Skip common site navigation and headers
United States Environmental Protection Agency
Exposure Research
Begin Hierarchical Links EPA Home > Research & Development > Exposure Research > Publications/Presentations > End Hierarchical Links

 

Pesticide Analytical Methods to Support Duplicate-Diet Human Exposure Measurements

spacer
spacer
Abstract: Historically, analytical methods for determination of pesticides in foods have been developed in support of regulatory programs and are specific to food items or food groups. Most of the available methods have been developed, tested and validated for relatively few analytes and food items. Method performance for composited duplicate diet samples, as collected in USEPA residential-based exposure monitoring programs, is largely unknown.
Several considerations impact development of methods to support duplicate diet human exposure measurements. The methods must generate useful dietary exposure data. Consequently, they must be sufficiently sensitive to detect pesticides in composite diet samples collected from the general population and they must be both accurate and precise. Detection limits should be comparable to those for other media collected in a total exposure monitoring program. Additionally, the methods should be as simple and cost effective as possible to minimize the costs associated with analysis of large numbers of samples.
A multi-class, multi-residue method utilizing a temperature-programmable pre-separation column in the gas chromatographic injection port for determination of a wide range of semi-volatile pesticides has been developed. Detection is performed by gas chromatography/mass spectrometry in the selected ion monitoring mode. Method detection limits are at or below 2 ng/g for most pesticides studied, with recovery between 70 and 125%. Sample preparation time and solvent consumption are reduced using this technique. Various extraction techniques have also been evaluated in conjunction with this method.
An organophosphate pesticide method has been developed which utilizes pressurized fluid extraction (PFE), diatomaceous earth and C18 clean-up and detection by gas chromatography with flame photometric detection. Detection limits for most analytes are in the low part per billion range with recoveries typically between 70 and 130%. Pulsed flame photometric and atomic emission detection have been evaluated in conjunction with this method. Additionally, PFE with in-line clean-up has been studied.
An overview of recent method development efforts, as summarized above, will be presented. Current research which focuses on determination of synthetic pyrethroids at sub-ppb levels by gas chromatography tandem mass spectrometry will also be discussed.
spacer
Citation:Morgan, J. N., P. Kauffman, T. E. Hieber, and J. Brisbin. Pesticide Analytical Methods to Support Duplicate-Diet Human Exposure Measurements. Presented at 5th European Pesticide Residue Workshop, Stockholm, Sweden, June 13-16, 2004.
spacer
spacer
Contact: Mary P. O'Bryant - (919)-541-4871 or obriant.mary@epa.gov
spacer
Division: Microbiological & Chemical Exposure Assessment Division
spacer
Branch: Chemical Exposure Research Branch
spacer
Product Type: Abstrct/Oral
spacer
Presented: 06/13/2004
spacer
Related Entries:
spacer
Bullet Item Analytical Methods Development for Dietary Samples
spacer Relationship Reason:   A Project of the Product
spacer
spacer
spacer

 

ORD Home | Search EPA | Search NERL | Search EIMS | Contacts | Help

 
Begin Site Footer

EPA Home | Privacy and Security Notice | Contact Us

Last Updated on Monday, October 22, 2007
URL: http://cfpub.epa.gov