Pressurized liquid extraction for the simultaneous analysis of polychlorinated biphenyls and polybrominated diphenyl...

Pressurized liquid extraction (PLE) system was optimized to simultaneously determine polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in soil samples by gas chromatography with time-of-flight mass spectrometry. PLE parameters (temperature, pressure, static time, and flush volume) and packing materials (activated copper and sorbents such as: Florisil, silica gel, and a combination of Florisil and silica gel) were studied to achieve a one-step extraction and cleanup that could be analytically rapid and reliable. Method detection limit was found to be in the range of 0.1-0.4 mg/kg for PCBs and 0.1-0.6 mg/kg for PBDEs with a relative standard deviation of 1.7-7.3% for PCBs and 2.6-6.3% for PBDEs. A standard reference material for PCBs, NIST-SRM 1939a, spiked with PBDEs standard, was analyzed to substantiate the validity of the optimized method. Experimental values agreed well with the certified values with recoveries of 71.6-117%, and the optimized PLE system has been proven to be useful for the simultaneous determination of PCBs and PBDEs with various congeners in soil samples.