Extraction of Organochlorine Pesticides in SedimentsUsing Soxhlet, Ultrasonic and Accelerated Solvent Extraction Techniques

The application of soxhlet, ultrasonic and accelerated solvent extraction techniques to the analysis of six organochlorine pesticides (α-HCH, β-HCH, γ-HCH, o, p'-DDT, p, p'-DDT and p, p'-DDE) in Taihu Lake sediment samples is described. It was found that the limits of quantification ranged from 0.002 μg g-1 to 0.004 μg g-1, and the recoveries of organochlorine pesticides with the three extraction techniques were acceptable (＞ 80.7%). With a mass selective detector,better results were obtained by accelerated solvent extraction using hexane-acetone (1: 1) as compared with soxhlet and ultrasonic extraction. It was shown that the accelerated solvent extraction was the optimum technique for the analysis of organochlorine pesticides in sediments. The general features of the three extraction techniques are also presented.