Determination of 2,3?7,8-Tetrachlorodibenzo-p-Dioxin in Fish, Using Electron Capture Gas Chromatography with Confirmation by Mass Spectrometry: Interlaboratory Study

1989 ◽  
Vol 72 (2) ◽  
pp. 394-398
Author(s):  
Norbert V Fehringer ◽  
Stephen M Walters ◽  
Richard A Niemann
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Electron Capture ◽  
Interlaboratory Study ◽  
Electron Capture Detection ◽  
Hexane Extraction ◽  
Relative Standard ◽  
Column Liquid Chromatographic ◽  
Tetrachlorodibenzo P Dioxin

Abstract An interlaboratory study of the determination of 2,3,7,8-tetrachlorodibenzo- p-dioxin (2,3,7,8-TCDD) in fish was conducted by 6 analysts in 4 laboratories using high resolution gas chromatography with electron capture detection (HRGC-EC) for quantitative screening analysis. Samples consisted of 3 Great Lakes channel catfish homogenates containing different levels of bioincurred 2,3,7,8-TCDD; 1 of these was prepared in duplicate and another was prepared both with and without standard 2,3,7,8-TCDD fortification for a total of 5 samples per set. All methods used included addition of 1,3,7,8-TCDD surrogate (to correct for procedural losses) followed by ethanolic KOH digestion and hexane extraction. Certain cleanup steps used, including sulfuric acid washing and multidimensional column liquid chromatographic procedures, varied among laboratories. Mean HRGC-EC results for the bioincurred residues were 56.6, 25.2, and 7.7 pg/g (ppt) with corresponding relative standard deviations (RSDs) of 9.1,18.6, and 53.2%. Average determination of standard 2,3,7,8- TCDD from the fortified sample (corrected for surrogate recoveries averaging 74.6%) was 106% of the added amount (30.9 pg/g) with 11.0% RSD. HRGC-multiple ion detection mass spectrometry (MS), monitoring 12 ions, was used for confirmation. With the exception of several results from 1 analyst, HRGC-MS and HRGC-EC quantitations were in good agreement. All but 1 result reported met all of the MS ide ntity criteria.

Surrogate-Assisted Determination of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin in Fish by Electron Capture Capillary Gas Chromatography

1986 ◽  
Vol 69 (6) ◽  
pp. 976-980
Author(s):  
Richard A Niemann
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Capillary Gas Chromatography ◽  
Capillary Column ◽  
Electron Capture Detection ◽  
Matrix Interference ◽  
Relative Standard ◽  
Tetrachlorodibenzo P Dioxin ◽  
Liquid Chromatographic

Abstract Surrogate spiking the sample with 1000 parts per trillion (pptr) 1,3,7,8-tetrachlorodibenzo-p-dioxin (1378-TCDD) has doubled analytical throughput in determining toxic 2378-TCDD (analyte) at the low partper- trillion level in fish, using multicolumn high resolution liquid chromatographic cleanup before quantitation by capillary gas chromatography with electron capture detection. The 1378- and 2378-TCDD were recovered equally and were well separated by the capillary column so that the earlier-eluting surrogate did not interfere with the quantitation of levels of analyte many-fold lower. Matrix interference contributed <1 % bias in surrogate quantitation. Using surrogate recovery to correct for analyte losses during analysis, accuracy averaged (n = 7) 105% in determining 18 or 45 pptr 2378-TCDD added to fish without detectable bioincurred analyte. Analyses of selected fish with bioincurred 2378-TCDD gave results comparable to earlier work where recovery correction required a second analysis of sample fortified with analyte. With surrogate fortification, repeatability of determination (n = 3 or 4) improved markedly to <5% relative standard deviation at 37-46 pptr.

scholarly journals Gas Chromatographic Determination of Pesticide Residues in Malt, Spent Grains, Wort, and Beer with Electron Capture Detection and Mass Spectrometry

2007 ◽  
Vol 90 (2) ◽  
pp. 544-549 ◽  
Author(s):  
Nuria Vela ◽  
Gabriel Prez ◽  
Gins Navarro ◽  
Simn Navarro
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Electron Capture ◽  
Pesticide Residues ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Selected Ion Monitoring ◽  
Spent Grains ◽  
Relative Standard

Abstract A method for the simultaneous determination of 9 pesticides (dinitroanilines, organophosphorus, triazoles, and pyrimidines) in several products (malt, spent grains, wort, and beer) of the beer industry is reported. Solid samples (malt and spent grains) are extracted by homogenization with a waterhexane mixture, and the pesticides are partitioned with dichloromethane. Liquid samples (wort and beer) are extracted by sonication with a hexanedichloromethane mixture. Determination of pesticide residues was made by capillary gas chromatography with an electron capture detector (ECD). Confirmation of the compounds was performed by gas chromatography/ion trap mass spectrometry in the selected ion monitoring mode. Detection limits for GCECD varied from 0.2 to 5.5 pg for trifluralin and malathion, respectively. Recoveries of the pesticides from spiked samples ranged from 81.2 to 113.7% with a relative standard deviation between 3.47.5%. The method presents good linearity over the studied range (0.0052 g/mL). The proposed method is rapid and reliable and can be useful for routine monitoring during brewing.

scholarly journals Broad-Spectrum Determination of Pesticides in Groundwater by Gas Chromatography with Electron Capture Detection, Nitrogen–Phosphorus Detection, and Tandem Mass Spectrometry

2001 ◽  
Vol 84 (6) ◽  
pp. 1751-1762 ◽  
Author(s):  
Antonia Garrido Frenich ◽  
Maria Del Carmen Pablos Espada ◽  
Jose Luis Martínez Vidal ◽  
Luis Molina
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Tandem Mass Spectrometry ◽  
Electron Capture ◽  
Electron Capture Detection ◽  
Tandem Mass ◽  
Relative Standard ◽  
Nitrogen Phosphorus ◽  
Pesticides In Groundwater

Abstract Gas chromatography with electron capture detector (ECD), nitrogen–phosphorus detector (NPD), and tandem mass spectrometry (MS/MS) was used to identify 36 pesticides, widely used to control various pest and diseases in vegetables, in water after a preconcentration step on C18 cartridges. The recoveries obtained ranged from 70 to 135% at a fortification level of 100 ng/L with relative standard deviations of <36.2%. The limits of detection and quantitation were ≤48 and ≤160 ng/L, respectively. Important advantages of MS/MS over ECD and NPD in the determination of pesticides are also presented. The proposed analytical methodology was applied to the determination of pesticides in groundwater samples from an agricultural area, the Campo de Dalías (Almería, Spain). The most frequently encountered pesticides were endosulfan sulfate and metalaxyl, whereas the pesticide found at the highest concentration was fenamiphos.

Residue Analysis of Organophosphorus and Organochlorine Pesticides in Fatty Matrices by Gas Chromatography Coupled with Electron-Capture Detection

2006 ◽  
Vol 61 (5-6) ◽  
pp. 341-346 ◽  
Author(s):  
Jae-Woo Park ◽  
A. M. Abd El-Aty ◽  
Myoung-Heon Lee ◽  
Sung-Ok Song ◽  
Jae-Han Shim
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Simple Procedure ◽  
Linear Regression Analysis ◽  
Residue Analysis ◽  
Electron Capture Detection ◽  
Relative Standard ◽  
Wide Range ◽  
Repeatability And Reproducibility

A multiresidue method for the simultaneous determination of 22 organochlorine (OCs) and organophosphorus (Ops) pesticides (including isomers and metabolites), representing a wide range of physicochemical properties, was developed in fatty matrices extracted from meat. Pesticides were extracted from samples with acetonitrile/n-hexane (v :v, 1:1). The analytical screening was performed by gas chromatography coupled with electron-capture detection (ECD). The identification of compounds was based on their retention time and on comparison of the primary and secondary ions. The optimized method was validated by determining accuracy (recovery percentages), precision (repeatability and reproducibility), and sensitivity (detection and quantitation limits) from analyses of samples fortified at 38 to 300 ng/g levels. Correlation coefficients for the 22 extracted pesticide standard curves (linear regression analysis, n = 3) ranged from 0.998 to 1.000. Recovery studies from 2 g samples fortified at 3 levels demonstrated that the GC-ECD method provides 64.4-96.0% recovery for all pesticides except 2,4′-DDE (44.6-50.4%), 4,4′-DDE (51.1-57.5%) and 2,4′-DDT (50.0-51.2%). Both repeatability and reproducibility relative standard deviation values were < 20% for all residues. Detection limits ranged from 0.31 to 1.27 ng/g and quantification limits were between 1.04 and 4.25 ng/g. The proposed analytical method may be used as a simple procedure in routine determinations of OCs and Ops in meat. It can also be applied to the determination of pesticide multi-residues in other animal products such as butter and milk.

Gas Chromatographic Determination of Captan, Folpet, and Captafol Residues in Tomatoes, Cucumbers, and Apples Using a Wide-Bore Capillary Column: Interlaboratory Study

1991 ◽  
Vol 74 (5) ◽  
pp. 830-835 ◽  
Author(s):  
Dalia M Gilvydis ◽  
Stephen M Walters
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Capillary Column ◽  
Chromatographic Determination ◽  
Interlaboratory Study ◽  
Electron Capture Detection ◽  
Coefficients Of Variation ◽  
Capillary Column Gas Chromatography ◽  
Ppm Level

Abstract An interlaboratory study of the determination of captan, folpet, and captafol in tomatoes, cucumbers, and apples was conducted by 4 laboratories using wide-bore capillary column gas chromatography with electron capture detection. The 3 fungicides were determined using the Luke et al. multlresidue method modified to Include additional solvent elutlon in the optional Florisll column cleanup step used with this method. The crops were fortified with each fungicide at 3 levels per crop. Mean recoveries ranged from 86.2% for a 25.1 ppm level of captan in apples to 115.4% for a 0.288 ppm level of captafol In apples. Interlaboratory coefficients of variation ranged from 3.4% (24.7 ppm folpet) to 9.7% (0.243 ppm captafol) for tomatoes; from 2.8% (2.0 ppm captafol) to 8.2% (24.8 ppm captan) for cucumbers; and from 1.5% (0.234 ppm folpet) to 22.1% (0.266 ppm captafol) for apples.

scholarly journals Pesticide Residue Analysis of Vegetables by Gas Chromatography with Electron-Capture Detection

2007 ◽  
Vol 90 (1) ◽  
pp. 263-270 ◽  
Author(s):  
José Fenoll ◽  
Pilar Hellín ◽  
Carmen M Martínez ◽  
Pilar Flores
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Electron Capture ◽  
Residue Analysis ◽  
Electron Capture Detection ◽  
Pesticide Residue Analysis ◽  
Selected Ion Monitoring ◽  
Green Pepper ◽  
Relative Standard ◽  
Residue Levels

Abstract A new and original analytical method was developed for the routine analysis of 28 multiclass pesticide residues in vegetables (green pepper, red pepper, and tomato). The extraction was performed with acetone, and the pesticides were partitioned into ethyl acetatecyclohexane (1 + 1, v/v). Residue levels in vegetables were determined by gas chromatography (GC) with electron-capture detection. Residue identities were confirmed by GC coupled with mass spectrometry in the selected ion monitoring mode. The average recoveries in pepper and tomato obtained for all analytes studied were 67.3 and 123.1%, respectively, with relative standard deviation between 1.8 and 7.0%. The detection limit for the pesticides studied varied from 0.1 to 2.6 μg/kg. The proposed method was applied to the analysis of these compounds in vegetables grown in experimental greenhouses.

Determination of Desaminosulfamethazine, Sulfamethazine, and N4-Acetylsulfamethazine by Gas Chromatography with Electron Capture Detection and Confirmation by Gas Chromatography-Chemical Ionization Mass Spectrometry

1987 ◽  
Vol 70 (3) ◽  
pp. 546-553
Author(s):  
Jean E Matusik ◽  
Greg C Guyer ◽  
Jaroslav N Geleta ◽  
Charlie J Barnes
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Electron Capture ◽  
Chemical Ionization ◽  
Ionization Mass Spectrometry ◽  
Chemical Ionization Mass Spectrometry ◽  
Electron Capture Detection ◽  
Ionization Mass ◽  
Veal Calf

Abstract An electron capture gas chromatographic method for the determination of sulfamethazine was modified to separate and quantitate simultaneously sulfamethazine and 2 of its metabolites, N4-acetylsulfamethazine and desaminosulfamethazine. The modified method was applied to incurred residues in a veal calf depletion study and to incurred residues in swine tissues. With capillary column gas chromatography-positive ion chemical ionization mass spectrometry, confirmation of the identities of incurred desaminosulfamethazine, N4-acetylsulfamethazine, and sulfamethazine in tissues was obtained from a single injection.

scholarly journals Multiresidue Determination of Pesticides in Honey by Matrix Solid-Phase Dispersion and Gas Chromatography with Electron-Capture Detection

2001 ◽  
Vol 84 (4) ◽  
pp. 1165-1171 ◽  
Author(s):  
Beatriz Albero ◽  
Consuelo Sánchez-Brunete ◽  
José L Tadeo
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Solid Phase ◽  
Organophosphorus Compounds ◽  
Organophosphorus Pesticides ◽  
Electron Capture Detection ◽  
Matrix Solid Phase Dispersion ◽  
Phase Dispersion ◽  
Relative Standard

Abstract A multiresidue method was developed for the determination of 15 pesticides (organochlorines, organophosphorus compounds, pyrethroids, and other acaricides) in various commercial honeys (eucalyptus, lavender, orange, rosemary, and multifloral). The analytical procedure is based on the matrix solid-phase dispersion of honey in a mixture of Florisil and anhydrous sodium sulfate; the mixture is placed in small plastic columns and extracted with hexane–ethyl acetate (90 + 10, v/v). The pesticide residues are determined by capillary gas chromatography with electron-capture detection. Recoveries with the method at concentrations between 0.15 and 1.5 μg/g ranged from 80 to 113%, and relative standard deviations were &lt;10% for all the pesticides studied. The pesticide detection limits were within the range 0.5–5 mg/kg for organochlorines, around 3 μg/kg for the chlorinated organophosphorus pesticides studied, near 15 μg/kg for fluvalinate, and about 3 μg/kg for the other pyrethroids.

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