Determination of 2,3,7,8-Substitituted Polychlorinated Dibenzo-p-dioxins-Dibenzofurans and Dioxin-like Polychlorinated Biphenyls in Environmental Samples by Gas Chromatography/High Resolution Mass Spectrometry

A method was evaluated for the determination of 17 kinds of 2,3,7,8-substitituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (DL-PCBs) in environmental samples with isotope dilution-gas chromatography/high resolution mass spectrometry (GC/HRMS). Sample extracts were cleaned up successively with acidified silica gel batch, multilayer silica gel column and gel permeation column chromatography. Florisil column was used to separate PCBs from PCDD/Fs. Precision and recoveries of the entire procedure were evaluated by replicate analysis (n = 4) of PCDD/Fs and PCBs standard solutions, with relative standard deviation (RSD) below 8.9% and 11% for PCDD/Fs and PCBs, respectively, and with the recoveries in the range of 60%–105%. The detection limits of PCDD/Fs and dioxin-like PCBs were 0.1–0.8 pg g−1 and 0.05–0.6 pg g−1, respectively. PCDD/Fs and DL-PCBs were successfully analyzed in environmental samples such as sediment, slurry, soil and fly ash, and then their toxic equivalent was calculated.