Feng Jialiang, Chan Chak K, Fang Ming, Hu Min, He Lingyan, Tang Xiaoyan
Department of Chemical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
Chemosphere. 2005 Nov;61(5):623-32. doi: 10.1016/j.chemosphere.2005.03.067.
Twenty-eight PM2.5 samples collected in Summer (July 2002) and Winter (November 2002) at two sites in Beijing, China were analyzed using GC/MS to investigate the impact of meteorology and coal burning on the solvent extractable organic compounds (SEOC). The characteristics and abundance of the n-alkanes, polycyclic aromatic hydrocarbons (PAHs), n-fatty acids and n-alkanols were determined. Source identification was made using organic species as molecular markers. Semi-volatile compounds of alkanes and PAHs had much higher concentrations in winter than summer because of the large difference in the temperature between the seasons. Plant wax emission was a major contributor to n-alkanes in summer, but fossil fuel residue was a major source (>80%) in winter. The seasonal differences in the distribution of pentacyclic triterpanes clearly shows the impact of coal burning for space heating in winter. The yield of PAHs in winter (148 ng m(-3) at the urban site and 277 ng m(-3) at the suburban site) was six to eight times higher than that in summer and was found to be mainly from coal burning. Higher pollutant concentrations were measured at the suburban site than the urban site in winter due to the rapid expansion of the city limit and the relocation of factories from urban to suburban areas over the last two decades.
2002年7月（夏季）和11月（冬季）在中国北京两个地点采集了28个PM2.5样本，使用气相色谱/质谱联用仪（GC/MS）进行分析，以研究气象条件和燃煤对可溶剂萃取有机化合物（SEOC）的影响。测定了正构烷烃、多环芳烃（PAH）、正脂肪酸和正链烷醇的特征和含量。利用有机物种作为分子标志物进行源解析。由于季节间温度差异较大，冬季烷烃和多环芳烃的半挥发性化合物浓度远高于夏季。夏季植物蜡排放是正构烷烃的主要来源，但冬季化石燃料残留是主要来源（>80%）。五环三萜分布的季节差异清楚地显示了冬季燃煤取暖的影响。冬季多环芳烃的产量（城市站点为148 ng m(-3)，郊区站点为277 ng m(-3)）比夏季高六至八倍，且主要来自燃煤。由于过去二十年城市边界迅速扩张以及工厂从市区迁至郊区，冬季郊区站点的污染物浓度高于市区站点。
