【摘要】 采集了4个北京大气沉降样品,包括3个总沉降与1个湿沉降样品.利用高分辨率气质联用仪(HRGC-HRMS),参照国际标准方法分析测定了其中的多氯联苯(PCBs)含量.总沉降样品的PCBs含量水平为4.47~7.08ng·g-1(平均为5·52ng·g-1)和TEQ为0.55~5.43pg·g-1(平均为2.27pg·g-1).湿沉降样品含量水平为15.02ng·g-1,其TEQ为2.87pg·g-1.首钢样品的TEQ远高于其它3个样品.根据我国大气降尘数据,粗略估计北京PCBs大气沉降通量平均值为67.9ng·m-·2m-1和TEQ平均通量为27.9pg·m-·2m-1.首钢样品中,IUPAC编号为77的类二英PCBs含量异常高,但TEQ仍以编号为126的PCBs所占比例最高.随着取代氯原子数的增加,同族体的含量逐渐降低.更多还原

【Abstract】 Four Beijing atmospheric deposition samples were collected, which included three total deposition samples and one wet deposition sample. According to EPA 1668 A, PCBs were analyzed by HRGC-HRMS. The TEQ average levels (range) were 5.52 (4.47~7.08) ng·g -1 and 2.27 (0.55~5.43) pg·g -1 for the total deposition samples. PCBs concentrations in the wet deposition sample were 15.02 ng g -1 and 2.87 pg·g -1 . TEQ in Shougang was higher than other 3 samples. According to the average year atmospheric deposition in China, PCBs deposition flux was estimated to be 67.9 ng·g -1 and 27.9 pg·g -1 . Congener 77 was very high in Shougang sample and differed very much with other three samples, which maybe due to this special polluting source. And congener 126 contributed the most percent of TEQ in all the four samples. With the chlorine increased from 4 to 7, PCBs homologue concentrations decreased in all the four samples.更多还原