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

We demonstrate the quantitative extraction of polychlorinated biphenyls (PCBs) from environmental solids by using a microscale adaptation of pressurized fluid extraction (μPFE). The stainless steel extraction cells are filled with a solid sample and solvent and are heated at elevated temperature. After cooling the cell to room temperature, we determined PCBs in the extract by direct injection to a gas chromatograph with an electron capture detection system. This extraction method was tested on a set of PCB-spiked solid matrices and on a PCB-contaminated river sediment (KIST SRM 1939). Recoveries were measured for eight PCB congeners spiked into two soil types with hexane extraction at 100°C (>81.9 ± 5.4% to 112.5 ± 10.1 %). The extraction process for SRM 1939 with hexane at 300°C provided significantly higher recoveries for several representative PCB congeners than reported for a duplicate 16-hour Soy-Wet extraction with a mixture of organic solvents (acetone/hexane).