bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extraction and Cleanup of Fish, Sediment, and Water for Determination of Triaryl Phosphates by Gas-Liquid Chromatography
Authors: Muir Derek C G , Grift Norbert P , Solomon John 
Published: February 2020

Abstract
Several techniques were evaluated for extracting triphenyl phosphate (TPP), 14C-labeled TPP, cresyl diphenyl phosphate, and tricresyl phosphate isomers (o-TCP, m-TCP, and p-TCP) from fish and sediment samples. Extracts of fish samples were cleaned up by gel permeation chromatography/alumina column chromatography; sediment extracts received alumina treatment only. Compounds were determined by gas-liquid chromatography (GLC) with nitrogenphosphorus detection. Methanol/Polytron and hexane/ball mill extraction of fish samples fortified at 0.01, 0.1, and 1.0 μg/g levels gave overall recoveries of the 5 compounds of 89 and 97%, respectively. Methanol recovered more radioactivity (97%) from fish exposed to 14C-TPP in aquaria for 24 h than did hexane from fish exposed for 16 h (79%). Refluxing fortified sediment (0.05 and 0.5 μg/g) with methanol-water (9+1) gave significantly higher recoveries (88%) of the 5 triaryl phosphates than did dichloromethane-methanol (1+1) reflux or acetone-hexane (1+1) Soxhlet extraction. Recoveries of TPP and o-, m- and p-TCP from fortified river water (0.5, 5.0, and 50 μg/L) by shaking with dichloromethane ranged from 91 to 118%. Some problems were encountered with interfering GLC peaks at low (μg/g) levels in fish and sediment extracts despite the use of nitrogen-phosphorus specific detectors.
Headspace Sampling and Gas-Solid Chromatographic Determination of Residual Acrylonitrile in Acrylonitrile Copolymer Solutions
Authors: Mcneal Timothy , Breder Charles V 
Published: February 2020

Abstract
A screening procedure, using manual headspace sampling and gas-solid chromatography, is described for the determination of residual acrylonitrile (RAN) in acrylonitrile-based copolymers. The polymers are dissolved in dimethylsulfoxide; the resulting solutions are equilibrated in a closed container at 90°C, and headspace aliquots are injected into a gas chromatograph. A nitrogen-phosphorus selective detector and the method of standard additions are used for quantitation. RAN is measured down to 70 ppb (polymer basis) with a standard deviation of 7%. Polymers analyzed by this method had RAN levels from 0.07 to 23.9 ppm.
Gas Chromatographic Determination of Propionic Acid in Bread and Cake
Authors: Isshiki Kenji , Tsumura Shusaku , Watanabe Tadao 
Published: February 2020

Abstract
A simple and accurate method is presented for gasliquid chromatographic (GLC) determination of propionic acid in bakery products. Propionic acid is extracted with a mixture of dichloromethane and formic acid to which isobutyric acid has been added as an internal standard. The extract is injected directly into the GLC system. A glass column packed with 5% SP-1000 is used. The simplicity and convenience of the method make it suitable for routine determination.
Use of Sunlight to Partially Detoxify Groundnut (Peanut) Cake Flour and Casein Contaminated with Aflatoxin B1
Authors: Shantha Thimmappaji , Murthy Venkateshaiah Sreenivasa 
Published: February 2020

Abstract
Sunlight destroyed 83 and 50% of the toxin added to casein and groundnut cake flour, respectively. Equilibrium dialysis revealed that both casein and groundnut protein bind aflatoxin but the toxin bound to casein appeared more photo-labile than that bound to groundnut protein.
High Performance Liquid Chromatographic Method Using Fluorescence Detection for Quantitative Analysis of Zearalenone and α-Zearalenol in Blood Plasma
Authors: Trenholm H Locksley , Warner Robert M , Farnworth Edward R 
Published: February 2020

Abstract
A sensitive, high performance liquid chromatographic method is described for quantitative determination of zearalenone and α-zearalenol in blood plasma. Blood plasma is extracted with 2-propanol in ether, the extract is evaporated to dryness, and the residue is dissolved in 0.18N NaOH. The aqueous phase is washed with chloroform, dichloromethane, and benzene, neutralized with 0.10M H3PO4, and extracted with benzene. The extract is evaporated, dissolved in methanol, and injected onto a reverse phase column containing LiChrosorb RP-8 under the following conditions: methanol-acetonitrile-water mobile phase, fluorescence detector, excitation wavelength 236 nm, and 418 nm cut-off emission filter. The limit of detectability (twice background) is 0.5 ng standard which is equivalent to 0.6 ng standard/mL blood plasma. Linear standard curves are observed over the range of 0-35 ng of injected zearalenone and α-zearalenol. The recoveries from blood plasma are 76-101% in the range of 1.5-6.0 ng standard/mL blood.
Turbidimetric Assay for Virginiamycin in Feeds and Premixes
Authors: Mueller-Brennecke Dorothy , Reed Shirley J , Barkate John A 
Published: February 2020

Abstract
A turbidimetric assay method applicable to virginiamycin at levels ranging from 5 g/ton in feeds to 50% inapremix is described. Incubation period is 4 h. Test organism is Streptococcus faecium ATCC 8043. On 6 levels of feed-grade material, the overall mean recovery was 95.4%, and the relative standard deviation (RSD) was 6.75%. Standard recovery studies resulted in RSD values ranging from 2.01 to 3.88% and a mean standard recovery of 100%.
High Pressure Liquid Chromatographic Determination of Phenol in Honey
Authors: Sporns Peter 
Published: February 2020

Abstract
A method is described for determining phenol in honey by using high pressure liquid chromatography (HPLC). An internal standard, 2-phenylethanol, was added to honey which was steam-distilled and chromatographed on a 25 cm × 3.2 mm id Spherisorb 5 µm silicic acid column using water as the mobile phase. Absorbance was monitored at 195 nm. Using a mixed standard of known concentration and peak height measurements, the amount of phenol in the honey could be quantitated. Recovery of added phenol was checked at levels from 0.1 to 33 ppm.
Determination of Color Intensity of Whisky and Other Alcoholic Products
Authors: Strunk Duane H , Timmel Bertha M , Hamman Jack W , Andreasen Arthur A 
Published: February 2020

Abstract
A comparison is presented of color intensity values of aged and caramel-colored distilled alcoholic products obtained with spectrophotometers and colorimeters operated at different wavelengths. Absorbances measured by a narrow (≤1 nm) and an 8 nm bandwidth spectrophotometer at 430,525, and 610 nm are compared. Colorimeters evaluated include the Klett-Summerson equipped with Nos. 42, 54, and 60 regular filters and 520, 540, and 560 nm narrow bandpass filters and a Coleman Nepho-Colorimeter, equipped with a 525 nm filter. A conversion chart can be used to convert colorimeter units to absorbance units. The procedure suggested uses an instrument with a bandwidth ≤10 nm at a wavelength of 525 nm; results are reported in absorbance units.
Ultraviolet Detection Procedure for Liquid Chromatographic Determination of Indole in Shrimp
Authors: Chambers Theodore L , Staruszkiewicz Walter F 
Published: February 2020

Abstract
In an ultraviolet detection procedure, indole was extracted from shrimp by blending with carbonate buffer and then partitioned into ethyl acetate. Before quantitation by high pressure liquid chromatography (HPLC), interferences were removed by the use of a polyamide cleanup column. Concentrated column effluent was injected into the chromatograph. Indole was detected by monitoring absorbance at 217 nm and quantitated by comparison of indole peak height to that of an internal standard, 2-methylindole. Recoveries of indole ranged from 72 to 117%. Results agreed well with those by the official AOAC gasliquid chromatographic (GLC) method.
Comparison of Manual and Benzenesulfonyl Chloride-Semiautomated Thiochrome Methods for Determination of Thiamine in Foods
Authors: Soliman Abdel-Gawad M 
Published: February 2020

Abstract
A semiautomated procedure was used to measure the fluorescence of sample extracts before and after the addition of benzenesulfonyl chloride (BSC). Addition of BSC inhibited thiochrome formation and provided a more representative blank based on the fluorescence of all the reactants except thiochrome. Thiamine standard was added to each sample extract so that thiamine concentration could be calculated after correcting for sample matrix effects on thiochrome fluorescence. Twenty food products were analyzed using this method, and the results were compared with those obtained using the manual AOAC method. The mean percent recoveries and standard deviations were 100.2 ± 5.3 and 101.1 ± 10.1 for the BSC-semiautomated and the AOAC manual methods, respectively. Replicate analyses using the BSC method gave an average coefficient of variation of 2.8%. Linear regression analysis showed that the BSC method gave higher values, with a mean increase of 14.8%, than those obtained using the manual method. Sixty-four percent of this difference was due to elimination of the column purification step and 36% was due to correcting for sample matrix effects on thiochrome and blank fluorescence. The BSC method provides a rapid, accurate, and reproducible method for thiamine assay in different food products, especially for those foods with low thiamine levels.
High Pressure Liquid Chromatographic Determination of Melengestrol Acetate in Dry Feed Supplements
Authors: Roybal Jose E 
Published: February 2020

Abstract
A high pressure liquid chromatographic (HPLC) method is described for the quantitative determination of melengestrol acetate (MGA) in dry animal feed supplements containing 0.000027-0.000220% MGA (0.125-1.00 mg/lb). Ground feed is Soxhletextracted with hexane, and the extract is partitioned from hexane into aqueous methanol and then into methylene chloride, followed by mixed column chromatography. MGA is then quantitated by HPLC. Average recovery of standard MGA through the method at 1.00 ppm (0.454 mg/lb).was 94.8% with a 3.58% standard deviation. Average spike recovery of MGA in fortified feed at 0.100 ppm (0.0454 mg/lb) to 2.00 ppm (0.907 mg/lb) level was 97.8% with a standard deviation of 5.39%. In addition, the method includes a 2-dimensional thin layer chromatographic confirmatory test for MGA.
Effect of Boiling, Frying, and Baking on Recovery of Aflatoxin from Naturally Contaminated Corn Grits or Cornmeal
Authors: Stoloff Leonard , Trucksess Mary W 
Published: February 2020

Abstract
Corn grits naturally contaminated with aflatoxins were used for making boiled grits, and portions of the boiled grits were used for making pan-fried grits; cornmeal naturally contaminated with aflatoxins was used for making corn muffins. Procedures and recipes were derived from cookbook and market package recommendations. From analyses of the products for aflatoxins before and after preparation of the table-ready products, it was determined that 72±9% (n = 15) of the aflatoxin found in the original grits could be recovered after the grits were boiled. The recovery of aflatoxin B1 after the grits were fried was either 66±10% (n = 6) or 47±8% (n = 9), depending on whether 3 cups of water or 4 cups of water per cup of grits, respectively, were used for preparing the boiled grits before frying. Similarly, it was determined that 87±4% (n = 9) of the aflatoxin B1 found in the original cornmeal could be recovered from the baked muffins. No detectable aflatoxin B2a was present in the extracts from any of the table-ready products.
Gas-Liquid Chromatographic Determination of Hexestrol Residues in Adipose Tissue
Authors: Tobioka Hisaya , Kawashima Ryoji 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method is described for determining hexestrol residues in adipose tissue. The extraction and purification procedures were based on a published method for determining diethylstilbestrol. To increase precision and sensi-(ivy, the sample was further cleaned up by silica gel column chromatography. The heptafluorobutyric (HFB) derivative of hexestrol was used for GLC analysis with HFB-docosanol as an internal standard. A variety of acetone-benzene mixtures were compared to determine the optimum ratio for hexestrol acylation. Acetone-benzene (90 + 10) or 100% acetone provided 16% higher GLC response than did a 50 – 50 mixture (P &lt;0.001) and was selected for use in the acylation procedure. A system for evaporating excess reagents was also studied. Overall percent recovery reached 72 ± 5. The method can be used to determine residual hexestrol at the 0.1 ppb level.
Modified Storherr Method for Determination of Organophosphorus Pesticides in Nonfatty Food Total Diet Composites
Authors: Carson Louis J 
Published: February 2020

Abstract
The method of Storherr et al. for organophosphorus pesticide residues in nonfatty foods has been modified to permit its use in analyzing the composites of nonfatty foods in the Food and Drug Administration Total Diet Program. Modifications were designed to permit the examination by gas-liquid chromatography (GLC) of the larger weight (100 mg) of sample equivalent required by the Total Diet program. To achieve a limit of quantitation of 2 ppb parathion, the organophosphorus pesticides are determined by GLC equipped with flame photometric detector (P-mode) and/or KCl thermionic detector. Recovery data, ranging from 70 to 133%, are presented for fortification (2-10 ppb) of organophosphorus pesticides in 7 nonfatty food Total Diet composites. The modified Storherr method was successfully tested in an intralaboratory method trial of 2 Total Diet composites (potatoes and legumes) fortified at 5-13 ppb with malathion, parathion, paraoxon, and monocrotophos. In addition, the modified Storherr method was compared to existing FDA Total Diet methodology for the determination of incurred organophosphorus residues. Residue levels found by both methods were similar for malathion (30 ppb), parathion (7 ppb), and diazinon (1 ppb), but only the modified Storherr method was capable of determining about 10 ppb dimethoate and phorate in the cereals and grains composite.
Gel Permeation System for Removal of Fats During Analysis of Foods for Residues of Pesticides and Herbicides
Authors: Hopper Marvin L 
Published: February 2020

Abstract
A gel permeation chromatography system has been developed for the rapid cleanup of fatty foods in the analysis for pesticide residues. The narrow elution bands of fats and pesticides coupled with the ease of evaporating the eluting solvent makes this system efficient because of the savings in time and solvents. This system allows a wide range of compounds including organochlorine pesticides, organophosphorus pesticides, industrial chemicals, herbicides, carbamates, and drugs to elute in the cleaned-up fraction.
General Method for Determination of Pesticide Residues in Samples of Plant Origin, Soil, and Water. III. Gas Chromatographic Analysis and Confirmation
Authors: Ambrus Árpád , Visi Éva , Zakar Ferenc , Hargitai Éva , Szabó László , Pápa Ágoston 
Published: February 2020

Abstract
Gas-liquid chromatography is widely used in pesticide residue analysis, and numerous packings of various polarity are recommended. We selected OV-22, OV-101, NPGS, SE-30 (3% on Gas-Chrom Q), and 1.95% SP-2401/1.5% SP-2250 on Supelcoport as basic packings. Relative retention times for aldrin and parathion-methyl were determined at 140,160, 180, or 200°C and during temperature programming. OV-22 and OV-101 were most suitable for general purposes. A study on the performance of thermionic delectors suggested that their performance can be characterized and should be regularly controlled with test substances containing different hetero elements. Columns as short as 45-90 cm were suitable for screening purposes, and their advantages over traditional long columns are demonstrated. The fractionation of pesticides in an extract on silica gel columns was effective and practical for the confirmation of pesticides.
Gas-Liquid Chromatographic Determination of Aniline Metabolites of Substituted Urea and Carbamate Herbicides in Aqueous Solution
Authors: Hargesheimer Erika E , Coutts Ronald T , Pasutto Franco M 
Published: February 2020

Abstract
A simple gas-liquid chromatographic (GLC) method has been developed which provides sensitivity and specificity for the analysis of complex mixtures of the commonly occurring herbicide metabolites aniline, 3-chloroaniline, 4-chloroaniline, 4-bromoaniline, and 3-chloro-4-methylaniline. All of these anilines react with acetic anhydride directly in basified aqueous solution. Further reaction of the acetylated anilines with trifluoroacetic anhydride gave diacyl derivatives which were readily resolved by gas chromatography. The structures of the N-acetylated and IV-trifluoroacetylated derivatives of benzylamine (internal standard) and the anilines were confirmed by GLC-mass spectrometry. In distilled water the minimum detectable concentrations of aniline and the substituted anilines, using electron capture GLC, are 0.1 nmole/100 mL and 0.05 nmole/100 mL, respectively. The detection limit for the anilines is 1 nmole/100 ml distilled water, using GLC with flame ionization detection. The technique was applied to the determination of anilines added to urine samples obtained from the general population.
Bromination Methods for Determination of Phenylephrine Hydrochloride in Nose Drops, Salicylamide in Tablets, and Tetracycline Hydrochloride in Capsules
Authors: Elsayed M Abdel-Hady , Obiakara A Christian , Uzodinma S Uchenna 
Published: February 2020

Abstract
Two methods, kinetic and titrimetric, based on an electrophilic substitution reaction with bromine, are described for the assay of phenylephrine hydrochloride in nose drops, salicylamide in tablets, and tetracycline hydrochloride in capsules. The kinetic method depends on the linear relationship between concentration of the drug (μg/mL) and time (s) for nuclear monobromination, indicated by bleaching of the methyl orange acid color. The titrimetric method is based on addition of excess of bromatebromide with subsequent determination of excess bromine by an iodide-thiosulfate procedure. This method is also used to count the number of bromine atoms necessary for the electrophilic substitution reaction. Preservatives or tablet/capsule bases do not interfere in either method. Recoveries of drugs added to laboratory-prepared samples were good. As indicated by the F-test, the methods are equally reproducible.
High Performance Liquid Chromatographic Determination of Clotrimazole in Pharmaceutical Formulations
Authors: Hoogerheide John G , Strusiak Suzanne H , Taddei Carlo R , Townley Edward R , Wyka Bruce E 
Published: February 2020

Abstract
A simple stability-indicating high performance liquid chromatographic (HPLC) method has been developed which separates clotrimazole from impurities and decomposition products in bulk drugs, creams, tablets, and solutions. Average recovery data for drug substance added to placebos were: tablet, 99.8%; solution, 99.5%; and cream, 100.0%. Average reproducibilities (RSD) on drug substance and formulations were: drug substance, 1.3%; tablets, 1.8%; solutions, 1.1%; and creams, 0.6%. HPLC assay results for both fresh and degraded samples agree with USP XX titration assay results. The method allows for the simultaneous determination of (o-chlorophenyl)-diphenylmethanol hydrolysis product impurity.
High Performance Size Exclusion Chromatograph with Computerized Data Reduction for Analysis of Polyethylene and Oligomers
Authors: Snyder Roger C , Breder Charles V 
Published: February 2020

Abstract
A liquid chromatograph is described for the size exclusion chromatography (SEC) of polyethylene and oligomers. The rigid column packing material was 10 µm diameter porous silica. An infrared spectrophotometer was used as the detector. The chromatograph was designed and operated to minimize the degree of chromatographic peak shape distortion resulting from factors such as system dead volume, detector cell design, sample injection volume, and sample concentration. To compensate for peak spreading and skewing, the chromatographic data were analyzed with an IBM 370/168 computer using an APL program. The molecular weight range covered by this SEC system was 100-500 000. Precision and accuracy of Jhe calculated weight average molecular weight (Mw) values for polyethylene standards over this range were ±3 and s±4%, respectively.
Thin Layer Chromatographic Determination of Aflatoxin in Corn Dust
Authors: Shotwell Odette L , Burg William R , Diller Thomas 
Published: February 2020

Abstract
Methods adopted by the AOAC and the American Association of Cereal Chemists for determining aflatoxin in corn were modified, and techniques were developed for application to samples of &lt;1 to 10 g instead of the specified 50 g samples. Analysis included chloroform extraction of dust samples or dust collected from glass fiber filters, purification of extracts on a silica gel column of appropriate size, and measurement of aflatoxin by either 1- or 2-dimensional thin layer chromatography (TLC). The solvent for 1-dimensional TLC was chloroform-acetonewater (91 + 9 + 1). Solvents for 2-dimensional TLC were, first direction, ether-methanol-water (95 + 4 + 1, lined tank) and second direction, chloroformacetone- water (91 + 9 + 1, unlined tank), or first direction, chloroform-acetone-water (91 + 9 + 1, unlined tank) and second direction, toluene-ethyl acetate- formic acid (60 + 30 + 10, unlined tank). When samples weighed ≤0.1 g, the entire concentrated extract was applied to the TLC plate. About 0.5-1.0 ng aflatoxin B1 could be detected on the plate, making the limit of detection about 9 ng/g for 0.1 g samples.
High Performance Liquid Chromatographic Determination of Furazolidone in Feed and Feed Premixes
Authors: Smallidge Robert L , Rowe Norman W , Wadgaonkar Nandan D , Stringham Rodger W 
Published: February 2020

Abstract
Furazolidone is separated from finished feeds by acetone-water extraction on a Goldfisch apparatus. Extracting solvent is removed, and the residue is dissolved in dimethylformamide-5% tetraethylammonium bromide (1 + 1), clarified, and chromatographed on a reverse phase C18 column. The mobile phase is CH3CN-2% acetic acid (20 + 80) with detection at 365 nm. The method was tested for linearity, recovery, and ruggedness, and compared with the AOAC colorimetric assay by using field samples containing 0.0055-0.055% furazolidone. Precision data suggest a cumulative relative standard deviation of 1.43% within days and 1.78% between days. The ruggedness test predicts a between-laboratory relative standard deviation of 3.67%. Recovery was 97.5 ± 2.0% and linearity was excellent (r2 = 0.9994) up to 0.06% furazolidone. Premixes are extracted by shaking with dimethylformamide. An aliquot of the extract is diluted (1 + 1) with 5% tetraethylammonium bromide, clarified, and chromatographed.
Neutron Activation Analysis of Total Diet Food Composites for Iodine
Authors: Allegrini Massimo , Boyer Kenneth W , Tanner James T 
Published: February 2020

Abstract
The iodine content of Total Diet food composites was measured using neutron activation analysis. The interfering element chlorine was separated using a modified combustion and gas phase procedure. The average recovery was 94.8% (standard deviation 2.9) for the 10 matrices that were tested. In addition, iodine was measured in National Bureau of Standards Standard Reference Materials, which have no certified values for this element. Preliminary findings ofiodine content of adult Total Diet market baskets collected during Fiscal Year 1980 in different regions of the United States ranged from 292 to 901 μg/day for a 2900 kcal intake.