bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organochlorine Contaminants in Microlayer and Subsurface Water of Alexandria Coast, Egypt
Authors: Abd-Allah Aly Mohammed Aly 
Published: February 2020

Abstract
The surface microlayer of seawater is a potential enrichment site for hydrophobic organic compounds. Concentrations of pesticidesand congeners of polychlorinated biphenyls (PCBs) in the microlayer and subsurface waters of Alexandria coast were assessed. A 0.22 m2 screen was used to collect microlayer samples at 12 stations in June 1997. The samples were analyzed by gas chromatography with electron capture detection (GCECD) and confirmed by GC with mass spectrometry. Ten organochlorine pesticides and 10 PCB congeners were measured. The surface microlayer was enriched 2- to 3-fold in pesticides and PCBs. The most contaminated locations studied were Abu-Quir Bay and the Eastern Harbor. This study provides the first record of residues of PCB congeners in the studied areasand the first data about microlayer enrichment at Alexandria's Mediterranean Coast.
Determination of Four Fluoroquinolones in Milk by On-Line Immunoaffinity Capture Coupled with Reversed-Phase Liquid Chromatography
Authors: Holtzapple Carol K , Buckley Sandra A , Stanker Larry H 
Published: February 2020

Abstract
An automated, on-line immunoaffinity extraction method was developed for the analysis of 4 fluoroquinolones in milk: ciprofloxacin, difloxacin, enrofloxacin, and sarafloxacin. This method involves analyte extraction using an immunoaffinity capture column containing anti-fluoroquinolone antibodies coupled on-line with reversed-phase column chromatography. Liquid chromatographic analyses were performed by isocratic elution using a mobile phase of 2% acetic acid-acetonitrile (85 + 15) and an Inertsil phenyl column with fluorescence detection at excitation and emission wavelengths of 278 and 444 nm, respectively. No significant interferences from the sample matrix were observed, indicating good selectivity with the immunoaffinity column. Recoveries from fortified raw milk samples (5–50 ppb of each fluoroquinolone) ranged from 72 to 90%, with standard deviations of ≤8%.
Maternal Body Burden of Organochlorine Pesticides and Dioxins
Authors: Nakagawa Reiko , Hirakawa Hironori , Iida Takao , Matsueda Takahiko , Nagayama Junya 
Published: February 2020

Abstract
To investigate the body burden of organochlorine pesticides and dioxins in Japanese women,125 milk samples were collected from 41 mothers in 1994, 42 in 1995, and 42 in 1996. Ofthe 125 samples, 82 were from primipara mothers (first delivery) and 43 were from multipara mothers (second or later delivery). By using capillary gas chromatography with electron capture detection, β-HCH and p,p′-DDE were detected as the major chlorine pesticides in human milk. Average levels of β-HCH and p,p′-DDE were 475 and 368 ng/g lipid, respectively, in primipara breast milk, 314 and 259 ng/g lipid in multipara breast milk, and 420 and 330 ng/g lipid in total breast milk. Dieldrin, heptachor epoxide, oxychlordane, trans-chlordane, and cis-chlordane were detected at lower average levels of 3, 4, 34, 41, and 5 ng/g lipid, respectively. By using high-resolution gas chromatography with mass spectrometric detec tion, dioxins were detected in all samples. Average levels of total polychlorinated dibenzo-p-dioxin (PCDD), total polychlorinated dibenzofuran (PCDF), total PCDD + PCDF, total coplanar polychlorinatedbiphenyl (CoPCB), and total dioxin were 10.0, 7.8, 17.7, 9.9, and 27.5 TEQ (toxic equivalent) pg/g lipid, respectively, in primipara breast milk; 7.0, 5.8, 12.8, 7.3, and 20.1 TEQ pg/g lipid in multipara breast milk; and 8.9, 7.1, 16.1, 8.9, and 25.0 TEQ pg/g lipid in total breast milk. In primipara breast milk, significant correlations were found among levels of β-HCH, p,p’-DDE, total PCDD-TEQ, total PCDF-TEQ, total CoPCB-TEQ, and total TEQ except for less correlation between p,p’-DDE and total PCDF-TEQ. Levels of these analytes also significantly increased depending on mother’s age, except for total Co-PCB-TEQ. For the correlation with food habit, the only positive correlation was between total PCDF-TEQs and fish intake.
Spectrophotometric Determination of Fenpropathrin and Fluvalinate in Their Formulations
Authors: Kaushik Nutan , Handa Swadesh Kumar 
Published: February 2020

Abstract
An economical and precise method for spectrophotometric determination of fenpropathrin and fluvalinate pyrethroids is reported. The method involves alkaline hydrolysis of the pyrethroids to release HCN, which is converted to cyanogen bromide to form a colored complex with benzidine-pyridine reagent. This method can be used effectively to determine actual concentrations of these pyrethroids in their formulations. Results are comparable with results obtained by gas-liquid chromatography.
A Bridging Study for Oxytetracycline in the Edible Fillet of Rainbow Trout: Analysis by a Liquid Chromatographic Method and the Official Microbial Inhibition Assay
Authors: Stehly Guy R , Gingerich William H , Kiessling Connie R , Jeffrey H Cutting 
Published: February 2020

Abstract
Oxytetracycline (OTC) is a drug approved by the U.S. Food and Drug Administration (FDA) to control certain diseases in salmonids and catfish. OTC is also a likely control agent for diseases of other fish species and for other diseases of salmonids and catfish not currently on the label. One requirement for FDA to extend and expand the approval of this antibacterial agent to other fish species is residue depletion studies. The current regulatory method for OTC in fish tissue, based on microbial inhibition, lacks sensitivity and specificity. To conduct residue depletion studies for OTC in fish with a liquid chromatographic method, a bridging study was required to determine its relationship with the official microbial inhibition assay. Triplicate samples of rainbow trout fillet tissue fortified with OTC at 0.3,0.6,1.2,2.4,4.8, and 9.6 ppm and fillet tissue with incurred OTC at approximately 0.75,1.5, and 3.75 ppm were analyzed by high-performance liquid chromatography (HPLC) and the microbial inhibition assay. The results indicated that the 2 methods are essentially identical in the tested range, with mean coefficients of variation of 1.05% for the HPLC method and 3.94% for the microbial inhibition assay.
Glycoalkaloid Concentration in Alberta Potatoes Determined by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry
Authors: Driedger Darcy R , Sporns Peter 
Published: February 2020

Abstract
Matrix-assisted laser desorption and ionization (MALDI) mass spectrometry was used to determine concentrations of individual potato glycoalkaloids in tubers. Samples were extracted with methanol–water and deposited on 2,4,6-trihydroxyacetophenone crystals. Positive ions were analyzed with a MALDI time-of-flight mass spectrometer equipped with a 337 nm laser. Analyte ion intensities relative to an internal standard were used to determine chaconine and solanine concentrations. Calibration curves were prepared by standard additions to potato tuber material. The relative standard deviations (RSDs) of triplicate measurements ranged from 1 to 16%, with an average of 9%. The day-to-day RSD for replicate determinations was 11 %. Recoveries of analyst-prepared spikes (50 μg/g) averaged 104% for chaconine (RSD, 8%) and 98% for solanine (RSD, 4%). The method limit of detection was estimated to be 2 μg/g.
IUPAC Collaborative Trial Study of a Method To Detect Genetically Modified Soy Beans and Maize in Dried Powder
Authors: Lipp Markus , Brodmann Peter , Pietsch Klaus , Pauwels Jean , Anklam Elke ,   Collaborators:, Börchers T , Braunschweiger G , Busch U , Eklund E , Eriksen F D , Fagan J , Fellinger A , Gaugitsch H , Hayes D , Hertel C , Hörtner H , Joudrier P , Kruse L , Meyer R , Miraglia M , Müller W , Philipp P , Pöpping B , Rentsch R , Sawyer J , Schulze M , van Duijn G , Vollenhofer S , Wurtz A 
Published: February 2020

Abstract
This paper presents results of a collaborative trial study (IUPAC project No. 650/93/97) involving 29 laboratories in 13 countries applying a method for detecting genetically modified organisms (GMOs) in food. The method is based on using the polymerase chain reaction to determine the 35S promoter and the NOS terminator for detection of GMOs. Reference materials were produced that were derived from genetically modified soy beans and maize. Correct identification of samples containing 2% GMOs is achievable for both soy beans and maize. For samples containing 0.5% genetically modified soy beans, analysis of the 35S promoter resulted also in a 100% correct classification. However, 3 false-negative results (out of 105 samples analyzed) were reported for analysis of the NOS terminator, which is due to the lower sensitivity of this method. Because of the bigger genomic DNA of maize, the probability of encountering false-negative results for samples containing 0.5% GMOs is greater for maize than for soy beans. For blank samples (0% GMO), only 2 false-positive results for soy beans and one for maize were reported. These results appeared as very weak signals and were most probably due to contamination of laboratory equipment.
High-Performance Liquid-Phase Separation of Glycosides Analytical and Micropreparative HPLC Combined with Spectroscopic and Enzymatic Methods for Generating a Glucosinolate Library
Authors: Arguello Lino G , Sensharma Dilip K , Qiu Feng , Nurtaeva Aliya , El Rassi Ziad 
Published: February 2020

Abstract
Analytical and micropreparative high-performance liquid chromatographic (HPLC) methods assisted by spectroscopic and enzymatic tools were developed for generating a glucosinolate library from white cabbage. This involved the study of the chromatographic behavior of glucosinolates by reversed-phase chromatography (RPC) using octadecyl-silica (ODS) stationary phases and ion-exchange chromatography with strong an ion-exchange (SAX) columns. The glucosinolate extract from white cabbage was fractionated on a micropreparative Zorbax ODS column of 250 × 6.2 mm id. The collected fractions from the ODS column effluent were further purified by rechromatographing the early eluting fractions on a SAX column and the late-eluting peaks on the same ODS column under different elution conditions. These studies demonstrated the benefits of using more than one HPLC method in the isolation of pure glucosinolates. These chromatographic separation schemes combined with efficient sample cleanup provided pure glucosinolate fractions that were readily identified by high-field nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (MS), namely negative-ion liquid secondary ionization mass spectrometry (LSIMS). The structural determination of a given glucosinolate by 1- and 2-dimensional NMR was further confirmed by LSIMS, which gives the mass of the molecular anion of glucosinolates. In addition, the structure of a given glucosinolate fraction was readily assessed by performing RPC of the myrosinase digest of the particular glucosinolate and that of the standard degradation product that has a structure that is reflective of the parent glucosinolate. Also, through the myrosinase degradation products (e.g., isothiocyanates) under controlled conditions, the quantitative determination by RPC of the corresponding glucosinolates in the white cabbage extract was reliably achieved. By using the ability of myrosinase to hydrolyze the glucosinolates, it was possible to profile the glucosinolates in the cabbage extract quite rapidly. For the glucosinolates present at very low amounts in white cabbage, and also for the HPLC fractions containing more than one glucosinolate, the isothiocyanate degradation products resulting from the hydrolyzing effect of myrosinase were analyzed by gas chromatography/MS, and their structures were determined. This in turn allowed the determination of the structure of the parent glucosinolates. In summary, white cabbage seems to contain at least 8 glucosinolates.
Studies in Improvement of Official Method 996.06
Authors: DeVries Jonathan W , Kjos Lori , Groff Linda , Bob Martin , Kristi Cernohous , Patel Hasmukh , Payne Mark , Leichtweis Harry , Shay Mike , Newcomer Leo 
Published: February 2020

Abstract
Quantitation of fat in foods has been performed successfully with AOAC Official Method 996.06. A number of situations have been encountered that render the method note, “Note: For any unknown or uncalibrated peaks, use the nearest calibrated fatty acid response factors and conversion factors,” inaccurate. Identification of extraneous compounds and availability of additional standard fatty acid methyl esters combined with mass spectral data lead to the recommendation of modifications in Official Method 996.06. The stepwise performance of the method remains unchanged.
Analyses of Polychlorinated Biphenyls and Chlorinated Pesticides in Biota: Method and Quality Assurance
Authors: Cleemann Marianne , Paulsen Gudrun B , Storr-Hansen Eva , Fromberg Arvid 
Published: February 2020

Abstract
An analytical method for polychlorinated biphenyls (PCBs) and chlorinated pesticides in mussels, fish liver, bird liver, and seal blubber is described. Different calibration functions were tested to establish the optimal fit to the nonlinear response of all included compounds. Detection limits and within-batch variations were determined from standard deviations of duplicate analyses of real samples. Within-batch, between-batch, and total relative standard deviations were calculated from regular use of control material. Percentage recovery was estimated by spiking samples with 3 selected PCB congeners and by spiking selected samples with all compounds included in the procedure. Quality assurance is described, covering analysis of about 450 samples divided into 38 batches. Because between-batch variation was twice the within-batch variation, the use of in-house control material and control charts is considered to be mandatory for this type of analyses. Use of certified reference material and regular participation in intercomparison exercises have demonstrated the high quality of the method and the adequacy of the quality assurance applied.
Supercritical Fluid Extraction of Ten Chloracetanilide Pesticides and Pyriminobac-Methyl in Crops: Comparison with the Japanese Bulletin Method
Authors: Yoshii Kimihiko , Okada Mai , Tsumura Yukari , Nakamura Yumiko , Ishimttsu Susumu , Tonogai Yasuhide 
Published: February 2020

Abstract
In Japan, the maximum residue limit and an analytical bulletin method for alachlor and pyriminobac-methyl were recently published. Because this method has some problems, such as many interfering chromatographic peaks for some residues in certain crops, time-consuming sample preparation, etc., we have developed an alternative method. In the bulletin method, pesticides are extracted with acetone, reextracted with ethyl acetate, partitioned with hexane–acetonitrile, cleaned up on a Florisil column, and quantitatively determined by gas chromatography with flame thermionic detector (GC-FTD). In the developed method, pesticides are extracted by supercritical fluid extraction and directly cleaned up with a trap column consisting of Extrelut and Florisil (acetone–n-hexane, 3 + 7, as the eluent) or Bond Elut SAX and PSA (acetone–n-hexane, 1 +1, as the eluent). The test solution was quantitatively determined by GC with mass spectrometry. Alachlor, pyriminobac-methyl, and 9 other chloracetanilide pesticides were studied. Average recoveries of spiked samples (0.1 ppm) were between 52 and 104% with the bulletin method and between 68 and 106% with the developed method. By using the Japanese bulletin method, 3 pesticides from Japanese radish could not be measured because of many interfering peaks on the GC–FTD chromatogram, even on selected-ion monitoring (SIM) chromatograms. On the other hand, by using the developed method, SIM chromatograms had fewer interfering peaks than did the Japanese bulletin method.
A Pilot Study for the Statistical Treatment of Nutritional Parameters in the Quality Control of Canned Fishing Goods
Authors: Bartos-Lorenzo Marta , Calviño-López Alberto , Dalama-Iglesias Fernando , Torre-Lamosa Maria de la , Martín-Pardo Guadalupe , Andrade Jose M 
Published: February 2020

Abstract
This pilot study was derived as a consequence of European Directives 496/90 and 493/91 in which a regulation on the labeling of canned fishing goods was established. The study was intended primarily to assess whether different Spanish canned fishing goods might be differentiated by their basic nutritional composition (i.e., ash, chlorine as NaCl, fat, humidity, total proteins, and dry residue) and, second, to study each particular type of good. Accordingly, a univariate nonparametric statistical test and 2 multivariate chemometric techniques (factor and cluster analyses) were used. The pilot study revealed that (1) the basic nutritional variables did not allow a clear distinction among canned goods when different commodities were considered, but they seemed useful for obtaining information for only one type of good; and (2) the variables that gave the most useful information to visualize the appearance of groups in the data sets were humidity, dry residue, fat, and proteins, although their particular usefulness was found to be different when different species were considered.
Synergistic Extraction of Gold(III) by Mixtures of Adogen-464 and Neutral Donors
Authors: Biswas Samira , Basu Sukalyan 
Published: February 2020

Abstract
Synergism was observed in the extraction of gold(III) from aqueous hydrochloric acid media by mixtures of Adogen-464 neutral donors. Synergistic coefficients and adduct equilibrium constants were calculated from distribution data and correlated with the relative donor abilities of the added bases.
Cadmium Levels in Feed Components and Kidneys of Growing/Finishing Pigs
Authors: Lindén Anna , Olsson Ing-Marie , Oskarsson Agneta 
Published: February 2020

Abstract
Cadmium (Cd) concentrations in pig feeds (one control feed and one feed with reduced nitrogen content), straw, water, and pig kidney cortex were determined in 2 breeds of growing/finishing pigs (n = 96). The total Cd intake from feed was calculated. Feed mixtures and components, straw and kidney cortex samples, and certified reference samples were microwave-digested and analyzed by atomic absorption spectrometry with graphite furnace technique. Total Cd concentration in the control feed was 37.1 μg/kg wet weight (w.wt). The highest Cd levels were found in nonlocally produced feed components: vitamin-mineral mixture, lime, dicalcium phosphate, soybean meal, and rapeseed meal. These components contributed 70% of the Cd content in the feed. The main component, barley, which was locally produced, contributed 30% of the total Cd content in feed. The feed with reduced nitrogen content contained less soybean and rapeseed meal and a lower Cd level than the control feed. The Cd levels in kidney cortex varied from 38.0 to 105 μg/kg w.wt, with a mean level of 70.9 μg/kg. The levels differed between breeds and feeds, but not between gender. There was a significant correlation between Cd level in kidney cortex and age at slaughter, with an increase of 2.8 μg/kg w.wt in the kidney for each additional week of survival. The contribution of Cd from nonlocally produced feed components could have environmental effects through application of farmyard manure to local soils.
A New Spectrophotometric Method for the Determination of Dithianon in Commercial Formulations and Its Residues in Foodstuffs
Authors: Verma Balbir C , Thakur Hari K , Singh Jasvir , Sharma Devender K 
Published: February 2020

Abstract
A new, simple, and rapid spectrophotometric method for the microdetermination of dithianon, on the basis of its reaction with a dithiocarbamate, is described. The red color, which develops instantaneously when mixing the fungicide with the reagent in acetonitrile, is stable for at least 1 h and is measured at 520 nm. Beer's law is applicable up to 12 μg/mL dithianon concentration. The method has been successfully adapted to the analysis of the fungicide in commercial formulations and its residues on grains and apple (fruit and leaves). A photometric titration method for formulation analysis of the fungicide has also been developed.
Kjeldahl Nitrogen Analysis as a Reference Method for Protein Determination in Dairy Products
Authors: Lynch Joanna M , Barbano David M 
Published: February 2020

Abstract
Measurement of total nitrogen by Kjeldahl analysis is the historical reference method for determination of the protein content of dairy products and is used for both calibration and validation of alternative methods for protein determination. Accurate evaluation of alternative methods is not possible if there is large uncertainty regarding the reference values. When Kjeldahl analysis is used to establish reference values, the performance of the Kjeldahl testing must be verified and within established expectations. Advice is given for Kjeldahl system optimization, evaluation of test results, and troubleshooting. Techniques for successful Kjeldahl nitrogen analysis of dairy products other than milk are discussed.
Solid-Phase Extraction and Gas Chromatography with Mass Spectrometric Determination of Capsaicin and Some of Its Analogues from Chili Peppers (Capsicum spp.)
Authors: Manirakiza Philemon , Covaci Adrian , Schepens Paul 
Published: February 2020

Abstract
A rapid and accurate method has been developed for the quantitative determination of capsaicin and its most important analogues, dihydrocapsaicin and nordihydrocapsaicin in chili peppers. These components were extracted with methylene chlo ride and separated from interfering substances with activated charcoal. Further cleanup on Florisil cartridges and elution with ethyl acetate were performed before gas chromatographic with mass spectrometric quantitation. The concentrations found were 440 ± 64 μg/g capsaicin, 81 ± 10 μg/g dihydrocapsaicin, and 11 ± 2 μg/g nordihydrocapsaicin. The mean recovery values for triplicate analysis were between 85-94%.
Determination of Trace Metal Ions in Common Salt by Stripping Voltammetry
Authors: Ali Azza M M 
Published: February 2020

Abstract
Sensitive voltammetric methods using cathodic and anodic differential pulse stripping techniques were applied for determination of trace ions cadmium(II), cobalt(II), copper(II), lead(II), manganese(II), nickel(II), and zinc(II), which are usually found in different grades of common salt as contaminants. The optimal conditions, i.e., deposition time, preconcentration potential, supporting electrolyte, and ionic strength, were investigated for each metal ion. Concentration of the metal ion was determined by the standard addition method. Metal content varied according to the quality of the table salt.
Multiresidue Analysis of Pesticides in Fresh Fruits and Vegetables Using Procedures Developed by the Florida Department of Agriculture and Consumer Services
Authors: Cook Joanne , Beckett Mary Pat , Reliford Brian , Hammock Walter , Engel Marc 
Published: February 2020

Abstract
Improved quality and efficiency of pesticide residue analysis were achieved by examining all aspects of the laboratory process. In an effort to eliminate methylene chloride hazardous waste, an acetonitrile extraction method, originally developed by the California Department of Agriculture, was modified and adopted. Sample size and solvent consumption were reduced with the new method. Custom glassware racks and disposable supplies reduced overall analysis time. Gravity-fed, solid-phase extraction simplified sample preparation and provided cleaner extracts for gas chromatographic analyses. Modifications to the method were made to achieve the ruggedness needed to maintain quality objectives during routine analysis. Instrumental improvements, including new selective detectors, retention time locking, and mass spectrometry screening for all samples, provided the laboratory with efficient, reliable, and confirmed analytical results.