bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collaborative Study of Ion Selective Electrode Method for the Direct Determination of Fluoride in Feeds
Authors: Torma Laszlo 
Published: February 2020

Abstract
A rapid and precise method for the determination of fluoride in feeds employs HC1 extraction of the sample. Acetate buffer and sodium citrate are added to control pH and ionic strength. The amount of fluoride is calculated from a standard curve after measuring the potentials of standard and sample solutions. Eight collaborators participated in the study of the method. Statistical values on 3 pairs of samples were calculated. The standard deviation, precision, coefficient of variation, and bias, respectively, were: Pair 1, 0.005071, 0.001763, 3.09, 0.0034; Pair 2, 0.037122, 0.006475, 1.82, 0.0258; Pair 3, 0.034587, 0.013021, 2.63, 0.0227. The results from the proposed method agreed favorably with the values obtained by using the official final action AOAC method, 7.089. The average and standard deviation, respectively, for individual samples by the proposed method were: Sample 3, 0.049, 0.0029; Sample 4, 0.059, 0.0021; Sample 5, 0.334, 0.0114; Sample 6, 0.341, 0.0101; Sample 7, 0.511, 0.0219; Sample 8, 0.492, 0.0237. By the official method the values were: Sample 3, 0.049, 0.0041; Sample 4, 0.058, 0.0029; Sample 5, 0.334, 0.0055; Sample 6, 0.331, 0.0082; Sample 7, 0.517, 0.0183; Sample 8, 0.499, 0.0175. The ion selective electrode method has been adopted as official first action.
Screening Method for the Detection of Aflatoxins in Mixed Feeds and Other Agricultural Commodities with Subsequent Confirmation and Quantitative Measurement of Aflatoxins in Positive Samples
Authors: Romer Thomas R 
Published: February 2020

Abstract
The method described will detect total aflatoxins (B1, B2, G1, and G2) in mixed feeds, grains, nuts, and fruit products in samples containing as little as 5–15 μg/kg. In addition, the presence of aflatoxins in the positive samples can be confirmed and the toxins can be quantitatively measured, using the same extract as that used for the screening method. In the screening method, aflatoxins are extracted with acetone-water (85+15), and interferences are removed by adding cupric carbonate and ferric chloride gel. The aflatoxins are extracted from the aqueous phase with chloroform and the chloroform extract is washed with a basic aqueous solution. A Velasco-type minicolumn is used to further purify the extract and capture the aflatoxins in a tight band. The screening method has been successfully applied to 24 different agricultural commodities. Quantitative thin layer chromatography was also performed with extracts of each of these commodities. An average recovery of 94% B1, 108% B2, 130% Gl, and 103% G2 was obtained compared to the official final action AOAC method for cottonseed products, 26.048–26.056. Within-laboratory coefficients of variation of 10–15% were obtained for each of the aflatoxins and total aflatoxins in a sample of peanut meal naturally contaminated with 11 μg B1 + 3 μg B2 + 11 μg G1+ 5 μg G2/kg.
Collaborative Study of a Gas-Liquid Chromatographic Method for the Analysis of Propazine
Authors: Hofberg Arthur H , Heinrichs Lee C , Gentry Gene A 
Published: February 2020

Abstract
A gas-liquid chromatographic method for the determination of propazine in wettable powder formulations containing about 80% active ingredient was collaboratively studied, using a matched pair scheme. The propazine was extracted from the powder with chloroform, with dieldrin as an internal standard, and chromatographed on Carbowax 20M, using a flame ionization detector. Two samples were analyzed using peak height measurements with the following results (13 collaborators): 1.2% overall coefficient of variation and 1.2% coefficient of variation for the random error. Statistical evaluation of these factors reveals no evidence of systematic error contribution. The method has been adopted as official first action.
Collaborative Study of the 2,4-Dinitrophenyl Ether Multiresidue Method for Use in Determining Four Carbamate Pesticides in Crops
Authors: Holden Edward R 
Published: February 2020

Abstract
Eight laboratories tested the 2,4-dinitrophenyl ether method for determining carbamate pesticide residues by gas-liquid chromatography. Propoxur, carbofuran, carbanolate, and carbaryl in apples, corn, green beans, and a leafy vegetable (kale, collards, cabbage, or turnip greens) were determined at the fortification levels of 0.1, 0.2, and 0.5 ppm. Average recoveries of propoxur were 87–95% ; carbofuran, 87–100% ; carbanolate, 89–102% ; and carbaryl, 77–92%. No serious background problems were encountered, other than that from field-incurred carbaryl residues in apples. The study revealed the need for certain precautions in determining carbaryl because of its instability in analytical operations. The method has been adopted as official first action.
Mycotoxin Bioassay, Using Bacillus stearothermophilus
Authors: Reiss Jürgen 
Published: February 2020

Abstract
Spores of Bacillus stearothermophilus in standardized spore strips are pretreated with solutions of the mycotoxins aflatoxin Bl, patulin, rubratoxin B, and diacetoxyscirpenol and subsequently incubated in a nutrient solution containing bromocresol purple as pH indicator. After 16.5 hr of incubation the color of the indicator medium inoculated with untreated spore strips of B. stearothermophilus changes from purple to yellow; no color change occurs in the indicator medium inoculated with spore strips treated 15 min with 0.01 μg of any of the 4 mycotoxins/ml during a 60 hr incubation.
Collaborative Study of the Pro-Milk Method for the Determination of Protein in Milk
Authors: Sherbon John W 
Published: February 2020

Abstract
Seven milk samples and 2 standard dye solutions were analyzed for protein content by the Pro-Milk method by 6 collaborating laboratories. Interlaboratory variations, although small, were significant, probably because of extremely good precision. Blind duplicates (2 sets) did not differ from each other. Tests of dilute dye solutions, involving only the colorimeters, showed interlaboratory variation, which indicates the need to carefully calibrate each instrument. The magnitudes of the variations encountered in the milk and dye solution studies were sufficiently small to allow adoption of the Pro-milk method as official first action.
Determination of Heavy Metals in Foods by Anodic Stripping Voltammetry after Sample Decomposition with Sodium and Potassium Nitrate Fusion
Authors: Holak Walter 
Published: February 2020

Abstract
A method is described for the simultaneous determination of several heavy metals in foods. The sample is predigested with nitric acid and decomposed completely by heating with a mixture of sodium and potassium nitrates. The resultant melt containing the metals is then dissolved in dilute nitric acid. After the pH is adjusted to an appropriate value, the metals, such as cadmium, copper, lead, and zinc, are determined by anodic stripping voltammetry. The average recoveries of these metals added to 5 commodities were 98, 98, 96, and 104%, respectively. The relative standard deviations, based on data from analyses of a commodity containing measurable levels of copper, lead, and zinc, were 12.0, 13.0, and 9.7%, respectively.
Residues in Broiler Chick Tissues from Low Level Feedings of Seven Chlorinated Hydrocarbon Insecticides
Authors: Onley John H , Giuffrida Laura , Watts Randall R , Ives N Fred , Storherr Robert W 
Published: February 2020

Abstract
Two chlorinated insecticide feeding studies from 1967–1968, using broiler chicks, have been completed. In Study I, lindane, heptachlor epoxide, dieldrin, endrin, methoxychlor, and DDT were fed in combination at 3 levels: 0.05, 0.15, and 0.45 ppm. Data show that, in fat tissues, heptachlor epoxide attained a level approximately 20 times the respective levels in the feed; dieldrin 15 times; endrin 10 times; p,p’-DDT 9 times; lindane 3 times; and o,p’- DDT less than the feeding levels. Of the DDT metabolites, p,p’-DDE and p,p’-DDD, only p,p’- DDE was significant at 3 times the 0.45 ppm feeding level. Endrin ketone, a metabolite of endrin, reached plateau levels approximately equal to feeding levels. All residue levels in liver tissues were &lt;0.02 ppm. In Study II, technical chlordane was fed singly at the 0.05, 0.15, and 0.45 ppm levels. Results are tabulated for both total chlordane and for 6 identifiable isomers. Total chlordane in fat tissues attained plateau levels 3–5 times the respective feeding levels. Total chlordane levels in liver and breast tissues were all &lt;0.01 ppm.
Total Protein Nitrogen: Evaluation and Comparison of Four Different Methods
Authors: Wall Larry L , Gehrke Charles W , Neuner Terry E , Cathey Robert D , Rexroad Paul R 
Published: February 2020

Abstract
This laboratory has evaluated 2 automated nitrogen methods, the Kjel-Foss and the Missouri-Technicon with block digestor. A modified Kjeldahl method using a low level (40 mg) of CuS04 as a catalyst was also studied. These 3 methods were compared with the official AOAC Kjeldahl method. The experimental set numbered 22 samples, consisting of amino acids, ammonium salts, meals, grains, forages, and American Association of Feed Control Officials check feed samples. This set was analyzed in duplicate 3 independent times by each method. The accuracy and precision values for the 4 methods were excellent, within a very close range, and were equal or superior to the AOAC method. All 4 methods gave average relative standard deviations of &lt;1 %. The 4 methods were compared for rapidity and timeliness of analysis, applicability, cost per sample, and labor and physical requirements to provide those who are responsible for protein nitrogen analysis with a basis for choosing a nitrogen method that would be most suitable for their needs.
Determination of Ancymidol in Formulations and Technical Material
Authors: Frank Richard , Wilson Joe T 
Published: February 2020

Abstract
A method for the determination of the plant growth regulator ancymidol (α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol) in formulations and technical grade material is presented. Technical grade material or the 4.5% emulsifiable concentrate formulation is dissolved in chloroform and the ancymidol is measured, using a gas-liquid chromatograph equipped with a flame ionization detector. The 0.026% aqueous concentrate formulation is extracted with ethyl acetate and purified by Florisil column chromatography; the ancymidol is measured with a gas chromatograph. The recovery of ancymidol from a Florisil column averaged 100.1%.
Gas Chromatographic Analysis of the Carbon Dioxide Content in Aluminum Hydroxide Gels
Authors: Wilkinson Donald R , Pavlikowski Fred 
Published: February 2020

Abstract
Samples of aluminum hydroxide were mixed with carbon dioxide-free water and agitated until a homogenous mixture resulted. A 400 μl sample was injected into a gas chromatograph equipped with a thermal conductivity detector and a ¼″ copper column packed with Chromosorb 102. The carbon dioxide contained in the aluminum hydroxide gel was separated from oxygen and nitrogen and then measured. The method is suitable for the analysis of gels containing 0.5–10.0% carbon dioxide.
High-Speed Liquid Chromatographic Determination of Biphenyl Residues in Citrus Products
Authors: Reeder Samuel K 
Published: February 2020

Abstract
A simple, direct, and rapid method is given for the analysis of citrus oils for the fungistat biphenyl by high-speed liquid chromatography. The method is extended to orange juice and various “dry flavors” by an extraction procedure. Analytical limits are &lt;1 ppm without need for any cleanup or concentration steps.
Extraction and Cleanup of Organochlorine, Organophosphate, Organonitrogen, and Hydrocarbon Pesticides in Produce for Determination by Gas-Liquid Chromatography
Authors: Luke Milton A , Froberg Jerry E , Masumoto Herbert T 
Published: February 2020

Abstract
A rapid, multiresidue procedure utilizing the minimal cleanup necessary for gas-liquid chromatographic (GLC) analysis is presented. The samples are extracted with acetone and partitioned with methylene chloride-petroleum ether to remove water. The organophosphorus and organonitrogen compounds are then quantitated by GLC, using a KCI thermionic detector. A Florisil cleanup of the extract is performed prior to the determination of organochlorine compounds by a GLC electron capture detector. Carbon-hydrogen compounds such as biphenyl and o-phenylphenol undergo the Florisil cleanup and may also be quantitated by GLC. Quantitative recoveries for 15 organophosphorus, 9 organochlorine, 5 organonitrogen, and 2 hydrocarbon pesticides show the range in polarities of pesticides recovered, from Monitor to biphenyl. The method is simple and fast with a great potential for the analysis of many more compounds.
Gas-Liquid Chromatographic Determination of Resmethrin in Corn, Cornmeal, Flour, and Wheat
Authors: Simonaitis Richard A , Cail R Spencer 
Published: February 2020

Abstract
gas-liquid chromatographic (GLC) method was developed for the determination of residues of resmethrin ((5-benzyl-3-furyl)methyl cistraras-(±)- 2,2-dimethyl-3-(2-methylpropenyl)-cyclopropanecarboxylate) in corn, cornmeal, flour, and wheat. The commodity, fortified with resmethrin, was extracted by tumbling with pentane and transferred to acetonitrile, the fat was partitioned off, and the sample was chromatographed with 3% ethyl acetate in pentane on Florisil containing 0.5% water. The resmethrin residue was determined by GLC with a flame ionization detector. The results were compared with known standards that had undergone the same cleanup procedures. The method was sensitive to concentrations of resmethrin to 0.2 ppm, recoveries averaged 83%, and reproducibility was good.
Filter Paper as a Source of Error in the Determination of Nitrite in Meat
Authors: Nicholas Fiddler Rosemary , Gentilcore Kathleen M 
Published: February 2020

Abstract
Samples of filter paper were found which contain sufficient nitrite to cause significant error in determining the nitrite content of cured meat products by the official AOAC method. Six of 28 boxes of filter paper examined were contaminated with nitrite. All 6 contaminated boxes were the same brand and grade. These samples of filter paper could contribute from 4.6 to 18.4 ppm nitrite to the amount of nitrite analyzed for in meat.
Bacillus subtilis GSY 1057 Assay for Aflatoxin B1 Activation by Rainbow Trout (Salmo gairdneri)
Authors: Schoenhard Grant L , Bishop Paul E , Lee Donald J , Sinnhuber Russell O 
Published: February 2020

Abstract
A rapid and sensitive microbial assay was developed to detect lethal products of anatoxin B1 metabolism by rainbow trout (Salmon gairdneri) Mt. Shasta strain. Bacillus subtilis GSY 1057 (hisA1, uvr-1, metB4), a DNA repair deficient strain, was incubated for 20 min in the 20,000 × g supernate from trout liver homogenates which had been preincubated for 10 min with various levels of aflatoxin B1. Serial dilutions of the incubation mixture were plated in triplicate on tryptose blood agar base plates and colonies were counted after 12 hr at 37°C. One μmole aflatoxin B1 in 3.2 ml incubation mixture reduced viability 60°.
Colorimetric and Gas-Liquid Chromatographic Determination of Atropine-Hyoscyamine and Hyoscine (Scopolamine) in Solanaceous Plants
Authors: Karawya Mohamed S , Abdel-Wahab Samia M , Hifnawy Mohamed S , Ghourab Mohamed G 
Published: February 2020

Abstract
Two colorimetric micromethods are described for the determination of atropine-hyoscyamine and hyoscine (scopolamine), using p-dimethylaminobenzaldehyde and citric acid-acetic anhydride as the color reagents. These methods are sensitive to 60-1200 and 10-360 μg alkaloid/10 ml. The colorimetric methods were also successfully applied after a preliminary thin layer chromatographic separation of the alkaloids. A gasliquid chromatographic procedure was also developed, which yielded comparable results with the colorimetric methods.
Preservatives in Cosmetics: Partition Chromatography and Ultraviolet Spectrophotometry
Authors: Sheppard E Patricia , Wilson Clifton H 
Published: February 2020

Abstract
Separation by partition chromatography and determination by ultraviolet (UV) spectrophotometry have been applied to the analysis of 16 preservative chemicals used in cosmetic products. The method, adapted from the official first action method for hexachlorophene, 35.023–35.027, has broad applicability for the determination of preservatives in cosmetics. Among the chemical classes investigated, phenols, parabens, biphenyls, carbanilides, and salicylanilides are represented. The partition chromatographic technique does not separate 3,4’,5-tribromosalicylanilide (TBS) from hexachlorophene or Irgasan DP 300. However, the UV determination of these compounds was accomplished by utilizing an absorption maximum of TBS which does not coincide with that of the other 2 preservatives. Recoveries averaged 97% for all the compounds studied.
Quantitative Determination of Coumestrol in Dried Alfalfa and Alfalfa Leaf Protein Concentrates Containing Chlorophyll
Authors: Knuckles Benny E , Miller Raymond E , Bickoff E M 
Published: February 2020

Abstract
An improved analytical method for the determination of coumestrol in dried alfalfa and leaf protein concentrates is described. In this method, chlorophyll is removed from an alcohol extract prior to the paper chromatographic-fluorometric measurement of coumestrol. Ninety-eight per cent of the coumestrol added to alfalfa leaf protein concentrates is recovered by this method. This improved method gives replicate values with lower standard deviations and coefficients of variation than the literature method.
Spectral Compilation of Dyes, Intermediates, and Other Reaction Products Structurally Related to FD&C Yellow No. 6
Authors: Bailey John E , Calvey Robert J 
Published: February 2020

Abstract
Spectral data are presented for 10 intermediates, 25 dyes, and 2 side-reaction products that are related to FD&C Yellow No. 6. Also included are purification procedures for the intermediates and side-reaction products and methods of synthesis and purification for the corresponding dyes. Spectral data consist of acid, base, and neutral curves in the visible and ultraviolet regions. Also included are infrared spectra. Molar extinction coefficients are calculated for the visible and ultraviolet spectra.
Pyrolysis-Gas Chromatographic Analysis of Black Paints
Authors: Schultz Blair W , Perros Theodore P 
Published: February 2020

Abstract
Samples of 79 black paints from 27 manufacturers in the United States were examined to determine the extent to which paints can be distinguished by pyrolysis-gas chromatography. Evaluation by a Carbowax column showed some differences among paints from different manufacturers and among batches of paints from the same manufacturer. However, it was not possible to conclude that paints with identical chromatograms had a common origin.
Rapid Determination of Fat in Meat and Meat Products by Foss-let Solvent Extraction and Density Measurement
Authors: Pettinati Julio D , Swift Clifton E 
Published: February 2020

Abstract
The commercially available Foss-let fat analyzer was evaluated for the determination of fat in meat and meat products by comparison with AOAC method 24.005(a). With the Foss-let procedure, mechanical and instrumental equipment is used to determine fat in 7–10 min. A sample is extracted with tetrachloroethylene in a mechanical orbital shaker for 2 min and the specific gravity of the extract is measured in a magnetic float cell controlled by a digital potentiometer. During extraction, anhydrous calcium sulfate absorbs moisture droplets originating from the sample. The variations of comparative determinations on 67 meat samples containing 1.1–95.4% fat and 17 frankfurter samples containing 17.3–37.3% fat were analyzed statistically by grouping the data according to meat type (beef or pork) or frankfurters and into 6 ranges of fat content, and by treating the entire set of data. Error analysis of the differences and standard deviation of each grouping of paired determinations by the Fosslet and AOAC methods indicated that meat type and fat content &gt;7.5% were not significant (P = 0.05) sources of variation as determined by t-tests on the statistics from the blocks of data. Determinations on samples containing ≤7.5% fat were consistently low and an additive correction of 0.25% was indicated. From the overall results, the accuracy and precision of the method were characterized as follows: the mean Foss-let method determination was high by 0.08% fat relative to that by the AOAC method; repeatability of ± 0.31% fat between duplicate determinations compared favorably with ±0.38% obtained with the AOAC method; and precision between paired determinations by the 2 methods was ±0.44%. Both a t-test for significance (P = 0.05) and the linear regression of the 84 comparative determinations indicated that the Foss-let method was equivalent to the AOAC method for determining fat.
Formaldehyde Titration Method for the Determination of Ammoniacal Nitrogen in Phosphate Fertilizers
Authors: R Anjaneyulu T S 
Published: February 2020

Abstract
The present formaldehyde titration method, applicable to ammonium nitrate and ammonium sulfate samples, has been improved for the analysis of ammoniacal nitrogen in phosphate fertilizers. Samples of 14-35-14 and 28-28-0 fertilizers are analyzed by the improved formaldehyde titration method and the results are compared with the Kjeldahl distillation method. The formaldehyde method is applicable for 14-35-14 and 28-28-0 fertilizer samples, provided the initial pH of the sample solution is adjusted to pH 7.7 prior to the addition of neutral formaldehyde solution. For the analysis of samples of phosphate fertilizers of the same grade, the improved formaldehyde method offers a distinct advantage over the Kjeldahl method, and can be used for the rapid analysis of process control samples.
Survey of U.S. Wheat for Ochratoxin and Aflatoxin
Authors: Shotwell Odette L , Goulden Marion L , Hesseltine Clifford W 
Published: February 2020

Abstract
A total of 291 hard red winter wheat samples, 286 hard red spring wheat samples, and 271 soft red winter wheat samples were analyzed for the presence of ochratoxin and aflatoxin. Samples in all grades came from those collected during crop years 1970–1973 for grade determinations by the Agricultural Marketing Service, U.S. Department of Agriculture. Sensitivity limits of the analytical method as carried out were 1–3 ppb aflatoxin B1 and 15–30 ppb ochratoxin A. No aflatoxin was detected in any sample. Three samples of hard red winter wheat (Grades U.S. No. 4 and 5 and Sample Grade) contained ochratoxin A (trace, 35, and 25 ppb, respectively). Eight of the hard red spring wheats contained ochratoxin A (15-115 ppb); these were in Grades U.S. No. 4 and 5 and Sample Grade.
Iodometric Determination of the Peroxide Value of Edible Oils
Authors: Gutfinger Tamar , Peled Micha , Letan Arieh 
Published: February 2020

Abstract
The results of peroxide value determinations in soybean oils depend on the temperature at which the experiments were carried out. The effect of temperature on the values obtained was more pronounced in oils which contained higher amounts of peroxides. When the determinations were carried out in the presence of air, the peroxide values of fresh and oxidized oils to which Fe3+ (20 ppm) had been added were considerably higher than those which were obtained for the same oils without added Fe3+. In the presence of nitrogen, lower values than expected were obtained for oxidized oils with added Fe3+, whereas values which were obtained for unoxidized oils, with or without Fe3+, were similar.