bluuebunny/crossref_metadata_2025_split huggingface dataset:
Occurrence of Pesticide Residues in Selected Agricultural Food Commodities Available in Canada
Authors: Neidert Eli , Saschenbrecker Peter W 
Published: February 2020

Abstract
During the 27-month period between January 1, 1992, and March 31,1994, Agriculture and AgriFood Canada analyzed 21 982 samples of fruit and vegetable commodities for pesticide residues. A multiresidue method capable of detecting over 200 analytes was used. In 5784 domestic samples a total of 676 residue findings were made. Of these, 32 (0.55%) were in violation of Canadian maximum residue limits (MRLs).In 16 198 imported products, 464 of 3193 residue findings exceeded MRLs, corresponding to a violation rate of 2.86%. One-half of domestic violations resulted from commodity–pes ticide combinations for which there are no Canadian approvals.
Determination of Bentazone in Waters by Solid-Phase Spectrofluorimetry
Authors: Vilchez José Luis , Torres-Bustos Diego , Blanc Rosario , Navalón Alberto 
Published: February 2020

Abstract
A sensitive method for determining trace amounts of bentazone was developed. The method is based on solid-phase spectrofluorimetry. Bentazone was fixed on a dextran-type anion-exchange gel, and the fluorescence of the gel, packed in a 1 mm thick quartz cell, was measured directly at an excitation wavelength of 338 nm and an emission wavelength of 436 nm by using a solid-phase attachment. The applicable concentration range was 2.0–120.0 μg/L, with a detection limit of 0.4 μg/L. The relative standard deviation at the 30.0 μg/L level was 1.2%. The method was used to determine bentazone in natural water samples. Recoveries were 96.0–102.5%.
Determination of Fat, Protein, and Lactose in Raw Milk by Fourier Transform Infrared Spectroscopy and by Analysis with a Conventional Filter-Based Milk Analyzer
Authors: Lefier Dominique , Grappin Remy , Pochet Sylvie 
Published: February 2020

Abstract
The accuracy of fat, crude protein (CP), true protein (TP), and lactose determinations of raw milk by Fourier transform infrared (FTIR) spectroscopy and by analysis with a conventional filter-based milk analyzer was assessed in 6 trials performed over a 10-month period. At each trial, 30 bulk milk samples collected from 15 European countries and 11 reconstituted milks made from raw milk components were analyzed. When calibrations were performed with reconstituted milks at each trial, accuracy standard deviations for fat, CP, TP, and lactose were, respectively, 0.050,0.048,0.035, and 0.076 g/100 g for the filter instrument and 0.047, 0.046,0.042, and 0.065 g/100 g for the FTIR instrument. When a single calibration was made instead of calibrations at each trial, accuracy standard deviations increased for the filter instrument to 0.130, 0.119,0.121, and 0.083 for fat, CP, TP, and lactose, respectively, and for the FTIR instrument to 0.082, 0.053,0.044, and 0.084 g/100 g. Because the FTIR instrument provides more spectral information related to milk composition than does the filter instrument, single-calibration FTIR analysis of milk samples collected in different seasons is more accurate. Using reconstituted milks, prepared such that there is no correlation between fat, CP, and lactose, provides a more robust calibration than using genuine bulk milk, especially when milks with unusual composition are analyzed.
Determination of Total Arsenic and Selenium in Soils and Plants by Atomic Absorption Spectrometry with Hydride Generation and Flow Injection Analysis Coupled Techniques
Authors: De Blas Oroncio Jiménez , Mateos N Rodriguez , Sanchez A Garcia 
Published: February 2020

Abstract
A procedure has been developed for determination of total arsenic and selenium in soils and plants by atomic absorption spectrometry with hydride generation associated with flow injection analysis (FIA-AAS-HG). Samples were wet-digested by using 2 systems: heating in a metal digestion block with controlled temperature and time and heating in a microwave oven. Total arsenic and selenium were reduced with NaBH4 and concentrated HCI, respectively. In both digestion systems used for the 2 matrix types, detection limits below 1 μg/L were found for both elements for an injection volume of 160 μL, with relative standard deviations of 3–6%. Recoveries by the method ranged from 93 to 105%; with the reference materials FD8 and MRG-1, the values obtained in all cases were consistent with the certified data. The FIA-AAS-HG procedure is highly suitable for determination of total arsenic and selenium in soils and plants, and because of the coupled system used, it is an improvement over other procedures in terms of sample treatment, sample consumption, and automation.
Levels of Organochlorine Pesticides in Mexican Butter
Authors: Waliszewski Stefan M , Pardío Violeta T , Waliszewski K N , Chantiri Jorge N , Infanzón Rosa M 
Published: February 2020

Abstract
Organochlorine pesticide residues were analyzed in 345 samples of butter purchased from Mexican supermarkets in 1994. Three national brands and one foreign brand were analyzed. Most samples contained residues of γ-HCH (91 %), HCB (90%), and p,p′-DDE (88%). Residues of α-HCH (63%), p,p′-DDT (42%), ß-HCH (38%), o,p′-DDT (17%), heptachlor epoxide (7%), and endosulfane sulfate (3%) were also detected. Mean values of pesticide residues determined were 0.093 mg/kg fat for total HCH and 0.056 mg/kg for total DDT. Mean values of organochlorine pesticide residues in Mexican butter were comparable with those in a foreign brand.
Thin-Layer Chromatographic Detection of Phosphorothionate and Phosphorothiolothionate Pesticides Using 4-Amino-N,N-Diethylaniline
Authors: Pasha Akmal , Vuayashankar Yadathora N , Karanth Nitturu G K 
Published: February 2020

Abstract
A thin-layer chromatographic method using a novel chromogenic reagent was developed to detect the phosphorothionate and phosphorothiolothionate groups of pesticides. On reaction with 4-am'mo-N,N-diethylaniline and subsequent exposure to bromine vapor, these compounds yield a deep magenta product. The chromogenic reagent is specific to these organophosphates and gives no response to phosphorothiolates and substituted phosphonates. The method is rapid and highly sensitive. The limit of detection is 0.05-0.5 μg.
Use of Urease-Bromothymol Blue-Agar Method for Large-Scale Testing of Urine on Grain and Seeds
Authors: Valdes Patricia A , Ziobro George C , Ferrera Robert S 
Published: February 2020

Abstract
The current AOAC method (963.28) for large-scale (50 g) testing of urine on grain is based on the reaction of sodium in urine with magnesium uranyl acetate. Detection of sodium suggests that urine is present and that a test for urea is appropriate. Urea is detected with urease-bromothymol blue-paper and is confirmed through its reaction with xanthydrol to form dixanthylurea crystals, which are detected microscopically. The initial nonspecific test for sodium can be influenced by the presence of salt or other sodium compounds. Furthermore, the magnesium uranyl acetate spray used in Method 963.28 potentially exposes the analyst to the aerosol of a volatile, toxic uranium compound. Excess reagents and analyzed test portions must be disposed of as radioactive waste. In addition, Method 963.28 requires several steps to determine the presence of urea. The alternative AOAC method (972.41) tests for the presence of urea from urine on individual seeds. Urea is enzymatically decomposed to ammonia and carbon dioxide by urease.Liberated ammonia shifts the pH, changing the color of the indicator in the agar from yellow to blue. This study adapts Method 972.41 to larger test samples. Up to 25 g grains and seeds are sprayed with urease test agar instead of being individually immersed in the urease test agar. The modified method was used to analyze urea on seeds and grains of 24 plants from 4 families. The method has a limit of detection of one seed contaminated with 1μg urea.
Determination and Survey of Deoxynivalenol in White Flour, Whole Wheat Flour, and Bran
Authors: Trucksess Mary W , Ready Duwayne E , Pender Marie K , Ligmond Cathy A , Wood Garnett E , Page Samuel W 
Published: February 2020

Abstract
A liquid chromatographic (LC) method for determining deoxynivalenol (DON) in white flour, whole wheat flour, and bran was developed. A 25 g test portion was extracted with acetonitrile-water (84 + 16), and the extract was filtered and applied to a column containing a combination of charcoal, Celite, and other adsorbents. The eluate was then chromatographed on a silica-based, reversedphase LC column by using a gradient of water and methanol. DON was measured at 220 nm. Average recoveries of DON from white flour, whole wheat flour, and bran spiked at 1 fig/g were 88,86, and 85%, respectively. The limit of determination of the method was &lt;0.5 μg/g. A total of 562 wheat-based products from the 1993 crop year were collected by 21 U.S. Food and Drug Administration District Offices and analyzed by this method in Kansas City, Seattle, and New Orleans District Laboratories. The numbers of samples with DON contamination ≥1 μg/g from 163 bran, 272 white flour, 90 whole wheat flour, and 37 miscellaneous test samples were 20,28,14, and 2, respectively. About 52,50,40, and 27% of the same test samples were contaminated with DON at levels ≥0.1 μg/g.
Supercritical Fluid Extraction of Volatile N-Nitrosamines in Fried Bacon and Its Drippings: Method Comparison
Authors: Fiddler Walter , Pensabene John W 
Published: February 2020

Abstract
N-Nitrosopyrrolidine (NPYR) and N-nitrosodimethylamine (NDMA), known animal carcinogens, are consistently formed in bacon during frying. As a result, commercial bacon has been subject to regulatory monitoring and compliance for the past 20 years to ensure that N-nitrosamines do not exceed the 10 ppb violative level. Currently, time-consuming distillation-solvent extraction and solidphase extraction (SPE) methods are used for this purpose. With an emphasis on reducing solvent use, we investigated supercritical fluid extraction (SFE) using supercritical carbon dioxide (SC-CO2) for isolation of volatile nitrosamines common to fried bacon. Eighteen fried bacon samples were analyzed for NPYR and NDMA by SFE, SPE, mineral oil distillation (MOD), and low-temperature vacuum distillation (LTVD) methods, using the same gas chromatographic-chemiluminescence detection (thermal energy analyzer) conditions. The range of values for SFE was 0.7 to 20.2 ppb for NPYR and none detected (ND) to 2.4 ppb for NDMA. Analysis of variance of the NPYR data showed a significant difference (p &lt; 0.05) between SFE and SPE results and significant differences between these and those obtained by MOD and LTVD. Overall, SFE was superior to the other methods with the highest recoveries, best repeatability, rapidity of analysis, and solvent-sparing characteristics. Similar results were obtained for SFE after comparison with distillation and SPE methods for determining the same nitrosamines in fried bacon drippings.
Determination of Methomyl in Insecticidal Formulations by Reversed-Phase Liquid Chromatography: Collaborative Study
Authors: Conaway James E ,   Collaborators:, Audino J B , Bane E , Carrigan S K , Glinsky R , King S W , Law M W , McDermott W H , Minyard J T , Schreiber M L , Sherwood G A , Skelly N E , Whaley D E , Winstead G R 
Published: February 2020

Abstract
A reversed-phase liquid chromatographic (LC) method for methomyl was studied. Twelve collaborators analyzed 3 solid and 4 liquid formulations on both a Zorbax octadecylsilane (ODS) column and a similar column of their choice. Methomyl and the internal standard were separated by using a mobile phase consisting of approximately 8% acetonitrile in water, which was monitored at 254 nm. The coefficient of variation on the Zorbax column ranged from 0.70 to 5.23%, while the range on the collaborators' house columns was 1.08 to 6.01%. Results with the Zorbax ODS column fell within the 5% 2-tail limits, and 10 of 11 collaborators' results fell within these limits on house columns. The LC method for determination of methomyl in insecticidal formulations has been adopted first action by AOAC INTERNATIONAL.
Determination of Total Free and Glucose-Conjugated 3-Phenoxybenzyl Alcohol Residues in Foods by Gas Chromatography with Electron Capture Detection
Authors: Mortimer Richard D , Shields J Brian 
Published: February 2020

Abstract
A method was developed to determine the combined amounts of residual, free 3-phenoxybenzyl alcohol (permethrin alcohol) and its acetone-extractable glucosides in representative fruits and vegetables after application of pyrethroid insecticides such as permethrin or cypermethrin. 3-Phenoxybenzyl glucoside was synthesized and used to spike food samples. Conditions were developed for extraction, enzymatic hydrolysis, derivatization with heptafluorobutyric anhydride, and cleanup prior to detection and quantitation by gas chromatography with electron capture detection. Limits of detection in various foods were ≤0.01 ppm. In addition, 2 sets of field trial samples that were sprayed with permethrin and collected at intervals were also analyzed. In general, the amounts of total permethrin alcohol in foods were small.
Liquid Chromatographic Determination of Ochratoxin A in Barley, Wheat Bran, and Rye by the AOAC/IUPAC/NMKL Method: NMKL Collaborative Study1
Authors: Larsson Kjell , Möller Tord ,   Collaborators:, Berg S , Berntsson I , Eklund E , Hald B , Jacobsson K-G , Langseth W , MacDonald S , Majerus P , Mann P , Rasmussen G , Wood G 
Published: February 2020

Abstract
In an inter laboratory study of the AOAC/lnternational Union of Pure and Applied Chemistry (IUPAC)/ Nordic Committee on Food Analysis (NMKL) liquid chromatographic method for ochratoxin A (OTA), 3 spiked samples each of wheat bran and rye and 3 naturally contaminated barley samples with expected OTA contents between 2 and 9 μg/kg were analyzed by 12 European laboratories. Mean recoveries ranged from 64 to 72%. Within-laboratory standard deviations were 21,17, and 12% for wheat bran, rye, and barley, respectively. Corresponding between-laboratory standard deviations were 23-28,20-28, and 18-31%. Horwitz ratio values ranged from 0.50 to 0.77. The method was accepted as an official NMKL method for determining OTA at ≥2 μg/kg in cereals and cereal products.
Spectrometric Determination of Chromium in FD&C Blue No. 1 by X-Ray Fluorescence
Authors: Hepp Nancy M 
Published: February 2020

Abstract
An X-ray fluorescence spectrometry (XRF) method was developed and validated for determination of chromium in FD&C Blue No. 1. Results of this analysis were compared with those obtained with an atomic absorption spectroscopy (AAS) method currently used by the U.S. Food and Drug Administration. Levels of Cr, as determined by the XRF and AAS methods, were comparable. The limit of quantitation for the XRF method is 4 μg Cr/g. The predicted 95% confidence interval at the specification level is 50 ± 5 μg/g.
Trace Determination of Zinc by Substoichiometric Isotope Dilution Analysis
Authors: Sandhya Devalla , Priya Sampath , Subramanian Mandakolathur S 
Published: February 2020

Abstract
A radiometric method based on substoichiometric isotope dilution analysis using 1,10-phenanthroline and a substoichiometric amount of eosin was developed for determining trace amounts of zinc. Evaluation of various metal ion interferences showed that as little as 0.2 μg Zn could be determined in an aqueous-phase volume of 60 mL The method has been successfully applied to the determination of Zn in city waste incineration ash, cadmium metal, Fourts-B tablets, Boro-plus ointment, and magnesium alloy samples.
Solid-Phase Extraction Cleanup for Determining Ascorbic Acid and Dehydroascorbic Acid by Titration with 2,6-Dichlorophenolindophenol
Authors: Verma Krishna K , Jain Archana , Sahasrabuddhey Bhushan , Gupta Kalpana , Mishra Sanjeev 
Published: February 2020

Abstract
Ascorbic acid is frequently determined by titration with 2,6-dichlorophenolindophenol. The determination is rapid, but the method is neither specific for ascorbic acid nor very sensitive. The coloring matter in the assay solution interferes with the visual endpoint, and iron(ll), copper(l), sulfite, and sulfhydryl substances such as cysteine and glutathione interfere with the color reaction. Sample cleanup by solid-phase extraction with C18 bonded silica was developed to remove the coloring matter. Extraction sorbent impregnated with 2,2′-bipyridyl, 2,9-dimethyl-1,10-phenanthroline (neocuproine) and Jv-ethylmaleimide removes Fe(ll), Cu(l), and sulfhydryl compounds, respectively. The procedure was applied to highly colored multivitamin pharmaceuticals, soft drinks, and fruit and vegetable juices. In contrast to the results from the original method, which is not applicable to such samples, the results obtained by the method incorporating cleanup were accurate and selective for ascorbic acid. The sample cleanup also permitted determination of dehydroascorbic acid by reducing it to ascorbic acid with cysteine and titrating the ascorbic acid formed with indophenol. As little as 3 μg ascorbic acid was determined by the method incorporating cleanup.
Biosensors for Measuring Pesticide Residues in the Environment: Past, Present, and Future
Authors: Krämer Petra M 
Published: February 2020

Abstract
Inexpensive, fast, reliable, sensitive biosensors and automated devices are being developed for broad-spectrum analysis or specific analysis of single analytes. This paper discusses biosensor research in environmental analysis, focusing on pesticide analysis. Examples are presented from major research fields to serve as a starting point for information about trends and to encourage more research in this interdisciplinary field
Comparison of Automated and Traditional Minimum Inhibitory Concentration Procedures for Microbiological Cosmetic Preservatives
Authors: Lenczewski Melissa E , McGavin Sean T , Vandyke Karl 
Published: February 2020

Abstract
Minimum inhibitory concentration (MIC) is used to test resistance of microorganisms against antibiotics and to test cosmetic preservatives. This research expanded traditional MIC with automation and application of colorimetric endpoint MIC. All experiments included common cosmetic preservatives and microorganisms used in testing preservative efficacy. An autodilutor using three 96-well microliter plates processed 6 preservatives against 1 microorganism in 15 min. The unique tip design made it possible to accurately deliver viscous test materials that cannot be dispensed accurately with vacuum or fluid-filled systems. Tetrazolium violet, a redox indicator, provided a visual color change from clear to purple at the MIC. Optimum concentration of tetrazolium violet was 0.01 % with addition of 0.2% glucose to Mueller-Hinton broth for both gram-positive and gram-negative bacteria. The colorimetric endpoint was evident after 24 h from previously cryogenically stored organisms that were thawed before use and after 4 h for 18–24 h broth cultures subcultured from agar plates. The autodilutor accurately pipetted viscous cosmetic products such as hand lotion and shampoo, which cannot be pipetted with a traditional micropipetter.
Rapid and Selective Ultraviolet Spectrophotometric Assay of Aspirin in Complex Tablet Formulations
Authors: Sanyal Asis K , Dutta Ashok 
Published: February 2020

Abstract
A simple UV spectrophotometric technique was developed for rapid estimation of aspirin in complex tablet formulations. The method is based on measurement of the change in absorbance at 302 nm due to formation of salicylic acid during hydrolysis of aspirin in 0.09N NaOH. The change in absorbance follows a linear relationship with aspirin concentration in the range of 10–50 μg/mL. The method was applied to various complex tablet formulations. Recoveries of aspirin from these formulations, excipients, additives, and active ingredients confirmed the applicability of the method to complex aspirin formulations.
Relative Effectiveness of Selenite Cystine Broth, Tetrathionate Broth, and Rappaport-Vassiliadis Medium for Recovery of Salmonella spp. from Raw Flesh, Highly Contaminated Foods, and Poultry Feed: Collaborative Study
Authors: June Geraldine A , Sherrod Patricia S , Hammack Thomas S , Amaguaña R Miguel , Andrews Wallace H ,   Collaborators:, Arling V , Ayers S , Ayotte E , Cirigliano M , Clifford D C , Cook D , Coles C , Dabney A , Davis T , Diaz B , Driggs R M , Eliasberg S , Fain A , Fung D Y C , Hammers A , Hu E , Jirele K , Keating K J , Kogan S , Kone K , Kuyyakamont B , Luebbert K , McDonagh S , McNally S , Mettler D , Milas J , Miller C , Nelson T , Nguyen P , Pfundheller R , Phebus R K , Redding R , Richardson S , Richter E , Robinson J , Romer J , Roo D W , Smoot L , Snow K , Tate C , Tompkins L , Vanderbilt K , Varney G W , Wagner D , Wang J , Wchienroj K 
Published: February 2020

Abstract
A collaborative study was performed in 18 laboratories to validate use of Rappaport-Vassiliadis (RV) medium in the standard culture method for recovery of Salmonella spp. from raw, highly contaminated foods and poultry feed. RV medium made from its individual ingredients and incubated at 42�C was compared with selenite cystine (SC) broth incubated at 35�C and tetrathionate (TT) broth incubated at 35� and 43�C for effectiveness in recovery of Salmonella spp. Four artificially contaminated foods (oysters, frog legs, mushrooms, and shrimp) and poultry feed and one naturally contaminated food (chicken) were analyzed. The artificially contaminated foods were inoculated with single serovars of Salmonella at target levels of 0.04 colony-forming units (CFU)/g for the low level and 0.4 CFU/g for the high level. For analysis of 1125 test portions, RV medium (42�C) recovered Salmonellairom 409 test portions; TT (43�C), from 368 test portions; TT (35�C), from 310 test portions; and SC (35�C), from 334 test portions. Overall, RV medium was comparable with or better than other selective enrichments for recovery of Salmonella from the foods in this study, except mushrooms. From mushrooms, SC broth (35�C) recovered more positive test portions than did RV medium (42�C) and TT broth (43�C). The method for detection of Salmonella in raw, highly contaminated foods and
Determination of Organochlorine, Organophosphorus, and Triazine Pesticide Residues in Wine by Gas Chromatography with Electron Capture and Nitrogen–Phosphorus Detection
Authors: Garcia-Repetto Rosario , Garrtoo Isabel , Repetto Manuel 
Published: February 2020

Abstract
A multiresidue analytical method is described for determining 6 pesticides in wine: chlorpyrifos, dimethoate, quinalphos, simazine, tetradifon, and endosulfan. Wine (200 mL) is extracted with dichloromethane (50 mL, 3 times), and the evaporated extracts are purified by silica gel chromatography. Pesticide residues are eluted with n-hexane, n-hexane-benzene (1 + 1), benzene, benzene–acetone (1 + 1), and acetone. Residues are determined by gas chromatography with nitrogen–phosphorus and electron capture detection, using CPSH-5CB, Carbo wax-20M, and CPSH-19CB columns. Recoveries of pesticides added at 0.025 μg/L were 83–97%, with standard deviations of 0.01–0.05%. Detection limits were 0.13–8.9 ng/L, except for simazine (36.7 μg/L). Results are compared with those obtained with a solid-phase extraction (C18) purification and with different eluant series.