A simple method for the quantitative microextraction of polychlorinated biphenyls from soils and sediments

We demonstrate the quantitative extraction of polychlorinated biphenyls (PC Bs) from environmental solids by using a microscale adaptation of pressuriz ed fluid extraction (mu PFE), The stainless steel extraction cells are fill ed with a solid sample and solvent and are healed at elevated temperature. After cooling the cell to room temperature, we determined PCBs in the extra ct by direct injection to a gas chromatograph with an electron capture dete ction system. This extraction method was tested on a set of PCB-spiked soli d matrices and on a PCB-contaminated river sediment (NIST SRM 1939). Recove ries were measured for eight PCB congeners spiked into two soil types with hexane extraction at 100 degrees C (>81.9 +/- 5.4% to 112.5 +/- 10.1%). The extraction process for SRM 1939 with hexane at 300 degrees C provided sign ificantly higher recoveries for several representative PCB congeners than r eported for a duplicate 16-hour Soxhlet extraction with a mixture of organi c solvents (acetone/hexane). (C) 1999 Elsevier Science Ltd. All rights rese rved.