bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interlaboratory Study of Acid Orange 12 Dye Binding for Measuring Protein in Meat
Authors: Heller Steven N , Sherbon John W 
Published: February 2020

Abstract
Six samples of beef and pork were analyzed by 4 laboratories, using the dye binding method. Dye binding protein was calculated by using a dye binding capacity of meat of 0.410 mg dye bound/g protein. Correlations of 0.976, 0.987, 0.996, and 0.995 were found between dye binding and Kjeldahl protein values. An analysis of covariance showed that the slopes of regression between dye binding and Kjeldahl protein for 3 laboratories were not significantly different at the 5% level. The adjusted means of the regression lines for the same 3 laboratories were significantly different at the 1% level. The results show that 3 of the laboratories were finding the same relationship between dye binding and Kjeldahl protein but were not in calibration with one another.
Fluorometric Determination of Methyl Anthranilate in Concord Grape Juice
Authors: Casimir Donald J , Moyer James C , Mattick Leonard R 
Published: February 2020

Abstract
A method is described for the determination of methyl anthranilate in Concord grape products. A sample of juice, concentrate, pulp, or essence is steam distilled in a micro-Kjeldahl unit and the fluorescence of the distillate collected in pH 7 buffer is measured directly with a fluorometer. The method is rapid and sensitive to 0.1 ppm methyl anthranilate. A correlation coefficient of 0.988 was found between the AOAC colorimetric procedure and the fluorometric method.
Comparison of Analytical Methods for Metribuzin
Authors: Betker William R , Smead C Fred , Evans R Thomas 
Published: February 2020

Abstract
Determinations of the active ingredient in technical and formulated metribuzin were compared by gas-liquid chromatography (GLC) using various solvents, infrared (IR) spectrophotometry, and high-pressure liquid chromatography (HPLC). Ketones could not be used as a solvent for GLC analysis because of Schiff base formation. The GLC method using ethylene glycol monomethyl ether gave results about 1 % higher for technical metribuzin than the other methods. GLC using methylene chloride solvent agreed with IR and HPLC results to within 0.4%. GLC using methylene chloride is the preferred method.
Determination of Vitamin B12 in Dry Feeds by Atomic Absorption Spectrophotometry
Authors: Whitlock Larry L , Melton James R , Billings Toby J 
Published: February 2020

Abstract
Vitamin B12 was determined in dry feeds by atomic absorption spectrophotometry (AAS). Samples containing B12 were extracted with an assay solution, 5 g EDTA was added to the filtrate, the pH was adjusted to 7 with NH4OH, and 5 g charcoal was added. The charcoal was removed by filtering through ashless paper which was then placed in a beaker and ashed at 600°C. After dissolving the cobalt oxide from the ash in 5N HNO3, cobalt content was determined by using AAS. To determine mg B12/lb feed, ppm cobalt in the feed is multiplied by 10.43. The sensitivity of the proposed procedure is 1 mg vitamin B12/lb. The procedure is rapid and precise, and results compare favorably with AOAC method 43.109.
A Screening Method for Protein Characterization and Differentiation
Authors: Pinto Gerson F , Costa-Carvalho Vera L A , Souza Edna R , Araújo Neto Julio S 
Published: February 2020

Abstract
A circular paper chromatographic method was developed for the separation of the amino acids in proteins into 7 subgroups. Butanol-acetic acid-water (4+1+1) was used as the developing solvent. Eluted ninhydrin-stained aminograms gave rise to graphic profiles or numerical indexes based on absorbance percentages. The profiles can be used to compare protein-containing samples. Twenty different samples were studied through 190 comparisons of graphic profiles and coefficients of correlation, with only 4% misleading results. The method showed excellent reproducibility for the identification or differentiation of proteins and has the advantage of being performed with low-priced apparatus and reagents.
Lactic and Succinic Acid Levels and Refractive Indices in the Determination of the Age of Eggs
Authors: Daenens Paul , Laruelle Leander 
Published: February 2020

Abstract
The increase in the concentration of lactic and succinic acids during storage was measured in an attempt to determine the age of eggs. The increase in succinic acid alone is not sufficient to indicate egg age. Although lactic acid concentrations increase more rapidly, the levels are still very low, the increase is not linear, and concentrations in fresh eggs vary widely. On the other hand, refractive indices showed a nearly linear correlation with age and very little variation between eggs. These measurements are reproducible and easy to perform and, with further study, should provide an alternative to the AOAC method.
Analysis of Pesticides by Chemical Derivatization. III. Gas Chromatographic Characteristics and Conditions for the Formation of Pentafluorobenzyl Derivatives of Ten Herbicidal Acids
Authors: Chau Alfred S Y , Terry Ken 
Published: February 2020

Abstract
The reaction conditions to form pentafluorobenzyl derivatives of 10 herbicidal acids, at pesticide residue levels, were studied. The optimum conditions were reaction at room temperature for at least 5 hr (or overnight), using potassium carbonate solution as catalyst. The gas chromatographic characteristics of these derivatives were also studied. Nine of 10 of these derivatives can be separated on an OV-101/OV-210 gas chromatographic column.
Gas-Liquid Chromatographic Analysis and Chemical Confirmation of Azodrin (Monocrotophos) Residues in Strawberries
Authors: Lawrence James F , McLeod Harry A 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method is described for the analysis and confirmation of azodrin (monocrotophos, 3-(dimethoxyphosphinyl)-N-methyl-cis-crotonamide) residues in strawberries. The strawberries are extracted with acetone, and the filtrate is partitioned with a mixture of methylene chloride and petroleum ether followed by further extraction with methylene chloride. The organic phases are combined, dried with anhydrous sodium sulfate, and concentrated to a small volume for GLC analysis on a 3% OV-210 column with flame photometric detection. Identity of the compound is confirmed by chromatography on the same column after trifluoroacetylation of an aliquot of the strawberry extract. The detection limit is about 2 ppb. The types of strawberry samples analyzed were fresh, frozen, pureed, and jam.
Collaborative Study of the Determination of the Amount of Shrimp in Shrimp Cocktail
Authors: King Frederick J , Ryan John J 
Published: February 2020

Abstract
An acceptable method to determine shrimp in shrimp cocktail is needed to determine compliance with proposed labeling regulations. Our method employs a sieve and washing technique to separate shrimp from other ingredients. The percentage of shrimp is calculated from its weight and the declared weight of the total content. For the collaborative study, duplicate samples from 3 different formulations were selected randomly. Eighteen collaborators estimated the amount of shrimp in shrimp cocktail with a standard deviation of 2. A simplified version of the collaborative method has been adopted as official first action.
Clarity Evaluation of Distilled Alcoholic Products with a Particle Counter
Authors: Strunk Duane H , Timmel Bertha M , Andreasen Arthur A 
Published: February 2020

Abstract
An HIAC particle counter is used to measure clarity of distilled alcoholic products. The number of particles is measured in 5 size ranges from 2 to 90 μm. Average data are given for whiskies, brandy, rum, white gin, and vodka. The highest counts are obtained for aged products and most of the particles are 2–5 μm. The particle counts of different brands of blended whiskies varied from 62 to 5265 particles/ml in the 2–90 μm range. There is no apparent relationship between nephelometer values and particle counts.
Gas-Liquid Chromatographic Determination of β-Asarone in Wines and Flavors
Authors: Dyer Randolph H , Martin Glenn E , Buscemi Peter C 
Published: February 2020

Abstract
Wine samples containing β-asarone (cis-2,4,5-trimethoxy-1-propenylbenzene) are distilled; β-asarone is extracted by hexane and then quantitatively determined by gas-liquid chromatography (GLC), using ethyl palmitate as the internal standard. The GLC procedure is rapid and yields precise and accurate results. Mass spectrometery confirmed the identity of the GLC peak as β-asarone. The ultraviolet spectra of β-asarone and its isomer were also determined.
Collaborative Study of a Method for the Analysis of Chlorotoluron and Its Formulations
Authors: Heizler Werner , Meier Juerg , Nowak Klaus , Suter Rolf , Bosshardt Hans P 
Published: February 2020

Abstract
Chlorotoluron technical and its 80% wettable powder were analyzed by 19 participants in a collaborative study. The analytical method used involves acid extraction to remove interfering free amines, followed by alkaline hydrolysis of the extraction residue, distillation, and titration of the liberated dimethylamine. Related by-products which may interfere are determined by semiquantitative thin layer chromatography. Results obtained from 19 government and industrial collaborators showed good repeatability within laboratories. Good agreement was also achieved between laboratories. An overall coefficient of variation of about 0.8% was obtained. In 1974 the analytical method was accepted as a full CIPAC method. In 1975, the method was adopted as an official first action AOAC method.
Collaborative Study of the High-Pressure Liquid Chromatographic Analysis of Picloram-2,4-D Formulations
Authors: Skelly Norman E , Russell Robert J , Porter Deborah F 
Published: February 2020

Abstract
A high-pressure liquid chromatographic method for the analysis of picloram-2,4-D formulations has been studied by 11 collaborators. The method requires no sample preparation other than weighing and dilution. Salicylic acid is used as the internal standard. The compounds are separated on DuPont Zipax SAX (strong anion exchange resin) with 0.01M sodium tetraborate and 0.002M sodium perchlorate as the mobile phase, and measured by ultraviolet spectroscopy at 280 nm. Coefficients of variation for the 6 samples studied ranged from 1.35 to 3.54% for picloram (4-amino-3,5,6-trichloropicolinic acid) and 0.83 to 2.30% for 2,4-D (2,4-dichlorophenoxyacetic acid). Comments from the collaborators were generally favorable. The method has been adopted as official first action for the determination of both picloram and 2,4-D in picloram-2,4-D formulations.
Collaborative Study of the Spectrophotometric Determination of Procainamide Hydrochloride
Authors: Hamm Jeffrey C 
Published: February 2020

Abstract
The USP analysis for procainamide HCl is titrimetric and relatively nonspecific, capsule and tablet dyes may interfere, and the method is not applicable to coated tablets. In the spectrophotofluorometric method the sample deteriorates when exposed to a xenon source. In the ultraviolet spectrophotometric method reported here, the sample is dispersed in acid medium, possible interferences are extracted in chloroform, base is added, procainamide is extracted in chloroform, the residue is dissolved in sodium hydroxide, and the compound is measured by absorption at 272 nm and comparison with a standard. Recoveries of standards added to capsule, tablet, and injection composites ranged from 99.3 to 102%. Twelve collaborators reported duplicate assay results for all 3 dosage forms with per cent standard deviations for 5 samples ranging from 1.01 to 1.27%. The method has been adopted as official first action.
Collaborative Study of the Microanalytical Determination of Phosphorus in Organic Compounds
Authors: Lalancette Roger A , Steyermark Al , Cherapak Norbert C 
Published: February 2020

Abstract
Seven collaborators studied a specific method for the determination of phosphorus, using wet combustion followed by acidimetric titration of the hydronium ions produced by the precipitation of lanthanum phosphate. Statistical evaluation of the data for 29 determinations on triphenylphosphine gave: x̿ = 11.55%, x̿ — theory = −0.26%, s̄ = 0.33, and sm = 0.37. Omitting the results of one collaborator gave, for 21 determinations: x̿ = 11.66%, x̿ — theory = −0.15%, s̄ = 0.18, and sm = 0.30. Evaluation of the data for 33 determinations on diphenylphosphinic acid gave: x̿ = 14.11%, x̿ − theory = −0.09%, s̄ = 0.40, and sm = 0.45. Omitting the results of the same collaborator mentioned above, for 25 determinations, gave: x̿ = 14.28%, x̿ — theory = + 0.08%, s̄ = 0.27, and sm = 0.08. Since the number of collaborators was small, the study will be continued to collect more data.
Spectrophotometric Determination of Diphenylamine in Ext. D&C Yellow No. 1
Authors: Dantzman John G 
Published: February 2020

Abstract
A separatory funnel procedure is presented that separates diphenylamine (DPA) from Ext. D&C Yellow No. 1. The DPA is extracted from the color with isooctane and the amount of DPA is determined spectrophotometrically. Recoveries of 0.02–1 % added DPA ranged from 95.5 to 104%.
Screening and Confirmatory Methods for Determining Lincomycin Residues in Animal Tissues
Authors: Barbiers Arthur R , Neff A William 
Published: February 2020

Abstract
Methods for screening and for confirming residues of lincomycin in animal tissues, both sensitive to 0.1 ppm, are described. In the screening technique, residues are extracted, cleaned up by solvent partition, and detected by microbiological plate assay. In the confirmatory technique, residues are cleaned up on an unfunctionalized macroreticular-type resin column, concentrated, chromatographed on thin layer plates, and detected by bioautography. This system was effective in identifying lincomycin in the presence of 20 other antibiotics and chemicals used in the animal health industry.
Gas-Liquid Chromatographic Determination of C22 Fatty Acids for the Certification of Low Erucic Acid Varieties of Rapeseeds
Authors: Barrette Jean P 
Published: February 2020

Abstract
A rapid gas-liquid chromatographic (GLC) procedure was developed for the determination of C22 fatty acids (mostly erucic acid) in rapeseeds containing less than 5% erucic acid. The method involves an oil extraction from a representative sample of rapeseeds, a vigorous boron trifluoride-methanol transesterification of the oil to methyl esters, and analysis by GLC with the aid of an electronic integrator. Six laboratories participated in a monthly check sample program. By adjusting the GLC detector response with 2 synthetic reference standard mixtures containing 1.0 and 3.0% methyl behenate, interlaboratory agreement within 0.3% C22 was consistently obtained.
Gas-Liquid Chromatographic Determination of 3-Trifluoromethyl-4-nitrophenol in Natural Waters
Authors: Coburn John A , Chau Alfred S Y 
Published: February 2020

Abstract
A procedure for the analysis of 3-trifluoromethyl-4-nitrophenol (TFM) in natural waters is described. The lampricide is extracted from acidified water samples on the macroreticular resin XAD-7 and eluted from the column with ethyl ether. The ether extract is dried, concentrated, and partitioned with potassium carbonate. TFM is acetylated in the aqueous alkaline solution and the acetate derivative is extracted into benzene for analysis by electron capture gas-liquid chromatography. Recoveries of TFM from natural waters exceeded 90% and as little as 0.01 μg TFM can be quantitated in a 1 L sample.
Study of Speaker Identification by Aural and Visual Examination of Non-Contemporary Speech Samples
Authors: Smrkovski Lonnie 
Published: February 2020

Abstract
In this study, 10 pairs of unfamiliar voices were aurally and visually (with spectrograms) compared by 12 examiners to determine whether they belonged to the same speaker. Five decisions could be made: positive identification, positive elimination, probable identification, probable elimination, and unable to make a decision with the samples submitted. Each speaker recorded 9 cue words twice, spoken as a sentence, within a 15 month interval. The pair of speakers in each task was of the same sex. Match and no match constituted 50% each of the total, presented in a random fashion. For each group of examiners there were 40 possible positive correct decisions (20 identifications and 20 eliminations). Group I (professional examiners with &gt;2 years experience) reported 90% correct positive identifications; the remaining 10% corresponded to probable identifications and no decision. Correct positive eliminations were 80%; the remaining 20% corresponded to probable eliminations and no decision. Group II (trainees with &lt;2 years experience) reported 80% correct positive identifications; the remaining 20% corresponded to probable identifications. Correct positive eliminations were 75%; the remaining 25% corresponded to probable eliminations and no decision. No errors were produced by either Group I or II. Group III (novices) reported 40% correct positive identifications; probable identifications and no decision constituted 35%. Correct positive eliminations were 75%; probable eliminations were 20%. The percentages of error for false identifications and false eliminations were 5 and 25, respectively. The collaborative results suggest that professional examiners perform better than trainess and the performance of both groups is far superior to that of novices. Examiners with academic training in speech and hearing sciences and with over 2 years of experience perform better than those lacking academic and/or practical experience. The 15-month interval between the non-contemporary speech samples used in this study did not yield any errors for Groups I and II and no significant difference was found in examiners’ ability to identify or eliminate male or female voices. Group III had more difficulty with female speakers than with male speakers. The results also suggest that trained professional examiners can make very reliable decisions using no more than 9 cue words, regardless of speaker sex, and non-contemporary speech samples up to 15-month intervals. On the basis of this study, the official first action voiceprint method, 45.A01–45.A03, has been adopted as official final action.
Evaluation and Confirmation of an Alkylation-Gas-Liquid Chromatographic Method for the Determination of Carbamate and Urea Herbicides in Foods
Authors: Lawrence James F 
Published: February 2020

Abstract
An alkylation technique using methyl iodide and sodium hydride in dimethyl sulfoxide has been evaluated for 3 carbamate and 7 urea herbicides in 9 foods. Recoveries ranged from 56 to 113%, depending on herbicide, concentration, and food type. Reproducibility was about ±6% at 0.1 and 1.0 ppm. Identities of the herbicides were confirmed at these and lower levels by cleaving the aniline moiety from the alkylated herbicides with sodium methoxide in methanol, followed by gas-liquid chromatography on the same column as the parent compound. An electrolytic conductivity detector in the nitrogen mode was used for all analyses. Minimum detectable levels were in the range of 0.005–0.01 ppm in the foods studied.
Evaluation of Two Microbiological Methods for Detecting Residual Antibiotics in Milk
Authors: Ouderkirk Larry A 
Published: February 2020

Abstract
Two methods described in the AOAC Official Methods of Analysis for the detection of penicillin residues in whole milk were evaluated to determine the capability of each method to detect residues of 12 antibiotics used in the dairy industry. The first method, a cylinder-plate method that uses Sarcina lutea as the test organism, detected levels of 1 ppm of 8 of the 12 antibiotics tested. The second method, using paper disks with Bacillus subtilis as the test organism, detected approximately 1 ppm of only 4 antibiotics. This disk method was unable to detect &lt;40 ppm of 5 of the antibiotics tested. The data indicate that the S. lutea cylinder-plate technique is more sensitive to more antibiotics than the B. subtilis disk method and is far superior for screening purposes.
Colorimetric Reagents for Determining Vitamin A in Feeds and Foods
Authors: Subramanyam Gurram B , Parrish Donald B 
Published: February 2020

Abstract
Selected blue-color developing reagents for determining vitamin A, effects of some carotenoids, tocopherol, and sterols commonly found in vitamin A extracts of feeds and foods, and effects of moisture and light on the colors developed under normal laboratory conditions were studied. Similar blue colors were obtained using SbCl3, CF3COOH, and CCl3COOH in solutions of CHCl3, CH2Cl2, and C2H4Cl2. In general, the reagents in CH2Cl2 solutions produced the most stable blue colors. The CCl3COOH-in-CH2Cl2 reagent developed slightly higher initial color, but CCl3COOH, especially in CHCl3 solution, was the least stable reagent. Small amounts of moisture affected only SbCl3 reagents, by forming cloudy solutions and precipitates. Carotene and monohydroxy and dihydroxy carotenoids reacted with all reagents tested to produce bluish colors, which, however, reached maximum development much later than the vitamin A blue colors. The presence of sterols slightly decreased color production of vitamin A solutions and frequently slightly increased rate of fading, especially for SbCl3 reagents. With proper precautions any of the reagents studied may be used to determine vitamin A. The preferred reagent for general use probably is CF3COOH-in-CH2Cl2, but it is not the most economical.
Identification of Cholesterol as a Possible Interference in the Analysis of Fish Tissue for Industrial Chemical Residues
Authors: Hollifield Henry C 
Published: February 2020

Abstract
The presence of cholesterol in cleaned up fish tissue extracts has been established by gas-liquid chromatography and confirmed by mass spectrometry. It was found both in extracts cleaned up by gel permeation chromatography and in those extracts prepared by the AOAC method for nonfatty foods. It is not normally observed in routine residue analyses because selective gas chromatographic detectors such as electron capture are commonly used.
Bis-Diazotized Benzidine as a Spray Reagent for Detecting Zearalenone on Thin Layer Chromatoplates
Authors: Malaiyandi Murugan , Barrette Jean P , Wavrock Paul L 
Published: February 2020

Abstract
Bis-diazotized benzidine is a highly sensitive spray reagent for detecting zearalenone (F-2) in corn samples. As little as 2.0 ng of this Fusarium toxin could be visualized on a thin layer plate after development. In addition, this spray reagent is more specific than the spray reagents currently used for zearalenone.
New Method for the Determination of Free Amino Groups in Intact Pure Proteins: Relationship to Available Lysine
Authors: Purcell James M , Quimby Daniel J , Cavanaugh James R 
Published: February 2020

Abstract
A new rapid method for the quantitative and routine determination of free amino groups in intact pure proteins has been developed. Primary amino groups are labeled with fluorescamine and the labeled groups are detected by absorption spectroscopy in the range 375–390 nm. The amino group concentration can be determined in a few minutes without hydrolyzing the labeled protein and extracting a lysine derivative. The method was tested with the following proteins: lysozyme, α-lactalbumin, β-lactoglobulin, bovine serum albumin, ribonuclease, ribonuclease-S-peptide, and αsl-rasciii B. Application of this method to the estimation of available lysine is discussed.
Thin Layer Chromatographic Estimation of Available Lysine in Dried Milk Powder
Authors: Datta Shompa , Datta Salil C 
Published: February 2020

Abstract
A rapid method for the estimation of available lysine in dried milk powder has been developed. Samples were treated with 2,4,6-trinitrobenzene sulfonic acid and then hydrolyzed with 6N HCl. The hydrolysate was purified and subjected to ascending thin layer chromatography to isolate ε-trinitrophenyl lysine in pure form. The color was read at 346 nm in a spectrophotometer.