Comparison of accelerated solvent extraction and soxhlet extraction for the determination of PCBs in Baltic Sea sediments

The effectiveness of the extraction conditions proposed in ASE U.S. EPA Method 3545 was evaluated for the extraction of polychlorinated biphenyls (PCBs) in Baltic Sea sediments with different sample characteristics such as organic carbon, soot carbon, sulfur, water content, and PCB concentration range. PCB concentrations determined with accelerated solvent extraction (ASE) using n-hexane/ acetone (1:1, v/v) as organic solvents were compared to Soxhlet extraction using toluene as organic solvent. The results indicated that sediments containing relatively low amounts of organic and soot carbon can be quantitatively extracted by ASE in 5 min with n-hexane/acetone (proposed in EPA Method 3545). However, for sediments with larger amounts of carbon, the total amount of PCBs present in th a sam pie might be underestimated when using n-hexane/ acetone. For these latter sediments, toluene seems to increase the extraction efficiency in ASE.