Formation of Light Absorbing Organo-Nitrogen Species from Evaporation of Droplets Containing Glyoxal and Ammonium Sulfate
Formation of Light Absorbing Organo-Nitrogen Species from Evaporation of Droplets Containing Glyoxal and Ammonium Sulfate
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DOI：
10.1021/es402687w
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发表时间：
2013-11-19
影响因子：
11.4
通讯作者：
Abbatt, Jonathan. P. D.
中科院分区：
文献类型：
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作者：
Lee, Alex K. Y.;Zhao, Ran;Abbatt, Jonathan. P. D.
在大气中，乙二醛等挥发性有机化合物可以分解成含有大量无机盐的水滴。当液滴蒸发时，有机物和无机离子都变得高度集中，加速了它们之间的反应。为了演示这一过程，我们研究了含有乙二醛和不同铵盐(包括(NH4)(2)SO4、NH4NO3和NH4Cl)的蒸发液滴中有机氮和光吸收材料的形成。我们的结果表明，乙二醛-(NH4)(2)SO4液滴在几秒钟的时间尺度上产生光吸收物质，这比在主体溶液中观察到的快了一个数量级。利用气溶胶-质谱仪，我们发现在使用铵盐时形成了高N：C比的颗粒相有机物，硫酸盐离子的存在促进了这一化学过程。由于硫酸盐还可以显著提高乙二醛的亨利定律分配，我们的结果强调了大气中这种无机有机相互作用在水相气溶胶化学中的重要性。
In the atmosphere, volatile organic compounds such as glyoxal can partition into aqueous droplets containing significant levels of inorganic salts. Upon droplet evaporation, both the organics and inorganic ions become highly concentrated, accelerating reactions between them. To demonstrate this process, we investigated the formation of organo-nitrogen and light absorbing materials in evaporating droplets containing glyoxal and different ammonium salts including (NH4)(2)SO4, NH4NO3, and NH4Cl. Our results demonstrate that evaporating glyoxal-(NH4)(2)SO4 droplets produce light absorbing species on a time scale of seconds, which is orders of magnitude faster than observed in bulk solutions. Using aerosol mass spectrometry, we show that particle-phase organics with high N:C ratios were formed when ammonium salts were used, and that the presence of sulfate ions promoted this chemistry. Since sulfate can also significantly enhance the Henry's law partitioning of glyoxal, our results highlight the atmospheric importance of such inorganic organic interactions in aqueous phase aerosol chemistry.