Determination of chlorinated pesticides in soil by solid phase extraction-gas chromatography

A multi-residue technique is presented for the extraction and quantitative determination of some widely used organochlorine pesticides such as lindane, heptachlor, aldrin, dieldrin, endrin and p,p'-DDT in soil. The chlorinated pesticides were extracted from soil with different solvents, followed by clean-up of the sample extract using C₁₈ solid phase extraction cartridge; the analytes were eluted with hexane and determined by gas chromatography with electron-capture detection. Average recoveries exceeding 89% were obtained for the pesticides. The solid phase extraction method was applied to extract the lindane from contaminated soil and soil-leachates. Column leaching tests were performed; we found some movement of the lindane between operationally defined soil phases or layers.