bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid Determination of Organochlorine Pesticides and Poly chlorinated Biphenyls, Using Selected Ion Monitoring Mass Spectrometry
Authors: Hargesheimer Erika E 
Published: February 2020

Abstract
Methane chemical ionization (CI)-selected ion monitoring (SIM) mass spectrometry was used to identify and conclusively distinguish 19 organochlorine pesticides from polychlorinated biphenyls (PCBs) at parts-per-trillion to parts-per-billion levels in environmental water sample extracts with minimal sample cleanup. Two CI-SIM screens were developed. One set of ions scanned specifically for the presence of 4 classes of pesticides: diphenylmethane derivatives, bridged polycyclic chlorinated hydrocarbons, chlorinated benzenes, and acetanilide pesticides. The second set of ions responded exclusively to PCBs with biphenyl moieties containing from 1 to 8 chlorine atoms. Eight commercial Aroclor mixtures were analyzed and distinguished from the pesticide groups. The detection limit for pesticides and PCBs by CISIM screening was 0.005 and 0.1 ppb, respectively. CI-SIM can be used as an alternative method for the analysis of biological or environmental samples containing interferences that complicate the detection of PCBs and chlorinated pesticides.
Liquid Chromatographic Determination of Trace Residues of Polynuclear Aromatic Hydrocarbons in Smoked Foods
Authors: Joe Frank L , Salemme Jean , Fazio Thomas 
Published: February 2020

Abstract
A liquid chromatographic (LC) method was developed and applied to the determination of polynuclear aromatic hydrocarbons (PAHs) in a variety of smoked, market basket commodities. The PAHs are extracted with l,l,2-trichIoro-l,2,2-trifluoroethane (Freon 113) from alcoholic KOH digests of the commodities. The extracts are purified by column chromatography through a deactivated silica gel/alumina column and by liquid-liquid partitioning between dimethyl sulfoxide and cyclohexane before separation of the PAHs by LC. Both fluorescence and UV detectors are used to monitor the LC column effluent to detect nanogram quantities of PAHs. Trace levels of carcinogenic and noncarcinogenic PAHs were found in all samples analyzed, although generally at &lt;1 ppb levels.
Direct Enzyme-Linked Immunosorbent Assay for Determining Aflatoxin M1 at Picogram Levels in Dairy Products
Authors: Fremy J Marc , Fun Sun Chu 
Published: February 2020

Abstract
Protocols for detecting picogram quantities of aflatoxin M1 in dairy products were established. Milk samples were subjected to a reverse phase Sep-Pak C18 cartridge treatment before analysis by an enzymelinked immunosorbent assay (ELISA) according to previously published procedures. M, in yogurt, brick cheddar, and ripened Brie cheese was extracted by a modified Pons method, subjected to a normal phase silica cartridge treatment, and analyzed by ELISA. The detection limits for M1 in milk, yogurt, cheddar, and Brie were 10, 10, 50, and 25 ppt (ng/kg), respectively. Recovery for M1 added to these products was in the range 70-110%. Good agreement was found for M1 levels in several naturally contaminated milk samples analyzed by both ELISA and liquid chromatography.
Reverse Phase Liquid Chromatographic Determination of Edifenphos in Technical and Emulsifiable Concentrate Formulations
Authors: Khazanchi Rajesh , Roy Nripendra K 
Published: February 2020

Abstract
A convenient reverse phase liquid chromatographic method has been developed for determination of edifenphos in its technical product and emulsifiable concentrate. The method allows determination of the active ingredient of the formulation directly, without any solvent extraction. In addition, reference standard edifenphos has been obtained by preparative liquid chromatography.
Quantitative Gas Chromatographic-Mass Spectrometric Assay of Five Sulfonamide Residues in Animal Tissue
Authors: Simpson Randall M , Suhre Francis B , Shafer J W 
Published: February 2020

Abstract
A gas chromatographic-mass spectrometric procedure using isotopically labeled internal standards and the technique of selective-ion monitoring was used to assay sulfamethazine, sulfadimethoxine, sulfabromethazine, sulfathiazole, and sulfaquinoxaline in liver and muscle tissue of swine, poultry, and cattle. The data presented clearly demonstrate the applicability of this procedure for confirmation of sulfonamide residues in animal tissue.
Determination of Neomycin in Animal Tissues, Using Ion-Pair Liquid Chromatography with
Fluorometric Detection
Authors: Shaikh Badar , Allen Edward H , Gridley John C 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for the determination of neomycin in animal tissues. Tissues are homogenized in 0.2M potassium phosphate buffer (pH 8.0); the homogenate is centrifuged, and the supernate is heated to precipitate the protein. The heat-deproteinated extract is acidified to pH 3.5-4 and directly analyzed by LC. The LC method consists of an ion-pairing mobile phase, a reverse phase ODS column, post-column derivatization with o-phthalaldehyde reagent, and fluorometric detection. The LC method uses paromomycin as an internal standard, and separates neomycin from streptomycin or dihydrostreptomycin because they have different retention times. The LC column separates neomycin in 25 min; the detection limit is about 3.5 ng neomycin. The overall recovery of neomycin from kidney tissues spiked at 1-30 ppm was 96% with a 9.0% coefficient of variation. The method was also applied to muscle tissue.
Determination of Nitrate in Dried Foods by Gas Chromatography-Thermal Energy Analyzer
Authors: Ross Holly D , Hotchkiss Joseph H 
Published: February 2020

Abstract
The method described for determining N03~ in dried foods is based on extraction of N03~ from the sample with subsequent nitration of benzene. The nitrobenzene is extracted with ethyl acetate, analyzed by using a gas chromatograph-thermal energy analyzer (GC-TEA), and quantitated against a nitrobenzene standard. Sensitivity is 100-200 μg/ kg. Coefficients of variation for analyses of dried foods were 3-13%. Recovery of N03" from nonfat dry milk spiked at 10 mg/kg averaged 100%.
Determination of Phosphine: Comparison of Rates of Desorption by Purge-and-Trap Method and by Sulfuric Acid Treatment
Authors: Saeed Talat , Abu-Tabanja Rohi 
Published: February 2020

Abstract
Two methods were compared for quantitative determination of phosphine present on fumigated food and materials. The rate of desorption of PH3 by using a purge-and-trap method was shown to be much slower when compared with sulfuric acid treatment and was also simpler. Application of the modified sulfuric acid treatment for real samples is described.
Residue Methodology for AMDRO Fire Ant Insecticide (AC 217,300) in Pasture Grass and
Crops
Authors: Stout Steven J , Steller William A , Tondreau Robert E , Manuel Arthur J , Dacunha Adrian R 
Published: February 2020

Abstract
Residue methodology is described for the determination of AC 217,300 residues in pasture grass and crop samples. After extraction and subsequent cleanup on an XAD-2 column, residues of AC 217,300 are determined by liquid chromatography (LC), using a reverse phase paired-ion chromatographic system and detection at 300 nm. The method has a validated limit of sensitivity of 0.05 ppm with corresponding control values for the commodities analyzed of &lt;0.01 ppm. Apparent residues over 0.05 ppm can be confirmed by either gas chromatography with an electron capture detector (GC-EC) or gas chromatographynegative ion chemical ionization mass spectrometry (GC-NICI). The direct GC-NICI method circumvents the need for sample cleanup on the XAD-2 column, and offers a greatly simplified procedure that is useful for screening samples. Recoveries of AC 217,300 from the commodities analyzed have been satisfactory with all methods of analysis
Extraction of Organic Acids by Ion-Pair Formation with Tri-w-Octylamine.
Part 6. Determination of Sorbic Acid, Benzoic Acid, and Saccharin in Yogurt
Authors: Puttemans Marc L , Branders Chris , Dryon Louis , Massart Desire L 
Published: February 2020

Abstract
The sorbate content of commercial yogurt samples is determined by reverse phase liquid chromatography following ion-pair extraction with tri-n-octylamine. Mean recoveries (70-88%), precision (1.1-3.3% RSD), and detection limit of the method are presented for sorbic acid, benzoic acid, and saccharin.
Colorimetric Determination of Sympathomimetic Amines Methyldopa and Noradrenaline
Authors: Walash Mohamed I , Ouf Abed Abou , Salem Fatma B 
Published: February 2020

Abstract
The chromogenic reagent p-dimethylaminocinnamaldehyde (PDAC) is introduced for the determination of the sympathomimetic amines methyldopa and noradrenaline. The method is based on measurement of the orange color developed when the alkaline solution of methyldopa and noradrenaline is allowed to react with PDAC at pH 5.0. The color developed obeys Beer's law in the concentration range 0.1-1.5 mL of 2 x 103M solution of noradrenaline and methyldopa. The results are compared with those obtained with another chromogenic reagent, pdimethylaminobenzaldehyde (PDAB). Determinations on dosage forms of the drugs, using PDAC and PDAB reagents, agreed well with results of determinations by official pharmacopoeia! methods.
Liquid Chromatographic Determination of Vitamin D in Milk and Infant Formula
Authors: Sertl David C , Molitor Bruce E 
Published: February 2020

Abstract
Vitamin D2 or vitamin D3 is determined by liquid chromatography (LC) in milk and infant formula. Vitamin D is extracted from the saponified sample, passed through an amino-cyano LC cleanup column to remove major interferences, and quantitated using normal phase LC. Within-day precision is 4.5% relative standard deviation (RSD); the overall method RSD (reflecting technician-to-technician, day-today, and within-day variability) is 7.7%. Overspike recoveries averaged 97% for milk, 98% for milk-based infant formula, and 93% for soy-based infant formula. The performance of the method is compared with that of the official AOAC vitamin D method (rat bioassay). The method is applicable to the determination of vitamin D in milk and in the major milk- and soy-based infant formulas available in the United States. The method can quantitate (but not distinguish) either vitamin D2 or vitamin D3. The method is applicable to milk and infant formula samples containing between 100 and 1500 IU vitamin D/L. Sample throughput is between 4 and 8 replicates per da
Performance Characteristics of Methods of Analysis Used for Regulatory Purposes.I. Drug Dosage Forms. D. High Pressure Liquid Chromatographic Methods
Authors: Horwitz William , Albert Richard H 
Published: February 2020

Abstract
Precision parameters of high pressure liquid chromatographic methods approved by AOAC for the analysis of drug dosage forms were recalculated on a consistent statistical basis, using the computer program "FDACHEMIST." Eleven collaborative studies of 12 compounds in 66 dosage forms analyzed by an average of 9 laboratories per study, with a total of 1150 determinations, were reviewed. For the approved methods and methods awaiting approval (9 studies, 11 compounds, 54 dosage forms, and 959 determinations), the average repeatability relative standard deviation (within-laboratory; RSDo) was 1.0%; reproducibility relative standard deviation (among-laboratories, including within-; RSDX) was 2.5%; the ratio RSD„/RSDX was an unusually low 0.40, with an average outlier rate of 0.6% of the reported values. The line of best fit for RSDX plotted against — log concentration increases with decreasing concentration, extending approximately from RSDX =2% at 100% concentration to RSDX = 3.6% at 0.01% concentration,a change in RSDX of about 0.4% for each 10-fold decrease in concentration,independent of analyte and matrix.
Atomic Absorption Spectrophotometric Determination of Tin in Canned Foods, Using Nitric Acid-Hydrochloric Acid Digestion and Nitrous Oxide-Acetylene Flame: Collaborative Study
Authors: Dabeka Robert W , Mckenzie Arthur D , Albert Richard H 
Published: February 2020

Abstract
Twenty-six collaborators participated in a study to evaluate an atomic absorption spectrophotometric (AAS) method for the determination of tin in canned foods. The 5 foods evaluated were meat, pineapple juice, tomato paste, evaporated milk, and green beans, each spiked at 2 levels. The concentration range of tin in the samples was 10-450 μg/ g, and each level was sent as a blind duplicate. Statistical treatment of results revealed no laboratory outliers and 6 individual or replicatetotal outliers, accounting for 3.3% of the data. Repeatability (withinlaboratory) coefficient of variation (CVo) ranged from 2.2 to 48%, depending on the tin level and food evaluated. For samples containing &gt;80 μg/g of tin, repeatability CV averaged 5.6% including outliers and 3.7% after their rejection. Overall among-laboratories coefficient of variation (CVX) varied from 3.3 to 58%; at levels &gt;80 μg/g, it averaged 7.3% with outliers and 5.3% after their rejection. Recovery of tin, based on spiking levels, ranged from 100.0 to 112.8% and averaged 105.4%. Detection limit range is 2-10 μg/g, and lower quantitation limit is 40 μg/g. This method has been adopted official first action.
Quantitative Colorimetric Method for Sulfamethazine in Swine Feeds
Authors: Schwartz Daniel P 
Published: February 2020

Abstract
Sulfamethazine (SM) in swine feeds is quantitated colorimetrically by using a relatively simple procedure. The drug is isolated from an extract of feed by trapping it on a small bed of anion-exchange resin buffered at pH 7.9 following the removal of possible interfering compounds by pre-columns. SM is then eluted, diazotized, and coupled using the Bratton-Marshall reagents. The intensity of color developed is determined spectrophotometrically at 540 nm and the concentration of SM is calculated using a molar absorptivity of 52 500. Feeds containing from 1 to 130 ppm can be analyzed with very good accuracy and precision. The method has satisfactory specificity, is inexpensive, and can be applied to a relatively large number of samples per day. A simple and safe method for preparing N1-methyl SM at the low microgram level is described together with a thin layer chromatographic system for tentatively verifying the presence of SM in the feed both as the underivatized drug and as N1-methyl SM
Gas Chromatographic Determination of Pentachlorophenol in Gelatin: Collaborative Study
Authors: Yip George 
Published: February 2020

Abstract
Eleven collaborators participated in this study of a gas chromatographic method for the determination of pentachlorophenol (PCP) in gelatin. Following acid hydrolysis of a 2 g sample, PCP is extracted with hexane and partitioned into KOH solution. After reacidification, PCP is again extracted with hexane for determination by electron capture gas chromatography on a 1 % SP-1240DA column. Three duplicate practice samples (0.0, 0.5, and 1.5 ppm) and 5 blind duplicate collaborative samples (0.0, 0.02, 0.1, 0.5, and 2.0 ppm) were analyzed by each collaborator. Mean recoveries of PCP in the collaborative samples ranged from 88% at the 0.02 ppm fortification level to 102% at the 0.1 ppm level; the overall mean recovery was 96%. Interlaboratory coefficients of variation ranged from 16.4% for the 0.1 ppm fortification level to 22.9% for the 0.5 ppm level; the overall interlaboratory coefficient of variation was 19.5%. The method has been adopted official first action.
Formulas for Calculation of Extraction Volumes for Commonly Used Pesticide Residue Extraction Procedures
Authors: Jeffus Marshall T , Stewart James G 
Published: February 2020

Abstract
Formulas are presented for the calculation of extraction volume for pesticide residue procedures that use a single extraction with acetone, acetonitrile, or methanol, with or without prior dilution of these solvents with water. These formulas account for the volume change on mixing and for the volume contribution from the soluble sugars sucrose, glucose, and fructose. Results using these formulas are in agreement with the observed volumes of such mixtures within 0.3% throughout the following ranges, expressed as percent water in the mixtures: 15- 38% for acetone, 4.8-59% for acetonitrile, and 9.3-33% for methanol
Radiocarbon 14C Differentiation of Sparkling and Carbonated Wines
Authors: Martin Glenn E , Krueger Harold W , Burggraff James M 
Published: February 2020

Abstract
Specific 14C-activities, percent of modern 14C-activity, and calculated percent of fermentation CO2 are presented for CO2 contained in commercial sparkling wines, labeled as champagne or produced by the bulk (charmat) process. These data are given for the production years 1976–1982. The survey encompassed effervescent wines produced in Spain, Italy, West Germany, California, and New York. Addition of synthetic CO2 to approximately 40 samples represented as sparkling wines was indicated by low 14C-activities of CO2 in these wines. Data for 14C-activity were also presented for the ethanol distilled from sparkling wines for the years 1977–1980. In all cases, the 14C-activity of ethanol was appropriate to the year of vintage.
Modification of the Rapid Screening Method for Aflatoxin in Corn for Quantitative Use
Authors: Spilmann Joseph R 
Published: February 2020

Abstract
A study was made to determine if the official AOAC method for screening of aflatoxin in corn could be modified for use as a quantitative method. Several different corn products were analyzed using the modified method, with an average savings of over 1 h/sample vs the CB method. Average recoveries for aflatoxin Bt were 94% for the low level spiked samples and 108% for the high level. Samples of corn and corn products containing naturally incurred aflatoxin were also analyzed with the modified method, and the results compared favorably with those obtained by the CB method.
Liquid Chromatographic Determination of Intermediates in D&C Yellow No. 7 and D&C Yellow No. 8
Authors: Calvey Robert J , Goldberg Allen L 
Published: February 2020

Abstract
A sensitive, reproducible method that uses liquid chromatography in the reverse phase mode has been developed for the determination of phthalic acid, resorcinol, and 2-(2',4'-dihydroxybenzoyl)benzoic acid in D&C Yellow No. 7 and D&C Yellow No. 8. The method uses a 10 p, C-8 column, a 1% acetic acid-methanol gradient, and UV absorption detection at 280 nm. Average recoveries of phthalic acid, resorcinol, and 2-(2',4'-dihydroxybenzoyI)benzoic acid were 100, 98, and 1(12%, respectively, from fluorescein standard (certifiable as D&C Yellow No. 7) spiked with each compound at levels ranging from 0.13 to 1.3%.
Liquid Chromatographic Determination of 2,4-Dinitroaniline and 2-Naphthol in D&C Orange No. 17
Authors: Scher Alan L 
Published: February 2020

Abstract
A method is described for the determination of the intermediates in D&C Orange No. 17 by reverse phase liquid chromatography. The pigment is dissolved in boiling dioxane and then precipitated. The filtrate is chromatographed by isocratic elution, which is followed by a wash and equilibration. Peak area calibrations were linear. At the provisional specification levels, 99% prediction limits were 0.200 ± 0.0012% 2,4-dinitroaniIine (2,4-DNA) and 0.200 ± 0.006% 2-naphthol. The limits of determination were 0.0023% for 2,4-DNA and 0.013% for 2-naphthol at the 99.5% confidence level. Recoveries were 98- 100% for 2,4-DNA added at the 0.005-2% level, and 93-103% for 2- naphthol added at the 0.025-2% level. A survey of certified D&C Orange No. 17 samples showed that the lots contained higher levels of the intermediates than were determined previously by a cellulose column method, in which the pigment is not dissolved.
Liquid Chromatographic Determination of Barbaloin (Aloin) in Foods
Authors: Yamamoto Masatoshi , Ishikawa Masaaki , Masui Toshio , Nakazawa Hiroyuki , Kabasawa Yozo 
Published: February 2020

Abstract
A simple and rapid liquid chromatographic method is described for the determination of barbaloin (aloin, 10-D-gIucopyranosyl-l,8-dihydroxy- 3-(hydroxymethyI)-9(10#)-anthracenone) in foods. Barbaloin is extracted with water from foods containing aloe and the extract is cleaned up on a disposable cartridge by using methanol-water (55 + 45) as eluant. The eluted barbaloin is separated by liquid chromatography on a YMC A-302 column with methanol-water (50 + 50) mobile phase, and detected at 293 nm. Recoveries of barbaloin added to foods at the levels of 0.05 and 0.50 mg/g were 94.4-100%. Assay results for commercial food samples indicated that the present method is applicable to a variety of foods supplemented with aloe.
Rapid Microchemical Identification of Four Phenothiazine Antiemetics with Gold Bromide and Iodine-Potassium Iodide Reagents: Collaborative Study
Authors: Rabkin Marshall 
Published: February 2020

Abstract
A microchemical method was developed for the rapid identification of 4 phenothiazine antiemetics. Perphenazine, promethazine, thiethylperazine, and triflupromazine were positively identified and differentiated with the aid of a gold bromide reagent and an iodine-potassium iodide reagent. Only promethazine and triflupromazine yielded microcrystalline derivatives with gold bromide; only perphenazine and thiethylperazine reacted with iodine-potassium iodide. For each pair of positive reactions, the crystalline products were morphologically distinguishable under a microscope. The 2 tests were collaboratively studied by 7 independent laboratories and found to be simple, rapid, and effective for identifying the phenothiazines of interest. The method has been adopted official first action
Reverse Phase Liquid Chromatographic Determination of Bisacodyl in Dosage Forms
Authors: Valenti Leonard P , Lau-Cam Cesar A 
Published: February 2020

Abstract
A method is described for the determination of bisacodyl in entericcoated tablets and suppositories by liquid chromatography (LC). The method will also determine the hydrolysis degradation products monoacetylbisacodyl and desacetylbisacodyl. The sample is dissolved in 2- propanol, and the extract is diluted with the mobile phase and injected into a liquid chromatograph fitted with a μBondapak C18 column and an ultraviolet detector set at 254 nm. The column is eluted with methanol- acetonitrile-0.01M citric acid (25 + 25 + 50). The pooled mean recovery value for bisacodyl from commercial enteric-coated tablets and suppositories was 99.7 % with a pooled coefficient of variation (CV) of 0.72%. For content uniformity assays, the CVs were 0.7 and 1.0% for groups of 10 individual commercial suppositories and tablets, respectively. Differences between assay values by the LC and USP XX methods were 0.2% of declared for enteric-coated tablets (n = 5) and 1.0% of declared for suppositories (n = 2). The LC method can determine as little as 0.015 μg of the monoacetyl or desacetyl degradation product.
Liquid Chromatographic Determination of Diazepam in Tablets: Collaborative Study
Authors: Tsougros Michael 
Published: February 2020

Abstract
A stability indicating liquid chromatographic method for the determination of diazepam in tablets was collaboratively studied by 6 laboratories. The method uses a Cig reverse phase column, a methanolwater mobile phase, p-tolualdehyde as the internal standard, and photometric detection at 254 nm. The collaborators were supplied with a synthetic tablet powder and 3 commercial tablet samples. The mean recovery of diazepam from the synthetic tablet powder was 100.2%. For all samples analyzed, the coefficient of variation was &lt; 1.5%. The method has been adopted official first action.