bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Melengestrol Acetate in Bovine Tissue: Collaborative Study
Authors: Krzeminski Leo F , Geng Shu , Cox Byron L 
Published: February 2020

Abstract
Seven laboratories collaboratively studied a method for the assay of melengestrol acetate at the 0, 10, and 20 ppb levels in bovine fat, liver, muscle, and kidney. The study included fortification of tissue by each laboratory and analysis of fat samples taken from treated heifers which had endogenous levels of 0, 10, and 20 ppb melengestrol acetate. The multistep cleanup procedure used included extraction, solvent partition, column chromatography, and electron capture gas-liquid chromatographic determination. Results of the study for muscle, liver, kidney, and fat showed that the method gave satisfactory recoveries and accuracy. In fat, the most critical tissue, recovery was &gt;93%. A statistical comparison of the results reported for fat tissue from treated heifers demonstrated that 5 of the 7 laboratories obtained similar results. The results produced by the method can be expected to be repeatable within and among laboratories. On the basis of the collaborative results the method has been adopted as official first action.
Turbidimetric and Diffusion Assay of Bacitracin in Feeds
Authors: Ragheb Hussein S , Black Lisa , Graham Sherrie 
Published: February 2020

Abstract
A manual turbidimetric method for determining zinc or methylene disalicylate bacitracin in feeds was developed. When zinc ions (10−4M) were added to the medium and the phosphate ion concentration in standard solutions was decreased to 1%, the median response of Streptococcus faecalis was about 0.038 unit. Feeds analyzed by the turbidimetric assay should be prewashed with petroleum ether and extracted with pyridine as in 42.204. Zinc bacitracin standards added to swine and broiler rations were recovered at 93.1–102.6% by the turbidimetric method. Excellent agreement between the manual turbidimetric method and the plate assay was also obtained for finished feeds containing the zinc or methylene disalicylate salt of the antibiotic. The turbidimetric method appears to have high accuracy and precision. It is more rapid and less costly than the plate assay.
Modified Assay Medium for the Turbidimetric Assay of Chlortetracycline in Feeds
Authors: Ragheb Hussein S 
Published: February 2020

Abstract
In previous experiments, the turbidimetric method for determining chlortetracycline-HCI (CTC-HCl) in feeds showed lower recovery than the AOAC plate method. Although the addition of vitamins to the turbidimetric medium improved results, values by the turbidimetric method remained about 10% lower than by the plate method. A modified (1.7 × the weight recommended by the manufacturer) turbidimetric assay medium decreased assay sensitivity but did not significantly change the slope of S. aureus response to CTC-HCl. There was no evidence that vitamin fortification of the modified medium had any significant effect on the growth rate of test organism. Examination of about 100 samples of commercial feeds containing CTC-HCl showed excellent agreement in results between the turbidimetric and plate methods.
Determination of Hexachloro-1,3-butadiene in Spinach, Eggs, Fish, and Milk by Electron Capture Gas-Liquid Chromatography
Authors: Yurawecz Martin P , Dreifuss Peter A , Kamps Laverne R 
Published: February 2020

Abstract
Hexachloro-1,3-butadiene (HCBD), a waste product formed in the manufacture of perchloroethylene and trichloroethylene, has been found in fish from the lower Mississippi River basin. The AOAC official method for organochlorine pesticide residues in fatty and nonfatty foods has been modified for the determination of HCBD residues in selected food commodities. Acetonitrile extracts of nonfatty foods, or the combined acetonitrile extracts obtained in acetonitrile-petroleum ether partitioning of fat isolated from fatty foods, are diluted with water and extracted with petroleum ether. The petroleum ether extracts are chromatographed on Florisil and HCBD is eluted with petroleum ether. The eluate is analyzed by gas-liquid chromatography with an electron capture detector. Average recoveries of HCBD from fortified samples of fatty and nonfatty foods were greater than 90% in the interlaboratory trials of the method.
Survey for Hexachloro-1,3-butadiene in Fish, Eggs, Milk, and Vegetables
Authors: Yip George 
Published: February 2020

Abstract
Eighty-four samples (fish, milk, eggs, vegetables) were collected from within a 25 mile radius of 10 perchloroethylene or trichloroethylene manufacturing plant sites and analyzed for hexachloro-1,3-butadiene (HCBD) by a gas chromatographic method. Residues of HCBD were found mainly in freshwater fish caught in the lower Mississippi River. The levels ranged from 0.01 to 1.2 ppm. Two of the 20 saltwater fish contained residues of 0.01 and 0.02 ppm. No HCBD residues were found in eggs and vegetables. One of 20 milk samples contained 1.32 ppm HCBD.
Quantitative Determination of 4,4′-(Diazoamino)-bis (5-methoxy-2-methylbenzenesulfonic Acid) in FD&C Red No. 40 by Ion Exchange Chromatography
Authors: Fratz D Douglas 
Published: February 2020

Abstract
An ion exchange chromatographic procedure is presented which separates 4,4′-(diazoamino)-bis(5-methoxy-2-methylbenzenesulfonic acid) (DMMA) from FD&C Red No. 40. The DMMA is determined spectrophotometrically. Recoveries of DMMA added to FD&C Red No. 40 at levels of 0.05 to 0.20% ranged from 90 to 110%. DMMA was found in commercial samples of FD&C Red No. 40 in amounts ranging from &lt;0.02 to 0.11%.
Phosphorus Pentoxide as a Drying Agent for Bacterial Culture Extracts Analyzed by Gas-Liquid Chromatography
Authors: Finne Gunnar , Matches Jack R 
Published: February 2020

Abstract
The procedure for gas chromatographic analysis of metabolic products of microbial fermentation includes solvent extraction of the aqueous growth media, drying of the extract, and direct chromatographic analysis of the solvent. In this study, 2 drying agents, magnesium sulfate and phosphorus pentoxide, were compared. Both were effective in removing water; however, phosphorus pentoxide removed water more completely and at a faster rate than magnesium sulfate. When a thermal conductivity detector is used, it is important to completely remove water from the solvent to prevent interference with volatile acids and alcohols. When water is present, short-chain alcohols (C2–C5) are eluted together with the water, causing peak overlap and shoulder separations. Phosphorus pentoxide quickly and effectively removed water so that a baseline was established following the solvent front on the chromatogram. The use of phosphorus pentoxide is particularly advantageous for identification or fermentation studies on Clostridium and Propionibacterium when rapid identification is desired or when large numbers of cultures are to be tested.
Collaborative Study of an Improved Method for the Enumeration and Confirmation of Clostridium perfringens in Foods
Authors: Harmon Stanley M 
Published: February 2020

Abstract
A collaborative study was conducted in 10 laboratories to evaluate the performance of a new method for the enumeration of vegetative cells of Clostridium perfringens in foods. Results obtained by the new method were compared with results from the official first action method, 46.049–46.053. Per cent recoveries of 4 C. perfringens strains from inoculated roast beef samples were higher and more consistent in tryptose-sulfite-cycloserine (TSC) agar with or without added egg yolk than in sulfitepolymyxin-sulfadiazine (SPS) agar, specified in the official first action method. The confirmatory technique utilized in the new method was also found to be more reliable than the technique described in the official first action method. Based on the collaborative results, the new method with TSC agar for enumeration and a modified motility-nitrate medium together with a lactose-gelatin medium for confirmation of C. perfringens has been adopted as official first action to replace 46.049–46.053.
Gas-Liquid Chromatographic Analysis of Ethephon and Fenoprop Residues in Apples and Their Decline Before and After Harvest
Authors: Cochrane William P , Greenhalgh Roy , Looney Norman E 
Published: February 2020

Abstract
Ethephon (2-chlorocthylphosphonic acid) and fenoprop (2-(2,4,5-trichlorophenoxy) propionic acid) may be determined in the same apple sample. After extraction with methanol, 2 separate methylation procedures were required to quantitatively convert each compound. Ethephon was esterified with diazomethane and analyzed by a flame photometric detector in the P-mode. Fenoprop was esterified with boron trifluoride/methanol and analyzed by electron capture gas chromatography. Average recoveries were about 95% at 0.05 ppm for both compounds. The limit of detection was 0.05 ppm for ethephon and 0.01 ppm for fenoprop in a 1 g sample. The persistence of both compounds before and after harvest was studied. Ethephon and fenoprop were applied simultaneously to apple trees at the recommended concentrations of 300 and 20 ppm, respectively. Ethephon residues averaged 1.6, 0.75, and 0.4 ppm at 2 hr, 10 days, and after washing at 13 days, respectively. The corresponding fenoprop residues were 0.70, 0.025, and 0.024 ppm.
Thin Layer Chromatography of Parathion as Paraoxon with Cholinesterase Inhibition Detection
Authors: Nanda Kumar Nanguneri V , Visweswariah Krishnamurthy , Majumder Suvendu K 
Published: February 2020

Abstract
A simple, sensitive, and rapid method is described for the quantitative estimation of ng amounts of parathion (O,O-diethyl O-p-nitrophenyl phosphorothioate) as paraoxon (O,O-diethyl O-p-nitrophenyl phosphate) on thin layer chromatograms. Paraoxon is detected by inhibition, using p-nitrobenzenediazonium fluoroborate as the chromogenic reagent. This chromogenic reagent is more sensitive than Fast Blue B or indoxyl acetate; 0.1 ng may be detected and amounts from 5 to 50 ng may be estimated. The method is a viable alternative to gas chromatographic analysis for parathion.
Methods of Analysis Approved by the Codex Alimentarms Commission. I. Acid Value
Authors: Horwitz William 
Published: February 2020

Abstract
Numerous variations exist for determining the acidity of fats and oils by titration. A Youden ruggedness test was performed, using extreme conditions existing in the methods, endorsed by various international organizations: aqueous and alcoholic standard alkali, 5 or 56 g sample, 50 or 150 ml alcohol or alcohol-ether solvent, titration at room temperature or 60°C with 2 ml or 8 drops of phenolphthalein indicator, to the first color change or to a pink persisting for 60 sec. The titration method was found to be extremely rugged at the 1 % oleic acid level with none of the variables influencing the result. At the 0.15% level, only the sample size affected the result.
Determination of Zearalenone in Corn: Collaborative Study
Authors: Shotwell Odette L , Goulden Marion L , Bennett Glenn A 
Published: February 2020

Abstract
Corn samples spiked at levels of 100, 300, 1000, and 2000 μg zearalenone/kg were sent to 22 collaborators for analysis by the Eppley method. All samples were yellow corn except one white corn sample spiked at 2000 μg/kg. Results from 16 collaborators were statistically analyzed. Only 4 of 16 collaborators detected zearalenone in the sample containing 100 μg/kg, but 11 detected the toxin in the sample containing 300 μg/kg. Average recoveries from all samples were 129% at 300 μg/kg, 101% at 1000 μg/kg, and 88% at 2000 μg/kg. The between-laboratory coefficients of variation were 53.0% at 300 μg/kg, 38.2% at 1000 μg/kg, and 27.0% at 2000 μg/kg. Five naturally contaminated corn samples, one in triplicate, were also provided. The mean level of zearalenone in the naturally contaminated samples ranged from 431 to 7622 μg/kg. The mean coefficient of variation for all samples was 40.5%. Two collaborators measured quantities of zearalenone on thin layer chromatographic plates densitometrically. Their results were not included in the statistical analysis, but the results indicated that densitometric measurement, given proper dilutions of solutions, could be used. The method has been adopted as official first action.
Spectrophotometric Determination of Allylisothiocyanate in Mustard Seed Oil
Authors: Devani Muljibhai B , Shishoo Chamanlal J , Dadia Bharti K 
Published: February 2020

Abstract
Allylisothiocyanate is determined spectrophotometrically after reaction with 2,3-dichloro-1,4-naphthoquinone. For pure samples, the color intensity is proportional to allylisothiocyanate content in the range 0.8–3.0 mg/ml reaction mixture. A modified procedure is used to estimate allylisothiocyanate content of mustard seed oil. The reaction is linear for allylisothiocyanate concentrations in the range 40–240 μg/ml reaction mixture. Two mustard seed oil samples contained 0.995 ± 0.020 and 0.981 ± 0.019% allylisothiocyanate.
Biological Parameters and the Acute LD50 Test
Authors: Sperling Frederick , McLaughlin Joseph L 
Published: February 2020

Abstract
The acute LD50 is an inadequate index of toxicity because the catastrophe of death obscures the mechanisms and sites of action. Thus, nonlethal toxicity is not evaluated, and the LD50 is not extrapolated to the possible effects of low level exposures for long periods of time. Collaborative studies should be undertaken which would develop methods to reasonably permit such evaluation and extrapolation.
Estimation of Milligram and Submilligram Amounts of Busan Fungicide
Authors: Miller Vernon L , Csonka Elizabeth , Gould Charles J 
Published: February 2020

Abstract
A procedure is described for the estimation of Busan 72 ((2-thiocyanomethylthio)benzothiazole) in the range of 0.01–1.0 mg/ml. An aqueous suspension of the material is heated with dilute sodium hydroxide, cooled, and treated with copper ion. The insoluble reaction product is filtered, and excess copper is determined by using a pyridine-thiocyanate procedure. Analysis may be completed by either spectrophotometry or comparison with described artificial standards.
Collaborative Study of the Determination of Color in White Wines Dust and Powder Formulations
Authors: McDermott William H 
Published: February 2020

Abstract
Some 10% and lower guarantee carbaryl dusts cannot be quantitatively extracted by shaking with chloroform as specified in the official first action infrared method for carbaryl formulations, 6.293–6.295. The official method has been compared in a collaborative study with an alternative method in which a simple rotator has replaced the wrist-action shaking machine and a solution of 10% (v/v) methanol in chloroform has replaced chloroform. The results indicate the alternative method is superior to the official method when applied to difficult-to-extract formulations and equal to it for all other formulations. The mixed solvent-rotator alternative method has been adopted as official first action to replace the present method for the carbaryl analysis of carbaryl formulations.
Determination of Sodium in Alkali-Treated Cereal Straws, Lye-Peel Wastes, and Brine-Frozen Foods with an Ion Selective Electrode Compared with Atomic Absorption Spectrometry
Authors: Secor Geraldine E , McDonald Gary M , McCready Rolland M 
Published: February 2020

Abstract
A simple procedure is described for determining sodium in sodium hydroxide-treated rice straw and rye grass, lye-peeled potato wastes, and brine-frozen vegetables. Samples containing ≤4% sodium were extracted with 0.05M ammonium carbonate and the extracts were analyzed directly by using a sodium ion selective electrode over the range 10−4 to 10−2M sodium ion. Comparable analyses of the same extracts by atomic absorption spectrometry agreed to within 10%. Recovery of sodium added to control rice straw was 102%.
Determination of the Congeners Produced from Ethanol During Whisky Maturation
Authors: Reazin George H , Baldwin Sidney , Scales Harry S , Washington Harold W , Andreasen Arthur A 
Published: February 2020

Abstract
A study was made to determine which congeners are derived from ethanol during maturation of whisky. Radioactive ethanol-1-14C was added to a barrel of new bourbon whisky and the radioactivity of the major individual congeners was determined during the maturation period. During 56 months of maturation, ethanol was transformed into acetic acid, acetaldehyde, ethyl acetate, and ethanol lignin as indicated by their radioactivity. No radioactivity was found in the solids, fusel oil alcohols, or the aromatic aldehydes derived from ethanol lignin. The chemistry of maturation is discussed.
Collaborative Study of the Gas-Liquid Chromatographic Determination of Coumarin (1,2-Benzopyrone) in Wine
Authors: Dyer Randolph H , Martin Glenn E 
Published: February 2020

Abstract
The determination of coumarin in wine by using gas-liquid chromatography of a chloroform extract was collaboratively studied. Eleven collaborators analyzed 6 samples: 3 containing 4.0 mg coumarin/L, 2 containing 8.0, and 1 containing 0.0. When the triplicate and duplicate recoveries for the 4.0 and 8.0 levels were averaged and treated singly for the collaborators, there was no statistically significant difference in the accuracy between the 2 levels. However, the accuracy for the 4.0 level was much better than that for the 8.0 level: 100.0 vs. 105.9%. An analysis of the individual values showed no significant differences among collaborator means at the 4.0 level, while there was a significant difference among means at the 8.0 level. All collaborators were within the allowable score limits in the ranking test. The method was adopted as official first action.
Ion-Pair Extraction Method for Quantitation of a Bisquaternary Ammonium Compound, Pancuronium Bromide
Authors: Michoel Armand J , Kinget Renaat D 
Published: February 2020

Abstract
Pancuronium bromide (PCBr), a neuromuscular blocking agent, was determined quantitatively in aqueous solution by ion-pair extraction. Separate determination of PCBr and degradation products was possible after thin layer chromatography. The procedure was developed by using a theoretical approach. Favorable conditions were calculated from the ion-pair extraction constant. The drug was determined with bromothymol blue at pH 9.0, using one extraction in the direct procedure and 2 successive extractions in the combined elution-extraction process after thin layer chromatography. In the direct method, 0.100 mg PCBr was determined with a reproducibility of ±1.0%.
Collaborative Study of a Spectrofluorometric Assay for Rauwolfia serpentina Tablets and Powdered Root
Authors: Smith William M , Clark Charles C 
Published: February 2020

Abstract
Reserpine-rescinnamine group alkaloids are extracted from Rauwolfia serpentina preparations into a dimethylsulfoxide (DMSO)-methanol mixture and diluted with 0.5N H2SO4. The chloroform extract of this solution is passed through a 0.1N NaOH-Celite column and then through a silica gel column. The weakly basic alkaloids trapped on the latter column are eluted with a methanol mixture; a portion of the eluate is treated with nitrous acid and the reserpine-rescinnamine content is determined by measuring the intensity of fluorescence of the oxidation product. The following means and standard deviations (11 collaborators) were obtained for the determination of reserpine-rescinnamine group alkaloids in 4 samples of Rauwolfia serpentina (NF reference powder, 100 mg and 50 mg commercial tablets, and a 45 mg synthetic tablet formulation): 0.174%±0.0112, 0.131%±0.0047, 0.160%±0.0100, and 0.153% ±0.0083, respectively.
Collaborative Study of the Extraction of Light Filth From Canned Crabmeat
Authors: Dent Russell G , Gorham J Richard 
Published: February 2020

Abstract
Canned crabmeat is boiled with mineral oil in a Wildman trap flask. The trappings are transferred to a Corning percolator and cycled at least 3 times. Average recoveries from 7 collaborators were 82.7 % for rodent hairs and 98.0% for flies. The proposed method has been adopted as official first action.
Collaborative Study of a Method for the Extraction of Light Filth from Ground Mace and Ground Caraway Seed
Authors: Thrasher Joel J 
Published: February 2020

Abstract
A new method has been developed for the extraction of light filth from ground mace and ground caraway seed. The method uses a 2-step chloroform-isopropanol pretreatment followed by separation of the light filth from 40% isopropanol with mineral oil. The collaborative study resulted in clean filter papers with more reproducible recoveries of light filth elements than the official first action method, 44.116(b). The method has been adopted as official first action.
Collaborative Study of the Modifications of the Official AOAC Method for the Determination of Biuret in Fertilizers
Authors: Corominas Luis F 
Published: February 2020

Abstract
Six collaborators participated in the second part of the study of the official AOAC method for the determination of biuret in fertilizers. Four samples of fertilizers containing 1.5–3.0% biuret were analyzed by using 2 standard curves prepared from biuret obtained from 2 different sources and having different melting points. Biuret contents higher than expected were obtained from the curve prepared from the low melting biuret. This confirms the necessity of checking the purity of the standard to be used and justifies a recrystallization step.
Comparison of Wet Ash and Dry Ash Methods for the Digestion of Mineral-Mix Feeds
Authors: Hoover William L 
Published: February 2020

Abstract
When some mineral-mix feed samples are digested by AOAC dry ash methods, the mineral components are not dissolved. A 50% error in phosphorus values is observed when these digestion methods are used. It is suggested that the wording in AOAC dry ash methods for minerals in feeds be changed to exclude mineral-mix feeds.
Multiresidue Screening by Negative Chemical Ionization Mass Spectrometry of Organic Polychlorides
Authors: Dougherty Ralph C , Piotrowska Krystyna 
Published: February 2020

Abstract
A multiresidue procedure, based on negative chemical ionization (NCI) mass spectrometry, for analyzing organochlorine residues in environmental substrates is described. The procedure is capable of routinely detecting about 1 ng unknown organochlorine residues. Semiquantitative data (order of magnitude) may be obtained for pentachlorophenol and 2,4,5-trichlorophenoxyacetic acid residues by calibration with internal p-chlorobenzophenone. Lipid-rich substrates were resolved into acidic and neutral fractions, and both fractions were further purified by gel permeation chromatography (GPC) prior to NCI analysis. In spite of the fact that recoveries were often low, the overall sensitivity for residues in lipid-rich substrates appeared to be higher than when the GPC step was omitted.
Direct Potentiometric Titration of Urea with Urease
Authors: Falls J Harold , Barnacascel William R , Britt Perry W 
Published: February 2020

Abstract
AOAC method 2.070–2.071 for determining urea with urease was shown to yield varying results according to the analyst’s interpretation of titrating to a neutral end point. The method was modified to allow the end point of the titration to correspond to the break point of ammonium carbonate (pH 4.2), which is the compound being titrated in the urea analysis. This modified method proved to be a more accurate means of urea analysis. The AOAC method was further modified and simplified by eliminating the back-titration step. Ammonium carbonate may be titrated directly to pH 4.2 without over-acidifying to eliminate carbon dioxide.
Dicofol: Collaborative Study of the Hydrolyzable Chlorine Method
Authors: Baum Harry , Black Ronald F , Kurtz C P 
Published: February 2020

Abstract
A collaborative study was performed on dicofol formulations, using a hydrolyzable chlorine method with a potentiometric end point. Five laboratories each analyzed 2 samples of Kelthane technical, Kelthane MF, Kelthane EC, and Kelthane 35 in duplicate on each of 2 days. Statistical analysis indicated that the between-laboratory standard deviation of the dicofol assay, excluding outliers, was 0.47, 1.09, 0.78, and 0.99% absolute, at the 20, 39, 44, and 86% assay levels, respectively. The method has been adopted as official first action.