Gas Chromatographic-Electron Capture Detection Method for Determination of 29 Organochlorine Pesticides in Finished Drinking Water: Collaborative Study

1990 ◽  
Vol 73 (2) ◽  
pp. 276-286
Author(s):  
Viorica Lopez-Avila ◽  
Raymond Wesselman ◽  
Kenneth Edgell
Keyword(s):  
Gas Chromatography ◽  
Drinking Water ◽  
Method Validation ◽  
Electron Capture ◽  
Validation Study ◽  
Matrix Effects ◽  
Collaborative Study ◽  
Electron Capture Detection ◽  
Chlorinated Pesticides

Abstract A joint U.S. Environmental Protection Agency/AOAC interlaboratory method validation study was conducted on EPA Method 508, Determination of Chlorinated Pesticides in Water by Gas Chromatography with an Electron Capture Detector, to determine the mean recovery and precision for analyses of 29 pesticides in reagent water and finished drinking water. The study design was based on Youden's nonreplicate plan for collaborative tests of analytical methods. The waters were spiked with 29 pesticides at 6 concentration levels, as 3 Youden pairs. Eleven volunteer laboratories extracted the spiked test waters with methylene chloride, performed a solvent exchange with methyl ferf-butyl ether, and analyzed an aliquot of each extract by gas chromatography with electron capture detection. Results were analyzed using an EPA computer program, Interlaboratory Method Validation Study (IMVS), which measured recovery and precision for each of the 29 pesticides and compared the performance of the method between water types. Method 508 was judged acceptable for all analytes tested. Only 3 analytes (α-chlordane, 4,4′-DDE, and methoxychlor) exhibited practical significant matrix effects. The method has been adopted official first action.

scholarly journals Gas Chromatographic/Electron Capture Detection Method for Determination of Chlorinated Acids in Water: Collaborative Study

1993 ◽  
Vol 76 (5) ◽  
pp. 1098-1112 ◽  
Author(s):  
Kenneth W Edgell ◽  
Elizabeth J Erb ◽  
Raymond J Wesselman ◽  
James E Longbottom ◽  
◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Drinking Water ◽  
Electron Capture ◽  
Environmental Protection Agency ◽  
Collaborative Study ◽  
Methyl Tert Butyl Ether ◽  
Electron Capture Detection ◽  
Butyl Ether ◽  
Relative Standard

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 <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.

Capillary Column Gas Chromatography with Nitrogen-Phosphorus Detection for Determination of Nitrogen- and Phosphorus-Containing Pesticides in Finished Drinking Waters: Collaborative Study

1991 ◽  
Vol 74 (2) ◽  
pp. 295-309
Author(s):  
Kenneth W Edgell ◽  
Elizabeth L Jenkins ◽  
Viorica Lopez-Avila ◽  
James E Longbottom
Keyword(s):  
Gas Chromatography ◽  
Drinking Water ◽  
Matrix Effects ◽  
Collaborative Study ◽  
Nitrogen And Phosphorus ◽  
Drinking Waters ◽  
Phosphorus Containing ◽  
Nitrogen Phosphorus Detector ◽  
Nitrogen Phosphorus

Abstract A joint U.S. Environmental Protection Agency/AOAC interlaboratory method validation study was conducted on EPA Method 507, Determination of Nitrogen- and Phosphorus- Containing Pesticides In Finished Drinking Water by Gas Chromatography with a Nitrogen-Phosphorus Detector, to determine the mean recovery and precision for analyses of 45 nitrogen- or phosphorus-containing pesticides in reagent water and finished drinking waters. The study design was based on Youden's nonreplicate plan for collaborative tests of analytical methods. The waters were spiked with 45 nitrogen- or phosphorus-containing pesticides at 6 concentration levels, prepared as 3 Youden pairs. Ten volunteer laboratories extracted the spiked test waters with methylene chloride, performed a solvent exchange with methyl ferf-butyl ether, and analyzed an aliquot of each extract by gas chromatography using a nitrogen-phosphorus detector. Results were analyzed using an EPA computer program, which measured recovery and precision for each of the 45 pesticides and compared the performance of the method between water types. Method 507 was judged acceptable for all analytes tested except merphos, which thermally decomposed in the Injection port of the gas chromatograph. Five compounds (carboxin, disulfoton, metolachlor, pronamlde, and slmazlne) exhibited statistically significant matrix effects for the finished drinking water. The method has been adopted official first action by AOAC.

Gas Chromatographic Determination of Deoxynivalenol in Wheat with Electron Capture Detection: Collaborative Study

1986 ◽  
Vol 69 (5) ◽  
pp. 899-901 ◽  
Author(s):  
George M Ware ◽  
Octave J Francis ◽  
Allen S Carman ◽  
Shia S Kuan ◽  
◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Collaborative Study ◽  
Control Sample ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Average Recovery ◽  
Repeatability And Reproducibility ◽  
The Mean

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.

scholarly journals Determination of Hydrazine in Maleic Hydrazide Technical and Pesticide Formulations by Gas Chromatography: Collaborative Study

2008 ◽  
Vol 91 (1) ◽  
pp. 5-12 ◽  
Author(s):  
Anthony S Riggs ◽  
David M Borth ◽  
David G Tutty ◽  
Wan S Yu ◽  
B Barclay ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Gas Chromatography ◽  
Electron Capture ◽  
Maleic Hydrazide ◽  
Collaborative Study ◽  
Test Sample ◽  
Electron Capture Detection ◽  
Pesticide Formulations ◽  
Liquid Concentrate

Abstract Twelve collaborating laboratories assayed hydrazine in technical maleic hydrazide (MH), 6-hydroxy-2H-pyridazin-3-one, and 2 formulated products, a liquid concentrate and a soluble granule, using gas chromatography (GC) with electron capture detection. The hydrazine content in the samples ranged from 0.03 ppm, in the liquid concentrate, to 0.26 ppm, in MH technical. Hydrazine and MH are dissolved in an aqueous solution. The MH is then precipitated out of solution by acidification. The solution containing hydrazine is treated with excess pentafluorobenzaldehyde (PFB) to form pentafluorobenzaldehyde azine (PFBA). The PFBA is extracted with hexane for analysis by GC using an electron capture detector. Peak area responses of PFBA are measured and quantified by external standardization. Hydrazine concentration is calculated from the PFBA determination. The laboratories weighed each test sample in duplicate with duplicate analysis for each weighing. Data from these laboratories were statistically analyzed. The average relative repeatability was determined to be 5.34 and the average relative reproducibility was 27.99.

Simple, Low-Cost Method for Determination of Selected Chlorinated Pesticides in Fat Samples

1982 ◽  
Vol 65 (3) ◽  
pp. 677-679 ◽  
Author(s):  
Stefan M Waliszewski ◽  
Grzegorz A Szymczyński
Keyword(s):  
Gas Chromatography ◽  
Petroleum Ether ◽  
Electron Capture ◽  
Silica Gel ◽  
Pesticide Residues ◽  
Low Cost ◽  
Electron Capture Detection ◽  
Chlorinated Pesticides ◽  
Qualitative Determination

Abstract A method is described for the quantitative and qualitative determination of selected chlorinated pesticides in fat samples. Pesticide residues are extracted with petroleum ether and separated from fat with concentrated H2SO4 instead of the commonly used adsorbents Florisil, alumina, or silica gel. Residues were analyzed by gas chromatography with electron capture detection. Recoveries of fortified samples were approximately 100%.

Extraction and Gas Chromatographic Screening of 14 Chlorinated Pesticides in Crayfish (Procambarus clarkii) Hepatopancreas

1993 ◽  
Vol 76 (3) ◽  
pp. 663-668 ◽  
Author(s):  
Heidi M Lott ◽  
Steven A Barker
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Procambarus Clarkii ◽  
Linear Regression Analysis ◽  
Internal Standard ◽  
Electron Capture Detection ◽  
Extraction Column ◽  
Chlorinated Pesticides ◽  
Isolation Technique

Abstract A multiresidue isolation technique using matrix solid-phase dispersion (MSPD) and gas chromatography/ electron capture detection is applied to crayfish (Procambarus clarkii) hepatopancreas for the extraction and determination of 14 chlorinated pesticides (α-BHC, β-BHC, lindane, heptachlor, aldrin, heptachlorepoxide, p,p'-DDE, dieldrin, endrin, 4,4'- DDD, endrin aldehyde, p,p'-DDT, endosulfan sulfate, and methoxychlor). Pureed crayfish hepatopancreata (0.5 g aliquot) are fortified with the 14 pesticides and with δ-BHC as an internal standard before blending with 2 g C18 (octadecylsilyl)- derivatized silica. The C18-hepatopancreas matrix blend and 2 g activated Florisil comprise an extraction column from which the pesticides are eluted by adding 8 mL acetonitrile. Two microliters of the eluate is directly analyzed by gas chromatography with electron capture detection. Unfortified blank controls are treated similarly. The eluate contained all the pesticide analytes and was free of interfering coextractants at most fortification levels. Correlation coefficients for the 14 extracted pesticide standard curves (linear regression analysis) ranged from 0.9685 to 0.9985. Average relative percent recoveries (recoveries for all pesticides ranged from 55 ± 10.4% to 118 ± 45.2%, n = 15 for each pesticide) over the range of concentrations examined, interassay variability (7.1 ± 5.7% to 16.0 ± 5.6%, n = 15 for each pesticide), and intra-assay variability (0.0-26.2%, n = 5 for each pesticide) indicated that the MSPD methodology allowed for the successful extraction and determination of the 14 chlorinated pesticides at 125-2000 ng/g levels in crayfish hepatopancreas.

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