bluuebunny/crossref_metadata_2025_split huggingface dataset:
Utilization of a Centrifuge for Gravimetrically Determining Phosphorus in Feeds and Fertilizers
Authors: Melton James R , Hoover William L , Howard Peggy A 
Published: February 2020

Abstract
The AOAC gravimetric quinolinium molybdophosphate method for the determination of P2O5 in fertilizers, 2.023–2.025, has been modified to allow centrifugation of the precipitate. Aliquots of the digested samples are placed in preweighed 16 ml centrifuge tubes, and quimociac reagent is added directly to the tubes. After formation of the precipitate, the samples are centrifuged and the supernatant is decanted. The precipitate is washed, recentrifuged, and decanted. After oven-drying, the weights of the precipitates are determined and per cent P2O5 is calculated. There were no significant differences between results of collaborative feed and fertilizer samples determined by the AOAC and the modified methods.
Sampling Bagged Fertilizers
Authors: Gehrke Charles W 
Published: February 2020

Abstract
Data pertaining to equipment and procedures used by 34 States in sampling bagged fertilizers are presented. All States reporting use the recommended slotted tube with solid cone tip, either as a single tube (25 States) or as a double tube (8 States). All but 2 States secure at least 10 cores. No serious sampling problems were reported. The recommended bag sampler specifications, based on the most widely used equipment, have been adopted as official first action for inclusion in 2.001(a).
Simple, Rapid Digestion Technique for the Determination of Mercury in Fish by Flameless Atomic Absorption
Authors: Holak Walter , Krinitz Benjamin , Williams John C 
Published: February 2020

Abstract
A simple and rapid digestion technique is described for the determination of mercury in fish by flameless atomic absorption. The sample is digested with nitric acid in a closed system in a commercially available vessel made of Teflon. A 30 min digestion at 150 °C is sufficient to convert the mercury to an inorganic form so that it can t h e n be reduced to the elemental state , aerated, and determined by atomic absorption. The proposed digestion compares favorably with the official AOAC sulfuricnitric- perchloric acid digestion.
Colorimetric Method for Estimation of Methyl Iodide Residues on Jo war (Sorghum) and Rice
Authors: Rangaswamy J R , Majumder S K , Poornima P 
Published: February 2020

Abstract
A new colorimetric method based on the catalytic action of iodide on oxidation of As(III) by Ce(IV) has been developed for the estimation of methyl iodide residues on grains. Methyl iodide residues, in methanolic KOH, are converted to potassium iodide which acts as a catalyst in the timed oxidation of As(III) by Ce(IV). Unreduced eerie salt is measured colorimetrically and the iodide in the sample is calculated. The method is sensitive in the range 0.01 to 0.1 μg iodide.
Thin Layer Chromatographic Identification Test for Sorbitol and Sorbitol Solution
Authors: Coles Zachary A , Upton R P 
Published: February 2020

Abstract
A simple, specific, and rapid method for the identification of sorbitol is described. This method is based on the thin layer chromatographic separation of sorbitol from its potential contaminants, using silica gel G treated with boric acid as the stationary phase and distilled water as the mobile solvent. The sorbitol is detected with an alkaline permanganate spray reagent and its Rf is compared with that of a sorbitol standard. The method is applicable to both crystalline and dissolved sorbitol.
A Simple Color Spot Test for Distinguishing Between Maneb, Zineb, Mancozeb, and Selected Mixtures
Authors: Stevenson A 
Published: February 2020

Abstract
Maneb, zineb, mancozeb, and selected fungicidal mixtures can be differentiated by a simple color spot test. Differentiation is based on the colors produced after successive application of acid dithizone, sodium hydroxide, and acid dithizone to the spot. The color depends on the type and concentration of metal present in the sample.
Neutron Activation Analysis of Mercury in Fish, Flour, and Standard Reference Orchard Leaves by Electrodeposition Radiochemistry
Authors: Heitzman M W , Simpson R E 
Published: February 2020

Abstract
A method for neutron activation analysis of mercury is described in which electrodeposition is used to isolate the mercury carrier in the recovery step. Although the recovery of mercury carrier is variable, the results yielded by this technique are comparable to those obtained using sulfide precipitation inneutr on activation analysis. The method was also compared to gas chromatography and atomic absorption techniques and similar results were obtained. No interferences were evident in the samples analyzed: fish, flour, and standard orchard leaves. The method can detect ppb levels of mercury.
Semia u torn ate d Method for the Analysis of Methyltestosterone Tablets and Testosterone Suspensions
Authors: Myrick James W , Page Donald P , Pfabe Yvonne H 
Published: February 2020

Abstract
A semiautomated analytical system has been developed to determine the amount of methyltestosterone in single tablets at a level of 5–25 mg/tablet or testosterone in suspensions. The active ingredient in an alcoholic solution was acidified and the drug was extracted into chloroform. Reaction with isonicotinic acid hydrazide produced a yellow color, which was recorded on a colorimeter. Relative standard deviations of the method did not exceed 1.38 and 1.50% for methyltestosterone tablets and testosterone suspensions, respectively.
Colorimetric Estimation of Pilocarpine in Drug Preparations
Authors: Karawya Mohamed S , Ghourab M G 
Published: February 2020

Abstract
The proposed method is based on oxidative cleavage of pilocarpine by benzoyl peroxide and colorimetric estimation of the formaldehyde formed after addition of chromotropic acid to the sample. The method yields comparable results with the USP hydroxylamine HC1 method for varied pilocarpine formulations and the interferences present in the latter method are removed. A thin layer chromatographic step is used to isolate pilocarpine from other drugs in the analyses of multicomponent preparations.
Improved Method for Determination of Xanthophyll in Fresh Alfalfa and Wet Fractions
Authors: Knuckles Benny E , Bickoff E M , Kohler George O 
Published: February 2020

Abstract
An improved method for the analysis of xanthophyll, as well as carotene, is described for fresh alfalfa. This method is also applicable t o low fiber materials such as whole juice and protein-xanthophyll concentrates. T h e method is rapid and gives xanthophyll values which are significantly higher than those by other procedures. Pigmenting xanthophylls are determined as trans-lutein equivalents.
Collaborative Study of the Gas-Liquid Chromatographic Assay for Vitamin E
Authors: Rudy B C , Mahn F P , Senkowski B Z , Sheppard A J , Hubbard W D 
Published: February 2020

Abstract
A collaborative study for the analysis of vitamin E in multivitamin tablets was conducted and the method was subsequently approved as official first action by the AOAC. Additional data were obtained by an extensive collaborative study sponsored by the Pharmaceutical Manufacturers Association, which verified the usefulness of GLC for the assay of α-tocopherol, α-tocopheryl acetate, and α-tocopheryI acid succinate. The mean coefficient of variation obtained from the 8 participating laboratories for duplicate samples, duplicate injections, was ±2.04, 1.75, and 2.71%, respectively. Further collaborative studies were conducted on samples of mixed tocopherol concentrate, multivitamin tablets, and multivitamin soft gelatin capsules. The mean coefficient of variation obtained from 13 collaborators was in the range of ±5%. The accumulated data demonstrate the utility of this technique for improved specificity and reliability of the analysis of vitamin E.
Gas Chromatographic Determination of Residual Hexane in Modified Hop Extract
Authors: Litchman Mark A , Turano Lewis A , Upton Ronald P 
Published: February 2020

Abstract
A method is described for the quantitative determination of hexane in modified hop extract by head-space gas-liquid chromatography. A sample of extract is weighed into a serum vial and water-methanol solution is added. The vial is sealed tightly and heated 1 hr in a 70°C bath. A sample of the head-space gas over the solution is injected onto a Porapak Q gas chromatographic column for determination. Recovery of 2–29 ppm hexane added to potassium isohumulone was 95.5–114.8%. The method may be applicable to other hop extracts.
Confirmation of Pesticide Residue Identity. IV. Derivative Formation in Solid Matrix for the Confirmation of α- and β-Endosulfan by Gas Chromatography
Authors: Chau Alfred S Y , Terry Ken 
Published: February 2020

Abstract
The new solid matrix derivation procedure has now been applied to the confirmation of endosulfan residue identity . This procedure in volves the conversion of endosulfans to the same diacetate in alumina impregnated with H2SO4 and acetic anhydride. Comparable yield of the diacetate was obtained from the present approach and from a previously reported acetylation method. The advantage of the present method over the reported procedure is also discussed.
Residues of Chlorpyrifos Insecticide in Various Crops. I. Sweep Co-Distillation Method for Extraction and Cleanup
Authors: Maini Paolo , Collina Arrigo 
Published: February 2020

Abstract
The sweep co-distillation technique was expanded for application to chlorpyrifos insecticide residues in various substrates. The published technique was followed without significant changes for samples of lettuce, carrot, sugar beet (leaves and roots), potato, apple, onion, cauliflower, orange (pulp and peel), corn grain, and agricultural soil. Recoveries ranged from 74.2 to 100.7% at the fortification level of 0.1 ppm. Recovery tests were carried out also at levels ranging from 0.05 to 1.0 ppm for some crop samples obtained from trial field tests, with good results. For tobacco samples, some changes in the extraction and cleanup procedure were introduced to avoid some GLC interferences, but recoveries were low. Low recoveries were also obtained from the unmodified method and from the extraction, partition, and Florisil cleanup method.
Fluorescence of Aflatoxin M Standards Stored in Solution and as Dry Films
Authors: Purchase Iain F H , Steyn Martin 
Published: February 2020

Abstract
Aflatoxin M standards were stored in solution in nylon, soda glass, or borosilicate glass test tubes in 4 different solvents (benzene, benzene-acetonitrile (98+2), chloroform, ethanol) or as a dry film for 24 weeks. The standards were stored under conditions which were expected to accelerate deterioration. It was found that solutions in chloroform or benzene-acetonitrile stored in borosilicate glass test tubes contained the largest amount of aflatoxin M at 6 weeks. In addition, the percentage loss of aflatoxin M was greater in tubes containing small amounts (0.18 or 0.9 μg) than in tubes containing the largest amount (9.0 μg) of aflatoxin M.
Gas Chromatographic Determination of O,O-Diethyl S-(N-Isopropylcarbamoylmethyl) Phosphorothiolothionate (Prothoate) in Technical Products and Liquid Formulations
Authors: Bazzi Brunetto , Galluzzi Guglielmo , Abruzzese Luigi 
Published: February 2020

Abstract
A gas chromatographic method has been developed for the analysis of O,O-diethyl S-(N-isopropylcarbamoylmethyl) phosphorothiolothionate . The acaricide or a convenient amount of an acaricidal preparation is dissolved in xylene, together with malathion as an internal standard, and analyzed by gas chromatography, using a thermal conductivity detector. The precision (P = 0.05) of the method is ±1.5% of the concentration level.
Disulfiram Determination by Proton Magnetic Resonance Spectroscopy and by Colorimetry
Authors: Sheinin Eric B , Benson Walter R , Smith Myron M 
Published: February 2020

Abstract
Disulfiram was determined in disulfiram drug substance and tablets by proton magnetic resonance (PMR) spectroscopy at the 100–480 mg level and by a colorimetric technique involving cuprous iodide at the 50 mg level. The tablet excipients do not interfere in the analysis. The average result for disulfiram in a tablet composite was 100.8±1.4% of label claim by PMR and 100.7±0.4% by the colorimetric method.
Collaborative Study of Improvements in the Distillation Procedure of the Official Method for Formaldehyde in Maple Sirup
Authors: Hébert Calixte 
Published: February 2020

Abstract
A collaborative study was conducted to show that in the quantitative extraction of formaldehyde from maple sirup by the official final action controlled distillation method, 31.184—31.189, accuracy is increased by the use of a thermostatically controlled flask heater, together with the proper insulation of the glass apparatus with asbestos cord. This eliminates undue condensation of the distillate and variations in the final and total distillation times. The modified method was tested by 9 laboratories and, from their individual results, the coefficients of variation for the total time of distillation proved that the method gave excellent control of the final operation. The changes have been adopted as official first action.
Collaborative Study of the Cation Exchange Capacity of Peat Materials
Authors: Thorpe Virginia A 
Published: February 2020

Abstract
To provide a measure of the total amount of exchangeable cations that can be held by peat expressed as mequiv./100 g air-dried peat, the modified method of Puustjärvi for cation exchange capacity has been proposed and studied collaboratively. The statistical treatment of the collaborators’ results indicate a satisfactory degree of precision and accuracy for the 3 products considered, moss, humus, and reed-sedge. The method for cation exchange capacity of peat materials, with the description of the transfer technique included, has been adopted as official first action. The 7 ASTM methods have been adopted as procedures.
Use of Isotopic Abundance Ratios in Identification of Polychlorinated Biphenyls by Mass Spectrometry
Authors: Rote James W , Morris William J 
Published: February 2020

Abstract
Polychlorinated biphenyls are industrial compounds which are being detected throughout the global ecosystem. Because of the presence of other residues, combined gas chromatography-mass spectrometry must be used for their confirmation. Using isotopic abundance ratios, the theoretical probability of the occurrence of ions of different masses in the molecular cluster has been calculated for the polychlorinated biphenyls, polychlorinated terphenyls, and chlorinated naphthalenes. Mass spectra of mono-through decachlorobiphenyl have been taken with a unit resolution, computer-controlled GC-MS system and parent ion clusters were matched with the theoretical isotopic patterns. This method provides the unambiguous identification of polychlorinated biphenyls in the presence of other substances.
Semiquantitative Microbiological Residue Method for Hygromycin B in Chicken Eggs
Authors: Begue William J , Kline Richard M 
Published: February 2020

Abstract
A method recently has been developed for the detection of hygromycin B residues in chicken eggs at the 15 ppb level. Protein is precipitated with trichloroacetic acid. After centrifugation, the supernatant liquid is adjusted to pH 7.0 and placed on an IRC-50 ion exchange column. The column is washed with water and then acetone, and subsequently the hygromycin B is eluted with ammonium hydroxide. The eluate is evaporated to dryness and reconstituted in a known amount of water; hygromycin B is microbiologically detected with Pseudomonas syringae by bioautography on thin layer chromatographic plates.
Electron Capture Determination of Melengestrol Acetate in Bovine Tissue
Authors: Krzeminski Leo F , Cox Byron L 
Published: February 2020

Abstract
An electron capture GLC method has been developed for the determination of melengestrol acetate (MGA) in frozen bovine tissue, which removes, through extraction, solvent partition, and chromatographic cleanup, most of the interfering materials before injection of the sample onto the column for detection. MGA is extracted from lean tissue with acetonitrile and partitioned against hexane to remove nonpolar impurities. MGA in fatty tissues is first extracted with hexane and then transferred into acetonitrile. The residue from either extract, after evaporation of the solvent, is chromatographed on an alumina column with hexane and a mixture of hexane-acetone to remove the interfering lipids. The MGA is then eluted with hexane-chloroform (1+1). The residue, after rotary evaporation, is dissolved in the appropriate volume of hexanemethanol (94+6) and injected onto a 2′ 1% OV-17 column in an all-glass system. MGA can be detected at 25 ppb (2–3 mm peak) with no interference from tissue or reagents. The observed recovery of MGA at 25 ppb in muscle, liver, fat, kidney, and bone marrow was 93 ±7%.
Collaborative Study of a Simplified Halphen Procedure for the Quantitative Determination of Low Levels of Cyclopropene Fatty Acids
Authors: Coleman Eugene C 
Published: February 2020

Abstract
A collaborative study was conducted on a simplified Halphen procedure for the quantitative determination of low levels of cyclopropene fatty acids. Twelve laboratories (some of these participated in a precollaborative study of this procedure) analyzed 9 samples, whose cyclopropene content ranged from 0.00 to 0.19%. The amount of cyclopropene fatty acids in the samples was estimated in the Associate Referee’s laboratory from HBr titration data. A statistical evaluation of the collaborative data indicated good precision and accuracy. Evidence for a significant between-laboratory systematic error could not be found. It is recommended that work be continued on development of a suitable calibration procedure and/or acquisition of a reference standard.
Fluorometric Determination of Estradiol Valerate in Sesame Oil or Ethyl Oleate Injectables. II. Collaborative Study
Authors: James Theron 
Published: February 2020

Abstract
A fluorometric method for determining estradiol valerate in sesame oil or ethyl oleate was subjected to collaborative study. The method utilizes a nitromethane-Celite column to isolate and purify the steroid, which is then measured fluorometrically. Four commercial samples and 3 synthetic samples, varying in concentration from 4 to 20 mg/ml, were used in the study. The collaborative results were acceptable: Coefficients of variation ranged from 2.48 to 3.55%; average recoveries for the synthetics ranged from 98.6 to 102%. The method has been adopted as official first action.
Distinction of Some Dialkyl Amides of Lysergic and iso-Lysergic Acids from LSD
Authors: Bailey Keith , Verner Denise , Legault Donald 
Published: February 2020

Abstract
The 10 lysergic and iso-lysergic acid amides described are N,N-dimethyl-, N,N-diethyl-, N-methyl-N-propyl, N-ethyl-N-propyl, and N,N-dipropyl-. Their ultraviolet spectra are insufficiently different for distinction. Mass spectra do not readily differentiate between isomers. Proton magnetic resonance spectra are distinct and provide a positive structural identification of the amide. Their infrared spectra are similar, but suitable for distinguishing these compounds from LSD. Various reference spectra are provided. Thin layer and gas-liquid chromatographic systems suitable for distinguishing these compounds from LSD are described.
International Aflatoxin Check Sample Program: 1972 Study
Authors: Coon Francis B , Baur Fred J , Symmes L Richardson L 
Published: February 2020

Abstract
In the second International Aflatoxin Check Sample Series, a single sample, peanut butter, was submitted to 152 laboratories throughout the world. Sufficient data were obtained from 117 responding laboratories to permit a statistical comparison of the BF, CB, and Pons methods. No significant differences in mean values were obtained. One quarter of the participating laboratories were from countries other than Canada and the United States.
Gas Chromatographic Determination of Ethylene Thiourea Residues
Authors: Haines Linwood D , Adler Irving L 
Published: February 2020

Abstract
Residues of ethylene thiourea on food crops are determined by extracting the sample with methanol, partially purifying the extract on an alumina column, and derivatizing the ethylene thiourea extracted with 1-bromobutane in the presence of dimethylformamide and sodium borohydride. The resulting derivative is measured by gas chromatography, using a flame photometric detector. The method is suitable for routine use and is sensitive to 0.01 ppm.
Residues of Lindane on Food and Utensils from a Thermal Lindane Vaporizer
Authors: Thomas R F 
Published: February 2020

Abstract
Food products and utensils were exposed to a thermal lindane vaporizer. The food products exposed showed residues from &lt;0.01 to 0.61 ppm lindane. Exposed utensils showed residues of 0.01–6.00 μg per object. Air samples taken during the test showed up to 0.048 μg lindane/L after 5 days of vaporizer operation.
Collaborative Study of the Nonaqueous Copper Colorimetric and Silver Titrimetric Methods for the Determination of Malathion in Technical Grade Malathion and in Malathion Formulation
Authors: Wayne Richard S 
Published: February 2020

Abstract
The nonaqueous copper colorimetric and the silver titrimetric methods for the determination of malathion were studied collaboratively. The study involved wettable powders, emulsifiable concentrates, dusts, and the technical grade product. The mean of all of the results indicates that both procedures will give comparable values for each sample type used in the study. Agreement between replicates in individual laboratories was excellent. Agreement between laboratories was satisfactory; coefficients of variation ranged from 1.3 to 4.8% for the samples studied. The 2 methods offer improved reliability and ease of operation when compared to the official first action colorimetric method, 6.265–6.269. The methods have been adopted as official first action.
Collaborative Study of Methods for the Analysis and Control of AG-Chlordane and Its Formulations
Authors: Malina Marshall A 
Published: February 2020

Abstract
Four methods for the analysis of AG-chlordane and its formulations were submitted to a collaborative study. Fifteen laboratories, including 5 CIPAC laboratories, participated in this study. The infrared method for the analysis of the content of the 2 chlordane isomers was precise, with a coefficient of variation of 0.015. The gas chromatographic method for the analysis of the heptachlor content also yielded good precision with a standard deviation of 0.16. The infrared assay method for granular formulations exhibited excellent accuracy and precision, with a coefficient of variation of 0.067 and an error of only +0.25% relative. The gas chromatographic assay method for emulsifiable concentrates exhibited poor accuracy and precision and was found unacceptable. The first 3 methods have been adopted as official first action.
Gas Chromatographic Determination of Ethanol and Isopropanol or Acetone in Drugs
Authors: Falcone Nicholas 
Published: February 2020

Abstract
A gas-solid chromatographic technique, using flame ionization detection and a Porapak Q column, is presented for the identification and determination of ethanol and isopropanol or acetone in pharmaceutical products. The technique involves direct injection of an aqueous dilution of the product and is therefore simple and direct. The commercial products and 3 simulated mixtures, at various concentration levels, were analyzed by 9 collaborators. Recoveries and standard deviations for all 3 components were satisfactory. The method has been adopted as official first action.