bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Supercritical CHF3 and CO2 and Methanol-Modified CHF3 and CO2 for Extraction of Sulfonamides from Chicken Liver
Authors: Ashraf-Khorassani Mehdi , Taylor Larry T , Schweighardt Frank K 
Published: February 2020

Abstract
Supercritical CHF3 and methanol-modified CHF3 were compared with supercritical CO2 and methanol- modified CO2 for extraction of sulfonamides from fortified chicken liver admixed with Hydromatrix. Results showed that solvating power and selectivity were higher for supercritical and methanolmodified CHF3 than for supercritical and methanolmodified C02. Visual observation showed that chicken liver extract obtained with methanol-modified CHF3 was cleaner than that obtained with methanol-modified C02. Fat precipitated in the solvent trap when CO2 was used as the extraction medium. Also, simple off-line collection of fortified chicken liver extract obtained with CO2 in a solidphase extraction cartridge (packed with either C18 or alumina) followed by phosphate buffer-methanol (50 + 50) rinse yielded an extract that required no further cleanup for analysis.
Rapid Screening for Mancozeb in Exposure IHals by Inductively Coupled Plasma-Atomic Emission Spectrometric Determination of Manganese
Authors: Headley John V , Massiah William , Laberge Donald , Purdy John R 
Published: February 2020

Abstract
An inductively coupled plasma-atomic emission spectrometric method was developed for rapid screening of samples for the dithiocarbamate fungicide mancozeb. The method was based on determining the level of manganese, which forms a major part of the compound formulation, and was used to analyze urine, wash water, tank mixes, cellulose acetate filters, gauze patches, and clothing in field operator exposure trials. Sample preparation was fast and simple, requiring only acid digestion in nitric acid or a nitric acid-hydrogen peroxide mixture, and subsequent analysis of the diluted digestate. Urine was acidified with nitric acid as soon as possible after collection and analyzed directly. The method detection limit for mancozeb was 0.020 mg/L (based on 0.004 mg Mn/L) in urine, wash waters, and tank mixes and 0.5 μg (based on 0.1 μg Mn) in cellulose acetate filters, gauze patches, and clothing. The working range of the method was 0.020-250 mg mancozeb/L (r2 ≥ 0.999) in urine, wash water, and tank mixes and 0.5- 6250 μg mancozeb (r2 ≥ 0.999) in filters, patches, and clothing. Higher levels may be determined by appropriate dilution.
Determination of Monensin in High-Moisture Cattle Rations by Liquid Chromatography with Postcolumn Derivatization
Authors: Bridges Debbie A , Roth Doug M , Cleveland Christine M , Moran John W , Coleman Mark R 
Published: February 2020

Abstract
An existing liquid chromatographic method using postcolumn derivatization has been used extensively to quantitate monensin in animal feeds. Because of the relatively high moisture content of many cattle feed rations, some modifications were made to this method. Several sample-processing steps were evaluated to determine optimum sample-processing procedure. The sample weight/sample diluent ratio was modified, and method linearity was validated for the lower monensin concentrations anticipated in high-moisture cattle rations. The accuracy and precision of data generated at these lower concentrations were also determined. Because of the high moisture content of these rations, data analysis for this method required correction of feed potency for loss on drying. With these modifications, monensin can be accurately determined in high-moisture cattle rations.
Fourier Transform Infrared Spectroscopic Determination of Fenvalerate in Emulsifiable Concentrate Formulation
Authors: Gupta Suman , Sharma Krishan K , Handa Swadesh K 
Published: February 2020

Abstract
Fenvalerate [(RS)-α-cyano-3-phenoxybenzyl-(RS)-2-(4-chlorophenyl)-3-methylbutyrate] is extracted from formulation with acetone. The extract is subjected to preparative thin-layer chromatography, and the fenvalerate zone is scraped from the developed plate. Fenvalerate is then eluted from the adsorbent with chloroform and determined by Fourier transform infrared spectroscopy by measuring the carbonyl absorption band at about 1755 cm−1. Recoveries from laboratory-prepared and commercial formulations were 93–99%. The validity of the method was further confirmed by comparing results with those obtained by liquid chromatography.
Microbiological Method for Determining Macrolides in Animal Feeds in the Presence of Other Drugs by Thin-Layer Chromatography Detection
Authors: Markakis Pantelis K 
Published: February 2020

Abstract
A method was developed to separate, detect, and quantitate erythromycin (ERY) and tylosin (TYL) in animal feeds in the presence of 11 other drugs: 3 nitrofurans, 2 tetracycline antibiotics, 3 sulfonamides, 2 coccidiostats, and 1 antibacterial growth promoter. ERY and TYL were separated from coexisting drugs, detected by thin-layer chromatography, and quantitated microbiologically by an agar diffusion method. Analysis of 125 experimental animal feed samples fortified at 5 levels (7.5–400 ppm) with ERY and TYL and at 1 level (50 ppm) with the rest of the drugs gave limits of quantitation of 2 and 5 ppm, recoveries of 90.3 and 92.4%, and relative standard deviations of 4.3–7.3% and 3.6–6.1%, respectively.
Quantitative Analysis of Lamotrigine in Plasma and Tablets by Planar Chromatography and Comparison with Liquid Chromatography and UV Spectrophotometry
Authors: Dreassi Elena , Corbini Gianfranco , Corti Piero , Ulivelli Monica , Rocchi Raffaele 
Published: February 2020

Abstract
A method using planar chromatography (PC) was developed for determining lamotrigine (LTG; 3,5- diamino-6-[2,3-dichlorophenyl]-1,2,4-triazine) in human plasma and tablets. LTG was extracted with acetonitrile in the presence of sodium carbonate. 3,5-Diamino-6-(2-methoxyphenyl)-1,2,4-triazine was used as internal standard. The detection limit was 0.27 μg/mL plasma and the recovery from human plasma fortified with various concentrations of LTG was 91.3 ± 3.4%. Interference from other common antiepileptic agents was checked. Results obtained with the PC method were compared with those obtained by a method using liquid chromatography (LC) for analysis of plasma and with methods using LC and UV for assay of tablets.
Headspace Gas–Liquid Chromatographic Determination of Dithiocarbamate Residues in Fruits and Vegetables with Confirmation by Conversion to Ethylenethiourea
Authors: Ahmad Nazir , Guo Lin , Mandarakas Peter , Farah Viola , Appleby Semeone , Gibson Trevor 
Published: February 2020

Abstract
Ethylene-bis-dithiocarbamate (EBDC) residues were determined as carbon disulfide (CS2) by an improved headspace gas-liquid chromatographic (GLC) procedure. Among 837 samples of 30 agricultural commodities tested, 43% contained residues above the detection limit for the method: 100% of broccoli samples; 80% of cabbage, kiwifruit, and grape samples; and 71% of cucumber samples. Most of the residues in kiwifruit were on or near the skin. Elimination of false-positive detections by the improved method was confirmed with kiwifruit in 2 independent procedures. Whole fruits were washed with 5% EDTA to remove surface residues of EBDC. Analysis of washes for CS2 by the headspace procedure after treatment with acidic stannous chloride and for ethylene thiourea by LC after prolonged treatment at 60°C qualitatively identified the EDTA-soluble residues as EBDC. Although the improved method does not produce false-positive results, peak area responses of CS2 and the internal standard, thiophene, are influenced by chemical composition of the matrix. With matrixes high in sugar or lipids, the apparent CS2 content may be overestimated by 4-fold. Accurate determination of EBDC residues in these sample types requires appropriate adjustments to matrixes.
Multiresidue Method for Determination of Organochlorine Insecticides and Polychlorinated Biphenyl Congeners in Fatty Processed Foods
Authors: Sannino Anna , Mambriani Paola , Bandini Mirella , Bolzoni Luciana 
Published: February 2020

Abstract
A previously published gel permeation chromatographic (GPC) procedure for determination of organophosphorous insecticides is used to determine 24 organochlorine (OC) pesticide and 9 polychlorinated biphenyl (PCB) residues in 8 fatty preserved foods of vegetable and animal origin. Samples are extracted with methylene chloride and cleaned up by automated GPC with a Biobeads SX3 column and a methylene chloride–cyclohexane (15 + 85) eluant. Compounds are quantitated by gas chromatography/mass spectrometry (GC/MS) with selected ion monitoring using a DB-5 column. Average recoveries of OC pesticides from samples fortified at 0.010–0.080 mg/kg ranged from 73 to 98%. Average recoveries of 9 PCB congeners spiked at 2 levels (0.0025 and 0.020 mg/kg) were between 85 and 104%. Quantitation limits were between 0.002 and 0.025 mg/kg, depending on the compound. The purified extracts were analyzed further by GC with electron capture detection (ECD), and the results were compared with those obtained by MS. Determination of some OC pesticides and PCB congeners was not possible by ECD because of matrix interference.
Potential Interference by Free Fatty Acids in Determination of Tricyclazole in Brown Rice by Gas Chromatography with Flame Thermionic Detection
Authors: Tsumura Yukari , Nakamura Yumiko , Tonogai Yasuhide , Shibata Tadashi 
Published: February 2020

Abstract
A convenient method is described for the determination of tricyclazole in brown rice, and the interference of free fatty acids with flame thermionic detection (FTD) is reported for the first time. Brown rice is extracted with acetone, the extract is filtered, and the filtrate is evaporated. To the residue is added 10% (w/v) NaCI solution, and the mixture is extracted with ethyl acetate. The extract is charged on a Sep-Pak Plus silica cartridge. Free fatty acids are removed from the rice by washing with diethyl ether, and tricyclazole is eluted with acetone-n-hexane (1 + 1). Tricyclazole is determined on a DB-1 capillary column by gas chromatography with FTD (GC–FTD). Linoleic acid and oleic acid, which have essentially the same retention time as tricyclazole, cannot be detected by FTD. Thus, without the Sep- Pak Plus silica cleanup, the peak height of tricyclazole in the chromatogram decreased, the extent depending on the concentration of linoleic acid, n-Hexane–acetonitrile partitioning was not used for cleanup because it could not remove 50% of the free fatty acids. Recoveries (mean ± standard deviation, n = 5) of tricyclazole from rice fortified at 2 and 0.1 ppm were 90.5 ±9.4% and 81.3±10.6%, respectively. The limit of quantitation was 0.05 ppm.
Determination of Decabromobiphenyl Ether in Water and Sediment Samples by Gas Chromatography with Electron Capture Detection
Authors: Yamamoto Hitoshi , Okumura Tameo , Nishikawa Yoshinori , Konishi Hiroe 
Published: February 2020

Abstract
Traces of decabromobiphenyl ether (DBBE) in water and sediment were determined by capillary gas chromatography with electron capture detection. Rapid sample preparation techniques such as disk-type C18 solid-phase extraction and cartridge- type Florisil extraction were used to clean up water and sediment samples, respectively. The detection limits of DBBE were 0.12 ng/mL and 9.7 ng/g in water and sediment, respectively. Average recoveries of DBBE added to river water, sea water, and sediment were 103%, with a relative standard deviation (RSD) of 8.6%; 87%, with an RSD of 10.7%; and 91%, with an RSD of 6.3%, respectively.
Determination of Boron in Plants and Plant-Derived Foods by Ultrasonic Nebulization-Inductively Coupled Plasma Atomic Emission Spectrometry with Addition of Mannitol
Authors: Sun Da-Hai , Waters James K , Mawhinney Thomas P 
Published: February 2020

Abstract
An ultrasonic nebulization-inductively coupled plasma (ICP) atomic emission spectrometry procedure was developed to determine boron in plants and plant-derived foods. Samples were ashed at 550°C for 4 h, and the resulting ash was dissolved into a mannitol-nitric acid solution to form a boron- mannitol complex. Solutions were directly nebulized into ICP by an ultrasonic nebulizer. The memory effect—the main drawback for determining boron with the ultrasonic nebulizer—was minimized with addition of mannitol. Two National Institute of Standards and Technology (NIST) standard reference materials (SRM 1515 apple leaves and SRM 1547 peach leaves) and 25 food and plant materials spiked with NIST SRM 1515 were analyzed to verify method accuracy. Boron contents found in NIST standard samples were in excellent agreement with certified values. A detection limit (2σ) of 0.5 μg/L and typical recoveries of 93 to 106% from spiked selected samples were obtained.
Assurance Escherichia coli 0157:H7: A Comparative Validation Study
Authors: Feldsine Philip T , Forgey Robin L , Falbo-Nelson Maria T , Brunelle Sharon L 
Published: February 2020

Abstract
A wide variety of food products, with emphasis on raw meat products, were analyzed simultaneously by 3 methods: the Assurance Escherichia coli 0157:H7 (EHEC) enzyme immunosorbent assay (EIA), the EHEC visual immunoprecipitate assay (VIP), and a modified Bacteriological Analytical Manual (BAM) culture method. This paper reports results of a comparative study of the Assurance and modified BAM methods. In this comparative study, 1050 samples and controls gave false-negative rates of 1.0 and 0%, respectively, for the Assurance EIA and the modified BAM culture methods. The overall agreement between the 2 methods was 99.4%. Cultural confirmation of presumptive positive samples was problematic because competitive flora were present in higher levels than EHEC in the enrichment broth after incubation and the target organism had nondescript characteristics on the primary selective agar, hemorrhagic coli agar, which necessitated picking of additional colonies in many instances.
Determination of Platinum in Wine by Graphite Furnace Atomic Absorption Spectrometry
Authors: Cabrera-Vique Carmen , Teissedre Pierra-Louis , Cabanis Marie-Thérèse , Cabanis Jean-Claude 
Published: February 2020

Abstract
A method based on graphite furnace atomic absorption spectrometry (GFAAS) was developed for determining platinum in wine. Wine samples were prepared by microwave acid digestion or dry mineralization. The method of standard addition was used for Pt determination in untreated wine samples and mineralized samples. Analyte modifiers and furnace conditions were optimized. Effects of cations (Mg2+, Ca2+, K+, Na+, and NH|) and anions (PO43, SO42) were tested separately and in combination. Analytical characteristics of the method were optimized for analyte recovery and signal enhancement. Recoveries ranged from 92.5 to 102%, and precision reproducibility relative standard deviation varied from 7.5 to 10%. Red, rosé, and white wines from France were analyzed. Platinum levels found in most wines were very low (&lt;10 μg/L).
Evaluation of Nonlinearity Testing Procedures on Simulated Data
Authors: Feinberg Max H , De La Rochette Arnauld J 
Published: February 2020

Abstract
When calibrating a method, use of a straight line is highly favorable because it is easy to compute sensitivity and the blank to be used to predict an unknown concentration. Therefore, when validating an analytical method, it is necessary to check whether linearity is acceptable over the method’s whole application range before trying another model. Available procedures for checking linearity are reviewed by using a simulation model that gives a complete family of curved calibration lines. From the simulated data, it is possible to compute the prediction error generated by the model curva ture as the relative difference between the linear extrapolated value and the observed value. It appears that the power of the classical “linearity test” depends on experimental design and that at least 25 measurements are necessary to detect curvature for an acceptable prediction error. An alternative model-fitting criterion, based on the χ2 probability law, also was evaluated. It is also applicable but seems less stable and more sensitive to data size. The question of the definition of nonlinearity is also raised because it is directly connected to the comparison of nonlinearity detection techniques.
Liquid Chromatographic Determination of Chloramine-T and Its Primary Degradation Product, ρ-Toluenesulfonamide, in Water
Authors: Dawson Verdel K , Davis Ruth A 
Published: February 2020

Abstract
N-sodium-N-chloro-ρ-toiuenesulfonamide (chloramine-T) effectively controls bacterial gill disease (BGD) in cultured fishes. BGD, a common disease of hatchery-reared salmonids, causes more fish losses than any other disease among these species. This study describes a liquid chromatographic (LC) method that is capable of direct, simultaneous analysis of chloramine-T and its primary degradation product, ρ-toluenesulfonamide (ρ-TSA), in water. The procedure involves reversed-phase (C18) LC analysis with ion suppression, using 0.01 M phosphate buffer at pH 3. The mobile phase is phosphate buffer-acetonitrile (60 + 40) at 1 mL/min. Both chemicals can be detected with a UV spectrophotometer at 229 nm; the method is linear up to 40 mg chloramine-T or ρ-TSA/L. Mean recoveries were 96.4 ± 6.1% for water samples fortified with 0.03 mg chloramine-T/L and 95.3 ± 4.6% for water samples fortified with 0.005 mg ρ-TSA/L. Limits of detection without sample enrichment for chloramine-T and ρ-TSA are 0.01 mg/L and 0.001 mg/L, respectively.
Volatile Antifungal Compounds in Maize Kernels: Effect of Ear Position on Aflatoxin Production
Authors: Zeringue Hampden J 
Published: February 2020

Abstract
Volatiles produced by ground maize kernels from 3 zonal areas of Pioneer Hybrid 3136 maize ear inhibited the growth of aflatoxigenic Aspergillus flavus and, therefore, production of aflatoxin B1 in a static culture bioassay. Volatiles from kernels obtained from the medial zonal area of the maize ear resulted in 75% mean inhibition of A. flavus radial growth and 76% mean inhibition of aflatoxin contamination. Volatiles from kernels obtained from the apical zone resulted in 19% mean inhibition of radial growth and 33% mean inhibition of aflatoxin contamination. Volatiles from kernels obtained from the basal zone resulted in 23% mean inhibition of radial growth and 37% mean inhibition of aflatoxin contamination. Volatiles were purged on Tenax columns and analyzed by gas chromatography/mass spectrometry. Compounds highly toxic to A. flavus, such as C4-C6 aldehydes, benzothia-zole, methyl jasmonates, and 2-furancarboxaldehy-des, were found mostly in volatiles from kernels obtained from the medial zone. These results demonstrate a relationship between volatile fungi-toxic compounds from kernels obtained from different zonal areas and aflatoxin contamination.
Determination of Sulfonylurea Herbicides in Water by Capillary Electrophoresis and by Liquid Chromatography/Mass Spectrometry
Authors: Krymtsky Alexander J 
Published: February 2020

Abstract
A capillary electrophoresis (CE) method and an electrospray ionization (ESI) liquid chromatography/mass spectrometry (LC/MS) confirmatory method were developed to analyze 12 sulfonylurea herbicides and one sulfonamide (Flumetsulam) in runoff water. The water used for fortification was collected from a local marsh that contained high levels of potentially interfering compounds. Good recoveries and adequate sensitivity at the 0.2 ppb level (limit of quantitation) were obtained. A portion of the water was acidified and extracted with reversed- phase solid-phase extraction (SPE). Extracts were cleaned up with a tandem system consisting of a strong-anion exchange SPE cartridge stacked on an alumina SPE cartridge. CE/ultraviolet quantitation was achieved by capillary zone electrophoresis at pH 4.75 with 50 mM ammonium acetate buffer and an acetonitrile modifier. ESI LC/MS quantitation was achieved by using a time-scheduled selective-ion monitoring (positive mode) of the M+H ions for each compound. The extraction/cleanup procedure provided extracts such that in-source collision-induced dissociation gave product ions for confirmation at the 0.2 ppb fortification level.
Simplified Determination of Imidazolinone Herbicides in Soil at Parts-per-Billion Level by Liquid Chromatography/ Electrospray Ionization Tandem Mass Spectrometry
Authors: Stout Steven J , Dacunha Adrian R , Safarpour Maximilian M 
Published: February 2020

Abstract
Imidazolinones are a significant new class of low-use-rate, reduced-environmental-risk herbicides for protection of a wide variety of agricultural commodities. Because of their low rates of application, residues of imidazolinones in soil need to be monitored at low parts-per-billion (ppb) levels. Greatly simplified cleanup procedures were reported recently for determining imidazolinones in soil at the 1 ppb level by combining microwave-assisted extraction (MAE) with gas chromatography/electron capture negative chemical ionization mass spectrometry (GC/ECNCI) and for determining imidazolinones in water by using liquid chromatography/electrospray ionization mass spectrometry (LC/ESMS) and liquid chromatography/electrospray ionization tandem MS (LC/ESMS/MS). By merging the extraction and cleanup procedures for determining imidazolinones in soil with LC/ESMS/MS, instrumental analysis time was reduced to that approximating sample preparation time, and the drawbacks of in situ methylation required for GC/ECNCI were eliminated. Recoveries of imazethapyr, the most widely used imidazolinone, from a variety of soil types fortified at 1–50 ppb averaged 92% with a standard deviation of 9.7%. Control soil extracts gave apparent residues of &lt;0.2 ppb. These results were almost identical to those previously reported for GC/ECNCI.
Determination of Pesticides in Soils by Gas Chromatography-Ion Trap Mass Spectrometry
Authors: Papadopoulou-Mourkidou Euphemia , Patsias John , Kotopoulou Athena 
Published: February 2020

Abstract
A multiresidue method is reported for determination of a variety of chemical classes of pesticides (organochlorines, organophosphates, triazines, phenylureas, acetanilides, pyrethroids, carbamates, and miscellaneous others) in soils. Soil samples are extracted with an acetonitrile-water mixture, and the pesticides are partitioned into petroleum ether-diethyl ether for direct analysis by gas chromatography-ion trap mass spectrometry (GC-ITMS) with the mass spectrometer operated in the electron ionization mode. Recovery values determined for a fortification range of 20–1000 ppb were &gt;80% for most of the pesticides. Detection limits determined in the full-scan mass spectrum mode were in the 1–10 ppb range for most analytes. This simple and rapid multiresidue method for determination of pesticides at trace levels in soils is appropriate for environmental behavior and pollution monitoring studies.