Comparative distributions of dicarboxylic acids and related polar compounds in snow, rain and aerosols from urban atmosphere
Comparative distributions of dicarboxylic acids and related polar compounds in snow, rain and aerosols from urban atmosphere
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DOI：
10.1016/1352-2310(94)90123-6
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发表时间：
1994-02
影响因子：
5
通讯作者：
R. Sempéré;K. Kawamura
中科院分区：
文献类型：
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作者：
R. Sempéré;K. Kawamura
采用毛细管气相色谱（GC）和质谱联用技术，研究了东京地区9个湿降水（雪、雨夹雪和雨）和4个气溶胶样品中二羧酸及其相关极性化合物（酮酸和二羰基）的分子分布。还分析了湿样品的溶解有机碳（DOC），而研究了气溶胶样品的总碳、总氮和水溶性有机碳。在湿降水（12-540 μg l−1）和气溶胶（1.1-3.0 μg m−3）样品中均检测到同源系列的二羧酸（c_2 - c9）。虽然草酸（c2）是研究样品中主要的二酸种类，其次是丙二酸、琥珀酸和邻苯二酸，但其在总二酸中的相对丰度在湿降水（34±8%）和气溶胶（51±5%）样品中存在差异。这些结果表明，草酸在近地面比对流层上层更富集。降水样品的时间序列表明，在降水过程中，经DOC归一化的二酸碳浓度随时间的变化呈下降趋势。这些结果表明，以颗粒形式存在的二酸比其他水溶性有机化合物更能有效地从大气中清除。
Nine wet precipitation (snow, sleet and rain) and four aerosol samples, collected from Tokyo, were studied for the molecular distributions of dicarboxylic acids and related polar compounds (ketoacids and dicarbonyls) by a capillary gas chromatography (GC) and GC-mass spectrometry. Wet samples were also analysed for dissolved organic carbon (DOC), whereas aerosol samples were studied for total carbon, total nitrogen and water soluble organic carbon. A homologous series of dicarboxylic acids (C 2–C 9) were detected in both wet precipitation (12–540 μg l− 1) and aerosol (1.1–3.0 μg m− 3) samples. Although oxalic acid (C 2) was generally the dominant diacid species followed by either malonic, succinic or phthalic acid in the samples studied, its relative abundance in total diacids was different between the wet precipitation (34±8%) and aerosol (51±5%) samples. These results suggest that oxalic acid is more enriched at near-ground level than upper levels of the troposphere. Time series of precipitation samples showed that diacid carbon concentration normalized by DOC decreased as a function of time during precipitation events. These results suggest that diacids, which exist as particles, are more efficiently scavenged from the atmosphere than other water soluble organic compounds.