A solid phase extraction method for the screening and determination of pyrethroid metabolites and organochlorine pesticides in human urine

A screening method has been developed for the determination of 23 organochl orine pesticides (OCPs) and 3-pyrethroid metabolities [cis- and trans-3-(2, 2-dichlorovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid, cis-3-(2,2- dibromovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid and 3-phenoxybe nzoic acid] from human urine. OCPs were directly detected in urine samples while pyrethroid metabolites required acid-induced hydrolysis to convert th eir conjugates into free acids; all compounds were then cleaned-up/preconce ntrated using solid phase extraction. Determination and quantitation was ac hieved by gas chromatography with a mass spectrometer detector operating in selected ion monitoring mode. Limits of detection varied between 0.1 and 0 .3 ng/mL with linear ranges from 0.3 to 700 ng/mL; the precision of the met hod was high (4.3-7.2%). Recoveries of all analytes from urine samples fort ified at levels of 30 ng/mL for each OCP and 15 ng/mL for each pyrethroid m etabolite ranged from 88 to 101% (captan gave the lowest recovery). The res ults obtained from the analysis of real urine samples show the suitability of the proposed method for monitoring people exposed to organochlorine and pyrethroid pesticides. Copyright (C) 2001 John Wiley & Sons, Ltd.