bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved Cleanup Technique for Estimation of Endosulfan Residues from Fish Tissues under Tropical Conditions
Authors: Rao Desiraju M R 
Published: February 2020

Abstract
A new solvent system, 1% and 2% acetone in hexane,was developed for chromatography on partially inactivatedFlorisil to facilitate the separation of isomersof endosulfan and its metabolites from fishtissues under tropical conditions. By using the colorimetricmethod of Maitlen et al. (1963), the minimumdetectable limit for each isomer of endosulfanin various fish tissues is 5 µg. With this solventsystem, the 2 isomers present in the technical materialcan be separated, so their toxicity to fish can be assessedseparately.
Spectrophotometric Determination of Chloramphenicol and Its Esters in Complex Drug Mixtures
Authors: Devani Muljibhai B , Shishoo Chamanlal J , Doshi Kokila J , Shah Ashok K 
Published: February 2020

Abstract
When aromatic nitro compounds are reduced with zinc and calcium chloride and reacted with trisodium pentacyanoaminoferrate they give a purple product having an absorbance maximum between 480 and 540nm. Applying this reaction, a quantitative method has been developed for the determination of chloramphenicol and its esters. Various reaction conditions have been standardized. Beer’s law is obeyed in the concentration range of 4 to 32 μg/mL reaction mixture. Average recoveries and standard deviations were 99.78 ± 0.627 and 99.90 ± 0.660; 101.06 ± 0.702; and 99.90 ± 0.880% for chloramphenicol, chloramphenicol sodium succinate, and chloramphenicol palmitate, respectively. The method has also been applied to determine chloramphenicol and its esters as well as chloramphenical in the presence of combination drugs in dosage forms. The presence of benzocaine, lignocaine, sulfadiazine, nitrofurantoin, ascorbic acid, hydrocortisone, prednisolone, streptomycin, and tetracycline does not interfere with the proposed spectrophotometric procedure. The method does not require prior separation of chloramphenicol from combination drugs.
Gas Chromatographic Determination of Cadaverine, Putrescine, and Histamine in Foods
Authors: Staruszkiewicz Walter F , Bond John F 
Published: February 2020

Abstract
A GLC procedure for the quantitative determination of the diamines putrescine and cadaverine has been developed, using their perfluoropropionyl derivatives. The amines were extracted from foods with methanol; an internal standard, hexanediamine, was added and a dry residue of their hydrochloride salts was prepared. The salts were derivatized with perfluoropropionic anhydride by heating for 30 min at 50°C. The reaction mixture was separated on an alumina column to remove excess reagent, and the derivatives were eluted with a solution of 30% ethyl acetate in toluene. GLC separations were performed on a 3% OV-225 column held at 180°C. The retention times were 4.3,5.7, and 7.0 min for the derivatives for putrescine, cadaverine, and the internal standard, respectively. Less than 1 μg diamine/g tissue could be quantitated, using either an electron capture detector or a nitrogen-specific detector. The procedure was applied to cheese and a variety of fishery products. An increase in the diamines correlated with the presence of decomposition in some of the products. A collaborative study of the method is planned.
Manual and Semiautomated Spectrophotometric Determination of Vitamin K3 by Reactions with Piperidine and Malononitrile
Authors: Hassan Saad S M 
Published: February 2020

Abstract
Simple, rapid, selective, and sensitive spectrophotometric methods are described for manual and semiautomated determination of vitamin K3. These methods are based on reactions with piperidine and malononitrile whereby intense red and blue colors with maximum absorption at 510 nm (E1%1cm 150) and 580 nm (E1%1cm 155), respectively, are developed. The reactions are sensitive enough to permit the determination of 2-100 μg vitamin K3/mL with an average recovery of 98% and a standard deviation of 1%. There is no interference from vitamins K1 and K2, and the reduced forms of K vitamins, or from many common pharmaceutical diluents and additives.
Fourth Interlaboratory Study of Methods for Determining Total Migration of Plastic Materials in Liquids Simulating Fatty Foodstuffs
Authors: Rossi Luigi 
Published: February 2020

Abstract
Results are reported for the fourth interlaboratory study organized by the Commission of the European Communities for the adoption of an official method for determining the total migration of plastic materials in liquids simulating fatty foodstuffs. In each method, a sample of plastic material was weighed before and after it was placed in contact with fatty simulants. The fat absorbed by the sample, extracted or dissolved by suitable solvents, was determined by gas chromatography or radiometry. The results obtained confirm the conclusions given previously. Each method was moderately satisfactory, but less so between laboratories.
Open Digestion Modification of AOAC Method for Determination of Mercury in Fish
Authors: Duve Ram N , Chandra Jeffery P , Singh Satend B 
Published: February 2020

Abstract
The vanadium pentoxide-catalyzed reflux method has been modified to allow open digestion of samples in preparation for determination of organic and inorganic mercury. The reflux digestion performed wilh a bunsen burner resulted in charred samples, but digestions performed in tubes in a 95-100°C water bath were satisfactory. As many as 40 digestions can be carried out simultaneously, and the technique offers a fast and simple approach to digestion, dilution, and transfer.
Modified Colorimetric Method for Determining Indole in Shrimp
Authors: Cheuk Wailun , Finne Gunnar 
Published: February 2020

Abstract
A modified spectrophotometry method for measuring indole in shrimp is described. The method was developed to eliminate the time-consuming steam distillation and expensive instrumentation required by the official AOAC methods. Indole is extracted with light petroleum from trichloroacetic acid-precipitated shrimp muscle. The extracted indole, soluble in light petroleum, is reacted and re-extracted with Ehrlich’s reagent; indole in the form of a rose indole complex can be determined spectrophotometrically. When shrimp at various degrees of decomposition were analyzed for indole by the modified method as well as by the official AOAC colorimetric method, the correlation coefficient between the data from the 2 methods was 0.98.
Gas-Liquid Chromatographic Determination of Terbuthylazine Technical and Its Formulations: Collaborative Study
Authors: Meier Juerg , Nowak Klaus , Suter Rolf , Tomann Andrea , Bosshardt Hans P ,   Collaborators:, Amadori A , Basters I J , Bátora V , Benoit A , Davies T , Demaurex A , Dobrat W , Gideon R P , Heegemann H , Henriet E , Hofberg A H , Laass H , Larsen M , Magallanes M , Martijn A , Müller W , Nabors J B , Nixon H , Paasivuo P , Pavel K , Povlsen H H , Reuthinger E , Rasero F Sanchez , Scheck L , Stettler J , Rossum A Van , Winsauer K 
Published: February 2020

Abstract
Terbuthylazine technical and its 80% wettable powder were analyzed in a CIPAC collaborative study. The content and the identity were determined by gas-liquid chromatography on a column of 3% Carbowax K20M on Gas-Chrom Q, using di-n-pentylphthalate as the internal standard. Results obtained from 27 government, university, and industrial collaborators showed within-laboratory repeatability of 1.3% for the technical and 1.0% for the wettable powder. Reproducibility was 2.1% for both samples. The method has been adopted official first action
Portable and Sensitive Detector Strips for Rapid Detection of Organophosphorus, Mercury, Copper, Cadmium, and Silver Compounds
Authors: Kumar Nanguneri V Nanda , Devi Yalavarthi Prameela 
Published: February 2020

Abstract
Portable and sensitive detector strips developed for rapid detection of organophosphorus, mercury, copper, cadmium, and silver compounds are inexpensive, indefinitely stable, and easy to use. The strips require mild moistening with distilled water and warming for the reaction involving cholinesterase and succinate dehydrogenase inhibition by organophosphorus and heavy metal compounds, respectively. The detector strips, designated A, B, and C, can be combined to detect heavy metals and organophosphates as their oxygen analogs at nanogram concentrations in 5-10 min with little cleanup, so the strips can be used under field conditions
High Pressure Liquid Chromatographic Determination of Sulfisoxazole in Pharmaceuticals and Separation Patterns of Other Sulfonamides
Authors: Roos Robert W 
Published: February 2020

Abstract
A high pressure liquid chromatographic method has been developed for the identification and determination of sulf isoxazole in tablet, liquid, and ointment dosage forms. The method specifies a µBondapak C18 column, an acetonitrile-acetic acid-water (22.5 + 1 + 76.5) mobile phase, and ultraviolet detection at 254 nm. For quantitative purposes, sulfabenzamide is used as an internal standard. Commercial preparations were analyzed by the proposed method and results were compared with those obtained by the U.S. Pharmacopeia XIX and National Formulary XIV methods; good agreement was obtained. The elution behaviors of 19 additional sulfonamides were also established to verify the specificity of the proposed method for sulfisoxazole. These elutions patterns show potential for separation and identification of all 20 sulfonamides
High Performance Liquid Chromatographic Analysis of Hydrocortisone Acetate Ointments: Interlaboratory Study
Authors: Hailey David M , Lea Anthony R 
Published: February 2020

Abstract
An interlaboratory study was carried out on a high performance liquid chromatographic method for determining hydrocortisone acetate in ointments. The method represents an alternative to the colorimetric procedure of the British Pharmacopoeia. Two samples of a commercially available hydrocortisone acetate ointment were analyzed by 14 laboratories. Column performance and precision of the assay were satisfactory. The total error standard deviation for the method was 3.69%.
Rapid Method for Estimation of N-Nitrosodimethylamine in Malt Beverages
Authors: Hotchkiss Joseph H , Havery Donald C , Fazio Thomas 
Published: February 2020

Abstract
A new, rapid column elution method is described for the estimation of N-nitrosodimethylamine in malt beverages. Recoveries for N-nitrosodimethylamine and N-nitrosodipropylamine fortified at 5 ppb averaged 90 and 91%, respectively. A study of 20 different malt beverages showed that the resuts obtained with this method compared favorably with those obtained by a direct distillation procedure.
High Performance Liquid Chromatographic Preparation of Alternariol, Alternariol Methyl Ether, and Altenuene
Authors: Chu Fun S , Bennett S Christopher 
Published: February 2020

Abstract
A solvent system was developed for the isolation of 3 major Alternaria mycotoxins by high performance liquid chromatography (HPLC). Alternariol (AOH), alternariol methyl ether (AME), and altenuene (ALT) were purified using either a semipreparative or a preparative HPLC column. Gram quantities of pure mycotoxins were obtained in a single preparative HPLC step. Distribution of other individual mycotoxins and metabolites in various fractions obtained from either chromatographic procedure is discussed.
Potential Mold Growth, Aflatoxin Production, and Antimycotic Activity of Selected Natural Spices and Herbs
Authors: Llewellyn Gerald C , Burkett Mary Lee , Eadie Thomas 
Published: February 2020

Abstract
Ground spices and herbs are evaluated as substrates for mycelial growth, sporulation, and aflatoxin production. Three toxigenic strains of Aspergilli, A. flavus ATCC 15548, A. flavus NRRL 3251, and A. parasiticus NRRL 2999, were cultured on moist, commercially packaged herbs and spices. All substrates used were ground and included thyme, celery seed, oregano, cinnamon, ginger, caraway seed, clove, mustard, sesame seed, and rosemary leaves. Following inoculation of the natural materials in sterile bottles containing sterile water, the cultures were incubated 30 days at 23 ± 4°C. Not all strains of Aspergilli grew, sporulated, or produced toxins. There were definite strain differences and definite substrate differences for the variables evaluated. Sesame seed produced toxins B1, G1, and G2, with a mean of 167 ppm for 3 strains. A. flavus ATCC 15548 was the greatest overall toxin producer followed by A. partsiticus NRRL 2999 and A. flavus NRRL 3251. Ginger and rosemary leaves were also substantial producer-substrates. Mustard, caraway seed, and celery seed were judged as intermediate-producing substrates. Absolute antimycotic substrates were cinnamon and clove. Antiaflatoxigenic substrates were thyme and oregano. Mustard also may be antimycotic. Aflatoxins B1 and G1 were the more commonly found toxins
Gas Chromatographic Determination of Trialkyl/Aryl Phosphates in Drinking Water, Following Isolation Using Macroreticular Resin
Authors: Lebel Guy L , Williams David T , Benoit Frank M 
Published: February 2020

Abstract
An XAD-2 screening method developed previously fororganophosphorus pesticides has been extended to determine trialkyl/aryl phosphates in drinking water at the ng/L level. Recovery studies at 1,10, and 100 ng/L levels were carried out by fortification onto XAD-2 resin and by direct on-stream fortification of drinking water. Recoveries were &gt;70% for tri-nbutyl, tris(2-chloroethyl), tri(2-ethylhexyl), tributoxyethyl, triphenyl, and tricresyl phosphate. Triethyl phosphate recoveries were about 25%. Analysis of drinking water samples collected at 6 eastern Ontario water treatment plants revealed the presence of several trialkyl/aryl phosphates at levels ranging from 0.2 to 75 mg/L.
Ultra Trace Determination of Furazolidone in Turkey Tissues by Liquid Partitioning and High Performance Liquid Chromatography
Authors: Winterlin Wray , Hall Gregory , Mourer Charles 
Published: February 2020

Abstract
A simple and sensiiive procedure is presented for the I determination of furazolidone in turkey tissues, j using liquid partitioning followed by high performance liquid chromatography (HPLC). Fat, liver, kidney, skin, and muscle tissues are ground with methylene chloride in a Polytron homogenizer, followed by solvent removal, partitioning in hexane-0.01M acetic acid, and back-partitioning the 0.01M acetic acid with methylene chloride. The determination by HPLC used a reverse phase Ultrasphere- ODS 5 μm column. The method is sensitive to 0.5 ppb, with a standard deviation of 6.39% at the 2 ppb fortification level. Recovery from fortified tissues j averaged 84% from samples fortified with 0.5-10 ppb furazolidone. An alternative cleanup procedure I using a Sep-Pak C18 cartridge is also presented.
Automated Determination of Urea and Ammoniacal Nitrogen (NPN) in Animal Feeds
Authors: Wall Larry L , Gehrke Charles W 
Published: February 2020

Abstract
A minor modification in the automated analytical system of the official AOAC semiautomated method for determining crude protein results in an automated method for determining urea and ammoniacal nitrogen in animal feeds and their ingredients. Urease enzyme which has high activity, yields a clear solution in water, has low ammonia impurity, and is inexpensive is used in the automated method. Weights from 1 to 2.5 g feed sample are dissolved in water, and sample solutions are analyzed at the rate of 40 samples/ h. Five AAFCO feed check samples were analyzed repeatedly by the automated method, and results were compared with the grand averages from the check sample reports. The official AOAC manual urease method was used by AAFCO participants. Average recovery of urea and ammoniacal nitrogen was 100.6% by the automated method relative to the AAFCO reported averages. The range of recoveries was 98.5-102.7%. The non-protein nitrogen (NPN) concentrations, expressed as protein equivalent, ranged from 3.40 to 63.04% protein on these samples. The average relative standard deviation for the automated analyses was 0.77%, compared with 1.54% for the manual method. This method is an important adjunct to laboratories using or considering use of the semiautomated method for crude protein and needing further information on NPN.
Ammonia-Selective Electrode Determination of Nitrogen in Fertilizers
Authors: Boy Victor M , Guijosa Manuel 
Published: February 2020

Abstract
The official AOAC magnesium oxide method (MOM), 2.065, for determining ammoniacal nitrogen in fertilizers not containing urea was compared with an alternative ammonia-selective electrode method (ASEM-1). Likewise, the official AOAC Raney powder method (RPM), 2.063-2.064, for determining total nitrogen in fertilizers, except nitric phosphates containing nonsulfate S, was compared with an ammonia- selective electrode method (ASEM-2). Each comparison included 6 samples. For ammoniacal nitrogen determination, MOM and ASEM-1 showed equivalent precision, although significant statistical differences were obtained in average values for the majority of samples. For total nitrogen determination, RPM and ASEM-2 showed equivalent precision, although significant statistical differences were obtained in 3 samples. The AOAC official methods showed better accuracy than ASEM-1 and ASEM-2. However, the accuracy and precision of ASEM-1 for ammoniacal nitrogen is suitable for routine work.
Headspace Sampling and Gas Chromatographic Determination of Styrene Migration from Food-Contact Polystyrene Cups into Beverages and Food Simulants
Authors: Varner Sandra L , Breder Charles V 
Published: February 2020

Abstract
Migration studies using coffee, tea, water, and 8% ethanol were conducted with various types of foodcontact polystyrene cups. Study conditions simulated filling and storage at room temperature and hot-filling or pasteurization above 150°F (65.6°C). The quantity of styrene migrating was determined by headspace sampling and gas chromatography (GC). The GC column was 6% Carbowax 20M on Chromosorb 101 with quantitation via a flame ionization detector. Detection limits ranged from 3 to 10 ppb in various liquids. The method and results of the migration studies are presented.
Infrared Spectrophotometry Method for Methazole Formulations: Collaborative Study
Authors: Forrette John E ,   Collaborators:, Audino J B , Bennett B R , Boyd W G , Carlstrom A A , Clarke D , Cohen C J , Gale G T , Grorud R B , Looker J B , Rozek A L 
Published: February 2020

Abstract
An infrared method was developed for the analysis of Probe 75% wettable powder formulation for methazole content. The procedure involves an extraction of the powder by agitation with acetone. The suspension is centrifuged, and the clear supernatant liquid is measured for absorbance at 755 cm−1. A collaborative study was conducted with 10 laboratories participating. One laboratory omitted the centrifugation, which resulted in a low assay. Statistical analysis of the data showed no significant variances. The coefficient of variation for 10 laboratories analyzing 2 samples in duplicate was 1.29%. The method has been adopted interim official first action.
Correction of Bias in Collaborative Check Sample Series Reporting
Authors: Kelly Patrick C 
Published: February 2020

Abstract
Scores or accuracy indices used in collaborative check series to evaluate laboratory performance are influenced by factors that have nothing to do with performance. Scores based on normalized deviations are affected by the number of results reported on a given method. The average score or overall accuracy index obtained by a given laboratory is affected also by the number of results reported by that laboratory. By judicious choice of methods on which to report, a laboratory can improve its score without making a corresponding improvement in analytical performance. These effects are revealed in an examination of the statistical distribution of normalized deviations. The magnitude of these effects on laboratory rankings is obtained from modeling experiments with computer-generated random numbers. The inherent unfairness of the conventional method of calculating performance indices can be eliminated by converting normalized deviations to numbers having a normal statistical distribution. This transformation is mathematically complicated, but is not too difficult for a computer. The resulting parameters accurately reflect laboratory performance, are relatively easy to interpret, and permit the establishment of confidence intervals for laboratory rankings.
Determination of Aflatoxins, Ochratoxin A, and Zearalenone in Mixed Feeds, with Detection by Thin Layer Chromatography or High Performance Liquid Chromatography
Authors: Howell Mary V , Taylor Philip W 
Published: February 2020

Abstract
A sensitive, reliable, and economical method for the determination of 6 mycotoxins in mixed feeds is described. The feed is extracted with chloroform-water and the extract is cleaned up by using a disposable Sep-Pak silica cartridge. The procedure requires less time (15 min from sample extraction to extract preparation) and less solvent (approximately one-tenth) compared with conventional methods and is suitable for a fast, economical screen. Additional cleanup procedures, involving dialysis or extraction into base, are described for samples containing high levels of interfering compounds. Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) with fluorescence detection are described for identification and estimation of mycotoxins. The method has been applied to a wide range of mixed feeds, including laboratory animal diets, and raw materials. The limit of detection is 1 μg/kg for all mycotoxins measured by HPLC.
Interaction Between Sample Preparation Techniques and Colorimetric Reagents in Nitrite Analysis in Meat
Authors: Fox Jay B , Zell Tatiana E , Wasserman Aaron E 
Published: February 2020

Abstract
The amount of nitrite measured in model and meat systems was a function of the interactions of the chloride and ascorbate concentrations with the method of sample preparation and the combination of Griess reagents used for colorimetric determination. Ascorbate caused loss of nitrite in the samples when heated and interfered in the Griess reaction, increasing the concentration of pigment formed from any given concentration of nitrite if sulfanilic acid and JV-(l-naphthyl)-ethylenediamine were used, and decreasing the amount if sulfanilamide and 1-naphthylamine were used. The interference was eliminated by both the AOAC procedure and mercuric chloride addition, although the former were less effective at higher ascorbate concentrations. Chloride increased the amount of pigment formed from a given amount of nitrite with sulfanilic acid but had no effect on the amount of sulfanilamide pigment.
Chloridometer Determination of Alien Halide Content of Iodine
Authors: Ferren William , Maltese Leonard 
Published: February 2020

Abstract
A coulometric method is described for measuring alien halide content (usually bromide and chloride) of iodine crystals at levels less than 50 ppm. Our method replaces the vintage visual turbidimetric (Nessler tubes) measurement of the USP and ACS methods with an accurate, precise electronic end point of a chloridometer. The limit of detection is about 1 ng chloride, with an uncertainty of about 3%. Our procedure avoids the inherent errors associated with visual comparison between sample, blank, and control systems with widely differing indifferent ion populations.