中文摘要：

利用气相色谱质谱联用法（GC-MS）分析我国变压器油样品中84种PCB的异构体并计算其毒性当量值（TEQ）．结果表明，国产变压器油所含PCBs主要是以三氯联苯为主．其含量高达63％．其次是四氯和二氯代联苯，分别占24％和9％，其含氯量约为42．9％，与美国产Aroclor 1242（氯含量约为40％～42％）的含氯量极为相似．国产PCBs中，共平面PCBs含量仅占测定总量的1．6％，其中以CB-77的含量最高，对TEQ的贡献最大，占6种PCBs的72％，其次是CB-105和毒性最强的CB-126，分别占15％和8％；国产PCBs的TEQ值仅相当于美国产Aroclor 1242的15％．

英文摘要：

Eighty-four PCB congeners in transformer oil produced in China were analyzed by gas chromatography mass spectrum （GC-MS） and the international toxicity equivalents （TEQ） indioxin-like PCBs found in Chinese transformer oil were also estimated. The major CB homologue in the total PCBs was CI3-CB （63%） followed by CI4-CB and C12-CB, accounted for 24% and 9% of ∑PCB, respectively. Low chlorinated biphenyls were the major components of the PCBs in transformer oil produced in China. PCBs in Chinese transformer oil contained 42.9% chlorine, similar to the Aroclor 1242 （contains 40%～42% chlorine）. The concentrations of the 6 dioxin-like PCBs found in Chinese transformer oil were low, accounted for 1.6% of ∑PCB. The TEQ of the 6 dioxin-like PC-Bs was approximately 5.53μg/mL which was 15% of those found in Aroclor 1242. Among the 6 dioxin-like PCBs, CB-77 had the highest TEQ value, which was 72% of total TEQ, and followed by CB-105 （15%） and the most toxic congener CB-126 （8%）.