bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas Chromatographic-Mass Spectrometric Determination of Six Sulfonamide Residues in Egg and Animal Tissues
Authors: Takatsuki Keigo , Kikuchi Tadashi 
Published: February 2020

Abstract
A gas chromatographlc-mass spectrometric method using selected Ion monitoring mode for simultaneous determination of 6 sulfonamides in egg and edible animal tissues has been developed. Sulfonamides are extracted from a sample with acetonltrlle. The extract Is passed through a silica cartridge column and concentrated. Dlazomethane in ether Is added to methylate sulfonamides. After evaporation, the residue Is dissolved In methylene chloride and cleaned up by silica gel column chromatography. The methylene chloride eluate containing sulfonamide-methyl derivatives Is evaporated to dryness, redlssolved In ether and partitioned between 6N hydrochloric acid. The acid phase is made alkaline, extracted with ether, and the ether solution, after concentration, Is analyzed by gas chromatography-mass spectrometry in selected Ion monitoring mode. Average recoveries from egg and silver salmon fortified at 1 and 0.2 ppm levels with 6 sulfonamides are 99.2 and 84.3%, respectively; coefficients of variation are 7.03 and 11.20%, respectively. Detection limits are 0.01-0.05 ppm.
Determination of Ivermectin in Medicated Swine Feeds at the 2 ppm Concentration Level
Authors: Doherty Stephen J , Fox Allen , Fink David W 
Published: February 2020

Abstract
An analytical method has been developed that Is applicable to the determination of Ivermectin in medicated feeds at the 2 ppm concentration level. It Is based upon liquid chromatographic analysis with a reverse-phase column and ultraviolet detection. After the drug Is extracted from the feed Into methanol, an analytical sample Is prepared by the consecutive use of column chromatography on alumina and solidphase extraction on Sep-Pak C18 and silica cartridges. This procedure has been applied to the concentration range 0.50- 3.0 ppm of Ivermectin In feed with an accuracy of ±2% mean relative error and a precision of ± 2% relative standard deviation at the 2 ppm concentration level.
Design And Analysis Of Qualitative Collaborative Studies: Minimum Collaborative Program
Authors: Mcclure Foster D 
Published: February 2020

Abstract
Collaborative studies Involving qualitative data are usually conducted under design constraints to fulfill the requirements for quantitative studies. The data from these qualitative studies are often analyzed In a manner that ignores the fact that collaborative studies Involve matching (I.e., each laboratory analyzes a portion of each test sample). This report presents some design considerations and analysis procedures for qualitative collaborative studies that take into account that the design Involves matching. Suggestions are offered as to the number of laboratories and test samples to use in the minimum collaborative program, and analysis procedures for outlier screening are detailed. Method performance Is assessed through such Indicators as sensitivity, specificity, false positive, and false negative rates. Methods for estimating the error of the performance indicator rates are explained, and procedures are given for estimating false positive and false negative rates for lot defect rates that may occur In practice.
Colorimetric and Fluorometric Substrate Immunoassays for Detection of Salmonella in All Foods: Comparative Study
Authors: Curiale Michael S , Joan Klatt Mary , Gehle Warren D , Chandonnet Heidi E 
Published: February 2020

Abstract
Two modified fluorescent enzyme Immunoassays for the detection of Salmonella In food have been developed. Both of the new procedures, which substitute a colorimetric substrate for the fluorescent substrate and In which results are read visually or with a photometer, are modifications of AOAC method 989.15. The visually read procedure uses the same antibody-coated wells as In method 989.15. The colorimetric end point of the assay is determined by comparing the solution color to a color chart. The assay result may also be read in a photometer, If the solution is first transferred to a transparent mlcrotiter well. The second procedure designed to be read in a photometer substitutes clear, antibody-coated wells for those used In the fluorescent assay. The colorimetric assays employ Identical monoclonal antibodies for capture and detection of Salmonella as used in the fluorescent assay. In this comparative study, the performance of each new assay was consistent with the performance of method 989.15. These methods have been adopted official first action by AOAC as alternative methods for the detection of Salmonella in foods.
Atomic Absorption Spectrophotometric Determination of Calcium and Magnesium and Colorimetric Determination of Phosphorus in Cheese: Collaborative Study
Authors: Pollman Roger M 
Published: February 2020

Abstract
The determination of calcium, phosphorus, and magnesium In cheese was collaboratively studied. The sample is dried and ashed and the residue is dissolved In an acidified aqueous solution. Calcium and magnesium are determined by atomic absorption spectrophotometry and phosphorus Is determined by colorlmetry. The study was repeated 3 times because of high within- and between-laboratory relative standard deviations (RSDr and RSDR, respectively). Poor precision In the first 2 studies was caused by a number of factors, Including use of contaminated glassware, Improperly maintained Instruments, and Impure reagents as standards. In each study, 5 varieties of cheese were distributed as 10 blind duplicate samples along with a practice sample. Thirteen laboratories participated in the third study, which was generally problem-free. The range of results and the average RSDr and RSDR found In the cheeses were: calcium, 608- 1107 mg/100 g, 1.5%, 2.6%; magnesium, 23.9-50.6 mg/ 100 g, 2.8%, 3.8%; phosphorus, 444-695 mg/100 g, 1.2%, 1.6%. The method has been adopted official first action by AOAC.
Liquid Chromatographic Multicomponent Method for Determination of Residues of Ipronidazole, Ronidazole, and Dimetridazole and Some Relevant Metabolites in Eggs, Plasma, and Feces and Its Use in Depletion Studies in Laying Hens
Authors: Aerts Rene M L , Egberink Irma M , Kan Cornelis A , Keukens Henk J , Beek Wim M J 
Published: February 2020

Abstract
A simple, rapid liquid chromatographic (LC) method that uses UV/VIS detection has been developed for the determination In eggs of residues of the hlstomonostats dlmetridazole (DMZ), ronldazole (RON), Ipronidazole (IPR), and side-chain hydroxylated metabolites of DMZ and RON. Sample pretreatment Includes an aqueous extraction, purification with an Extrelut® cartridge, and acid partitioning with Isooctane. An aliquot of the final aqueous extract Is Injected Into a reversephase LC system; detection Is performed at 313 nm. The limits of determination are in the 5-10 µgkg range. A UV/ VIS spectrum can be obtained at the 10 µg/kg level by using diode-array UV/VIS detection. Recoveries are between 80 and 98% with a coefficient of variation of about 5%. Some 20 samples can be analyzed per day. A side-chain hydroxylated metabolite of IPR can also be detected with this method, as demonstrated with samples from animal experiments. After a single oral dose of the drugs to laying hens, residues of the parent compound and/or the hydroxylated metabolites could be detected In eggs 5-8 days after dosing. Plasma distribution and excretion in feces were established both with and without deconjugatlon. DMZ and IPR were extensively metabolized to hydroxylated nltrolmldazole metabolites; RON was excreted mainly as the parent compound.
Liquid Chromatographic Determination of Aflatoxin Levels in Peanut Butters Using an Immunoaffinity Column Cleanup Method: International Collaborative Trial
Authors: Patey Alan L , Sharman Matthew , Gilbert John 
Published: February 2020

Abstract
Thirteen laboratories In 7 different countries participated in a collaborative trial to evaluate an Immunoaffinity column cleanup procedure with quantitation by fluorescence liquid chromatography (post-column derivatization) for the determination of aflatoxins In peanut butters. Participants were sent 10 randomly numbered samples of roasted peanut butter for analysis (5 pairs of undisclosed duplicates). Two of the pairs were "blank" peanut butters to which aflatoxin standards had been added; these "spiked" samples were used for recovery purposes. The other 3 pairs of samples were a nominal "blank" and 2 naturally contaminated peanut butters. A full statistical presentation of the results is given. Coefficients of variation (CVs) for the total aflatoxin determinations for mean levels of 4,15, and 38 µ/kg were between 32 and 44% for the blank and 2 trial samples. Recovery levels for the 2 spiked samples were 51-67%, with aflatoxin B1 recovery of 60%. Relative standard deviations for method repeatability (RSDr) and reproducibility (RSDR) for the 3 trial samples were 15-26% and 33-45%, respectively.
Immunoaffinity Column Coupled with Solution Fluorometry or Liquid Chromatography Postcolumn Derivatization for Determination of Aflatoxins in Corn, Peanuts, and Peanut Butter: Collaborative Study
Authors: Trucksess Mary W , stack Michael E , Nesheim Stanley , Page Samuel W , Albert Richard H , Hansen Thomsen J , Donahue Kevin F 
Published: February 2020

Abstract
An AOAC/IUPAC (International Union of Pure and Applied Chemistry) collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column for the determination of af latoxin. The test portion Is extracted with methanol- water (7 + 3), filtered, diluted to ⦟30% methanol with water, and applied to the affinity column. The column Is washed with water and the concentrated aflatoxins are eluted with methanol. Total aflatoxins are determined by solution fluorometry with bromine (SFB), and Individual toxins are determined by reverse-phase liquid chromatography with postcolumn derlvatizatlon with Iodine (PCD). Corn naturally contaminated with aflatoxins, and peanuts, peanut butter, and corn containing added aflatoxins ( B1:B2:G1G2 = 7:1:3:1) were sent to 24 collaborators In the United States, France, Canada, and the Republic of South Africa. Twelve collaborators used the SFB method, 9 used the PCD method, and 3 used both SFB and PCD methods. Twenty collaborators completed the study (10 used the SFB method, 7 used the PCD method, and 3 used both SFB and PCD methods). Test portions were spiked at 10, 20, and 30 ng/g. For SFB analyses, recoveries of total aflatoxins were 123,105, and 107%, respectively; the relative standard deviation for repeatability (RSDr) ranged from 11.75 to 16.57%, and the relative standard deviation for reproducibility (RSDR) ranged from 10.97 to 33.09%. For PCD analyses, recoveries were 81, 81, and 83%, respectively; the RSDr ranged from 5.20 to 17.22%, and the RSDR ranged from 4.68 to 50.77%. The RSDr for aflatoxins B1, and G1 for spiked test portions ranged from 5.45 to 23.55%, and the RSDR ranged from 4.21 to 57.28%. The RSDr and RSDR for aflatoxins B2 and G2 were higher because of the small amounts added. Analyses by both SFB and PCD methods showed acceptable within-laboratory and betweenlaboratories precision. The method has been adopted official first action by AOAC as an AOAC-IUPAC method.
Determination of Dioxins and Furans in Foods and Biological Tissues: Review and Update
Authors: Firestone David 
Published: February 2020

Abstract
Determination of trace residues of polychlorlnated dlbenzo- p-dloxlns and dibenzofurans (PCDDs and PCDFs) In various matrixes Is carried out by a limited number of laboratories In the United States, Canada, and other countries. Current methods for analysis of foods and biological tissues Include a combination of preparation, extraction, cleanup, isolation, determination, and Identity confirmation procedures. Soxhlet, liquid/liquid, solid-phase, and column extraction procedures are used as well as treatment with acid or base before solvent extraction. Cleanup and isolation steps Include sulfuric acid partitioning; adsorption chromatography on Florlsil, silica gel, or alumina; gel permeation chromatography; multistage column chromatography on sulfuric acid silica and alkali silica; carbon column chromatography; and liquid chromatography fractionation with size exclusion, normalphase, and reverse-phase columns. Activated carbon and multistage chromatographic columns are widely used in cleanup schemes. Isomer-speclflc Identification and quantitation of PCDD and PCDF congeners at parts-per-trllllon levels or lower are carried out by high resolution (capillary) gas chromatography (HRGC) and multiple Ion detection mass spectrometry. In addition to chemical methods, bloassay procedures have been recommended (e.g., use of monoclonal antibodies, for immunoassay determination of PCDDs and PCDFs).
Determination of Nabam Fungicide in Crops by Liquid Chromatography with Postcolumn Reaction Detection
Authors: Miles Carl J , Zhou Min 
Published: February 2020

Abstract
The ethyleneblsdlthlocarbamate (EBDC) fungicide, nabam, was determined In several crop matrixes using liquid chromatography with postcolumn reaction detection. After separation by mlcellar liquid chromatography, nabam (EBDC sodium salt) was acid hydrolyzed to ethylenedlamlne and fluorogenlcally labeled with o-phthalaldehyde-mercaptoethanol (OPA-MERC). Standard curves were linear from the detection limit of ca 1 ng to 1000 ng. Nabam was recovered In high yield (89 ±7.7%) over a range of concentrations (0.1 to 20 ppm) from fortified samples of papaya, lettuce, cucumber, spinach, and applesauce using a simple extraction method. Efforts to convert the more popular EBDC fungicides, maneb and mancozeb, to nabam are discussed.
Determining Organohalides in Animal Fats Using Gel Permeation Chromatographic Cleanup: Repeatability Study
Authors: Goodspeed Donald P , Chestnut Larry I 
Published: February 2020

Abstract
Evaluation of a previously published gel permeation chromatographic (GPC) procedure was undertaken to determine whether It can be used for additional organochlorine pesticides. After repeatability studies of many pesticides, the following compounds were approved for Inclusion in the U.S. Department of Agriculture Domestic Residue Monitoring Program: coumaphos-S, stirophos, chlorpyrlfos, ronnel, carbophenothlon, chlorfenvlnphos, phosalone, kepone, captan, llnuron, and endosulfan I and II. Recoveries ranged from 54% for captan to 123% for ronnel. Ranges of CVs varied from 0- 9.5% for carbophenothion to 7.1-47.7% for kepone. Although the minimum acceptable recovery of 50% was attained for all 12 pesticides, the anticipated CV of 20% was waived to Include chlorpyrlfos, endosulfan I and II, and kepone. For a multlresidue procedure involving approximately 40 compounds, these results were within the acceptable criteria.
Liquid Chromatographic Determination of Clidinium Bromide and Clidinium Bromide-Chlordiazepoxide Hydrochloride Combinations in Capsules
Authors: Yuen Stella M , Lehr Gary 
Published: February 2020

Abstract
A specific liquid chromatographic method was developed for determination of clidinium bromide and clidinium bromidechlordiazepoxide hydrochloride combinations in capsules. The procedure uses a Partisil 10 ODS-3 column and a mobile phase consisting of acetonitrile-0.3M ammonium phosphate (32 + 68) (pH = 4.3). The detection wavelength is 235 nm. Accuracy, reproducibility, and linearity were within accepted criteria. Four commercial samples of the single ingredient were tested; results compared favorably with the compendial method. Two commercial samples of the combination product were tested by the proposed method and results reported. The system was found to be free from any interferences from the 4 known related compounds of the 2 major components and Is useful as a screening procedure for 7- chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one- 4-oxide, the principal degradation product of chlordiazepoxide hydrochloride.
Determination of Penicillin G Residues in Edible Animal Tissues by Liquid Chromatography
Authors: Boison Joe O , Salisbury Craig D C , Chan Wayne , Macneil James D 
Published: February 2020

Abstract
An Improved method has been developed for the determination of benzyl penicillin In animal tissues. Tissues are fortified with a known amount of penicillin V (Internal standard) and extracted with water. The extract Is deproteinlzed with sulfuric acid and sodium tungstate, filtered, and concentrated on a conditioned C18 solid phase extraction column. Penicillin V and benzyl penicillin are then eluted from the column with 1 mL 60% acetonitrile-35% water-5% 0.2M phosphate buffer solution and derivatlzed with 1 mL 1,2,4-trlazole-mercuric chloride solution at 65°C for 30 min. An aliquot of this sample Is analyzed by reverse phase liquid chromatography with UV detection at 325 nm. The limit of detection is 5 μg/kg (ppb) penicillin G (8.4 lU/kg) In liver, kidney, and muscle tissues
Quantitative Analysis of Limonin in Grapefruit Juice Using an Enzyme-Linked Immunoassay: Interlaboratory Study
Authors: Widmer Wilbur W , Rouseff Russell L 
Published: February 2020

Abstract
Eleven laboratories participated in an interlaboratory study of an enzyme-linked immunoassay for limonin in grapefruit Juice. Participating laboratories received training and practice samples until familiar with the procedure. Laboratories then received 8 sample pairs of grapefruit Juice as blind duplicates. Samples were refrigerated and analyzed within 4 days of receipt. Results from 1 laboratory and 6 Individual samples were excluded from the statistical analysis. Method performance was measured by the one-way component of variance analysis. Repeatability relative standard deviations (RSDr) ranged from 7.0 to 15.6%. Reproducibility relative standard deviations (RSDR) ranged from 12.9 to 29.4%
Quantitative Determination of Mono- and Diglycerides with and without Derivatization by Capillary Supercritical Fluid Chromatography
Authors: Lee Theresa W , Bobik Emil , Malone William 
Published: February 2020

Abstract
Mono- and diglycerides, as well as commercial monoglyceride emulsifiers, were analyzed by capillary supercritical fluid chromatography (SFC). Carbon dioxide without modifier was used as the mobile phase in the chromatography. Samples were prepared by simply being dissolved in solvents or by propionyl ester derivatization. A capillary SFC methyl silicone column (SB-methyl 100, 100 μm X 10 m, 0.5 μm film thickness, Lee Scientific) was used for the separation, and a flame ionization detector was used for the detection. A calibration standard containing known concentrations of monomyristln, monopalmitin, monostearin, dimyristin, dlpalmitin, and distearin were used for the determination of the response factor (unit weight per peak area) of each analyte. The response factors were used in the quantitation of the analytes in the test samples from their respective integrated peak areas. Monomyristin was used as an internal standard for the quantitation of monoglycerides In commercial emulsifiers. The accuracy of the methods was demonstrated by comparing the percent area (%A) determined by the chromatography with the percent weight (%W) of each of the components in the standard mixture, and the precision of the methods was indicated by the relative standard deviation (RSD). The mean ratio and RSD of %A/%W were 0.98 ± 0.09 (&lt;5%) and 1.01 ± 0.03 (&lt;2.5%) for underlvatized and derivatized samples, respectively. Two lots of commercial monoglyceride emulsifiers were analyzed with and without derivatization, and the results were compared to those obtained by gas chromatography (GC). 7-tests comparing the method means did not indicate any significant mean differences (95% confidence level) between the GC and SFC methods. Nor did the variance ratio F-test indicate that the overall variances of the methods were significantly different. However, the error variance of the SFC-underivatized method was significantly higher than that of the GC and SFCderivatized methods. These results demonstrated the feasibility of applying the SFC technology in the analysis of monoand diglycerides with and without derivatization
Zinc Chloride-Diphenylamine Reagent for Thin Layer Chromatographic Detection of Some Organophosphorus and Carbamate Insecticides
Authors: Sevalkar Murlidhar T , Patil Vitthal , Katkar Harischandra N 
Published: February 2020

Abstract
Zinc chlorlde-diphenylamlne reagent, whose use has been reported for the detection of organochlorine insecticides by thin layer chromatography, was further studied for its ability to detect the organophosphorus insecticides phorate, phosphamldon, DDVP, and phosalone and the carbamate Insecticides carbaryl and aldicarb. These Insecticides give Intense blue-green spots with this reagent. The procedure can be applied to the detection of the insecticides in biological materials and thus has a potential use in forensic toxicology
Comparison of Microwave Digestion with Conventional Wet Ashing and Dry Ashing Digestion for Analysis of Lead, Cadmium, Chromium, Copper, and Zinc in Shellfish by Flame Atomic Absorption Spectroscopy
Authors: McCarthy Helen T , Ellis Christopher P 
Published: February 2020

Abstract
A closed vessel microwave digestion procedure was developed for shellfish samples. This procedure was compared with wet and dry ash procedures for levels of lead, cadmium, chromium, copper, and zinc. Results obtained for microwave and conventional wet ash digestion were comparable. The dry ashing procedure produced results consistently lower than either of the other methods. Recoveries ranged from 80-92% for microwave and wet ashing procedures and 54- 72% for the dry ashing procedure. Accuracy was also determined by analyzing lobster hepatopancreas marine reference material. Values for Pb, Cd, and Cr fell within the range specified for the reference material for all 3 digestion procedures; however, values were lower for Cu and Zn. Results of this study show that microwave digestion is comparable to wet ashing.
Improved Selenium Recovery from Tissue with Modified Sample Decomposition
Authors: Brumbaugh William G , Walther Michael J 
Published: February 2020

Abstract
The present paper describes a simple modification of a recently reported decomposition method for determination of selenium In biological tissue by hydride generation atomic absorption. The modified method yielded slightly higher selenium recoveries (3-4%) for selected reference tissues and fish tissue spiked with selenomethionine. Radiotracer experiments indicated that the addition of a small volume of hydrochloric acid to the wet digestate mixture reduced slight losses of selenium as the sample initially went to dryness before ashing. With the modified method, selenium spiked as selenomethionine behaved more like the selenium in reference tissues than did the inorganic spike forms when this digestion modification was used