bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential Pulse Polarographic Determination of Sulfites in Foods: Collaborative Study
Authors: Holak Walter , Patel Bhailal 
Published: February 2020

Abstract
A differential pulse polarographic (DPP) method for the determination of "free" and "total" sulfite in foods was collaboratively studied by 8 laboratories. The collaborators analyzed blind duplicate samples of shrimp, orange juice, peas, dried apricots, and dehydrated potatoes. Collaborators also analyzed the same samples spiked with sulfites at 2 levels, which ranged from 10 to 1100 ng added S02/g. The variability of free S02 results was excessive for quantitative analysis, but the method can be used for qualitative detection of free S02. The method for total S02 determination was suitable for as low as approximately 10 μg/g. Recoveries are comparable to those for the official Monier-Williams method at high levels and are superior at low levels. The method has been adopted official first action for determination of total S02 in the foods studied.
Monitoring Residues of Carbendazim (Applied as Benomyl) and Thiabendazole in Wellspur Apples
Authors: Monico-Pifarre Amalia , Xirau-Vayreda Maria 
Published: February 2020

Abstract
Residues of benomyl (determined as carbendazim, widely accepted as MBC) and of thiabendazole in Wellspur apples were monitored after the apples were treated postharvest by immersion in a bath with each of the fungicides separately and stored under refrigeration. Whole fruit and pulp analyses were conducted over the period beginning 1 day after treatment and lasting up to 200 days afterwards. Under the conditions described, both benomyl (expressed as parts per million of carbendazim) and thiabendazole were found in the fruits in the following average amounts: 0.44 ± 0.03 and 0.11 ± 0.03 ppm benomyl (as carbendazim) in whole fruit and in pulp, respectively; 0.98 ± 0.10 and 0.39 ± 0.10 ppm thiabendazole in whole fruit and in pulp, respectively.
Determination of Vitamin D3 in Liquid Multivitamin Preparation, Using Reverse Phase, Solid Phase Extraction Liquid Chromatography
Authors: Pluscec Josip , Owies Said 
Published: February 2020

Abstract
A method is described for the determination of vitamin D,in a liquid multivitamin preparation by liquid chromatography. Samples are purified on a disposable reverse phase extraction (SPE) column with a mobile phase of methanol-2-propanol (97 + 3) and are analyzed on a Zorbax ODS (5 μm) column with an acetonitrile-2-propanolwater( 90 + 8 + 2) solvent system. Vitamin D3is completely resolved from other interfering compounds within approximately 21 min and is detected with a UV detector at 254 nm. A mean of 98.5% of theory with a coefficient of variation of 3.8% was found for determination of vitamin D, in a commercial preparation.
Quantitative Connrmation of Dimetridazole and Ipronidazole in Swine Feed by Capillary Gas Chromatography/Mass Spectrometry with Multiple Ion Detection
Authors: Morris William J , Nandrea Gene J , Roybal Jose E , Munns Robert K , Shimoda Wilbert , Skinner Henry R 
Published: February 2020

Abstract
Extracts from 4 types of swine feed containing 0.11 ppm each of dimetridazole (DMZ) and ipronidazole (IPR) were analyzed by capillary gas chromatography/mass spectrometry (GC/MS) using multiple ion detection (MID) techniques. We demonstrate in this paper that the quantitative results obtained by capillary GC/MS with MID are comparable for both compounds to results obtained by liquid chromatography and have a lower coefficient of variation for DMZ. Moreover, consistency in the ion ratios (5 ions in DMZ and 6 ions in IPR) permits identification of these compounds by electron ionization MS.
Simplified Plate Diffusion System for Microbial Assays of Antibiotics
Authors: Brady Marietta Sue , Katz Stanley E 
Published: February 2020

Abstract
A protocol for microbial assays of antibiotics, using the plate diffusion system, is presented. The system is based on the concept that a complete standard curve and assay unknowns can be placed on an issay plate and that 2 plates can be a complete assay with an accuracy and precision essentially equivalent to the official AOAC diffusion procedure. Four antibiotics, bacitracin, chlortetracycline, oxytetracycline, and streptomycin, were used in the design and comparison studies with the AOAC protocol. The coefficients of variation (CVs) for the AOAC design, using 10 replicates, ranged from 1.4 to 10.3% with a mean of 4.5%. The CVs for the single-plate option of the simplified design ranged from 4.3 to 9.6% with a mean of 6.6%; the CVs for the 2-plate option ranged from 2.5 to 6.8% with a mean of 43%; the CVs for the 3-plate option ranged from 1.2 to 5.0% with a mean of 3.0%.
Simultaneous Analysis of T-2 Toxin and HT-2 Toxin by an Indirect Enzyme-Linked Immunosorbent Assay
Authors: Fan Titan S L , Xu Yi-Chun , Chu Fun Sun 
Published: February 2020

Abstract
An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of HT-2 toxin in the presence or absence of T-2 toxin is described. In the indirect ELISA, the relative cross-reactivities of antibodies against T-2 toxin (anti-T-2) with T-2 toxin and HT-2 toxin were 1 and 0.1, whereas anti-HT-2 cross-reactivities with T-2 toxin and HT-2 toxin were 0.33 and 1, respectively. Using such relationships, a formula was established that could be used to calculate the individual toxin concentration in a mixed sample after experimentally analyzing for T-2 and HT-2 toxins in the 2 indirect ELISAs. This method was tested by analyzing urine samples spiked with HT-2 toxin alone and samples spiked with both T-2 toxin and HT-2 toxin. A cleanup protocol for treatment of urine samples before ELISA was also established. The overall analytical recovery of HT-2 toxin when it was added at concentrations of 0.1-10 parts per billion (ppb) to the urine samples was ca 89%. When both T-2 and HT-2 toxins were added to the urine samples at equal concentrations of 0.5 to 5.0 ppb, their recoveries were 112 and 109%, respectively.
Liquid Chromatographic Determination of Cinnamic and Benzoic Acids in Benzoin Preparations
Authors: Wahbi Abdel-Aziz M , Abounassif Mohammad A , Gad-Kariem El-Rasheed A , Ibrahim Mahmoud W 
Published: February 2020

Abstract
A liquid chromatographic method for the individual determination of benzoic and cinnamic acids in 2 benzoin preparations is presented. The method specifies a reverse phase column and 0.01M KH2P04- methanol (85 + 15) as mobile phase at a flow rate of 1.8 mL/min, with detection at 254 nm. The method has been applied to 2 benzoin preparations and the results were compared with those from the British Pharmacopoeia method.
Liquid Chromatographic Determination of Free and Added Niacin and Niacinamide in Beef and Pork
Authors: Takatsuki Keigo , Suzuki Shigeru , Sato Makiko , Sakai Keiich , Ushizawa Isamu 
Published: February 2020

Abstract
A simple liquid chromatographic (LC) method is described for the determination of free and added niacin and niacinamide in meats. A sample is homogenized and extracted with water, and the water extract is centrifuged, deproteinized with zinc hydroxide, and filtered first through a fluted paper and then through a microporous filter. The filtrate is subjected to liquid chromatography with UV detection at 263 nm. Different ion-pair systems are needed for the measurement of niacin and niacinamide on a reverse phase column. Methanolwater (1 + 9) containing 5mM tetrabutyl ammonium ion is used to separate niacin. Water containing lOmM heptane sulfonic acid is recommended for niacinamide. Recoveries (CV,%) are 104.8% (2.9%) for niacin and 96.3% (2.7%) for niacinamide at a 10 mg/100 g fortification level. Detection limit is 1 mg/100 g sample for niacin and niacinamide.
Simultaneous Liquid Chromatographic Determination of Residual Synthetic Antibacterials in Cultured Fish
Authors: Nose Norihide , Hoshino Youji , Kikuchi Yoshinori , Horie Masakazu , Saitoh Kouichi , Kawachi Takashi , Nakazawa Hiroyuki 
Published: February 2020

Abstract
A liquid chromatographic method is described to determine simultaneously the following 11 synthetic antibacterial agents used in a fishery: nitrofuran derivatives furazolidone, nifurpirinol, difurazone, and furamizole; sulfa drugs sulfamerazine, sulfisozole, sulfamonomethoxine, and sulfadimethoxine; and, oxolinic, nalidixic, and piromidic acids. A Nucleosil C18 column was used with tetrahydrofuran- acetonitrile-phosphoric acid-water (29 + 1 + 0.06 + 69.94) as the mobile phase. Pretreatment of the fish meat sample with acetone extraction and alumina column cleanup gave good separation of the LC peaks without interference from any other components. Recovery of the antibacterial agents was ca 80%. The lower limit of detection of the drugs was 1-2 ng for 10 μL injection.
Capillary Column Gas Chromatographic Determination of Ethyl Carbamate in Alcoholic Beverages with Confirmation by Gas Chromatography/Mass Spectrometry
Authors: Conacher Henry B S , Page Denis B , Lau Benjamin P Y , Lawrence James F , Bailey Ruth , Calway Patrick , Hanchay Jean-Pierre , Mori Brian 
Published: February 2020

Abstract
A method is described for determining ethyl carbamate at low \i%l kg levels in several types of alcoholic beverages by capillary column gas chromatography with Hall electrolytic conductivity detection and confirmation by mass spectrometry. Samples are diluted to obtain a uniform concentration of ethanol (ca 10%) then saturated with NaCl and extracted with methylene chloride. Extracts are evaporated to a small volume and injected in ethyl acetate solution for chromatographic analysis. The method was evaluated by 5 laboratories, 4 employing the Hall detector and one using mass spectrometric detection. Overall between-laboratory mean percent recoveries were: wine, 85.3 ± 21.0% coefficient of variation (CV) (spiking level 20- 45 μg/kg); sherry, 83.8 ± 16.1% CV (spiking level, 81-142 μg/kg);whiskey, 79.5 ± 13.9% CV (spiking level 127-190 Mg/kg); and brandy, 85.0 ± 12.5% CV (spiking level 297-446 μg/kg). Mass spectrometric results agreed well with the Hall results for all commodities. Detection limits were about 5 μg/kg for the Hall detector and about 0.5 μg/kg for mass spectrometric detection.
Lead, Cadmium, and Fluoride Levels in Market Milk and Infant Formulas in Canada
Authors: Dabeka Robert W , Mckenzie Arthur D 
Published: February 2020

Abstract
Lead, cadmium, and fluoride were determined in 68 samples of market milk and about 115 infant formulas. Mean and median levels (ranges) in ng/g found for cow milk were as follows: lead, 1.12, 1.19 (0.01-2.48); cadmium, 0.10, 0.039 (0.005-0.74); and fluoride, 41, 40 (7-86). In canned, ready-to-use formulas, lead, cadmium, and fluoride levels averaged 37.3,1.50, and 840 ng/g, respectively. In concentrated liquid formulas, the respective levels were 21, 3.54, and 600 ng/g. In powder formula concentrates, respective levels were 73.7, 6.78, and 1130 ng/g. On the basis of this study and literature data, lead levels in market milk exceeding 5 ng/g appeared to signify contamination of the milk either directly or via the cow. For formulas considered on an as-consumed basis, lead levels exceeding about 10-15 ng/g were attributed to contamination from either the can used to store the formula or the formula ingredients. Infant formulas in lead-free cans contained about 1.7 ng/g of lead on a ready-to-use basis. Milkbased formulas contained about 0.26 ng/g of cadmium on a readyto- use basis. Soy-based or milk-free formulas contained about 8-15 times more cadmium than did milk-based formulas. Canadian and U.S. ready-to-use formulas contained 900 and 230 ng/g fluoride, respectively, and this difference was attributed to the level of fluoride in the processing water used by the manufacturers.
Evaluation of AOAC Microbial Diffusion Procedure for Analysis of Chlortetracycline in High
Mineral Feeds
Authors: Katz Stanley E , Ragheb Hussein S , Black Lisa B 
Published: February 2020

Abstract
The performance of the AOAC microbial diffusion assay procedure for the analysis of chlortetracycline was evaluated in mixed feeds and premixes as well as laboratory-prepared feeds, all with various mineral contents. In 100 mixed feeds with a calcium content ranging from &lt; 1 to &gt; 22%, no relationship was shown between calcium content and incidence of chlortetracycline deficiency. In 106 premixes, a relationship was shown between chlortetracycline content and adherence to guarantee: below 10 g/lb, the incidence of deficiency was high; in premixes containing 20 g chlortetracycline and above, the incidences of deficiency were less than 5%. In laboratory-prepared feeds containing 12-15% calcium, grinding and storage at both 4°C and at room temperature (20°C) caused no decrease in the chlortetracycline concentration. Only storage of the ground feed at 37°C caused a distinct loss of activity. The temperature-related loss was attributed to the epimerization of chlortetracycline.
Determination of /V-Nitrosodiethanolamine in Dinoseb Formulations by Mass Spectrometry
and Thermal Energy Analyzer Detection
Authors: Wigfield Yuk Y , Gurprasad Narine P , Lanouette Monique , Ripley Sharon 
Published: February 2020

Abstract
A new method is described to determine trace quantities of A'-nitrosodiethanolamine (NDE1A) in aqueous diethanolamine (DE1A) formulations and in oil solutions of dinoseb. A formate anion-exchange column is used in series with a cation-exchange column if there is DE1A in the formulation. The eluate is then passed through a Clin Elur8 column. Depending on the concentration of NDE1A in the sample, a packed silica-gel column is used to purify the extract further. This extract is analyzed on a liquid chromatograph coupled with a thermal energy analyzer (LC/TEA), using a mixture of methanol- hexane-methylene chloride containing 0.1% acetic acid (8 + 56 + 35) as the mobile phase. This solvent system gives good separation of NDE1A from trace quantities of dinoseb remaining in the extract. The NDE1A is also converted to the trimethylsilyl derivative and analyzed by gas chromatograph coupled with a mass spectrometer (GC/MS). Analyses of 11 commercial samples of dinoseb diethanolamine salt showed NDE1A levels of 116-2409 ppm expressed relative to the weight of dinoseb. In contrast, analyses of 2 samples of organic solutions of technical dinoseb showed NDE1A levels to be nondetectable and 0.3 ppm, respectively. Limit of detection by LC/ TEA is 6.5 ng (0.5 ppm), and by GC/MS it is 0.02 ng (0.15 ppm). Recoveries from samples spiked at 0.514-1664 ppm range from 92.2 to 105.2%
Determination of Ethylene Oxide in Ethoxylated Surfactants and Demulsifiers by Headspace
Gas Chromatography
Authors: Dahlgran James R , Shingleton Carroll R 
Published: February 2020

Abstract
A headspace gas chromatographic method for the determination of traces of ethylene oxide in ethoxylated surfactants and demulsifiers was developed. Samples are analyzed directly by the technique to a 1.0 ppm (w/w) quantitation limit. The procedure also performs well for propylene oxide, acetaldehyde, and 1,4-dioxane. It is simple, sensitive, and linear. The percent relative standard deviations for 0.5 and 30 ppm ethylene oxide in the surfactant were 2.8 and 8.3%, respectively.
Liquid Chromatographic Determination of Depletion of Bithionol Sulfoxide and Its Two
Major Metabolites in Bovine Milk
Authors: Mourot Dominique , Dagorn MichÈle , Delepine Bernard 
Published: February 2020

Abstract
A liquid chromatographic method is described for determining bithionol sulfoxide and its metabolites, bithionol and bithionol sulfone, in milk. Samples are treated with HC1 to precipitate proteins and to permit extraction of bithionol sulfoxide in nonionized form. Tetrahydrofuran is added to the organic phase to facilitate extraction in diethyl ether; the dried residue is dissolved in chloroform, hexane, and sodium hydroxide and subjected to LC analysis. Residues of bithionol sulfoxide and its 2 metabolites were determined in milk of lactating cows. Holstein-Friesian dairy cows were administered a single oral dose of bithionol sulfoxide (50 mg/kg). Milk samples were analyzed with a reliable detection level of 0.025 pg/mL for each compound. Residues of bithionol sulfoxide and bithionol were detected during 30 and 16 milkings, respectively; bithionol sulfone was never present at detectable levels
Analysis of Piperazine Drug Formulations for /V-Nitrosamines
Authors: Dawson Brian A , Lawrence Robert C 
Published: February 2020

Abstract
A quantitative method is described for the measurement of /V-mononitrosopiperazine (NPIP) and TV.A^-dinitrosopiperazine (DNPIP) in drug formulations containing piperazine, using a gas chromatograph interfaced to a thermal energy analyzer (GC/TEA). The method has detection limits of 20 ppb for NPIP and 12 ppb for DNPIP. In a survey of 6 products available on the Canadian market, all contained NPIP at levels of 0.38-15.3 µg NPIP/g piperazine and none contained any detectable amount of DNPIP
Gas Chromatographic Relative Retention Data for Pesticides on Nine Packed Columns: II.
Organophosphorus and Organochlorine Pesticides, Using Electron-Capture Detection
Authors: Prinsloo Susan M , De Beer Pieter R 
Published: February 2020

Abstract
The retention time relative to parathion, absolute retention time, concentration range, peak asymmetry factor, and peak shape class are given for each of 42 organophosphorus pesticides and 28 organochlorine pesticides analyzed by gas chromatography (GC) on 9 different packed columns. The packing materials used were 3% SP- 2100, 1% Dexsil-300, 3% OV-17, 1.5% OV-17 + 1.95% QF-1, 4% SE-30 + 6% QF-1, 3% OV-17 + 3% OV-210, 5% DC-200 + 7.5% QF-1,3% Carbowax-20M, and 4% Reoplex-400. Retention data were determined at 200°C with a carrier gas flow at ūopt using a 63Ni electron-capture detector. Results should be useful for preliminary identification of environmental samples and also for single or multiple pesticide residue analysis
Correlations between Selected Trace Elements and Organic Matter and Texture in Sediments
of Northern Prairie Wetlands
Authors: Martin Dan B , Hartman William A 
Published: February 2020

Abstract
Total concentrations of arsenic, cadmium, lead, mercury, and selenium previously determined in wetland sediments were grouped according to habitat type and geologic location and related to sediment organic matter and particle size by stepwise multiple regression analysis. Cadmium and Se were significantly correlated with the measured sediment properties in every geologic and hydrologic category. Arsenic and Pb were consistently correlated with sediment properties in riverine habitats but not in potholes. In contrast, good correlations were found with Hg in potholes but not riverine wetlands. Organic matter concentration was the most consistent overall predictor of trace element concentrations, but texture was also a good indicator in some instances. The lack of correlation observed for some of the elements within given geologic categories suggests that other factors, such as external loading or deposition rates, were responsible for the observed variation
Gas Chromatographic Determination of Capsaicinoids in Green Capsicum Fruits
Authors: Krajewska Anna M , Powers John J 
Published: February 2020

Abstract
A new gas chromatographic (GC) method is described that uses a simple on-column methylation for the quantitative determination of the major naturally occurring capsaicinoids. Capsaicinoids are extracted from the dry sample with acetone in a Soxhlet apparatus, purified by extraction with petroleum ether and water, mixed in a microsyringe with trimethylanilinium hydroxide solution, and injected onto the GC column. The methylated capsaicinoids thus formed require 16 min for elution. The gas chromatographic response is linear with increased concentration of capsaicinoids
Enzyme-Linked Immunosorbent Assay of Benomyl and Thiabendazole in Some Foods
Authors: Newsome Harvey W , Collins Peter G 
Published: February 2020

Abstract
Enzyme-linked immunosorbent assays were developed for benomyl as its decomposition product, methyl 2-benzimidazoIe carbamate, and thiabendazole in foods. Immunogens consisting of human serum albumin coupled to 2-succinamidobenzimidazole or 2-{2'-succinamido- 4'-thiazolyl)benzimidazole were used in rabbits to raise antisera that were specific for the respective fungicides. Lower limits of quantitation of 0.35 ppm for benomyl and 0.03 ppm for thiabendazole were established without cleanup of the ethyl acetate extract. Recoveries of benomyl from 3 crops spiked at 0.5 to 10 ppm averaged 89% (range 73-109%) and of thiabendazole from 5 crops spiked at 0.1 to 2.0 ppm were 93% (range 81-105%).
Determination By Liquid Chromatography With Electrochemical Detection Of Cysteamine And
Cysteine, Possible Precursors Of /V-Nitrosothiazolidine
Authors: Pensabene John W , Doerr Robert C , Fiddler Walter 
Published: February 2020

Abstract
A method is described that is selective, sensitive, rapid, and accurate for the quantitative measurement in meat products of both cysteamine and cysteine, potential precursors for TV-nitrosothiazolidine (NTHZ) and Ar-nirrosothiazolidine-4-carboxylic acid (NTHZC), respectively. In general, a ground meat sample is homogenized with acetonitrileformate buffer in the presence of dithiothreitol, and then is centrifuged, filtered, and recentrifuged in a disposable microfilter. The thiols are quantitated by liquid chromatography using an amperometric detector equipped with a gold/mercury electrode operated in the oxidative mode. Cysteamine was found in 6 of 20 samples of raw pork belly in concentrations ranging from 150 to 450 ppb, and cysteine was found in all samples in concentrations ranging from 2.4 to 36.5 ppm. Analysis for the thiols and their corresponding nitrosamines— NTHZ and NTHZC—of bacon before and after processing showed no correlation between cysteamine and cysteine levels before processing nor with nitrosamine levels after processing. Liquid chromatography with electrochemical detection was found to be an extremely selective technique to measure the 2 free sulfhydryl compounds in a complex food substrate.
Comparison of Methods for Determination of Lactose (Nonfat Dry Milk) in Meat Products
Authors: Ellis Christopher P , Rand Arthur G 
Published: February 2020

Abstract
Four enzymatic methods were compared with the official AOAC yeast fermentation procedure for determining nonfat dry milk (NFDM) as lactose in meat products. The four enzymatic procedures included a commercially available UV test kit, 2 colorimetric assays using kits prepared in the laboratory, and a commercially available instrument with an immobilized enzyme electrode to detect lactose electrochemically. The enzyme procedures were compared with the AOAC method in terms of analysis time, accuracy, precision, sensitivity, specificity, and ease of performance. The UV kit and immobilized enzyme electrode appeared to be the most promising alternatives to the AOAC method on the basis of statistical data and analysis time. Particular needs of a laboratory would dictate the method of choice, but either one could be used as a screening procedure for regulatory purposes. Samples containing levels of NFDM in excess of 3.5% by weight could then be verified by the AOAC yeast method.
Sample Accountability Quality Assurance for the "Integrated Air Cancer Project" Research
Program of the U.S. Environmental Protection Agency
Authors: Watt Randall R , Cupitt Larry T 
Published: February 2020

Abstract
A sample accountability quality assurance (QA) program is described for a field and laboratory research effort which resulted in collection of approximately 2000 samples for analysis by several EPA and contractor laboratories. A QA program was specifically developed for this research program to include sample transfer from collection site to storage maintenance, record development, transfer to researchers, and sample tracking at all stages. A sample identification system and sample custody records are described for field and laboratory application. The functions of a sample coordinator are also described as relating to sample custody, coordination of sample analysis with researchers, and development of computer record files to facilitate research and sample tracking.