bluuebunny/crossref_metadata_2025_split huggingface dataset:
Food Analysis for Lead Using Furnace Atomic Absorption and a L’vov Platform
Authors: Koirtyohann S Roy , Kaiser Millie L , Hinderberger Edward J 
Published: February 2020

Abstract
Furnace atomic absorption is a very sensitive method for determination of lead and other trace metals in variety of samples, but it is prone to matrix interferences. A majoi improvement in the method is achieved by the use of a L’vov platform, a small piece of graphite placed inside the furnace tube, onto which the sample solution is pipetted. The temperature of the platform rises more slowly than that of the tube wall during the atomization cycle, and sample vaporization is delayed until the furnace atmosphere is at a high and nearly constant temperature. The resulting atomization behavior is more consistent and less matrix-dependent for numerous analyte elements, including lead. Results are further improved by addition of ammonium phosphate to all samples and standards as a matrix modifier. For example, in comparing analyte sensitivity (slope of the absorbance vs concentration curve) in a variety of food sample types to the sensitivity in dilute HNO3, the average lead response showed 60 ± 15% suppression due to the sample matrices. Use of the L’vov platform and matrix modifier virtually eliminated the suppression and improved the precision.
Quantitative Determination of 1-131, Cs-137, and Ba-140 in Milk: Collaborative Studies
Authors: Shuman Frederick G D , Easterly David G , Baratta Edmond J 
Published: February 2020

Abstract
The official method for Cs-137 in milk by gamma-ray spectroscopy was extended to include 1-131 and Ba- 140. A collaborative study was performed on this method applied to 1-131 concentration in cow's milk; the original collaborative study of the method including all 3 nuclides was reviewed. In the 1-131 study, 1 aliquot of a milk sample containing 82 pCi/L was sent to each of 60 laboratories for triplicate analyses. From 40 responses, the mean of the reported values was 81.6 pCi/L, indicating a method bias below the 5% statistical detectability limit. Within- and between-laboratory coefficients of variation (CVs) were 7 and 8%, respectively. In the 3-nuclide study, 2 samples were sent to 25 laboratories for triplicate analyses; one sample contained 633,305, and 515 pCi/L, respectively, of 1-131, Cs-137, and Ba-140 and the other contained 98,52, and 72 pCi/L. For the high-activity sample, within-laboratory CVs were 4-5% for the 3 nuclides and between-laboratory CVs were 4-7%. For the low-activity sample, the corresponding results were 6-9% and 8-16%. The method bias was statistically significant at 95% confidence only for Cs-137 in the high-activity sample; reported results were 3% below the known concentration. The extended method was adopted official first action.
Drug Quality Assessment Methods. I. Gas-Liquid Chromatographic Assay and Identification of Seven Barbiturates
Authors: Black Donald B , Kolasinski Halina , Lovering Edward G , Watson James R 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) procedure has been developed for the assay and identification of amobarbital, butabarbital, heptabarbital, mephobarbital, pentobarbital, phenobarbital, and secobarbital in single component capsule, elixir, injectable, suppository, and tablet formulations. After extraction into chloroform from an acidified aqueous mixture of the product, the drug is eluted isothermally from a methylphenylsilicone GLC column at 210 or 240°C and quantitated relative to thiamylal internal standard. Results were in good agreement with those obtained using pharmacopeial assay methods. The method is suitable for the rapid assessment of commercial formulations.
High Performance Liquid Chromatographic Determination of Primidone in Tablets
Authors: Roberts Stanley E 
Published: February 2020

Abstract
A high performance liquid chromatographic (HPLC) method is described for the quantitative determination of primidone in tablets. A ground tablet sample is diluted directly in the mobile phase, at a concentration of about 1 mg/mL of primidone, mixed and deaerated, and filtered. The resulting solution is then quantitated by HPLC. The average spike recoveries for the 50 mg and 250 mg tablets were 101.2% and 99.0%, respectively. The average recovery for an authentic mixture formulated at the 250 mg level was 100.1% with a relative standard deviation of 0.45%.
Evaluation of Glutaraldehyde and Hydrogen Peroxide for Sanitizing Packaging Materials of Medical Devices in Sterility Testing
Authors: Eskenazi Samuel , Bychkowski Olga E , Smith Marilyn , Macmillan James D 
Published: February 2020

Abstract
External surfaces of packaging materials used for sterile medical devices may introduce contaminants into working areas used for sterility testing. Light wiping with tissues moistened with alkaline 2% glutaraldehyde (Cidex) or 3% hydrogen peroxide effectively reduced counts on 5 X 8 cm strips of packaging material (Tyvek) inoculated with 107 spores of Bacillus subtilis. The ability of antimicrobial agents to penetrate packaging material and kill contaminants on the medical device was tested by inoculating filter membranes with ca 100 cells of Pseudomonas aeruginosa or Staphylococcus aureus or ca 100 spores of Bacillus subtilis. A sterile square of test packaging material placed over the inoculated membrane (direct method) or 0.5 cm above the membrane (indirect method) was wiped with the antimicrobial agent. Except for polyethylene film (3 mil), all materials tested, including glassine and several types of coated and uncoated Tyvek, were penetrated by the agents, killing cells on the inoculated membranes. Death rates varied, depending on the organism, packaging material, and testing method. It is suggested that penetration tests be performed before using antimicrobial agents for sanitizing packaging materials during sterility tests.
Improved Method for High Pressure Liquid Chromatographic Determination of Chlorophacinone in Mouse Tissue
Authors: Addison Joseph B 
Published: February 2020

Abstract
A simplified method is described for the determination of chlorophacinone, 2-[(p-chlorophenyl)- phenylacetyl]-l,3-indandione, in homogenized mice. Chlorophacinone is extracted with acetonitrile. After Florisil cleanup, the extract is injected into a high pressure liquid chromatograph for reverse phase chromatography on a polar Lichrosorb NH2 (10 μm) column, with a mobile phase of acetonitrile-water (80 + 20). An injection containing 70 ng chlorophacinone produces 1/2 scale peaks at 254 nm with a full scale absorbance of 0.1 unit, an order of magnitude improvement over the sensitivity reported earlier with a 280 nm detector. Six homogenized mice samples and six spiked homogenized mice samples were quantitatively analyzed for trace levels of chlorophacinone by this method. Recoveries from spiked samples, as determined by peak height measurement, were &gt;95%. Mean retention time for the chlorophacinone peaks in all samples was 6.05 ± 0.05 min. Chlorophacinone levels determined in homogenized whole mouse samples ranged from 0 to 63 ppm.
Simultaneous Liquid Chromatographic Determination of Thiabendazole, o-Phenylphenol, and Diphenyl Residues in Citrus Fruits, Without Prior Cleanup
Authors: Kitada Yoshimi , Sasaki Michiko , Tanigawa Kaoru 
Published: February 2020

Abstract
A simple, rapid, efficient method has been developed for determining thiabendazole, o-phenylphenol, and diphenyl in citrus fruits by using high performance liquid chromatography, with fluorescence or ultraviolet detection. The compounds are extracted with ethyl acetate and separated from soluble fruit components on a LiChrosorb RP-8 column. Recovery of these compounds added to citrus fruits at 5 or 50 ppm levels was &gt;93%; the limit of detection for the compounds is 1 ppm.
Evaluation of CH Stretch Measurement for Estimation of Fat in Aqueous Fat Emulsions Using Infrared Spectroscopy
Authors: Mills Bernice L , Van De Voort F R 
Published: February 2020

Abstract
Measurement of infrared absorption by the use of a CH stretch filter which isolates wavelengths in the order of 3.4-3.5 μm has been suggested as a replacement for the conventional carbonyl stretch absorption measurement or as an additional measurement for the estimation of fat in aqueous fat emulsions. To determine the merits of this CH stretch measurement, a study was conducted with a series of natural fats selected for their differences in average molecular weight, fatty acid composition, and degree of unsaturation. In this study, the use of the CH stretch filter, the C ═ 0 stretch filter, or the combination thereof could predict the fat content with equal accuracy if the fat was consistent in average molecular weight and degree of unsaturation. For a fat which varied in its degree of unsaturation, the CH filter measurement could be used in conjunction with the iodine value to produce accurate results. The combination C ═ 0 filter, CH filter, and the iodine value produced the most accurate results when the intent was to analyze a variety of fats on a single calibration.
Microdetermination of Ethylene Dibromide in Air by Gas Chromatography
Authors: Dumas T , Bond E J 
Published: February 2020

Abstract
Using a new, sensitive photo-ionization detector in a portable gas chromatograph that operates at ambient temperature, a method was developed for determining ethylene dibromide in air as low as 19 ppb. Vapor standards were prepared for calibration of the detector; concentrations in these standards were accurately determined by using a flame ionization detector. This detector was previously calibrated with an aqueous standard of ethylene dibromide. Using the 2 gas chromatographs, the loss of ethylene dibromide through sorption from the atmosphere of the vapor standards was determined. Solubility of ethylene dibromide in water was also established at 3 temperatures, using the flame ionization detector.
Spectrophotometric Determination of Oxidizing Substances in Food-Grade Hydrochloric Acid
Authors: Levey Brian J , Reigler Paul F 
Published: February 2020

Abstract
A spectrophotometric method has been developed for the determination of oxidizing substances in food-grade hydrochloric acid. The method is based on the reaction of oxidizing substances with potassium iodide to form triiodide ion (I-3) whose absorbance is then measured at 485 nm. Oxidizing substances is reported as fig Cl2/mL. The method is applicable to oxidizing substances in the range of approximately 9-37 μgCl2/mL.
Gas-Liquid Chromatographic Determination of Chlordimeform and Its Metabolites in Cargo Rice and Husk
Authors: Fan De-Fang , Ge Shin-Ding 
Published: February 2020

Abstract
A specific method is described for the alkali flame ionization gas-liquid chromatographic determination of chlordimeform (N-(4-chloro-o-tolyl)-N,N-dimethylformamidine) and 3 potential metabolites in cargo rice and husk. Samples are extracted with absolute alcohol or hexane, and cleaned up on neutral alumina columns. Residues of chlordimeform and its metabolites are chromatographed directly on a column of 1% DEGS coated on 60-80 mesh 405 support (PEG 20M bonded phase). The detection limits for chlordimeform, 4-chloro-o-toluidine, 2,2’-dimethyl- 4,4’-dichloroazobenzene, and N-formyl- (4-chloro-o-toluidine) are 0.03, 0.028, 0.11, and 0.43 ppm for cargo rice and 0.03,0.028,0.22 and 0.43 ppm for husk, respectively.
13C/12C Ratios of Citrus Honeys and Nectars and Their Regulatory Implications
Authors: White Jonathan W , Robinson Frank A 
Published: February 2020

Abstract
Application of isotope ratio testing for adulteration to predominantly citrus honeys without using the recommended confirmatory testing has caused regulatory difficulties for several Florida honey packers. It is demonstrated that δ13C of citrus honey is significantly less negative than that of other honey types. Analysis of citrus nectar shows that the less negative values are not due to the inadvertent mixing of cane or corn syrups used for spring feeding of the bee colonies previous to the citrus nectar flow. Means for identifying citrus honey and specific limiting values of δ13C for adulteration testing of this honey type are proposed.
High Performance Liquid Chromatographic Determination of Bifidobacterium bifidum Growth Factors in Human Milk
Authors: Ashoor Samy H , Monte Woodrow C 
Published: February 2020

Abstract
An isocratic high performance liquid chromatography (HPLC) method has been developed for the determination of Bifidobacterium bifidum growth factors in human milk. The method involves the gradual addition of 3 volumes of ethanol to the milk sample, filtration, and analysis of the growth factors in the filtrate by HPLC. The HPLC system consisted of a carbohydrate analysis column, a water-acetonitrile (70 + 30) solvent system, a flow rate of 1.0 mL/min, and a refractive index detector. The method is simpler and requires less time than the present microbiological method. Moreover, it revealed for the first time the presence of 2 separable growth factors in all human milk samples tested. The HPLC method developed is sensitive and can be used to monitor the type and the amount of growth factors in mothers’ milk during lactation.
Evaluation of Fluorometric Determination-Thin Layer Chromatographic Identification of Aminacrine Hydrochlbride in Drug Preparations
Authors: Bunch Elaine A 
Published: February 2020

Abstract
Utilizing the fluorescent property of aminacrine hydrochloride and a filter fluorometer, a fluorometric method for aminacrine hydrochloride in drug combinations was developed, collaboratively studied, and adopted as official first action in the 11th edition of Official Methods of Analysis. Identity was confirmed by thin layer chromatography (TLC). Additional analytical work was undertaken with a grating fluorometer to support a change in the method status to official final action. The grating instrument recorded the aminacrine hydrochloride spectrum as opposed to the total fluorescence emission measured by the filter instrument. The spectrum of aminacrine hydrochloride showed that the molecule was exhibiting self-absorption of the emitted radiation even at concentrations of 10-6M and that the ratio of the 2 peaks in the emission spectrum varied with concentration. Additional analyses of an authentic cream preparation that also contained sulfanilamide gave an average recovery of 86.0% for aminacrine hydrochloride in 10 replicate portions. Because of these observations, the current Associate Referee’s recommendation to delete the fluorometric procedure from the 13th edition of Official Methods of Analysis was adopted. A recommended deletion of the TLC identification test was also adopted.
Comparison Between Potentiometric Titration and Enzyme-Catalyzed Determination of Hydrogen Peroxide
Authors: Chin Henry B , Cortes Antoni 
Published: February 2020

Abstract
A titrimetric procedure has been recommended for the determination of residual amounts of hydrogen peroxide on packaging surfaces as a result of its use as a sterilant. Enzymatic assays have been described for the determination of hydrogen peroxide in various substrates. We compared the enzymatic assay based on the oxidation of leuco crystal violet by peroxidase and the potentiometric titration procedure for the determination of hydrogen peroxide in distilled water, as required in the approval of this material as a packaging sterilant. The correlation between the 2 procedures is 0.976.
Interlaboratory Calibration Results of Polychlorinated Biphenyl Analyses in Herring
Authors: Musial Charles J , Uthe John F 
Published: February 2020

Abstract
Twenty-three laboratories from 13 countries in continental Europe, Scandinavia, the British Isles, and North America participated in a polychlorinated biphenyl (PCB) Check Sample Program conducted under the auspices of the International Council for Exploration of the Sea (ICES). PCBs were determined in unspiked and spiked (1.00 mg Aroclor 1254/kg oil) herring (Clupea harengus harengus) oil by the participants, each of which used his or her own cleanup and quantitation techniques; a common Aroclor 1254 mixture was used as a standard and a common quantitation technique was used for comparative purposes. Results for the unspiked oil ranged from 0.48 to 3.416 mg PCB/kg oil, while spiked oil results ranged from 0.70 to 3.891 mg/kg. Calculated spike recoveries ranged from 22 to 136%. Serious deficiencies were found in most steps in the procedures. No evidence was found to support the use of a common PCB standard or a common method of calculation using packed column chromatography. The chromatographic stationary phase used appeared to affect the PCB levels obtained. Florisil cleanup adsorbent yielded higher mean results for both unspiked and spiked oils than did alumina. Large coefficients of variation were found (25-50%), the principal source of which was systematic error (interlaboratory).
Gas-Liquid Chromatographic Determination of Polychlorinated Biphenyls and a Selected Number of Chlorinated Hydrocarbons in Serum
Authors: Burse Virlyn W , Needham Larry L , Korver Margaret P , Lapeza Chester R , Liddle John A , Bayse David D 
Published: February 2020

Abstract
A method is proposed for concurrently determining the levels of multiple intact exogenous compounds in serum, particularly polychlorinated biphenyls (PCBs) as Aroclor (AR) 1254 and chlorinated hydrocarbons (CHs). Bovine serum pools containing in vivo-bound PCBs (as AR 1254) and in vitro-spiked CHs are used to evaluate the method, which encompasses serum denaturation with methanol, mixed solvent extraction, multiple solvent fractionation from activated silica gel, and determination by electron capture gas-liquid chromatography. Mean recoveries of the in vitro-spiked 9 CHs at levels of 2.0-29.1 ppb ranged from 52.8 to 98.4% from trial environmental pools; mean recoveries of the in vivobound PCBs (as AR 1254) were 114.1 and 92.6% at levels of 10 and 50 ppb, respectively.
Gas-Liquid Chromatographic Determination of Volatile Phenols in Matured Distilled Alcoholic Beverages
Authors: Lehtonen Matti 
Published: February 2020

Abstract
Volatile phenols in matured spirits were determined by gas-liquid chromatography as their 2,4-dinitrophenyl derivatives. Phenol, o-cresol, m-cresol, p-cresol, guaiacol, p-ethylphenol, p-ethylguaiacol, eugenol, and p-(n-propyl)guaiacol, which occurs only in dark rum, were studied at concentrations ranging from 0 to 2 ppm depending on the phenol and the beverage. Scotch, Spanish, and Japanese whiskies, unlike other whiskies examined, contained o-, m-, and p-cresols. Cresols occur in whiskies as a consequence of the raw materials used, in particular peated malt. The level of p-ethylguaiacol is usually somewhat higher in cognac and other brandies than in whiskies. Dark rums differ from the other spirits examined in containing p-(n-propyl)guaiacol, and, typically, higher levels of p-ethylphenol, p-ethylguaiacol, and eugenol. These phenols also occur in higher quantities in some white rums than in whiskies and brandies. Two discriminant functions were obtained by discriminant analysis, which did not, however, allow the spirits to be classified adequately into their respective groups. By using these functions, 82% of the whiskies, 57% of the brandies, and 50% of the rums were correctly grouped.
High Pressure Liquid Chromatographic Assay for Prednisone in Bulk Drug Substances and Tablets
Authors: Graham Robert E , Biehl Edward R , Uribe Margarito J 
Published: February 2020

Abstract
A high pressure liquid chromatographic (HPLC) method was developed for the assay of prednisone in bulk drug substances and tablets. The sample was dissolved in water-methanol and an aliquot was analyzed by using HPLC. The average recovery of prednisone added to a prednisone tablet composite was 99.5% with a coefficient of variation of 1.07%. Prednisone was determined in 46 tablets (1-50 mg prednisone/tablet) formulated by 22 manufacturers, using the HPLC method and the USP blue tetrazolium assay. The results show that the HPLC method is more specific and faster than the USP method.
Simultaneous Detection of Some Fusariotoxins by Gas-Liquid Chromatography
Authors: Bata Aŕpád , Ványi Andŕas , Lásztity Radomir 
Published: February 2020

Abstract
A method was developed for the simultaneous determination of 6 Fusarium mycotoxins (deoxynivalenol, diacetoxyscirpenol, HT-2 toxin, T-2 toxin, karenon-x, and zearalenone). Cereal samples were first extracted with ethyl acetate, then with a mixture of methanol-water. The crude extracts were combined and purified by silica gel chromatography. The purified extract was reacted with BSTFA (N,O-bis(trimethylsilyl)-trifluoroacetamide) to form the derivative, and chromatographed on an SE-52 wallcoated open tubular column. Kováts’ retention index was determined for the 6 mycotoxins investigated. Recoveries and standard deviations were determined forpure toxin mixed in cereal. Recovery was 70-80%; relative standard deviation was 10-18%. The method developed was applied to different cereal samples.
High Pressure Liquid Chromatographic Determination of Xanthomegnin in Grains and Animal Feeds
Authors: Carman Allen S , Kuan Shia S , Francis Octave J , Ware George M , Gaul Jean A , Thorpe Charles W 
Published: February 2020

Abstract
A high pressure liquid chromatographic (HPLC) method is described for the determination of xanthomegnin in grains and mixed animal feeds at levels ranging from 150 to 1200 ng/g. This is equivalent to actual amounts of xanthomegnin injected on the HPLC system at from 15 to 120 ng/injection. Xanthomegnin is extracted with chloroform and 0.1M phosphoric acid. An aliquot of the crude extract is purified by column chromatography using a commercially available silica gel cartridge. Xanthomegnin is then separated from the remaining interferences by HPLC with a reverse phase C-8 column, and subsequently determined by absorbance detection at 405 nm. Elapsed time for the method from initial extraction to final HPLC determination is approximately 1 h. Recoveries of xanthomegnin added to grains and animal feeds at levels from 150 to 1200 ng/g averaged 82% with a coefficient of variation of 10.2%.
Determination of Copper, Nickel, and Chromium in Foods
Authors: Holak Walter 
Published: February 2020

Abstract
A collaboratively studied method for Pb, Cd, As, Se, and Zn that uses a closed system digestion technique has now been extended to include 3 additional elements, Cu, Ni, and Cr. Cu is determined by either atomic absorption spectrophotometry or anodic stripping voltammetry, depending on the concentration. Ni and Cr are determined by differential pulse polarography. Analysis of National Bureau of Standards reference materials by this procedure gives values in close agreement with the accepted values. Recoveries from applesauce and chicken spiked at 0.6-4 μg/g are in the 92-101% range. The sensitivity of the multielement procedure is 0.34,0.14, and 0.24 μg/g for Cu, Ni, Cr, respectively, at the 90% confidence level.
High Pressure Liquid Chromatographic Determination of Tartrazine in Rice Milk Following Ion-Pair Extraction with Tri-N-Octylamine
Authors: Puttemans Marc L , Dryon Louis , Massart Desiré L 
Published: February 2020

Abstract
Tartrazine is separated from the dried and powdered rice milk matrix by elution with methanol-ammonia mixtures, the extract is purified by ion-pair extraction with tri-n-octylamine and back-extraction with sodium perchlorate, and the dye is determined by high pressure liquid chromatography.
Gas-Liquid Chromatographic Determination of S,S,S-Tributyl Phosphorotrithioate (DEF) in Water and Fish Tissue
Authors: Lehmann R G , Smith L M , Wiedmeyer R H , Petty J D 
Published: February 2020

Abstract
Methods are described for determination of S,S,S-tributylphosphorotrithioate (DEF) at levels as low as 5 parts per billion in fish and 200 parts per trillion in water. Fish tissue extracts are subjected to gel permeation chromatography (GPC) and silica gel chromatography; water samples are extracted with dichloromethane. Analyses are carried out by gas chromatography in which either electron capture or thermionic specific detectors are used. The applicability of the methods is demonstrated by analyses of water and fish samples from exposure studies