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Detection of pyrethroid pesticides and their environmental degradation products in duplicate diet samples
Citation:
MacMillan, D., Dan Zehr, AND M. Morgan. Detection of pyrethroid pesticides and their environmental degradation products in duplicate diet samples. Presented at Asilomar Conference on Mass Spectrometry, Pacific Grove, CA, October 18 - 22, 2013.
Impact/Purpose:
Pyrethroids have been found in individual foods (i.e., fruits, vegetables) and duplicate diet composites. Pyrethroids have low mammalian toxicity, but some may be carcinogenic. Pyrethroid analysis in composite samples requires multiple extractions and clean-ups; concurrent detection of the degradation products has not been reported. As the degradants also serve as urinary biomarkers, their presence in food samples could lead to over-estimates of dietary exposure. As part of an exposure reconstruction (Ex-R) study, we developed a rapid analytical method for pyrethroids and degradation products in duplicate diet samples, and demonstrated the method on 782 food composites.
Description:
The abstract is for an oral presentation at the Asilomar Conference on Mass Spectrometry: Mass Spectrometry in Environmental Chemistry, Toxicology, and Health. It describes analytical method development and sample results for determination of pyrethroid pesticides and environmental degradation products in duplicate diet samples from the Ex-R study. Introduction: Pyrethroids have been found in individual foods (i.e., fruits, vegetables) and duplicate diet composites. Pyrethroids have low mammalian toxicity, but some may be carcinogenic. Pyrethroid analysis in composite samples requires multiple extractions and cleanups; concurrent detection of the degradation products has not been reported. As the degradants also serve as urinary biomarkers, their presence in food samples could lead to over-estimates of dietary exposure. As part of an exposure reconstruction (Ex-R) study, we developed a rapid analytical method for pyrethroids and degradation products in duplicate diet samples, and demonstrated the method on 782 food composites. Methods: Fifty adult participants collected 48-hour duplicate diet samples for six days over a six-week monitoring period. Samples were collected during three consecutive time periods each sampling day. Samples were analyzed for seven pyrethroids including bifenthrin and permethrin, and six degradation products. A modified QuECHERS approach was used for extraction and clean-up followed by LC/MS/MS. Results: Method validation demonstrated detection limits from 0.010 - 2.5 ppb. At least one pyrethroid was detected in 49.7% of the food samples, with trans-permethrin observed most frequently (21.7%). However, the degradation products were detected in only 2.6% of the samples. Additional method parameters and study results will be detailed. Conclusions: We developed a fast, sensitive, and accurate analysis for several pyrethroids and degradation products in food composites. Pyrethroids were detected in nearly half of the duplicate diet samples from the Ex-R study. The low incidence of degradation products suggests detection in bio fluids is not likely to be due to direct dietary ingestion. This abstract does not necessarily reflect EPA policy.