Characterization of dicarboxylic acids in PM2.5 in Hong Kong
Characterization of dicarboxylic acids in PM2.5 in Hong Kong
复制标题
DOI：
10.1016/j.atmosenv.2003.10.048
复制
发表时间：
2004-03
影响因子：
5
通讯作者：
X. Yao;M. Fang;C. Chan;K. Ho;Shuncheng Lee
中科院分区：
文献类型：
--
作者：
X. Yao;M. Fang;C. Chan;K. Ho;Shuncheng Lee
大气气溶胶中的二羧酸因其对全球气候的潜在影响而受到广泛关注。于2000年冬季和2001年夏季在香港的一个偏远地区和两个城市的站点的PM2.5中的二羧酸的组成和来源进行了研究。草酸是所有样品中占主导地位的二羧酸。冬季草酸浓度较高且空间分布均匀，平均值为0.36μgm−3，而夏季草酸浓度较低且空间变异较大。研究了气象因子对二羧酸浓度的影响。丙二酸与琥珀酸的比率用于区分这些酸的主要来源和次要来源。这一比例在所有三个网站是接近的，从直接车辆废气在冬季，但它是接近的，在夏季的二次反应。因此，这些酸在冬季被归因于车辆排放，在夏季被归因于二次来源。这一假设也支持了良好的相关性草酸盐与硫酸盐在夏季，但在冬季穷人。草酸与丙二酸，琥珀酸，硫酸和K+的相关性也进行了研究，在这些二羧酸的二次形成的路线。
Dicarboxylic acids in atmospheric aerosols have received much attention because of their potential roles in affecting the global climate. The composition and the sources of dicarboxylic acids in PM2.5 were studied at one remote and two urban sites in Hong Kong in the winter of 2000 and in the summer of 2001. Oxalate was the dominant dicarboxylic acid in all samples. The winter oxalate concentrations were high and spatially uniform, with an average value of 0.36μgm−3, but the summer oxalate concentrations were low and had a large spatial variation. The influence of meteorological factors on the concentrations of dicarboxylic acids was also studied. The ratio of malonate to succinate was used to distinguish primary sources from secondary sources of these acids. This ratio at all three sites was close to that from direct vehicular exhaust in the winter, but it was close to that of secondary reactions in the summer. Hence, the acids were attributed to vehicular emissions in the winter and secondary sources in the summer. This hypothesis is also supported by a good correlation of oxalate with sulfate in the summer but a poor one in the winter. The correlations of oxalate with malonate, succinate, sulfate and K+were also studied in terms of the routes of secondary formation of these dicarboxylic acids.