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

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.

1986 ◽  
Vol 69 (6) ◽  
pp. 976-980
Author(s):  
Richard A Niemann

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 &lt;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 &lt;5% relative standard deviation at 37-46 pptr.


2007 ◽  
Vol 90 (1) ◽  
pp. 263-270 ◽  
Author(s):  
José Fenoll ◽  
Pilar Hellín ◽  
Carmen M Martínez ◽  
Pilar Flores

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.


1989 ◽  
Vol 72 (2) ◽  
pp. 394-398
Author(s):  
Norbert V Fehringer ◽  
Stephen M Walters ◽  
Richard A Niemann

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.


2001 ◽  
Vol 84 (4) ◽  
pp. 1165-1171 ◽  
Author(s):  
Beatriz Albero ◽  
Consuelo Sánchez-Brunete ◽  
José L Tadeo

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.


1986 ◽  
Vol 69 (5) ◽  
pp. 899-901 ◽  
Author(s):  
George M Ware ◽  
Octave J Francis ◽  
Allen S Carman ◽  
Shia S Kuan ◽  
◽  
...  

Abstract Ten laboratories participated in a collaborative study of a method for the determination of deoxynivalenol in wheat by gas chromatography with electron capture detection. Each laboratory analyzed 6 samples in duplicate. Each collaborator received samples spiked at the 100.3, 501.3, and 1002.6 ng/g levels; a control sample; and 2 naturally contaminated samples. The average recovery (outliers excluded) for the spiked samples was 92.2%. The mean repeatability and reproducibility, respectively, were 32.2 and 41.3% for the spiked samples and 30.9 and 47.6% for the naturally contaminated samples. The method was adopted official first action.


2007 ◽  
Vol 90 (6) ◽  
pp. 1670-1676 ◽  
Author(s):  
Jose Fenoll ◽  
Pilar Hellin ◽  
Josefa Lopez ◽  
Alberto Gonzalez ◽  
Pilar Flores

Abstract A sensitive, rapid, and simple multiresidue method for the simultaneous determination of 19 pesticides in different varieties of lettuce (Lactuca sativum) was developed. Lettuce samples were extracted by homogenization with acetone and partitioned into ethyl acetatecyclohexane. Subsequent sample cleanup was not needed. Final determination was made by capillary gas chromatography (GC) with electron-capture detection (ECD). Confirmation analysis of pesticides was performed by GC coupled with mass spectrometry in the selected ion monitoring mode. The average recovery by the GCECD method obtained for these compounds varied from 66.4 to 119.2 with relative standard deviations &lt;7.7. The GCECD method has good linearity, and the detection limit for the pesticides studied varied from 0.1 to 3.8 g/kg. The proposed method was used to determine pesticide levels in different types of lettuce grown in soils from experimental fields.


2007 ◽  
Vol 90 (2) ◽  
pp. 544-549 ◽  
Author(s):  
Nuria Vela ◽  
Gabriel Prez ◽  
Gins Navarro ◽  
Simn Navarro

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.


2020 ◽  
Vol 103 (5) ◽  
pp. 1243-1249
Author(s):  
Mehdi Nabi ◽  
Sayed Mehdi Ghoreishi ◽  
Mohsen Behpour

Abstract Background A simple, rapid, selective and sensitive sample preparation and derivatization method was performed for determination of bromate ions in water by means of dispersive liquid-liquid extraction (DLLE) by gas chromatography-electron capture detection (GC-ECD). This method is based on 2-methyl-2-butene derivatization by bromine produced from bromate ions in acidic medium and extraction by n-hexane. Objective Derivatizing agent: It is cheap and available and it has high efficiency in reaction with Br2. Simplicity: Preparation and extraction process don't need to any specific equipment and procedure is completely simple and fast. Limit of detection: DL is as low as 0.43 µg/L. Methods Various effective factors on the derivatization and extraction efficiency, such as amount of derivatizing agent, volume of extraction solvent, bromide concentration, volume and concentration of sulfuric acid, type and volume of extracting and dispersing solvent, ionic strength, storage time before extraction and ECD makeup-gas flow rate were investigated. Results Under the optimum conditions, the method had a linear calibration curve ranging from 1.0 to 200.0 µg/L for bromate ions with a determination coefficient (R2) of 0.994 and the detection limit was 0.43 µg/L. The recovery percent and relative standard deviation for the determination of 1.0, 5.0 and 50.0 µg/L bromate ion was between 90 and 110%, and 3.0 and 8.0% (n = 3), respectively. Conclusions Finally, the method was successfully applied for the preconcentration and determination of bromate ions in water samples, and satisfactory results were obtained. Highlights (1) Fast, easy, accurate and economical innovative analysis of bromate ions in water and wastewater. (2) Determination of inorganic ion by GC-ECD after derivatization (3) Low detection limit (4) Optimization of different method parameters to obtain accurate results based on requirements of international standards, specifically ISO/IEC 17025.


1993 ◽  
Vol 76 (5) ◽  
pp. 1098-1112 ◽  
Author(s):  
Kenneth W Edgell ◽  
Elizabeth J Erb ◽  
Raymond J Wesselman ◽  
James E Longbottom ◽  
◽  
...  

Abstract A U.S. Environmental Protection Agency (USEPA) inter laboratory method validation study was conducted on USEPA Method 515.1, "Determination of Chlorinated Acids in Water by Gas Chromatography with an Electron Capture Detector. "This method is one of the 6 pesticide methods developed for the USEPA National Pesticide Survey (NPS). Method recovery and precision for analyses of sub-ppb to low-ppb concentrations of chlorinated acids were determined in reagent water and finished drinking waters. The analytes evaluated in the study included the 12 pesticides that were quantitatively measured in the National Pesticide Survey (bentazon, 2,4-D, 2,4-DB, 3,5-dichlorobenzoic acid, DCPA-diacid, dicamba, dichlorprop, 5-hydroxydicamba, pentachlorophenol, picloram, 2,4,5- T, and 2,4,5-TP) and 5 pesticides (acif luorfen, chloramben, dalapon, dinoseb, and 4-n it ro phenol) that were only qualitatively assessed in the National Pesticide Survey because of recognized method imprecision. The study design was based on Youden's nonreplicate plan for collaborative tests of analytical methods. The waters were spiked with 17 chlorinated acids, each at 6 concentration levels, prepared as 3 Youden pairs. Eight laboratories extracted the spiked test waters at pH &lt;2 with ethyl ether, performed a solvent exchange with methyl tert-butyl ether, prepared methyl esters of the extracted acids using diazomethane, and analyzed an aliquot of each derivatized extract by gas chromatography with electron capture detection. The submitted data were analyzed using a USEPA computer program, which measured recovery and precision for each of the 17 compounds and compared the performance of the method between water types. Method 515.1 was judged acceptable for the 12 NPS analytes recovered quantitatively; mean percent recoveries at 10-15 times the method detection limits ranged from 79 to 105% in reagent water and from 75 to 123% in finished drinking water. In reagent water, overall precision (reproducibility relative standard deviation, RSDR) ranged from 9.6 to 34.2% and in finished drinking water, the RSDR ranged from 11.9 to 37.0%. Single-analyst precision (RSD for repeatability, RSDr) ranged from 5.8 to 17.7% in reagent water and from 4.6 to 27.9% in drinking water. Results for the 5 other NPS analytes were too inaccurate or imprecise and, for these compounds, supported use of the method for qualitative measurements only; the 5 compounds are not included in the adopted method. The method has been adopted first action by AOAC INTERNATIONAL for determination of residues of 12 chlorinated acids in finished drinking water.


2001 ◽  
Vol 84 (6) ◽  
pp. 1751-1762 ◽  
Author(s):  
Antonia Garrido Frenich ◽  
Maria Del Carmen Pablos Espada ◽  
Jose Luis Martínez Vidal ◽  
Luis Molina

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 &lt;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.


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