北京西三环地区大气颗粒物中多环芳烃的分布

摘要

2012年3-8月对北京西三环地区大气颗粒物进行分级采样,利用气相色谱(GC)/质谱(MS)联用仪对颗粒物中多环芳烃(PAHs)含量进行测定.结果表明,检出的16种PAHs总质量浓度(∑16PAHs)平均为46.73ng/m3;苯并[a]蒽(BaA)等6种单体浓度与∑16PAHs呈良好线性关系；PAHs粒径分布特征表明,其更易富集在细颗粒物上；不同环数PAHs分布特征为:3环＞4环＞5环＞6环＞2环,随着颗粒粒径减小,高环数PAHs含量增加.温度、湿度和紫外线(UV)指数与∑16PAHs呈负相关.通过特征化合物比值分析法对PAHs进行源解析发现,采样期间PAHs主要来源为燃烧源,交通源影响微弱.%Aerosol particle samples were collected in different size during March to August 2012,Beijing.The 16kinds of polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulate were detected by GC-MS.Results showed that the average concentration of total PAHs was 46.73ng/m3 ;six PAHs homologs,including BaA,presented perfect linear relationship with total PAHs;the size distribution feature indicated that PAHs was preferentially accumulated in the smaller aerosol;3-ring PAHs had the highest mass proportion,and others successively were 4-ring,5-ring,6-ring and 2-ring PAHs; the proportion of multiple ring PAHs was increased in aerosol with smaller particle size.PAHs total amount displayed well negative correlation with the surrounding temperature,humidity and UV index.Through the analysis of characteristics compounds ratio,it could be found that PAHs mainly came from combustion sources,and the contribution of traffic was less.