bluuebunny/crossref_metadata_2025_split huggingface dataset:
Codex Alimentarius Approach to Pesticide Residue Standards
Authors: Maybury Ronald B 
Published: February 2020

Abstract
To protect consumers' health, most countries have maximum legal limits for pesticide residues in foods. Trade difficulties can arise when limits differ between countries. The Codex Alimentarius Commission was established in 1962 to implement the Joint FAO/WHO Food Standards Programme, the purpose of which is to protect consumer health and ensure fair practices in international food trade. The Codex Committee on Pesticide Residues (CCPR), an intergovernmental body which advises the Commission on matters related to pesticide residues, is responsible for establishing maximum residue limits (MRLs) for pesticides in foods and feeds that move in international trade. Codex MRLs are based on residue data obtained mainly from supervised trials that reflect approved pesticide use in accordance with "good agricultural practice." MRLs must be toxicologically acceptable in terms of estimated pesticide intake by consumers. CCPR Working Groups examine problems related to establishing and implementing MRLs, including sampling and methods of analysis. Despite time and effort expended, acceptance and application of Codex MRLs face many problems in international trade.
Liquid Chromatographic Method for Determination of Vanillin and Related Flavor Compounds in Vanilla Extract: Collaborative Study
Authors: Kahan Sidney 
Published: February 2020

Abstract
A liquid chromatographic method for determination of vanillin, vanillic acid, p-hydroxybenzaldehyde, and p-hydroxybenzoic acid was collaboratively studied. The compounds are separated on a reversephase C-8 column using an acidic 10% methanol solvent and are detected at 254 nm. Recoveries for the 4 compounds present in vanilla extract ranged from 94 to 99%. Method performance as measured by repeatability and reproducibility standard deviations (sr and sR) and relative standard deviations (RSDr and RSDR), respectively, for determination of the 4 flavor compounds in authentic and adulterated vanilla extracts were as follows: p-hydroxybenzoic acid—sr 0.29, SR 0.39, RSDr 8.98%, RSDR 11.68%; p-hydroxybenzaldehyde—sr 0.92, sR 1.20, RSDr 6.16%, RSDR 6.95%; vanillic acid—sr 0.85, sR 1.12, RSDr 7.47%, RSDR 9.97%; vanillin—sr 7.45, sR 7.50, RSDr 3.43%, RSDR 3.48%. The method has been approved interim official first action.
Gas Chromatographic Determination of Poly chlorinated Biphenyls (as Aroclor 1254) in Serum: Collaborative Study
Authors: Burse Virlyn W , Korver Margaret P , Needham Larry L , Lapeza Chester R , Chester R Elizabeth L , Head Susan L , Liddle John A , Bayse David D 
Published: February 2020

Abstract
A gas chromatographic-electron capture detection method for determining the concentration of polychlorinated biphenyls (PCBs) as Aroclor 1254 (AR 1254) in serum was evaluated through a 2-phase collaborative study. In Phase I, each collaborator's lot of Woelm silica gel (70-150 mesh) was evaluated for elution and recovery of AR 1254, which had been added in vitro at 25 ng/mL to a serum extract. In Phase II, each collaborator analyzed a series of bovine serum samples that contained the following: (1) in vitro-spiked AR 1254; (2) in vivo AR 1254 and 8 in vitro-spiked chlorinated hydrocarbons; (3) in vivo AR 1254 only; (4) 8 in vitro-spiked chlorinated hydrocarbons only; and (5) neither AR 1254 nor chlorinated hydrocarbons above the detection limit of the method. In Phase I, the average recovery of AR 1254 from silica gel for the 6 collaborators was 87.9 ± 15.44% (mean ± 1 SD; N = 18; range = 52.3-105.8%). In Phase II, the analysis of in vitro spikes of AR 1254 in serum at 8.58,16.8, 41.8, and 84.3 ppb gave mean (X) interlaboratory recoveries of 89.0, 83.3, 79.4, and 76.9%, respectively, with within-laboratory (repeatability) relative standard deviations (RSDr) of 18.8, 20.5, 10.2, and 14.1%, respectively, and among-laboratory (reproducibility) relative standard deviations (RSDR) of 21.5, 21.1, 14.6, and 20.8%, respectively. The determination of in vivo AR 1254 in samples containing approximately 10, 25, 50, and 100 ng/mL of AR 1254 resulted in interlaboratory means of 10,22,39, and 79 ng/mL, respectively, with RSDr = 6.7,9.7,6.4, and 5.8%, respectively, and RSDR = 20.6,16.0, 10.9, and 10.3%, respectively. The precision of the method for incurred AR 1254 showed a maximum RSDr of less than 10% and a maximum RSDR of less than 21% for a concentration range of 10-100 ng/mL. The accuracy of the method as demonstrated by the mean recovery of in vitro-spiked AR 1254 over a concentration range of 8.58-84.3 ng/mL was 82.2%. The method has been approved interim official first action.
Thin-Layer Chromatography/Bioautography Method for Detection of Monensin in Poultry Tissues
Authors: Vanderkop Perry A , Macneil James D 
Published: February 2020

Abstract
Monensin is an effective anticoccidial agent widely used in the poultry industry. Because of concerns over its toxicity, a sensitive, reliable, fast, and simple method for residue detection in poultry tissues is desirable from both a diagnostic and a regulatory view. Many methods of detection are excluded due to this ionophore's complex chemical and biological nature. A common method used for its detection is thin-layer chromatography/bioautography (TLC/B), although this is usually only semiquantitative. A new TLC/B method for monensin detection in poultry tissues was developed and is reported here. Recovery from cardiac muscle, skeletal muscle, and liver and kidney tissues is in the range of 93-97%. A detection limit of 250 Mg/kg with 99% reliability was achieved with this method. Lower limits (to 10 Mg/kg) were detectable, but with lower reliability (60%). Quantitative analysis is not possible on samples from fatty tissue.
Isolation and Gas Chromatographic Determination of Chlorsulfuron in Milk
Authors: Long Austin R , Hsieh Lily C , Malbrough Marsha S , Short Charles R , Barker Steven A 
Published: February 2020

Abstract
A method for the isolation and gas chromatographic determination of chlorsulfuron in milk is presented. Blank or chlorsulfuron-spiked milk samples were blended into C-18 (octadecylsilyl derivatized silica, ODS) packing material. A column made from the C-18/milk matrix was washed with hexane after which chlorsulfuron was eluted with dichloromethane (DCM). The DCM eluate contained chlorsulfuron which was free from interfering co-extractants when analyzed by gas chromatography utilizing a nitrogen/phosphorus detector. Chlorsulfuron was found to undergo a thermally induced decomposition to give 2-amino-4-methoxy-6-methyl-l,3,5-triazine, which was detected and quantitated by this method. Standard curves for these analyses were linear (r = 0.992 ± 0.004, n = 5), with an average percentage recovery of 91.6 ± 10.8%, over the concentration range examined (62.5-2000 ng/mL). The inter- and intra-assay variabilities were 11.6 ± 7.5% and 6.2%, respectively.
Preparation of Reference Water and Soil Samples for Performance Evaluation of Volatile Organic Analysis
Authors: Maskarinec Michael P , Johnson Lynne H , Bayne Charles K 
Published: February 2020

Abstract
Methodology was developed to reproducibly prepare performance evaluation materials for volatile organics analysis in soils and waters. Tedlar gas sampling bags are used to prepare the volatile organics spike solutions. The bags allow large volumes of sample or spike solution to be prepared to a high degree of homogeneity while using less methanol. Preparation of a large volume of sample or spike solution allows for increased accuracy of fortification. The accuracy is generally ±20% or better, and the precision is generally ±10% or better for water samples. The precision for preparation of soil samples is also good, but the accuracy suffers from variable recovery efficiencies from the soils. Most volatile organics were well preserved in 3 water samples by storage at refrigerator temperature for 14 days.
Comparison of AOAC and ISO Methods for Extraction of Water-Soluble Phosphates in Fertilizers
Authors: Farley James A 
Published: February 2020

Abstract
A wide range of phosphate fertilizers were analyzed for watersoluble phosphorus to compare 2 recognized methods: AOAC method 2.040 and the International Organization for Standardization (ISO) method No. 5316. In general, the ISO method extracted more phosphorus from triple and normal superphosphates; the AOAC method extracted more phosphorus from diammonium, monoammonium, and nitric phosphates. Both methods exhibited similar precision. The results indicate that care must be exercised when data for watersoluble phosphate are reported.
Enzyme-Linked Immunosorbent Assay of Aflatoxins Bi, B2, and Gi in Corn, Cottonseed, Peanuts, Peanut Butter, and Poultry Feed: Collaborative Study
Authors: Trucksess Mary W , Stack Michael E , Nesheim Stanley , Park Douglas L , Pohland Albert E 
Published: February 2020

Abstract
A direct competitive enzyme-linked immunosorbent assay (ELISA) screening method for aflatoxins at 20 ng/g was studied by 12 collaborators. Test samples of peanut butter were extracted by blending with methanol-water-hexane (55 + 45 + 100) and heating the test extracts on a steam bath; test samples of the other commodities were extracted by blending with methanol-water (80 + 20). All test extracts were filtered and the filtrates were diluted with buffer to a final methanol concentration of &lt;30%. Each diluted filtrate was applied to a cup containing a filter with immobilized polyclonal antibodies specific to aflatoxins B1, B2, and G1. Aflatoxin B1-peroxidase conjugate was added, the cup was washed with water, and a mixture of hydrogen peroxide and tetramethylbenzidine was added. The test sample was judged to contain &gt;20 ng aflatoxins/g when, after exactly 1 min, no color was observed on the filter; when a blue or gray color developed, the test sample was judged to contain &lt;20 ng aflatoxins/g. All collaborators correctly identified naturally contaminated corn and raw peanut positive test samples. No false positives were found for controls containing &lt;2 ng aflatoxins/g. The correct responses for positive test samples spiked at levels of 10, 20, and &gt;30 ng aflatoxins/g (the ratio of B1, B2, and G1 was 10:1:3) were 52, 86, and 96%, respectively. The method, which is rapid and simple, has been adopted official first action for screening for aflatoxins at &gt;20 ng/g in cottonseed and peanut butter and for aflatoxins at &gt;30 ng/g in corn and raw peanuts. The procedure will require further study for poultry feed. Positive test samples may require reanalysis by an official, quantitative method.
Chemical Derivatization Analysis of Phenols. Part VI. Determination of Chlorinated Phenolics in Pulp and Paper Effluents
Authors: Lee Hing-Biu , You Hong R L , Fowlie P J A 
Published: February 2020

Abstract
Based on the in-situ acetylation procedure, a method for the determination of 31 chlorinated phenols, guaiacols, catechols, syringols, and vanillins in pulp and paper effluent samples has been successfully developed. Except for 4-chlorocatechol, this procedure provided satisfactory recovery for all phenols at 3 levels of fortification, namely, 400, 40, and 4 μg/L. The acetyl derivatives were analyzed by gas chromatography using a 30 m DB-5 capillary column interfaced to an electron-capture detector. Mass spectral abundance data for the characteristic ions of the acetyl derivatives were used for confirmation of compound identities. By operating a mass selective detector in the selected ion monitoring mode, this procedure was further extended to the monochlorinated phenolics. Using a 50 mL effluent sample, the method detection limit was 0.5 μg/L for all except the monochlorinated compounds, which had a detection limit of 1 μg/L. Several effluent samples from a Canadian paper mill were analyzed by this procedure and the results are presented.
Determination of Daminozide in Apples by Gas Chromatography /Chemical Ionization Mass Spectrometry
Authors: Liu Chao-Hong , Mattern Gregory C , Singer George M , Rosen Joseph D 
Published: February 2020

Abstract
A method using gas chromatography/chemical ionization mass spectrometry (GC/CIMS) for the determination of daminozide residues in apples has been developed. Daminozide was separated from the sample matrix by water extraction and cation exchange, converted to the methyl ester by treatment with HCl-methanol, and determined by GC/CIMS using succinonitrile as an internal standard. The detection level was 0.05 ppm. Recoveries were 92-104% from apples spiked at the 0.05-0.5 ppm levels. Of the 25 apple samples analyzed, only 2 were positive for daminozide (1.04 and 0.32 ppm).
Determination of Copper, Iron, and Nickel in Oils and Fats by Direct Graphite Furnace Atomic Absorption Spectrometry: Summary of Collaborative Study
Authors: Capar Stephen G 
Published: February 2020

Abstract
A collaborative study of a method for the determination of copper, Iron, and nickel in edible oils and fats by direct graphite furnace atomic absorption spectrometry was recently conducted by the International Union of Pure and Applied Chemistry. The quantitation limits of the method are 5 μg/kg for copper and 10 μg/kg for iron and nickel. The method has been adopted official first action as an IUPACAOAC method.
Adsorption of Aqueous Nonylphenol Ethoxylate Surfactants on Metal Sample Loops: Effect on Quantitation by Liquid Chromatography
Authors: Sithole B B , Zvilichovsky B , Lapointe C , Allen L H 
Published: February 2020

Abstract
In aqueous solutions of Igepal CO 610, a nonionic nonylphenol ethoxylate surfactant, adsorption of the surfactant takes place onto stainless steel metal surfaces. This adsorption results in increased peak height of the surfactant when a sample loop is purged with increasing volumes of the surfactant. This, in turn, affects the quantitation of the surfactant. However, the adsorption is reproducible at constant purging volumes and results in calibration curves with good precision.
Rapid Analysis of Nutritionally Important Free Amino Acids in Serum and Organs (Liver, Brain, and Heart) by Liquid Chromatography of Precolumn Phenylisothiocyanate Derivatives
Authors: Sarwar Ghulam , Botting Herbert G 
Published: February 2020

Abstract
An amino acid analysis method for protein hydrolysates, using precolumn phenylisothiocyanate (PITC) derivatlzatlon and liquid chromatography, was modified for its application In rapid analysis of commonly occurring free amino acids in serum and other physiological samples. The modifications Included changes In column temperature (47.5°C compared to 25-35°C used In analyzing protein hydrolysates), method of preparing standard and test samples, and gradient conditions. By using a Waters Pico-Tag amino acid analysis 15 cm long column (which Is also used for analyzing protein hydrolysates), separation of 27 PTC-amino acids in human serum and rat liver, brain, or heart was completed in 20 mln by the modified method. The total time for analysis and equilibration was 30 mln. The modified method was much faster than the traditional ion-exchange methods (2-3 h) or the existing liquid chromatographic methods using PITC derivatlzatlon (66-80 mln) for determining nutritionally Important free amino acids In physiological fluids and tissues. Variability of the method (expressed as coefficients of variation) for the determination (Including deprotelnizatlon, derivatlzatlon, and liquid chromatography) of all amino acids was less than 5%, which compared favorably with the reproducibility of Ion-exchange methods
Comparative Evaluation of Commercially Available Aflatoxin Test Methods
Authors: Koeltzow Donald E , Tanner Steven N 
Published: February 2020

Abstract
Five qualitative methods and 1 quantitative aflatoxin analytical method were compared with the Holaday-Velasco (HV) mlnlcolumn and thin-layer chromatography (TLC) methods for corn In an evaluation Involving 4 U.S. Department of Agriculture Federal Grain Inspection Service (USDA-FGIS) laboratories, 1 laboratory at the University of Georgia, and 1 laboratory at the University of Arizona. Samples analyzed Included 1 set of artificially contaminated corn containing both aflatoxin B1 and B2 (ratio of B1:B2 of 92:8), 1 set of artificially contaminated corn containing only aflatoxin B1t and 1 set of naturally contaminated corn. Levels of total aflatoxin tested were 0, 10, 15, 20, 25, 30, and 40 ppb. Results of analysis of these samples with each method evaluated are reported. Chl-square analyses Indicated that performance of the Afla-20-Cup, Aflatest, EZ-Screen, OXOID, and SAM-A methods was not statistically different from that of the HV mlnlcolumn. Agri-Screen results were not statistically different from those obtained with TLC.
Validation of a Method for Determination of Tetracycline Antibiotics in Salmon Muscle Tissue
Authors: Reimer Gerry J , Young Larry M 
Published: February 2020

Abstract
A method was validated for analysis of oxytetracycllne (OTC), tetracycline (TC), and chlortetracycllne (CTC) In fortified salmon muscle tissue. Recoveries of OTC were 100 ± 6, 86 ± 6, and 82 ± 5% (n = 6) at fortification levels of 1.0, 0.5, and 0.2 ppm, respectively. Recoveries of TC were 68 ± 4, 65 ± 6, and 66 ± 7%; recoveries of CTC were 45 ± 9,48 ± 8, and 0%, respectively. Detection limits for OTC and TC were 0.08 and 0.09 ppm, respectively
Comparison of Liquid Chromatographic Methods for Determination of Cis-Trans Isomers of β-Carotene
Authors: O'Neil Constance A , Schwartz Steven J , Catignani George L 
Published: February 2020

Abstract
Four liquid chromatographic columns and various solvent systems were evaluated for their ability to resolve and quantitate cls-trans Isomers of β-carotene. The Vydac C18 201 TP and Ca(OH)2 columns were most effective in resolving alltrans-, 13-cls-, and 9-cls-β-carotenes. Additionally, the 15- c18 Isomer was separated using the method employing a Ca(OH)2 column. Peak Identification was based on absorption spectra (obtained from photodlode array data), retention times, and coelutlon in comparison to authentic standards. A quantitative analysis of vegetable extracts using both the Vydac and Ca(OH)2 columns showed comparable results. However, both procedures lacked complete resolution of 2 minor clsβ-carotenes, tentatively identified as dl-cis Isomers. High selectivity for carotene Isomers as well as fewer interferences were observed with the Ca(OH)2 procedure for analysis of plant tissue extracts and thus, It is preferred for determination of β-carotene cis-isomer content In these samples.
Spectrophotometric Determination of Diethylpropion Hydrochloride Bulk Drug and Tablets in the Presence of Its Degradation Products
Authors: Saleh Gamal A 
Published: February 2020

Abstract
The charge transfer complex formation between diethylpropion and iodine was investigated and used as the basis for a simple and sensitive spectrophotometric method for diethylpropion and Its dosage forms. The solution exhibited blueshifted iodine bands at 295 and 365 nm. A Job's plot Indicated a 1:1 complexatlon ratio. At 295 nm, the absorbance was linear (r = 0.9995) over the 0.2-2.4 μg/mL concentration range. The method has been applied successfully to the analysis of commercially available diethylpropion hydrochloride tablets without interference from thiamine hydrochloride, pyridoxine hydrochloride, nicotinamide, and riboflavin. Interference from the degradation products 1-phenyl-1,2- propanedione and diethylamine was avoided. Molar absorptivity, association constant, and free energy change were investigated further.
Determination of Carbadox-Related Residues in Swine Liver by Gas Chromatography/Mass Spectrometry with Ion Trap Detection
Authors: Lynch Martin J , Mosher Franklyn R , Schneider Richard P , Fouda Hassan G , Risk James E 
Published: February 2020

Abstract
The Ion trap detector (ITD), in combination with a capillary gas chromatograph and under chemical ionization conditions, offers sufficient sensitivity to determine carbadoxrelated residues as the methyl ester derivative of quinoxaline- 2-carboxylic acid at 3 μg/kg or higher in porcine liver. A tetradeuterated internal standard of QME effectively compensates for losses incurred during sample preparation. The method produced mean levels of 3.3 (±0.5), 5.5 (±0.8), and 10.1 (±0.9) μg/kg for liver fortified at 3, 5, and 10 μg/kg. When applied to analysis of samples containing incurred residues of 14C-carbadox at the low μg/kg level, results were comparable to those obtained by reverse isotope dilution analysis.
A Rapid Method for the Determination of Chlorine, Phosphorus, and Sulfur in Flours of Grains and Legumes Using Wavelength Dispersive X-Ray Flourescence Spectrometry
Authors: Ruiz Tomás Pérez , Córdoba Manuel Hernández , González Roque Ortiz 
Published: February 2020

Abstract
A rapid method for the determination of chlorine, phosphorus, and sulfur In commercial flours of wheat, barley, maize, rice, field bean, and soybean by wavelength dispersive x-ray fluorescence spectrometry has been developed. The flours are strained through a 425 μm sieve, then pelletized and measured. The total analysis time for the quantitation of chlorine, phosphorus, and sulfur is less than 20 min per sample. Calibration is carried out using a standard additions method with mixed standards. The method is accurate and precise, and appears to be adequate for routine analyses.
Headspace Gas Chromatographic Estimation of Some Yogurt Volatiles
Authors: Ulberth Franz 
Published: February 2020

Abstract
A headspace gas chromatographic method Is described for the determination of acetaldehyde, ethanol, acetone, dlacetyl, and 2-butanone In yogurt. Yogurt (2 g) is equilibrated 1 h in a 10 mL vial at 60 °C, and 0.25 mL headspace gas Is splitinjected. The volatiles are baseline-separated In less than 5 min by using a thick film capillary column coated with SE-54. An external standard calibration method fulfills the requirements for an accurate determination of the yogurt aroma components. The accuracy of this method was checked by the standard addition method. The precision of the method, In terms of the relative standard deviation, depends on the analyte concentration. At the 10 ppm volatile level, RSD Is 2%, and at the 0.1 ppm level, 15%.
Dry Rehydratable Film for Enumeration of Total Coliforms and Escherichia coli in Foods: Collaborative Study
Authors: Curiale Michael S , Sons Therese , Mclver Dawn , McAllister J Sue , Halsey Barbara , Roblee Diane , Fox Terrance L 
Published: February 2020

Abstract
Rehydratable dry-film plating methods for total coliforms and Escherichia coll In foods have been compared to the AOAC most probable number methods. Fourteen laboratories participated In the collaborative study. Three coliform and £. coll levels In 6 samples of 4 product types (flour, nuts, cheese, and beef with gravy) and in 3 samples of 2 product types (mushrooms and raw turkey) were tested In duplicate by the participants. The mean log counts for the 3 methods were comparable. In general, the repeatability and reproducibility variances of the plating methods were as good as or better than that of the MPN method. The method has been adopted official first action by AOAC.
Liquid Chromatographic Determination of Fluometuron and Metabolites in Soil
Authors: Mueller Thomas C , Moorman Thomas B 
Published: February 2020

Abstract
A rapid, sensitive method Is described for the determination of fluometuron and Its soil metabolites In 4 soil types. The method consists of extraction of moist soil samples with methanol, filtration, liquid chromatographic separation of methanol-soluble components using a C18 column, and fluorescence detection with excitation at 292 nm and emission measured at 345 nm. Fluometuron recoveries from fortified soils were &gt;90% from the Dundee, Okalona, Cecil, and Ships soils. Recoveries from a Dundee silt loam for desmethyl fluometuron, 3-(trlfluoromethyl)phenyl urea, and 3- (trifluoromethyl)anillne were 77, 77, and 35%, respectively. Average percent relative standard deviations of Dundee soil extracts were 5.3% for fluometuron and &lt;8.0% for each metabolite. The limit of detection for fluometuron and each of its soil metabolites was 25 ng/g soil.