Distribution of PAHs in aerosol particles of the area of West Sanhuan in Beijing

Aerosol particle samples were collected in different size during March to August 2012,Beijing.The 16 kinds 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.