Solid-Phase Extraction for Cleanup of Pesticide Residues Suspected as Endocrine Disruptors in Foods

Abstract

Solid-phase extraction cartridges, Silica, Florisil, ethylenediamine-N-propylsilane-bonded silica (PSA), trimethylaminopropylsilane-bonded silica (SAX) and graphitized nonporous carbon (ENVI-Carb) were investigated for cleanup of pesticides residues suspected as endocrine disruptors in food extracts. Elution patterns and recoveries were examined for 38 pesticides with 2 types of eluting solvents : acetone/n-hexane and diethyl ether/n-hexane. A 2% acetone-n-hexane eluant used with the Silica cartridge gave the best recovery for 33 pesticides and minimized interference from coextractants. The remaining 5 pesticides were eluted successively with 20% acetone-n-hexane from tandem connected Silica and PSA cartridges. Thirty-eight pesticides were analyzed in 30 duplicate meals with the limits of detection ranging from 0.01 to 0.5ppb. trans-Chlordane, trans-nonachlor and p, p'-dichlorodiphenyldichloroethylene (p, p'-DDE) were found frequently (Tr.-1.1ppb). Dietary daily intakes were 0.27μg/d for total chlordane, 0.85μg/d for total dichlorodiphenyltrichloroethane (DDT), which were significantly below the acceptable daily intake (ADI) values.