bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Copper in Infant Formula by Graphite Furnace Atomic Absorption Spectroscopy with a L’vov Platform
Authors: Hutchinson Donald J , Disinski Francis J , Nardelli Christy A 
Published: February 2020

Abstract
A rapid method for the determination of sub-part-per-million levels of copper in infant formula, which does not require decomposition of the sample matrix before analysis, has been developed. The method uses L’vov platform graphite furnace atomic absorption spectroscopy (GFAAS), a technique that greatly reduces matrix interferences limiting the applicability of normal GFAAS. The sample preparation consists of dilution of a weighed sample of infant formula to a known volume with a 0.5% solution of Triton X-100 in deionized water. The accuracy of the method, as assessed from the results of overspike recovery studies (96.5-101.3% recovery) for different matrix types and comparison to results generated with alternative methodologies, can be considered excellent. The overall precision of the method ranges from 2.5 to 4.3% RSD for different matrix types.
Determination of cis,cis-Methylene Interrupted Polyunsaturated Fatty Acids in Fats and Oils By Capillary Gas Chromatography
Authors: Athnasios Albert K , Healy Edward J , Gross Anthony F , Templeman Gareth J 
Published: February 2020

Abstract
A capillary gas chromatographic (CGC) method is described for the determination of cis,cis-methylene interrupted polyunsaturated fatty acids (cis-PUFA) in fats and oils. The sample is saponified and the liberated fatty acids are esterified to the corresponding methyl esters. The latter are analyzed by CGC using a 60M SP2340 capillary column. Area percent values for 9,12-cis,cis-C18:2 and 9,12,15-cis,cis,cis-C18:3 fatty acid methyl esters are summed to give the total cis-PUFA content. Gas chromatographic results agreed well with those obtained by an enzymatic lipoxygenase method at the 31-48% cis-PUFA levels with a correlation coefficient of 0.98. The method has a precision (relative standard deviation) of 0.33% at a 44.4% cis-PUFA level in margarine oil.
Determination of Fish Core Content in Coated Products: Interlaboratory WEFTA Studies of Three Procedures
Authors: Bon Johannes , Brünner Kerst K , Aitken Angus 
Published: February 2020

Abstract
Four collaborative trials are described in which 3 different methods for the estimation of fish content of coated products were compared to determine their suitability. The methods are a modified version of AOAC method 18.003, an alternative “scraping” method, and a “soaking” method. Seven West European laboratories participated in this collaborative exercise, which was performed on 4 types of coated fish products: raw coated portions of cod (Gadus morhua), partly cooked cod sticks, raw fillets of plaice (Pleuronectes platessa), and partly cooked plaice fillets. The results indicate that precooking strongly affected fish recovery by all 3 methods. Regular portions (of cod) gave higher recoveries than irregular shaped fillets (of plaice). The results do not lead to the conclusion that any method was better than the others.
Uses and Analysis of Sulfites in the Corn Wet Milling Industry
Authors: Coker Lowell E 
Published: February 2020

Abstract
This paper reviews the purpose and principal uses of sulfiting agents in corn wet milling, together with the residual levels of sulfiting agents in finished products. Comparative results of the Monier-Williams method, an iodometric method, and a pararosaniline method for sulfur dioxide are discussed.
Gas Chromatographic Determination of Electron Capture Sensitive Volatile Industrial Chemical Residues in Foods, Using AOAC Pesticide Multiresidue Extraction and Cleanup Procedures
Authors: Yurawecz Martin P , Puma Bartholomew J 
Published: February 2020

Abstract
Electron capture (EC) gas chromatographic (GC) parameters have been developed for determining some of the more volatile industrial chemicals that can be determined by the AOAC multiresidue method for organochlorine and organophosphorus pesticides with modified GC operating conditions. Retention times relative to pentachlorobenzene are reported for 143 industrial chemicals, pesticides, and related compounds on OV-101 GC columns at 130°C. Also reported for most of the compounds are recoveries from fortified samples carried through the AOAC extraction and cleanup procedures for fatty and/or nonfatty foods, Florisil elution characteristics, and GC relative retention times on mixed OV-101 + OV-210 columns at 130°C. Our laboratory has used the modified EC/GC parameters with the AOAC multiresidue extraction/cleanup procedures to determine many volatile halogenated industrial chemical contaminants in foods, chiefly in samples of freshwater fish. Other modifications of the AOAC method are described to improve the tentative identification and quantitative measurement of these volatile residues.
Comparison of Methodology for Determination of Ethylene Dibromide in Grains and Grain-Based Foods
Authors: Clower Marion , McCarthy James P , Carson Louis J 
Published: February 2020

Abstract
Three commonly used methods for determination of ethylene dibromide (EDB) in grains and grain products have been compared. EDB residues were extracted by (1) soaking in hexane, (2) triple co-distillation with hexane from an aqueous sample solution, and (3) soaking in acetone-water (5 + 1). Each method was used for triplicate analyses of 12 samples containing incurred residues of EDB ranging from about 10 to 1000 ppb and representing whole grains (wheat and oats) and intermediate grain-based products such as corn meal and flour. The 4-day hexane soaking method extracted the least EDB. In some cases, this was half of the amount determined by the other methods. Levels from soaking in acetone-water were equal to, or up to 25% greater than, those from distillation. Although soaking for 2 days is required for whole grains in the method, a period of only 16 h was found acceptable for ground products. Results were obtained faster with the distillation method, but more analyst time per sample was required. A single distillation recovered about 80% (40-60% from wheat) of total EDB extracted by triple distillation. Foaming was reduced by the addition of concentrated H2SO4 to the aqueous hexane-sample mixture, plus stirring during distillation, thereby allowing complete recovery of the hexane.
Evaluation of Capillary Gas Chromatography for Pesticide and Industrial Chemical Residue Analysis. II. Comparison of Quantitative Results Obtained on Capillary and Packed Columns
Authors: Fehringer Norbert V , Walters Stephen M 
Published: February 2020

Abstract
Results of pesticide and industrial chemical residue determinations, using both capillary and packed column gas chromatography (GC), in 3 Food and Drug Administration (FDA) laboratories have been compiled and compared. Samples consisted of food products collected for routine residue screening by the respective laboratories. Extracts were prepared by conventional multiresidue methodology. Capillary column systems and operating conditions were selected at the discretion of each laboratory and were therefore variable, although split/splitless injectors in the split mode were used with prescribed precautions in all cases. Packed column systems were operated as specified in the FDA Pesticide Analytical Manual (PAM). Overall correlation between the 2 systems, expressed as the average ratio of packed column result to capillary column result, was 0.99 for 120 determinations in 41 samples. The higher resolving power of the capillary systems allowed quantitation of several residues that were incompletely separated and therefore unquantifiable using the packed columns. Capillary column GC with the split injection technique, used with appropriate precautions, was found to be both reliable and advantageous for regulatory determination of pesticide and industrial chemical residues in foods and feeds.
Minimum Criteria for Validation of Analytical Methods
Authors: Williams D R 
Published: February 2020

Abstract
Two aspects must be considered in outlining minimum criteria for validation of analytical methods: management issues and technical issues. Management needs background information and information on issues, options, and implications to identify priorities. The value of the work should be clear to ensure its support and implementation. International adoption of AOAC guidelines for collaborative interlaboratory studies would provide technical criteria for future tests.
Determination of Halogenated Contaminants in Human Adipose Tissue
Authors: Lebel Guy L , Williams David T 
Published: February 2020

Abstract
&lt;A method has been developed for determination of organochlorine contaminants in human adipose tissue. After fat extraction from the tissue with acetone-hexane (15 + 85, v/v), organochlorines were fractionated from fat by gel permeation chromatography with methylene chloride-cyclohexane (1 + 1, v/v) as solvent. After Florisil column cleanup, the GPC extract was analyzed by capillary column gas chromatography using 2 columns of different polarity. Compound identity was confirmed by gas chromatography-mass spectrometry using selected ion monitoring. Recoveries for fortification levels of 10-500 ng/g were greater than 80 % except for trichlorobenzene and hexachlorobutadiene (ca 60%).
Rapid Method for Determination of 2-Hydroxy-4-(Methylthio)butanoic Acid in Poultry Feeds by Capillary Isotachophoresis
Authors: Vinjamoori Dutt V , Schisla Robert M 
Published: February 2020

Abstract
Capillary isotachophoresis, which involves the separation of charged species under an electric field, has been applied to the rapid determination of 2-hydroxy-4-(methylthio)butanoic acid at 0.04-0.50% concentration levels in corn/soy-based poultry feeds, using conductivity detection. The procedure merely involves a 15 min cold water extraction of the sample and a 15 min analysis after injection of the filtrate into the instrument. Since only charged species migrate and non-ionic species stay virtually at the front of the column, extraordinary selectivity can be achieved. The isotachophoresis method is an order of magnitude faster than the gas chromatographic method reported recently and also provides information on HMB-monomer/dimer ratio in the same run. The sample recoveries exceeded 90% in all concentration ranges studied with coefficients of variation less than ± 10%.
Colorimetric Determination of Certain Phenothiazine Drugs by Using Morpholine and Iodine-Potassium Iodide Reagents
Authors: Youssef Adel F , El-Shabouri Salwa R , Mohamed Fardous A , Rageh Abdel Maboud I 
Published: February 2020

Abstract
A colorimetric method was developed for the quantitative estimation of 11 phenothiazine drugs. The method is based on the interaction of unsulfoxidized drug with morpholine and iodine-potassium iodide reagents. The interaction for all studied phenothiazine drugs yields a blue product with 2 absorption maxima: one in the range of 620-640 nm with lower molar absorptivity and the other in the range of 662-690 nm with higher molar absorptivity. The color was stable for at least 10 h. The reproducibility and recovery of the method were excellent. The method was applied successfully to the analysis of various commercially available phenothiazines in different dosage forms. The results were comparable to those obtained by official procedures. The suitability of the method for detection and estimation of promethazine excreted in urine has been suggested by preliminary experiments. Reaction products have been isolated and identified.
Nonaqueous Titration of Halides of Nitrogenous Bases, Using Trifluoromethyl Sulfonic Acid
Authors: Zakhari N Aziz , Kovar K Artur 
Published: February 2020

Abstract
Trifluoromethyl sulfonic acid in glacial acetic acid has been compared with perchloric acid as a titrant in 4 solvent systems: glacial acetic acid, acetic anhydride, a mixture of both, and acetone. The comparison was limited to the determination of halides of nitrogenous bases with and without the use of mercury(II) acetate reagent. The results of the visual titrations showed that both acids are comparable tit rants. However, trifluoromethyl sulfonic acid proved to be superior to perchloric acid in potentiometric titrations carried out in acetic acid-acetic anhydride mixtures. Moreover, the nonoxidizing properties exhibited by trifluoromethyl sulfonic acid proved advantageous over perchloric acid in the visual detection of end points in the titration of phenothiazine derivatives in anhydrous acetic acid, using crystal violet indicator.
Spectrophotometric Determination of L-Pyroglutamic Acid as Indicator of Decomposition or Abuse of Processed Foods
Authors: Ekström Lars-Gösta , Kuivinen Jorma 
Published: February 2020

Abstract
An analytical procedure is described for determination of L-pyroglutamic acid in molasses, wastewater, and catsup. In the cleanup procedure, proteins in the matrix are precipitated with ethanoi and, after acidification, amino acids are retained on a cationic exchanger. The lactam-binding in the pyroglutamic acid ring is quantitatively cleaved by acid hydrolysis to glutamic acid, which is determined spectrophotometrically with an enzymatic method. A commercial test kit is available for performing the latter. Levels of 0.01 mg pyroglutamic acid/mL can be quantitatively determined. This method requires only basic laboratory equipment and is therefore suitable for laboratories with limited resources.
Electron Capture Gas Chromatographic Determination of Traces of Formaldehyde in Milk as the 2,4-Dinitrophenylhydrazone
Authors: Buckley Katherine E , Fisher Lorne J , MacKay Vernon G 
Published: February 2020

Abstract
A quantitative method is described for the determination of formaldehyde in milk by packed-column gas chromatography and electron capture detection. Aldehyde derivatization was carried out in situ with 2,4-dinitrophenyIhydrazine followed by extraction and analysis using an external standard. Average recoveries of 96.3 ± 1.6% were characteristic of the chromatographic method with an estimated detection limit of 0.026 mg/kg. The technique was applied to determination of formaldehyde in milk from cows consuming a formalin-treated feedstuff.
Preparation and Stability of Animal Feed Mixtures Dosed with Rotenone
Authors: Kline David A , Hanna Garry R , Honaker Carl B , Kuhn Gustav O , Jameson C William 
Published: February 2020

Abstract
Studies at Midwest Research Institute for the National Toxicology Program show that rotenone/animal feed mixtures prepared by drymixing are more stable than mixtures produced by dosing the feed with alcoholic solutions of rotenone and then stripping the solvent. Also, recoveries of rotenone from the dry mix feeds are higher than those from feeds dosed by the solution method. A simplified analytical method from one previously reported for rotenone in feed is described.
Colorimetric Determination of Total Iodine in Foods by Iodide-Catalyzed Reduction of Ce+4
Authors: Fischer Peter W F , L’Abbé Mary R , Giroux Alexandre 
Published: February 2020

Abstract
An earlier acid digestion determination of iodine in foods was modified to provide an improved detection limit and to allow for the analysis of a greater variety and larger amounts of foods. The organic material in the sample was oxidized overnight by concentrated nitric acid, followed by digestion in a mixture of concentrated sulfuric and 70% perchloric acid. The iodine was determined by an automated colorimetric method based on the iodide-catalyzed reduction of Ce+4 by As+3. The method had an average relative standard deviation of 3.1% for the samples analyzed, and a detection limit of 0.1 ng/mL in the digested solution and 5 ng/g in a 2 g sample prior to digestion. The recovery of added iodine ranged from 90.3 to 101.3%, using external standards. Samples analyzed included NBS Standard Reference Material 1549, and composites of a variety of dairy products, meat, eggs and fish, cereals, and potatoes. The iodine detected in these samples ranged from 9 ng/g for the potato group to 3360 ng/g for the standard reference material.
Gas Chromatographic Determination of Avilamycin Total Residues in Pig Tissues, Fat, Blood, Feces, and Urine
Authors: Formica Giuseppe , Giannone Carmine 
Published: February 2020

Abstract
A gas chromatographic (GC) procedure is presented for the determination of residues of avilamycin and all its metabolites/conjugates which can be converted to the common moiety dichloroisoeverninic acid (DIA). The method involves alkaline hydrolysis to DIA, cleanup by partitioning with chloroform, acidification of the aqueous phase, and partitioning of DIA into methylene chloride. After methylation of DIA, the product, 3,5-dicMoro-4,6-dimethoxy-2-methylbenzoic acid methyl ester, is cleaned up on a silica gel column prior to the final determination by electron capture GC. The method is sensitive to 0.1 mg/kg avilamycin equivalent. Overall average recoveries were 85.4%, with a standard deviation of 9.1 % for n = 20. Analyses of feces, urine, tissues, and fat of pigs treated with avilamycin demonstrated that 93% of the administered substance is excreted in feces and urine, within 72 h after treatment, and that no residues (&lt;0.1 mg/kg) can be found in the tissues and fat of the animals at any time between 0 and 7 days after treatment with medicated feed.
Residues of Captan and Folpet in Strawberries and Grapes
Authors: Gilvydis Dalia M , Walters Stephen M , Spivak Eugene S , Hedblad Raymond K 
Published: February 2020

Abstract
Fresh strawberries and grapes grown in Michigan and Indiana were surveyed for residues of captan and folpet, 2 fungicides commonly used on these crops. The fungicides were reportedly applied to the crops by overhead irrigation, tractor sprayer, or aerial spraying, in amounts ranging from 0.5 to 6 lb formulation/acre for captan and from 1 to 4 lb formulation/acre for folpet. Reported dates of last application ranged from just 2 days to nearly 5 months before samples were collected. Twenty-eight strawberry samples and 24 grape samples were collected of crops field-treated with one or both of these fungicides. Samples were analyzed by previously described methodology. Captan residues were found in all strawberry samples, ranging from &lt; 0.01 to 1.5 ppm. Folpet was found in only one strawberry sample at 0.041 ppm. Captan residues were found in only 6 grape samples, ranging from &lt; 0.01 to 0.082 ppm. Folpet residues were found in 12 grape samples, ranging from &lt; 0.01 to 0.50 ppm. All residues were well below the current tolerances of 25 ppm for both captan and folpet in strawberries and 50 ppm for captan and 25 ppm for folpet in grapes. Residue levels of these surface-applied, nonsystemic fungicides were inconsistent with amounts and dates of application, most likely because of variations in weather conditions, especially rainfall. Residues were quite stable in frozen sample homogenates, declining only 5-10% after 2 months.
Evaluation of Capillary Gas Chromatography for Multicomponent Drug Analysis
Authors: Thompson Don W 
Published: February 2020

Abstract
Capillary gas chromatography is evaluated for multicomponent drug analysis. A 0.32 mm id × 30 m fused silica column and a 0.75 mm id × 30 m borosilicate glass column (both with OV-1 bonded phase) are investigated. Retention times (relative to caffeine) are presented for 39 drug components representing a variety of chemical classes and pharmacological activities. Reproducibility data are presented for both isothermal and programmed temperature runs on selected drug mixtures. Recovery data are provided for 2 multicomponent drug mixtures prepared to approximate over-the-counter antihistaminic and antitussive preparations.
Colorimetric Determination of C-2 Unsubstituted Phenothiazines, Using Morpholine and N-Bromosuccinimide
Authors: El-Shabouri Salwa R , Youssef Adel F , Mohamed Fardous A , Rageh Abdel Maboud I 
Published: February 2020

Abstract
A colorimetric method for quantitative determination of 6 C-2 unsubstituted phenothiazine derivatives is described. The method is based on reaction of phenothiazine derivative with morpholine and N-bromosuccinimide reagents in aqueous methanol at 60°C to produce a blue color. Beer's law is obeyed in a wide range of concentrations for all 6 compounds at 660 nm. Optimum analytical conditions were determined and the produced color is stable for at least 24 h. Analytical data for determination of the pure compounds are presented together with the application of the proposed method to analysis of some pharmaceutical preparations. The results compare favorably with those of official methods. Furthermore, the method is specific for intact drug in the presence of oxidative decomposition products. The reaction product has been isolated and identified and a possible reaction mechanism is suggested.
Determination of Cadmium, Copper, and Lead in Sodium Chloride Food Salts by Flame Atomic Absorption Spectroscopy
Authors: Alvarez de Eulate M Jesus , Montoro Rosa , Ybañez Nieves , Guardia Miguel De La 
Published: February 2020

Abstract
A method for determination of Cd, Cu, and Pb in sodium chloride food salt samples has been developed. It consists of extraction in 4- methj 1-2-pentanonc of the complexes formed with ammonium pyrrolidine dithiocarbamate and further analysis of the extracts by flame atomic absorption spectroscopy. Detection limits in ng/g salt were 0.2 for Cd, 0.7 for Cu, and 10.0 for Pb. The coefficients of variation of 12 independent analyses were 13% for Cd (at a level of 0.4 ppb), 18% for Cu (1.6 ppb), and 5% for Pb (40 ppb). The recoveries were 100 ± 0% for Cd, 115 ± 14% for Cu, and 100 ± 13% for Pb.
Thin Layer Chromatographic Confirmation of Aflatoxin Mi Extracted from Milk
Authors: Serralheiro Maria Luisa , Quinta Maria De Lourdes 
Published: February 2020

Abstract
Aflatoxin M1 can be confirmed directly on a thin layer plate by reacting the toxin with a mixture of reagents containing p-anisaldehyde. This confirmatory procedure requires only 2 elutions in the same direction using 2 different solvents. The mixture containing p-anisaldehyde is overspotted on Mi after the plate has been developed in toluene-ethyl acetate-ethyl ether-formic acid (25 + 35 + 40 + 5). The plate is heated at 110°C for 10 min and then developed in hexanc-acetonechloroform (15 + 50 + 35). The Rf value of the green fluorescent derivative is less than that of the M1 standard. This confirmatory procedure requires only one-dimensional TLC, so several sample extracts and the standard can be run simultaneously. The minimum detectable quantity of aflatoxin M1 on the TLC plate with this test is 0.3 ng. p- Anisaldehyde reagent solution may also be used as a spray reagent for the confirmation of aflatoxin M1. The procedures described were satisfactory for confirming the mycotoxin in spiked samples of powdered and liquid milk.
Liquid Chromatographic Determination of Zearalenone and Zearalenol in Animal Feeds and Grains, Using Fluorescence Detection
Authors: Bagneris Renee W , Gaul Jean A , Ware George M 
Published: February 2020

Abstract
A liquid chromatographic (LC) method was developed for the determination of zearalenone and zearalenol in grains and mixed animal feeds. Samples are extracted with chloroform and purified by a baseacid liquid-liquid partition. Zearalenone and zearalenol are separated by reverse phase LC and determined by fluorescence detection, excitation wavelength 236 nm with a 418 nm cutoff filter. The method was applied to the determination of zearalenone and zearalenol in 395 survey samples of corn, oats, barley, sorghum, silage, and finished feeds. The limit of detection is 10 ng/g for both toxins. The range of naturally occurring toxins found was 10-4000 ng/g. Average recoveries were 84% for zearalenone and 69% for zearalenol. Coefficients of variation were 24.6% for zearalenone and 30.8% for zearalenol for crop year 1980, and 28.3% for zearalenone and 22.0% for zearalenol for crop year 1981.