广州市夏季大气中多氯联苯和多溴联苯醚的含量及组成对比

Comparison of PCBs and PBDEs concentrations and compositions in the Guangzhou atmosphere in summer

用GC-ITD-MS和GC-NCI-MS分别测定了广州市区4个代表性的地点大气中多氯联苯(PCBs)和多溴联苯醚(PBDEs)的含量.∑64PCBs的含量范围为307.2～2720.8pg.m-3,含量处于世界中等水平;除工业区两侧的黄浦和天河2个采样点外,市区Σ10PBDEs和BDE-209的含量范围分别为41.5～256.8pg.m-3和116.3～888.7pg.m-3,Σ10PBDEs的含量和世界其它地方相当,而BDE-209的含量高于其它地区.PCBs中主要以三、四和五氯代PCBs为主,它们的含量占∑64PCBs的80%以上,同系物分布与国外不同,原因可能是我国曾生产和使用不同的工业产品.PBDEs中以四、五和十溴BDEs为主,其含量占Σ11PBDEs的80%以上,BDE-209、BDE-47和BDE-99是主要成分,表明污染主要来自于五溴和十溴联苯醚工业品.4个采样点Σ10PBDEs和∑64PCBs含量的分布表明这两类污染物有不同的排放源,PCBs主要来自于老城区,而PBDEs主要来自于新工业区.

The PCBs and PBDEs in atmospheric samples collected from four representative locations of Guangzhou were analyzed using gas chromatography mass spectrometry with ion trap detector （GC-ITD-MS） and gas chromatography mass spectrometry with negative chemical ionization （GC-NCI-MS）. The concentrations of ∑64PCBs ranged from 307.2 to 2720.8 pg·m^-3, which fall among the intermediate values of the world-wide concentration ranges. Except samples from the industrial locations, the concentrations of ∑l0 PBDEs and BDE-209 in urban atmospheric samples ranged from 41.5 to 256.8 pg·m^-3 and from 116.3 to 888.7 pg·m^-3. The∑l0 PBDEs levels were comparable to those values reported from other places in the world, whereas the BDE-209 concentrations were higher than those reported in other studies. The PCBs were dominated by the tri-, tetra- and penta-PCBs, which accounted for more than 80% of the ∑ 64 PCBs. The PCB homolog and congener profiles in this study area were different from the profiles reported from other regions in the world. This may be due to differences in the type of PCBs mixtures used and produced historically in China as compared to other countries. The contributions of tetra-, penta- and deea-BDEs to the ∑ 11 PBDEs were more than 80% . The dominant congeners in the∑ll PBDEs were BDE-209, BDE- 47 and BDE-99. Thus the penta- and deea-BDE commercial products were the major sources of PBDEs in atmosphere of Guangzhou. The distributions of ∑10 PBDEs and ∑ 64 PCBs concentrations in the four sampling locations suggest that these contaminants came from different emission sources. PCBs mainly came from the old industrial area, whereas PBDEs mainly came from the newly developing industrial area.