关键词: 类二癋英类多氯联苯, 前处理, 双柱气相色谱, 电子捕获检测器

Abstract: A new and simple method was developed for the determination of 12 dioxin-like polychlorinated biphenyls (dl-PCBs) in samples using complementary separation on a dual column system with low and intermediate polarities. PCBs were extracted from the sample by soxhlet extraction, concentrated and purified by a two-step clean-up with 98％ sulfuric acid／permanganate and Florisil column, qualitative and quantitative analyses of dl-PCBs at Pg／g level were performed by the two retention data on dual capillary gas chromatography with a 63Ni electron capture detection (GC-ECD), and the co-elution between 12 dl-PCBs and the bulk PCBs and pesticides was solved. The accuracy of qualitative analysis was confirmed by the gas chromatography mass spectrometry (GC／MS) using selective ion mode (SIM) technique. This method was validated: accuracy was estimated from the recovery of spiked analytes from the matrix; precision was estimated from the relative standard deviation (RSD) of the duplicate analyses of unspiked sample. The recoveries of target analysts were found to be in the range of 82-109.8％, dropped in the range of certified value by US.EPA 70-140％, the RSDs of 12 dioxin-like PCBs were in ranged of 1.62-14.86％, and were all less than 20％. The application of this analysis method to the determination of dioxin-like PCB in dust-deposition, sediment and soil samples from the Yellow River delta is successful.

Key words: dioxin-like PCBs, pretreatment, dual capillary column system, electron capture detector