Glyoxal in aqueous ammonium sulfate solutions: products, kinetics and hydration effects.
Glyoxal in aqueous ammonium sulfate solutions: products, kinetics and hydration effects.
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DOI：
10.1021/es200989n
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发表时间：
2011-07
影响因子：
11.4
通讯作者：
G. Yu;Amanda R. Bayer;M. M. Galloway-M.;K. Korshavn;C. G. Fry;F. Keutsch
中科院分区：
文献类型：
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作者：
G. Yu;Amanda R. Bayer;M. M. Galloway-M.;K. Korshavn;C. G. Fry;F. Keutsch
研究了乙二醛与盐在水溶液中的反应及相互作用。发现乙二醛与铵反应生成咪唑、咪唑-2-甲醛、甲酸、N-乙二醛取代的咪唑和极低浓度的次要产物。测量每种主要产物的总体反应级数和速率。在水溶液中，硫酸根离子与乙二醛具有强而特异的相互作用，这使乙二醛的水合平衡从未水合的羰基形式转变为水合形式。这种离子特异性效应有助于在含硫酸盐溶液中观察到的乙二醛的有效亨利定律系数的增强。乙二醛与铵盐、甲胺盐和二甲胺盐的溶液的紫外-可见吸收和NMR光谱研究的结果表明，光吸收化合物需要形成含氮分子。这些发现对乙二醛在大气中的作用具有影响，无论是在乙二醛形成二次有机气溶胶（SOA）的贡献模型中，含氮物质对气溶胶光学特性的作用，还是在预测大气中其他羰基化合物或二羰基化合物的行为中。
Reactions and interactions between glyoxal and salts in aqueous solution were studied. Glyoxal was found to react with ammonium to form imidazole, imidazole-2-carboxaldehyde, formic acid, N-glyoxal substituted imidazole, and minor products at very low concentrations. Overall reaction orders and rates for each major product were measured. Sulfate ions have a strong and specific interaction with glyoxal in aqueous solution, which shifts the hydration equilibria of glyoxal from the unhydrated carbonyl form to the hydrated form. This ion-specific effect contributes to the observed enhancement of the effective Henry's law coefficient for glyoxal in sulfate-containing solutions. The results of UV-vis absorption and NMR spectroscopy studies of solutions of glyoxal with ammonium, methylamine, and dimethylamine salts reveal that light absorbing compounds require the formation of nitrogen containing molecules. These findings have implications on the role of glyoxal in the atmosphere, both in models of the contribution of glyoxal to form secondary organic aerosol (SOA), the role of nitrogen containing species for aerosol optical properties and in predictions of the behavior of other carbonyls or dicarbonyls in the atmosphere.