Quantitative method for the determination of organochlorine pesticides in serum

A method for the determination of six organochlorine pesticides in human serum is proposed. Serum samples containing in vitro spiked pesticides (alpha-HCH, beta-HCH, gamma-HCH, p,p'-DDE, o,p'-DDT, and p,p'-DDT) were used to evaluate the method. The method involved pesticide extraction from a serum-silica suspension with n-hexane-acetone (9:1), extract purification using alumina-column chromatography, and analysis of the final extract using gas-liquid chromatography with electron-capture detection. Mean recoveries for the pesticides spiked from 1 to 7.5 ng/mL ranged from 82 to 97%; for those spiked from 4 to 30 ng/mL, recoveries ranged from 85 to 99%; and for those spiked from 20 to 150 ng/mL, recoveries ranged from 80 to 87%. The method is simple and rapid, requires a minimum of reagents and solvents, and provides high recovery values.