Determination of 25 Organochlorine Pesticides and Polychlorinated Biphenyls in Soils by Gas Chromatography

A method for the determination of 17 organochlorine pesticides (OCPs) and 8 polychlorinated biphenyls (PCBs) in soils by gas chromatography was developed. Accelerated solvent extraction (ASE) technique was used to extract the target compounds and solid phase extraction (SPE) technique was worked as cleanup procedure. The compounds were eluted by 20 mL of mixed solvent of hexane and ethyl acetate (V/V=8/2) in 3% toluene with satisfactory purification result. The detection limits for the target compounds were 0.06~0.27 μg/kg with linear range of 1.38~55.2 ng/mL. The average recoveries for two different concentration levels ranged from 65% to 97% with precision of less than 17.11% RSD for all the compounds. The method provides the advantages of high sensitivity, good accuracy, high efficiency and has been applied to the routine analysis.