable and equitable fill tolerances. This paper compares and evaluates 2 methods (volumetric and gravimetric) for the determination of the fill of beer containers. These 2 methods were shown to give comparable results. Samples from 4 large and 4 small breweries were examined. The densities of the different samples and the contents in fluid ounces are tabulated. The effect of beer retention inside the container in the volumetric determination and the variations in container tare weights in the gravimetric method are examined. The effects of carbon dioxide on both methods are also discussed.
Colorimetric Method for Ester Content of Alcoholic Beverages
Authors: Coe G R , Baldwin S , Andreasen A A 
Published: February 2020

Abstract
A colorimetric method for determination of esters in alcoholic products was studied for the effect of procedural variables. It is based on the quantitative reaction of esters with hydroxylamine in alkaline solution to form a hydroxamic acid which, upon acidification, forms a colored complex in the presence of Fe(III) ions. Mathematical data are presented to demonstrate that the colorimetric method is superior to the AOAC saponification method, 9.051-9.052, for comparing samples which contain widely differing ester compositions. The colorimetric method is rapid and requires a small sample.
Gas Chromatographic Analysis of Kelthane Technical
Authors: Black R F , Kurtz C P , Baum H 
Published: February 2020

Abstract
A new gas chromatographic method for the analysis of Kelthane and minor impurities is under investigation. The separation is made on a 6′ glass column packed with 3% Oronite Polybutene 128 on Gas-Chrom Q, using temperature programming from 135 to 205°C. Retention time data for all known components in Kelthane Technical are reported. Work on a quantitative procedure for the determination of active ingredients and minor impurities, utilizing an internal standard (methyl myristate), is in progress.
Simultaneous Gas-Liquid Chromatographic Determination of Four Sulfonamides in Feeds
Authors: Daun Robert J 
Published: February 2020

Abstract
A procedure is described for the gas-liquid chromatographic determination of sulfathiazole, sulfamerazine, sulfamethazine, and sulfaquinoxaline in finished feeds at levels from 0.002 to 0.05%. The procedure utilizes a double derivatization technique to modify the sulfonamides so that they can be determined by gas-liquid chromatography with electron capture detection. The conditions for extraction, derivatization, and gas-liquid chromatography are given, along with recovery data.
Comparison of Two Infrared Methods for the Determination of Isolated Trans Unsaturation in Fats, Oils, and Methyl Ester Derivatives
Authors: Huang Anita , Firestone David 
Published: February 2020

Abstract
A study was made to compare the rapid method reported by Allen with the tentative method of the American Oil Chemists’ Society for the determination of isolated (unconjugated) trans isomers of unsaturated fatty acids. The rapid method was found to be less accurate. The accuracy of the rapid method can be improved by using an oil or methyl ester matrix with the same composition as the sample matrix for the determination of K-and f-values used for calculation of per cent trans isomers. Results obtained with both methods for methyl esters were more accurate than results for vegetable oils. An analysis of variance was performed to compare the methods.
Distribution of Chick Edema Factors in Chick Tissues
Authors: Firestone David , Flick D F , Ress J , Higginbotham G R 
Published: February 2020

Abstract
A study was made of hexa-, hepta-, and octachlorodibenzo-p-dioxin (higher chlorodioxins) absorption and tissue distribution in White Leghorn chicks fed a diet containing 3% toxic fat or the equivalent amount of the unsaponifiable fraction isolated from the toxic fat. Over 90% of the ingested higher chlorodioxins was excreted. Increasing chlorine content resulted in decreased absorption so that no octachlorodioxin could be detected in the tissues. Chlorodioxins were widely distributed in a number of tissues and it was estimated that 49% of the chlorodioxins detected in various tissues was present in the liver of the chicks fed the toxic unsaponifiable fraction.
Chromatography of Crude Aflatoxins on Adsorbosil-5
Authors: Chu Fun Sun 
Published: February 2020

Abstract
A method is described involving the use of Adsorbosil-5 silica gel as a stationary phase for aflatoxin purification. This method is especially advantageous for obtaining large quantities of aflatoxins B1 and G1 in a single chromatographic step. The distribution of individual aflatoxins in the different fractions obtained from chromatography on an Adsorbosil column is illustrated.
Improved Detection of Ochratoxin A on Thin Layer Plates
Authors: Trenk Hugh L , Chu Fun Sun 
Published: February 2020

Abstract
The fluorescent spectra of ochratoxins A, B, and C, one of the hydrolysis products of ochratoxin A, i.e., 5-chloro-3,4-dihydro-8-hydroxy-3-methylisocoumarin-7-carboxylic acid, and their respective ammoniated derivatives have been studied. The excitation maxima of these compounds shifted to a longer wavelength after exposure to ammonia fumes, whereas the emission maxima shifted to a shorter wavelength. The fluorescence intensity of ammoniated ochratoxin A was found to be almost twice that of ochratoxin A. It is suggested that TLC plates be exposed to ammonia fumes prior to densitometric analysis to increase the sensitivity of the assay for ochratoxin A.
Negative Ion Mass Spectra of Some Pesticidal Compounds
Authors: Rankin Peter C 
Published: February 2020

Abstract
A study of the negative ion mass spectra of a number of complex organic molecules (pesticides) was undertaken to determine what information this technique would yield for structural analysis. The simplicity of the negative ion mass spectra was a characteristic feature and the most abundant negative ions in the spectra were assumed to be similar to the stable carbanions postulated in classical organic chemistry. The simplicity of the mass spectra suggested a possible application of the technique to the identification of carbamate pesticides.
Determination of Residues of Carbofuran and Its Toxic Metabolites by Electron Capture Gas Chromatography after Derivative Formation
Authors: Butler Lillian I , Mcdonough Leslie M 
Published: February 2020

Abstract
Residues of carbofuran and its toxic metabolites (3-hydroxycarbofuran and 3-ketocarbofuran) were determined in cucumbers, lettuce, potatoes, tomatoes, tomato foliage, and soil. Samples were extracted with 0.25N HCl, partitioned into dichloromethane, and chromatographed on alumina. Liquid chromatography serves the dual purpose of cleaning up the sample and separating the phenols from the earbamates. The carbamate residues were then converted to trichloroacetates and determined by electron capture GLC. Recoveries ranged from 67.2 to 139.5% with most recoveries being 80-100%.
Air Sampling for Pesticides in the Human Environment
Authors: Tessari John D , Spencer David L 
Published: February 2020

Abstract
A simple and inexpensive method is described for the analysis of pesticides in air samples. The method involves quantitative extraction from a nylon chiffon cloth screen which has been exposed to the atmosphere for 5 days, followed by cleanup with aluminum oxide and Florisil column chromatography. Recovery studies were run on a cloth screen and results for the organochlorine pesticides ranged from 86 to 100% recovery. Evidence seems to indicate that an environment containing high residue levels has a direct relationship to pesticide body burden.
Mechanized Extraction and Cleanup of Atrazine Residues in Soil Prior to Gas Chromatographic Analysis
Authors: Ott D E , Formica G , Liebig G F , Eberle D O , Gunther F A 
Published: February 2020

Abstract
Complete mechanization of extraction and cleanup steps has been developed for atrazine residues in soils for analysis by nitrogen detector gas chromatography. Manually sieved and weighed soil samples are mechanically presented at a maximum rate of 6 per hour to this system, which delivers cleaned-up solvent extracts of the samples at the same rate to a fraction collector. Adjustment of final solvent volume in collection vessels and gas chromatography are performed manually in the present work. Atrazine residues in soils are thus rapidly determined down to a lower limit of 0.05 ppm.
Determination of Total Solids in Heterogeneous Heat-Sensitive Foods
Authors: Emmons D B , Larmond Elizabeth , Beckett D C 
Published: February 2020

Abstract
A study was conducted to determine the cause of poor precision in the determination of total solids in heterogeneous heat-sensitive foods. A larger, more representative sample and preliminary freeze-drying rather than air-drying of samples gave greater precision than a modified AOAC method. The standard deviation for creamed cottage cheese was ±0.060 for the modified AOAC method and ±0.016 for the method tested. Decreases in standard deviations were also obtained for fluid milk, uncreamed cottage cheese, and goose meat.
Screening Method for Aflatoxin in Corn and Various Corn Products
Authors: Dantzman John , Stoloff Leonard 
Published: February 2020

Abstract
An abbreviated AOAC method has been developed for detecting aflatoxin in corn. The residual oil from a water-chloroform extraction of the sample is used for spotting the thin layer chromatogram. The silica gel cleanup column is omitted, thereby realizing a substantial saving in time and materials. Sensitivity of the method is less than 5 μg aflatoxin Bi per kg corn sample. The method is applicable to shelled corn, corn meal, canned sweet corn, and corn breakfast cereal.
Collaborative Study of the Gas-Liquid Chromatographic Method for Determination of Stereochemical Composition of Amphetamine
Authors: Wells Clyde E 
Published: February 2020

Abstract
Eight laboratories collaboratively studied a method for the quantitative GLC determination of d- and l-amphetamine in tablets. The drugs are separated from tablet excipients by column chromatography and reacted with Ntrifluoroacetyl-( 0-prolyl chloride, and the resulting derivatives are analyzed by GLC. The samples consisted of commercial d-amphetamine sulfate tablets (with and without butabarbital), dl-amphetamine sulfate tablets, and a mixed d- and l-amphetamine sulfate standard. Recoveries were acceptable, and the standard deviations never exceeded 0.64%. The results demonstrate that the method gives good precision and accuracy, and the method is recommended for adoption as official first action.
Determination of Bismuth in Pharmaceutical Dosage Forms by Conventional DC Polarography
Authors: Plank William M 
Published: February 2020

Abstract
A method has been investigated for the determination of bismuth in pharmaceutical dosage forms by conventional dc polarography. The method is applicable to tablets, emulsions, suspensions, injectables, and bulk powders. A collaborative study has shown the method to be superior in accuracy and precision to the present official colorimetric method, 36.300- 36.304. The results from 16 determinations performed by 8 collaborators were: 100.0±1.5% recovery on a synthetic powder mix, a relative standard deviation of 1.9% on a commercial tablet sample, and a relative standard deviation of 2.1% on a magma sample. By comparison, the collaborative data reported for the present official method gave relative standard deviations of 3.4 and 3.2% on 2 samples of powder mixtures. It is recommended that the polarographic method be adopted as official first action.
Collaborative Study of the Determination of Dichlorophene in Veterinary Preparations by Ultraviolet Spectrophotometry
Authors: Gilvydis Dalia M 
Published: February 2020

Abstract
Dichlorophene is determined in veterinary preparations by a liquid-liquid extraction and UV quantitation. Eight collaborators each analyzed 4 commercial preparations and one synthetic mixture. The average recovery for dichlorophene in the synthetic mixture is 100.3% with a standard deviation of 2.13. The standard deviations obtained for the 5 samples range from 0.13 to 3.69 with coefficients of variation from 0.69 to 3.43. It is recommended that the method be adopted as official first action.
Assay of Strychnine in Nux Vomica Galenicals and in Formulations
Authors: Karawya M S , Ghourab M G 
Published: February 2020

Abstract
A colorimetric method is described for the estimation of strychnine in the presence of brucine. Strychnine is reduced with zinc amalgam and hydrochloric acid, and the color obtained by the action of nitroprussideacetaldehyde reagent on the reduced compound is measured. Brucine does not give this color reaction. The method was successfully used for the assay of strychnine in galenicals of nux vomica, as well as in various formulations.
Collaborative Study of a Colorimetric Determination of Nitroglycerin in Sublingual Tablets
Authors: Pfabe Yvonne H 
Published: February 2020

Abstract
The colorimetric determination of nitroglycerin in tablets (JAOAC 53, 579–581 (1970)) was collaboratively studied by 13 laboratories. The nitroglycerin is hydrolyzed to nitrite, which diazotizes p-chloroaniline; this diazotization product is coupled with N-(l-naphthyl)- ethylenediamine dihydrochloride and measured at 560 nm. Samples were analyzed at a composite level (1.2 mg) and at an individual tablet level (0.15–0.6 mg). Coefficients of variation ranged from 4 to 14%, with the highest variation in the individual assay of low dosage tablets. Samples analyzed by the Associate Referee 6 months after the first analysis showed lower assay results, indicating deterioration. It is recommended that this study be continued.
Analysis of Trisulfapyrimidine Preparations by Thin Layer Chromatography
Authors: Brunner Charlotte A 
Published: February 2020

Abstract
A method for the analysis of trisulfapyrimidine preparations is described. The total sulfonamide content is measured on the intact sample, and the ratio of the components is determined by colorimetric measurement of the individual compounds after separation by thin layer chromatography. A collaborative study will be performed.
Malonate Dulcitol Lysine Iron Agar—A New Differential Medium for the Identification of Salmonella Subgenera I—III
Authors: Stroup John R 
Published: February 2020

Abstract
A new differential medium, malonate dulcitol lysine iron agar, containing malonate, dulcitol, L-lysine, and an H2S indicating system has been developed for use at the triple sugar iron agar stage for the identification of Salmonella subgenera I–III. This medium differentiates the subgenera on the basis of the malonate and dulcitol reactions. L-Lysine is incorporated to confirm lysine decarboxylase activity for dulcitol-positive subgenus I cultures. Since it is a near minimal medium, it i? advantageous to inoculate triple sugar iron agar or lysine iron agar slants in parallel with the new medium to act as a source of cells for “O” group serology and to avoid missing aberrant biochemical types. Although a few atypical reactions were noted, all of the 35 typical Salmonella of subgenera I–III tested were typical on malonate dulcitol lysine iron agar medium. Triple sugar iron agar can be considered as giving a presumptive test for Salmonella. However, as it does not differentiate the subgenera, this distinction must be made when the results of in-depth biochemical tests are known. As the subgenera can be differentiated on the basis of malonate and dulcitol reactions, the new medium should allow for the presumptive identification of Salmonella subgenera at least 24 hr earlier than is now possible with conventional procedures.
Gas-Liquid Chromatographic Characterization of Sunscreens in Suntan Preparations
Authors: Paulus Geordie L 
Published: February 2020

Abstract
The spectrophotometric determination of isolated sunscreen compounds is often not specific enough to distinguish between closely related compounds. For this reason a procedure was developed for the identification of sunscreen compounds by gas-liquid chromatographic retention times. Partition chromatography is used to isolate the sunscreen from the cosmetic sample. Retention time data are listed for 16 sunscreens.
Rapid Spectrophotometry Method for the Determination of Sorbic Acid in Fresh Dairy Products
Authors: Maxstadt J J , Karasz A B 
Published: February 2020

Abstract
A rapid and accurate spectrophotometry method for sorbic acid in fresh dairy products has been developed. Sorbic acid is extracted from the dairy product with aqueous metaphosphoric acid and partitioned into an ethyl ether-petroleum ether mixture. The concentration of sorbic acid is determined from its absorbance at 250 nm and its presence is confirmed by the disappearance of this absorbance maximum after shaking the ether solution with aqueous permanganate. The procedure is very rapid; an analysis can be completed in 1 hr. Recoveries of added sorbic acid from various dairy products average 97.9%.
Collaborative Study of a Method for the Extraction of Light Filth from Dehydrated Potato Products
Authors: Gecan John S 
Published: February 2020

Abstract
In the method proposed for the extraction of light filth from dehydrated potato products, the sample is hydrolyzed with HC1, wet sieved, deaerated, and extracted with Ught mineral oil from hot 40% isopropanol. Collaborative studies resulted in good recoveries of light filth spike elements and easy-to-examine extraction papers. It is recommended that the method be adopted as official first action.
An Improved Urease-Bromothymol Blue Agar Medium for Detection of Wheat Grains Contaminated with Urine
Authors: Thrasher Joel J 
Published: February 2020

Abstract
Recommendations are made to delete sections 40.131–40.132, the urease-bromothymol blue paper test, and t o revise method 40.A09–40.A10 to reflect improvements in manipulations and reagent stability. The warm 1% agar is replaced by a 0.25% agar with a mold inhibitor and is useful up to 4 months.
International Aflatoxin Check Sample Program: 1971 Study
Authors: Coon F B , Baur F J , Symmes L R L 
Published: February 2020

Abstract
An International Aflatoxin Check Sample Committee was formed in 1971 to establish a check sample program of commodities or materials with aflatoxin contamination, which would be available to laboratories throughout the world. A set of 4 aflatoxin-contaminated peanut samples was prepared and mailed to 150 participating laboratories. Sufficient data were obtained from this study to permit a statistical comparison of 3 of the 4 AOAC methods for analysis of peanuts and peanut commodities. The analysis showed significantly higher means for the CB method tbun for the BF or Pons method for 2 of the samples examined.
Conversion of DDT and Its Metabolites to Dichlorobenzophenones for Analysis in the Presence of Polychlorinated Biphenyls
Authors: W Miles J R 
Published: February 2020

Abstract
The separation of DDT compounds from interfering polychlorinated biphenyls (PCB) has been effected by oxidation of DDE and DDMU (l-chloro-2,2-bis(p-chlorophenyl)ethylene) to the more polar dichlorobenzophenone. DDT and DDD (o,p’ - and p,p’-) are dehydrochlorinated by a convenient technique, utilizing l,5-diazobicyclo[5.4.0]undec-5-ene, and the resulting olefins are oxidized by chromic acid in acetic acid. In subsequent Florisil fractionation, the interfering PCB compounds, relatively unchanged by the dehydrochlorination and oxidation, are eluted in the hexane fraction, while the dichlorobenzophenones are eluted by benzene. Recoveries of p,p’-DDE and p,p’-DDT added to fish extracts at 5 ppm each were 82.5±2.1 and 86.0±2.2%, respectively.
Quantitative Dehydrochlorination of Perthane Residues and Effect of Alcoholic Potassium Hydroxide on Other Pesticides
Authors: Krause Richard T 
Published: February 2020

Abstract
An alkaline dehydrochlorination procedure is described for the quantitative analysis of Perthane residues in food products by electron capture gas chromatography. Perthane, as the olefin, is detected at a level as low as 0.02 ppm in vegetables and fruits and 0.2 ppm in fatty food products. Perthane is quantitatively recovered from fresh spinach, fresh pears, and butterfat by the appropriate official AOAC multiple residue method. The average recoveries obtained for these products are 102, 104, and 98%, respectively. Retention data are given for 46 pesticides before and after alkaline treatment for the 10% DC-200, 10% DC-200/15% QF-1, and 3% DECS columns. Only toxaphene and Strobane cannot be separated from Perthane before dehydrochlorination. After the alkaline treatment, only chlordane, toxaphene, and Strobane cannot be separated from the Perthane olefin.