Department of Chemistry and Biochemistry, University of San Diego, San Diego, California 92110, United States.
Environ Sci Technol. 2011 Feb 1;45(3):984-91. doi: 10.1021/es102933x. Epub 2010 Dec 20.
Reactions of methylglyoxal with amino acids, methylamine, and ammonium sulfate can take place in aqueous aerosol and evaporating cloud droplets. These processes are simulated by drying droplets and bulk solutions of these compounds (at low millimolar and 1 M concentrations, respectively) and analyzing the residuals by scanning mobility particle sizing, nuclear magnetic resonance, aerosol mass spectrometry (AMS), and electrospray ionization MS. The results are consistent with imine (but not diimine) formation on a time scale of seconds, followed by the formation of nitrogen-containing oligomers, methylimidazole, and dimethylimidazole products on a time scale of minutes to hours. Measured elemental ratios are consistent with imidazoles and oligomers being major reaction products, while effective aerosol densities suggest extensive reactions take place within minutes. These reactions may be a source of the light-absorbing, nitrogen-containing oligomers observed in urban and biomass-burning aerosol particles.
甲基乙二醛与氨基酸、甲胺和硫酸铵的反应可以在水气溶胶和蒸发的云滴中发生。通过干燥这些化合物的液滴和本体溶液（分别在低毫摩尔和 1 M 浓度下）并通过扫描迁移率粒子粒径分析、核磁共振、气溶胶质谱 (AMS) 和电喷雾电离 MS 分析残留物来模拟这些过程。结果与亚胺（而不是二亚胺）在秒的时间尺度上形成一致，随后在分钟到小时的时间尺度上形成含氮低聚物、甲基咪唑和二甲基咪唑产物。测量的元素比与亚胺和低聚物是主要反应产物一致，而有效气溶胶密度表明在几分钟内发生了广泛的反应。这些反应可能是在城市和生物质燃烧气溶胶颗粒中观察到的吸光含氮低聚物的来源。
