【摘要】 利用高分辨率气质联用仪(HRGC-HRMS)测定了北京土壤中的多氯联苯(PCBs)含量.结果表明,PCBs总含量平均为3.1ng·g-1(范围为0.39~13ng·g-1),毒性当量TEQ为0.37pg·g-1(范围为0.72~1.8pg·g-1),与其它研究结果相比处于较低水平.类二英PCBs含量最大的3种为118>105>77(IUPAC编号),约90%的TEQ由异构体126产生.PCBs同族体含量以低氯取代为主,虽然与国内环境介质相似,但与国外不同.国内对低氯取代PCBs化学品的使用可能是造成这种不同的主要原因.高氯取代PCBs更容易吸附在土壤有机质中.PCBs总含量的高低顺序为路边土壤>公园土壤>农田土壤>山地土壤,城区与近郊土壤>远郊土壤,推测城市机动车尾气的排放和农用化学品的使用等是造成北京土壤PCBs含量升高不可忽视的原因.更多还原

【Abstract】 Polychlorinated Biphenyls (PCBs) in Beijing soil were analyzed by HRGC-HRMS. PCBs are detected in all soil samples. And the average levels (range) of the content are 3.1 (0.39~13) ng·g -1 , at the same time, the TEQ are 0.37 (0.72~1.8) pg·g -1 , which is lower than other references. The concentration of PCB 118 (IUPAC No.) is higher than any other dioxin-like PCBs, which followed by 105 and 77. And PCB 126 is the dominant TEQ congener, accounting for about 90% of the total TEQ on average. Low chlorinated homologues of PCBs are dominant, which is very different from other soils overseas but similar to domestic environmental samples where low chlorinated PCBs productions had been applied. High chlorinated PCBs are more inclined to be absorbed by soil organic materials. PCBs in soils of different land use decrease by roadside, park, farmland and mountain area, and PCBs in urban and outskirts is higher than suburb, which may be due to the emission sources such as automobile exhaust and the usage of agrochemicals and so on.更多还原