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Comparison of Five Extraction Methods for Determining Incurred and Fortified Pesticides in Dietary Composites
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| Abstract: | U.S. EPA's National Exposure Research Laboratory conducts research to measure exposure of individuals to chemical pollutants through the diet. In support of this research, methods are being evaluated for determination of pesticides in dietary composite samples. In the present study, Soxhlet, blender, microwave-assisted, pressurized fluid, and supercritical fluid extraction methods were compared for the determination of incurred and fortified pesticides in four dietary composites, which varied in fat and water content. Incurred pesticides were chlorothalonil, chlorpyrifos, DDE, dicloran, dieldrrin, endosulfan, endosulfan I, malathion, cis and trans permethrin, and trifluralin. Fortified pesticides were x- and y-chlordane, hexachlorobenzene, and fonofos. Concentrations of the individual pesticides were between 0.2 and 20 ng/g composite. All five methods tested were able to extract pesticides from dietarycomposites. Most incurred pesticides were recovered from the dietary composites within the range of 59-140% of expected values. Recovery of fortified pesticides was between 60 and 130%. Microwave extraction led to significantly higher concentrations of seven pesticides. Blender extraction yielded significantly higher concentrations of chlorothalonil and fonofos. Water content was a signficant factor in recovery of chlorothalonil, and fat content was a significant factor in recovery of fonofos. In designing an exposure study, the method selected would be determined by number of samples to be extracted, analyte stability, and cost. |
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| Citation: | Morgan, J. N., L. Rosenblum, and S. Garris. Comparison of Five Extraction Methods for Determining Incurred and Fortified Pesticides in Dietary Composites. JOURNAL OF AOAC INTERNATIONAL 85(5):1167-1176, (2002). |
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| Contact: |
Mary P. O'Bryant - (919)-541-4871 or obriant.mary@epa.gov
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| Division: |
Microbiological & Chemical Exposure Assessment Division |
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| Branch: |
Chemical Exposure Research Branch |
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| Product Type: |
Journal |
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| Published: |
09/01/2002 |
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