武汉大气PM_(2.5)中烃类有机物污染特征及来源辨析

Distribution and Source Identification of Hydrocarbons in Atmospheric PM_(2.5) in Wuhan

采集了武汉工业区、交通区和植物园秋冬季大气PM2.5样品，采用GO／MS定量分析了细粒子中烃类有机物污染特征。共检测出C10～C33正构烷烃、11种甾烷和12种萜类化合物、2～6环的母核以及少量C，取代的共27种PAHs，并运用分子地球化学参数和特征比值法对污染源进行初步示踪研究。结果表明，武汉市PM妯平均浓度为144．71μg／m^3，正构烷烃CPI值、植物蜡百分数（％WaxCn）呈现出比较明显的功能区差异，具体表现为植物园秋季％WaxCn最高，交通区冬季CPI值最低。16种优控PAHs全被检出，不同环数PAHs分布规律为：（4～5）环〉（6～7）环〉（2～3）环。工业区特征比值和分子地球化学参数明显指示了燃煤烟尘污染，交通区指示了汽油车和柴油车混合污染和地面扬尘污染，植物园受到高等植物输入、木材、秸秆等燃烧影响，同时，部分污染来源于工业区的长距离传输。

PM2.5 samples were collected at various sites in Wuhan, including Wuhan botanical garden, industrial area, and traffic region. Hydrocarbons of airborne particles were analyzed by gas chromatograph-mass spectrometer. The nal-kane homologs from C10 to C33, 11 kinds of steranes and 12 types of terpenoids,Twenty-seven polycyclic aromatic hydro-carbons （PAHs）were detected, some molecular geochemical parameters and the Molecular Diagnostic Ratio（MDR）tech-nique were used to preliminarily trace the pollutant source. The results indicate that the average concentration of PM2.5 was 144. 71 μg/m^3, CPI, %WaxCn, revealed certain regional variation： %WaxCn, reaching maximum in autumn in botanical garden, and CPI lowest in winter at industrial area. 16 priority controlled PAHs were all detected and the distribution pro-files of the total PAHs appeared in the following order ： （4 - 5）-ring72〉（6 - 7）-ring〉 （ 2-3）-ring. Molecular geochemical parameters and MDR displayed that the atmosphere in industrial area and traffic region were mainly polluted by coal-fired boilers,heavy-duty diesel trucks and road dust. The Botanical garden showed obvious input of pollutants from high plant wax, biomass burning,and long range transport from the industrial area.