【摘要】 2002年3月14—19日在南京大学校园内进行了为期1周的采样,用以研究大气气溶胶PM2.5中的低分子量(C2~C10)二元羧酸的昼夜变化规律。结果表明,南京市大气气溶胶中二元羧酸的夜间质量浓度(平均为460 ng/m3)普遍高于相应的白天质量浓度(平均为350 ng/m3)。草酸是含量最高的二元羧酸,其次是丁二酸与丙二酸,这3种二元羧酸占所检测到的水溶性有机酸总量的89%。由C3/C4(ρ(丙二酸)/ρ(丁二酸))(平均为1.00)可以判断采样期间气溶胶中有机酸主要来源于大气的光化学氧化反应,从C6/C9(ρ(己二酸)/ρ(壬二酸))(平均为0.88)可以认为生物源是有机酸的一个重要来源。更多还原

【Abstract】 The diurnal and nocturnal variations of low molecular weight dicarboxylic acids(C₂～C₁₀) in the fine atmospheric aerosols of Nanjing were monitored in the campus of Nanjing University in March 14^th—19^th,2002.The results showed that the diurnal mass concentration of total diacids（average,350 ng/m³） was lower than the nocturnal one（average,460 ng/m³）.Oxalic acid was the most abundant diacids,followed by succinic and malonic acid.These C₂～C₄ diacids accounted for 89% of the total diacids.Based on the ratio of malonate to succinate（C₃/C₄ average,（1.00）） which is used to distinguish primary sources from secondary sources of these diacids,it could be found that secondary sources contribute more to the atmospheric dicarboxylic acids than primary ones.And the ratio of adipic acid to azelaic acid（C₆/C₉）,an indicator of source strength of anthropogenic and biogenic precursors to the aerosol diacids,is（0.88） on average,suggesting that biogenic organic matter was a significant contributor to the diacids in Nanjing air.更多还原