2007年春节期间北京大气细粒子中正构烷烃的污染特征

利用大流量颗粒物采样器分昼夜采集了2007年春节前后大气气溶胶中PM_2.5样品，并采用气相色谱-质谱技术对PM_2.5样品中的正构烷烃进行了检测和分析.结果表明，春节期间大气细粒子平均浓度全部超过WHO阈值，且夜间平均浓度要高于白天.细粒子中检测出C₁₀～C₃₃的正构烷烃，总浓度为201.7～2 715.6　ng·m^-3，夜间正构烷烃的平均总浓度（943.5 ng·m^-3）要高于白天(581.1 ng·m^-3），除夕前的平均总浓度（1025.5 ng·m^-3）要高于除夕后（536.6 ng·m^-3）.主峰碳为23、 24和25，CPI值为0.9～1.4，平均为1.15，表明春节期间北京大气细粒子中的正构烷烃主要由化石燃料的不完全燃烧产生，%WaxC_n的结果表明生物源对气溶胶中正构烷烃的贡献率为8.5%～47%.

Pollution Characteristics of n-alkanes in Atmospheric Fine Particles During Spring Festival of 2007 in Beijing

Research PM_ 2.5 aerosols had been carried out with sampler of high-volume sampler during Spring Festival of 2007 in Beijing,and the concentrations of n-alkane in PM_ 2.5 samples were determined via GC-MS.The average concentrations of PM_ 2.5 which were all exceeded WHO threshold values were higher in the night than those in the day time.The n-alkane homolog from C_ 10 to C_ 33 were detected with the major peak carbon numbers ranging from 23 to 25.The total concentrations of n-alkane were higher in the nigh...