Enhanced pressurized liquid extraction technique capable of analyzing polychlorodibenzo-p-dioxins, polychlorodibenzofurans, and polychlorobiphenyls in fish tissue.

A high-throughput enhanced pressurized liquid extraction technique was developed by incorporating pressurized liquid extraction and multiple cleanup techniques. USEPA methods of polychlorodibenzo-p-dioxins, polychlorodibenzofurans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) analysis in fish tissue include independent silica gel, florisil, alumina, and carbopack/celite column cleanup techniques following extraction. Under the improved method, fish composites (10 g) were extracted and cleaned simultaneously using alumina (10 g), florisil (10 g), silica gel (5 g), celite (5 g), and carbopack (0.5 g). Clean extracts were concentrated and then analyzed by high resolution gas chromatography coupled with electron capture negative ionization mass spectrometry. Carbopack/celite within the extraction cell provided the analytical separation of dl-PCBs from PCDD/Fs, reducing potential molecular interferences. The average recoveries (n=3) of dl-PCBs in dichloromethane:hexane (1:1, v/v) extracts were 93±2.4% and PCDD/Fs in toluene extracts were 85±3.0%. The developed method was applied to measure the PCDD/Fs and dl-PCBs in catfish from San Jacinto River Waste Pits, a Superfund site in Houston, TX. The dl-PCBs were measured at 5.0-17,000 pg g(-1) ww. Sample preparation time and solvents were reduced as much as 95% and 65%, respectively, as compared to USEPA method 1613.