Comparison of Extraction Techniques with Different Solvents for DDT Analogues in Sediments

Four techniques, Soxhlet extraction (SOX), ultrasonic extraction (USE), fluidized-bed extraction (FBE) and accelerated solvent extraction (ASE) with different solvents (methanol, hexane/acetone and acetonitrile) were used for the extraction of DDT analogues in sediments. Results revealed that the four extraction techniques had high recoveries (＞86.0%) with low standard deviations (＜ 12.0%) for most of DDT analogues, meaning that they could all successfully extract DDT analogues in sediments. Accelerated solvent extraction using methanol and hexane/acetone (1:1), fluidized-bed extraction using hexane/acetone (1:1) and the ultrasonic extraction using hexane/acetone (1:1) were comparable or better than Soxhlet extraction using hexane/acetone (1:1). Considering solvent- and time-consumption, level of automation,and environmental risk, accelerated solvent extraction with hexane/acetone (1:1) was better than the other extraction techniques.