bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Thiamine in Pinto Beans by Gas Chromatography of the Sulfite Cleavage Product 5-(2-Hydroxyethyl)-4-methylthiazole
Authors: Seifert Richard M , Miller Charlotte Fung 
Published: February 2020

Abstract
A gas chromatographic method has been developed for the analysis of thiamine in pinto beans. The method should be applicable to other products. Thiamine is extracted and then quantitatively split by sulfite treatment to give the ether-extractable 5-(2-hydroxyethyl)-4-methylthiazole. The thiazole was analyzed by GLC. Its purity and identity were confirmed by mass spectrometry and GLC retention time. Total thiamine (as the HCl) calculated from the analyzed thiazole averaged 164 ±16 μg/25 g pinto beans. Recovery of total thiamine in 25 g pinto bean samples containing added thiamine HCl (100–500 μg) ranged from 97 to 83%. GLC analysis of pinto bean samples was in good agreement with analysis by the thiochrome method at levels of 5.9–8.6 μg/g, but results were more variable at lower levels.
Collaborative Study of a Gas-Liquid Chromatographic Method for the Determination of Water-Soluble Menadione (Vitamin K3) in Feed Premixes
Authors: Winkler Victor W 
Published: February 2020

Abstract
A GLC method for the determination of menadione bisulfite addition products in feed premixes was tested by 8 laboratories. Menadione sodium bisulfite complex (trihydrate) is extracted with methanol containing 1 mg diethyl phthalate/ml as internal standard and injected directly onto a 2% OV-17 (silylated) GLC column. The principle of the method is on-column pyrolysis of menadione bisulfite and subsequent GLC analysis of the pyrolytic product, menadione. The method is simple, rapid, and free from interference. The average recovery values for 4 samples at 16.0, 14.4, 4.0, and 3.6 g/lb ranged from 95.8 to 100.4% with coefficients of variations between 5.5 and 6.5%. The method has been adopted as interim official first action.
Quantitative Fluoro densitometric Determination of Quinine in Soft Drinks
Authors: Beljaars Paul R , Koken Paul J 
Published: February 2020

Abstract
A quantitative fluorodensitometric method is described for the determination of quinine in soft drinks such as tonic water, lemonades, and fruit juices. This method is based on treatment of sample with an alkaline mixture of methanol-25% ammonia (485+15), followed by TLC analysis on silica gel G plates. The plates are developed with a mixture of chloroform-methanol-acetic acid (80+20+3) in saturated tanks. After development, the TLC plates are scanned with a reflectance flying-spot densitometer. The relationship between recorded peak area and concentration of bluish fluorescent standard spots is linear for 0.1–1.0 μg quinine. HCI.2H2O. Coefficients of variation of 2.0–2.5% are obtained for the fluorodensitometric determination of quinine in spiked tonic water as well as fruit juice. Results obtained in this study are compared with those found by methods prescribed by the AOAC, van Gils and Hidskes, and Hey. Coefficients of variation for the direct and indirect UV Spectrophotometric methods range from 0.75 to 1.40%. Recoveries of 96.9–100.7% are obtained for spiked beverages analyzed by either the densitometric or the Spectrophotometric methods. Despite its lower accuracy, the fluorodensitometric method is suitable as a screening procedure for routine analysis and is applicable to the determination of quinine in several types of soft drinks.
Determination of Residues of Benomyl, Its Hydrolysis Product, and Thiabendazole in Various Crops
Authors: Aharonson Nadav , Ben-Aziz Abraham 
Published: February 2020

Abstract
An analytical procedure is described for residue determination of benomyl, its hydrolysis product, 2-benzimidazole carbamic acid methyl ester (MBC), and thiabendazole (TBZ) in various plants. The method involves acetone extraction, partitioning between acetone-water and ethyl acetate, and cleanup on a magnesium oxide-Celite-alumina column. Benomyl is quantitatively converted on the chromatographic column to MBC, whereas TBZ is unchanged. The compounds are quantitatively measured by direct fluorometric measurement of either MBC or TBZ. The method is sensitive to 0.1 ppm benomyl and 0.02 ppm TBZ. The results from check samples have shown very good reproducibility and accuracy.
Determination of Malathion in Enzymic Digests by the Ferric-Hydroxamate Method
Authors: Bhagwat Vasanti M , Ramachandran Bhikshandar V 
Published: February 2020

Abstract
The ferric-hydroxamate method of Hestrin for the determination of esters, when applied to aqueous suspensions of malathion, yields low absorbance values; the molar absorbance indicates that only one ester group is being hydroxamated. However, when the compound is dissolved in methanol the absorbance is doubled, both the ester groups presumably taking part in the reaction. With this modification the method is sensitive enough for routine assays of malathion residues. The absorbance is proportional to the amount of malathion between 0.5 and 2.0 μmoles. Malathion can be quantitatively recovered from aqueous media by a single extraction with cyclohexane. Aliquots of the extract are evaporated to dryness and the residue is dissolved in methanol and assayed. The procedure described is suitable for the analysis of a large number of samples, such as in malathion esterase studies, and may be used for the determination of malathion in formulations.
Gas-Liquid Chromatographic Determination of Dursban Insecticide (Chlorpyrifos) in Formulations
Authors: Fuzesi Martha 
Published: February 2020

Abstract
A simple and rapid gas-liquid chromatographic method is described for the quantitative determination of chlorpyrifos in liquid and granular formulations. The sample is extracted with benzene and equal amounts of sample and reference solution in the same concentration range are injected into a gas chromatograph equipped with an electron capture detector and an SE-30/Diatoport S column. Peak heights are used for quantitative measurements. The method has been applied successfully to laboratory-prepared and commercial samples.
Steroids in Aged Whisky
Authors: Black Robert A , Andreasen Arthur A 
Published: February 2020

Abstract
Steroids were isolated from aged whisky and identified as β-sitosterol-D-glucoside, β-sitosterol, stigmasterol, and campesterol. Only β-sitosterol-D-glucoside has been reported in whisky. These steroids were characterized by gas-liquid chromatography, thin layer chromatography, and infrared spectrophotometry. They are extracted from the barrel during maturation and can contribute to clarity instability in finished whisky products.
Automated Determination of Fat in Milk: Preliminary and Collaborative Studies
Authors: King Raymond L 
Published: February 2020

Abstract
The principles and operation of an Auto-Analyzer system are described and the system was compared to the Babcock method. Initial calibration studies verified the manufacturer’s claim of linear response between 2 and 6% fat. Homogenization and heat treatment caused slightly higher and lower results by the AutoAnalyzer system and the Milko-tester, respectively, when raw milk was used for calibration. Use of formalin as a preservative resulted in a positive bias of less than 0.04% fat. Mercuric chloride and potassium dichromate caused no effect. Standard deviation of the difference from the Babcock method for the calibration studies was less than 0.05%. The standard deviations ranged from 0.031 to 0.077 for 345 raw milk samples from individual dairy farms. Collaborative studies encompassed 15 samples ranging from 3 to 6% fat, including 3 blind duplicates plus calibration standards. Samples were analyzed in triplicate by 6 laboratories, using 2 methods of AutoAnalyzer calibration. The standard deviation was less for the AutoAnalyzer than for the Babcock method (0.048 and 0.047% fat, respectively). Differences between 3 pairs of blind duplicates were 0.013, 0.021, and 0.012% fat by the Babcock and AutoAnalyzer analyses, respectively.
Aflatoxin-Solvent Interactions Induced by Ultraviolet Light
Authors: Wei Ru-Dong , Chu Fun Sun 
Published: February 2020

Abstract
The effect of UV light on the fluorescence intensity of aflatoxins in various solvents and on the photocatalyzed addition of alcohols and water to the vinyl ether double bond of aflatoxins B1 and G1 was investigated. Four groups of new aflatoxins, designated as Bm, Be, Gm, and Ge, were found to result from the UV light-catalyzed aflatoxin-solvent interaction. These compounds were less toxic to chicken embryos than the parent toxins.
Method for the Determination of Aflatoxin in Animal Tissue
Authors: Brown Nathan L , Nesheim Stanley , Stack Michael E , Ware George M 
Published: February 2020

Abstract
The method consists of methanol extraction, purification of the extract by transfer from aqueous methanol to chloroform, silica gel column chromatography, partition chromatography according to Pons on a celluloseaqueous methanol column, and quantitation by TLC fluorodensitometry. Average recoveries of B1, B2, G1, G2, and M1 from liver, kidney, heart, and round steak spiked at 0.05, 0.1, and 0.2 μg/kg were 43–123% as measured by TLC fluorodensitometry. The method was successfully applied to the analysis of naturally contaminated liver, kidney, and heart tissues.
Analysis and Survey of Ground Black, White, and Capsicum Peppers for Aflatoxins
Authors: Scott Peter M , Kennedy Barry P C 
Published: February 2020

Abstract
Reports of contamination of condiments prepared from Piper nigrum (black and white pepper) and Capsicum spp. by toxicogenic strains of Aspergillus flavus pointed to the need for methods of analysis for aflatoxins in these products. Use of 2-dimensional thin layer chromatography readily allowed the detection of 1.3–2.5 μg aflatoxin B1, B2, G1, or G2/kg in pepper extracts obtained by AOAC official first action methods for the analysis of aflatoxins in peanuts and peanut products. Approximate percentage recoveries of the aflatoxins added to the ground pepper at levels of 10–40 μg/kg ranged from 60 to 100%. A survey of 24 ground black and white pepper samples and over 70 capsicum pepper samples for aflatoxins revealed the presence of low concentrations (up to about 8 μg aflatoxin B1/kg) in 3 types of capsicum pepper: ground cayenne pepper (10 of 17 brands), Indian chilli powder (6 of 6 brands), and crushed, dried chillies (1 of 1).
Spectrophotofluorometric Estimation of Low Levels of Diethylstilbestrol in Feedstuffs
Authors: Jeffus Marshall T , Kenner Charles T 
Published: February 2020

Abstract
A method for the determination of low levels of diethylstilbestrol in feedstuffs is described. Interfering feed extractives are removed by using a tripotassium phosphate-Celite column prior to irradiation. The dione produced by irradiation is oxidized to a phenanthrenediol and extracted into CH2CI2 for measurement of fluorescent intensity. The amount of diethylstilbestrol found in several feed samples ranged from 0 to 10 ng (0.0–0.5 ppb) with an average of 4 ng (0.2 ppb). Recoveries of 100 ng standards (equivalent to 5 ppb) added to the same samples averaged 91 ng with a standard deviation of 14 ng. Recoveries of 1000 ng standards (equivalent to 50 ppb) added to the same samples averaged 820 ng with a standard deviation of 14 ng. For 100 ng standards analyzed beginning with the irradiation procedure, the standard deviation was 5.6%, and for 1000 ng standards, the standard deviation was 2.8%.
Simplex Optimized Acetylacetone Method for Formaldehyde
Authors: Czech Fred P 
Published: February 2020

Abstract
The AOAC colorimetric acetylacetone method for formaldehyde in sugar products is optimized by means of the simplex experimental design process. The resultant method is almost 4 times as sensitive as the original AOAC method. It is about 33% more sensitive than the simplex optimized J-acid procedure and 45% more sensitive than the simplex optimized chromotropic acid method and, thus, represents one of the most sensitive methods now available. The average relative standard deviation is about ±2.7%. The limit of detectability is estimated to be 30 ppb. The didactic exposition of the simplex optimization process reported earlier is applied to the AOAC acetyl-acetone method. Further insights into simplex operations are provided and certain advantages of simplex application are pointed out. It is shown that, by sacrificing the high sensitivity of the optimized method the parameters of the new method result in about a 10-fold increase in analytical speed. Further application of kinetic considerations and the advantages of high quality, productivity, and economy in chemical analytical methods by means of the simplex experimental design process are described.
Semiautomated Method for More Precise and Sensitive Determination of Nonpolar Anticholinesterase Insecticides with Technicon Modules
Authors: Voss Günther 
Published: February 2020

Abstract
The problem of adsorption of relatively nonpolar anticholinesterase insecticides to Technicon® proportioning pump tubing is now eliminated by manually injecting sample solutions into a special injection chamber just downstream from the pump, rather than pumping them through tubing. Experimental results demonstrate that the problems of cross-contamination, prolonged interwash periods, shifts of baselines, and reduced sensitivity are satisfactorily solved by this technical modification.
Sensitive Cellulose Column for the Rapid Detection of Aflatoxins in Agricultural Products
Authors: Jemmali Mongi 
Published: February 2020

Abstract
A simple and rapid screening method has been developed for the detection of less than 5 ppb aflatoxin B1 in corn. Cellulose tubing is layered with acidic alumina, anhydrous sodium sulfate, and silica gel. The sample is applied to the column, which is developed in chloroform-acetonitrile-2-propanol. A sharp blue fluorescent band is an indication of the presence of aflatoxin. Sulfuric acid treatment, which will yield a yellow color in the presence of aflatoxin, may be used as a further confirmatory test.
Gas-Solid Chromatographic Determination of Carbon Monoxide and Carbon Dioxide in Cigarette Smoke
Authors: Horton Arthur D , Guerin Michael R 
Published: February 2020

Abstract
Gas-solid chromatographic methods are presented for the determination of carbon monoxide, carbon dioxide, or both simultaneously in the gas phase of cigarette smoke. The methods are optimized to allow quantitative determinations on the entire gas phase delivery of the cigarettes rather than single puffs and to allow the use of small numbers of cigarettes. Shortcomings of several sampling techniques are defined, and evidence is presented supporting the utility of Saran bag sampling and containment. Carbon monoxide and carbon dioxide analyses may be performed with relative standard errors of 2—3% and relative confidence intervals (95%) of 6—9% for determinations involving 4—6 cigarettes.
Automated Proof Determination of Liquors by Gas-Solid Chromatography
Authors: Venturella Vincent S , Graves Donald , Lang Robert E 
Published: February 2020

Abstract
A gas-solid chromatographic method, specifically designed for ease of automation, has been developed for the determination of the ethanol and/or methanol content of a variety of liquors. Both manual and automated procedures and results are described. The method is precise and accurate, and the results are comparable with the distillation/specific gravity technique. Using the automated procedure, 13 samples can be analyzed in duplicate during a workday.
Liquid Chromatographic Determination of Bergapten Content in Treated or Natural Bergamot Oils
Authors: Porcaro Peter J , Shubiak Peter 
Published: February 2020

Abstract
The method presented is a simplified and sensitive liquid chromatographic approach to the assay of the furocoumarin, bergapten, present in oil of bergamot. The method is faster and more reliable than thin layer chromatographicultraviolet assays currently in use. Various oils, treated and untreated, are tested for detection down to 0.001% or 10 ppm levels. Repetitive analyses give a standard deviation of 0.139 or a relative value of 1.61 %.
Gel Permeation Chromatographic System: An Evaluation
Authors: Griffitt Kenneth R , Craun John C 
Published: February 2020

Abstract
A gel permeation chromatography (GPC) system, including an automated GPC instrument, was evaluated and was found to be a reliable and efficient tool for fat-pesticide separations. In most cases more than 98% of the fat or oil was eluted from the column before the pesticides fraction began to elute. Cleanup efficiency was better than that obtained with acetonitrile partitioning, even when a petroleum ether backwash was used. Recoveries of several pesticides and industrial chemicals from milk fat were determined, with GPC as the only cleanup technique employed before gas chromatographic determination. Recoveries generally were better than those obtained with acetonitrile partitioning followed by Florisil cleanup. The automated instrument can be in operation unattended during non-working hours and, after loading, will automatically clean up 23 individual fat samples.
Rapid Gas Chromatographic Method for Screening of Pesticide Residues in Milk
Authors: Gabica Joe , Watson Michael , Benson Woodrow W 
Published: February 2020

Abstract
A rapid version of the official AOAC milk extraction method, modified to exclude lengthy chromatographic cleanup, is described. Lipid-soluble material is extracted with a diethyl ether-hexane mixture. Pesticides are then partitioned into acetonitrile and are reextracted with hexane. The concentrated hexane extracts are analyzed by gas chromatography, providing relatively sensitive results with a minimum of interfering extraneous peaks. This method may be useful in screening large numbers of samples and indicating those that may require more thorough analysis.
Gas-Liquid Chromatographic Determination of Acephate and Ortho 9006 Residues in Crops
Authors: Leary James B 
Published: February 2020

Abstract
A gas chromatographic method is described for determining acephate (O,S-dimethyl acetylphosphoramidothioate) and a metabolite, Ortho 9006 (O,S-dimethyl phosphoramidothioate), in a variety of crops. After extraction of the sample with ethyl acetate, the solvent is evaporated, and an ether solution of the residue is passed through a silica gel column to remove interferences. Acephate and Ortho 9006 are eluted from the column with 10% methanol in ether and measured simultaneously by programmed temperature gas chromatography, using an alkali flame ionization detector.
Multiresidue Method for the Determination of Triazine Herbicides in Field-Grown Agricultural Crops, Water, and Soils
Authors: Ramsteiner Klaus , Hormann Wolf D , Eberle Dieter O 
Published: February 2020

Abstract
A gas chromatographic multiresidue method is described for the following triazine herbicides: ametryn, atraton, atrazine, desmetryn, metoprotryn, GS-13529, GS-14254, terbutryn, prometon, prometryn, propazine, and simazine. The method consists of a methanol extraction, cleanup on an alumina column, and determination on a Carbowax column with nitrogen-, sulfur-, and chloride-specific detectors. Extraction and recovery data are given.
Chromous Chloride Reduction. VIII. Reaction of Some Derivatives and Degradation Products of Heptachlor with Chromous Chloride-Ethylenediamine Complex and Nuclear Magnetic Resonance and Mass Spectra of the Products
Authors: Chau Alfred S Y , Demayo Adrian , Apsimon John W , Buccini John A , Fruchier Alain 
Published: February 2020

Abstract
The use of the chromous chloride-ethylenediamine (CrCl2-en) complex to speed dechlorination and minimize side-products has been explored for heptachlor metabolites and degradation products. Five pentachloro heptachlor derivatives are synthesized, and their nuclear magnetic resonance and mass spectra are presented and discussed. Nuclear magnetic resonance data support the anti assignment of H- in the major products from CrCl2-en reduction of cyclodiene pesticides. The use of this reagent for possible development of chemical confirmatory tests for heptachlor metabolites and degradation products is also briefly discussed.
Modified Extraction Procedure for Ipronidazole in Feeds Containing Bentonite
Authors: Osadca Modest , Araujo Mercedes , De Ritter Elmer 
Published: February 2020

Abstract
The extraction procedure in the AOAC method for ipronidazole in feeds, 38.A01— 38.A07, has been modified to eliminate the interference of bentonite with recovery of ipronidazole from mash feed and pellets. Quantitative extraction from mash feed or ground pellets is achieved by shaking the sample with benzene after a brief soaking with warm, aqueous pH 8 buffer. Gas-liquid chromatography is used to measure ipronidazole in the benzene extract as in the AOAC method. A preliminary collaborative test of the modified method by 3 laboratories on 8 samples of feed containing 0, 2, or 5% bentonite yielded average assays of 0.0061, 0.0058, and 0.0062% ipronidazole, with coefficients of variation averaging 2.4, 6.2, and 4.4%, respectively. Further collaborative study of the modified method is recommended.
Semiautornated Determination of Ormetoprim in Feeds
Authors: Osadca Modest , Araujo Mercedes , De Ritter Elmer 
Published: February 2020

Abstract
An automated spectrofluorometric method has been developed for determining ormetoprim in feeds at use levels of 0.0037-0.0075%. After manual extraction involving enzyme digestion, blending with alkali and chloroform, and cleanup of the extract by solvent transfers, the oxidation and fluorescence measurement steps are fully automated. The automated system includes oxidation with permanganate, removal of excess permanganate with nitrous acid and of excess nitrous acid with urea, acidification, extraction of the fluorescent derivative with hexane-tert-amyl alcohol, and fluorescence measurement in a spectrofluorometer with a recorder and printout. Recoveries of ormetoprim added to feeds are good, the fluorescence response is linear over a suitable working range, and blank values on unmedicated feeds are negligible. Twenty to thirty extracts per hr can be assayed by the automated method with increased precision over an allmanual operation.
Comparison of Babcock and Roese-Gottlieb Methods for Determining Butterfat in Milk
Authors: Moore John M , Russell Sargent , Pelsue Neil H 
Published: February 2020

Abstract
Raw milk of varied fat content was analyzed by the Roese-Gottlieb and Babcock methods. The Babcock test level averaged 0.03 units higher than the Roese-Gottlieb test level for milk containing 3.066—5.580% butterfat. The standard deviations of the Babcock and Roese-Gottlieb methods were 0.039 and 0.010, respectively.
Evaluation of Automated Dye Binding Determination of Protein in Milk
Authors: Park Douglas L , King Raymond L 
Published: February 2020

Abstract
The Technicon AutoAnalyzer dye binding system for protein determination in milk was compared with the Kjeldahl and Udy methods. Individual cow and mixed herd milk samples were analyzed, including such variables as the effect of aging, chemical preservation, laboratory manipulation of protein content, and experimental changes in instrumental parameters. The Udy and Kjeldahl methods showed better agreement than the Technicon procedure in all treatments. Aging resulted in slight decreases in apparent protein content by both dye binding methods. Variation due to treatment with formaldehyde and mercuric chloride was considerable for the Technicon system (+ 0.72 and +0.20% protein, respectively). Individual cow milks varied more than herd milks and Guernsey more than Holstein milk. Milk samples standardized for protein content showed a high correlation with the Kjeldahl results. Replication by the Technicon system was superior to both the Udy and Kjeldahl methods. Performance of the Technicon system improved with increased dialyzing time, decreased dye concentration, and decreased sampling rate. Instrument performance was also influenced by dialysis membrance replacement.