大气气溶胶中二元酸、酮酸和羰基化合物研究进展

Characterization of dicarboxylic acids,oxocarboxylic acids,and α-dicarbonyls in atmospheric aerosols: A review

论述了以低分子量二元酸(C_2-C_(12))、酮酸(ωC_2-ωC_(12)和pyruvic acid)和α-羰基化合物(C_2-C_3)为代表的水溶性有机气溶胶的分布特征与季节变化,阐述二元酸及相关化合物的实验测定方法,探究了该类有机酸的光化学氧化机制、粒径分布、来源与形成转化过程、诊断比值等。基于不同城市、海洋与极地二元羧酸的实验分析及数据对比,指出陆地气溶胶主要受一次源排放影响,如化石燃料燃烧、生物质燃烧、食物烹制和塑料垃圾焚烧等,而海洋气溶胶则受陆源和海表浮游植物等释放的未饱和脂肪酸、生物挥发性有机物,以及大气长距离传输途中气溶胶光氧化过程的共同影响。此外,本文对二元酸的单体稳定碳同位素组成进行了讨论,揭示了稳定碳同位素值是判断气溶胶光化学氧化过程的重要手段,同时讨论了气溶胶长距离传输与二元酸及相关化合物的稳定碳同位素组成的潜在联系。

In this study, we summarized the seasonal variation, molecular distribution of low mo- lecular weight （LMW） dicarboxylic acids, oxocarboxylic acids and （x-dicarbonyls in atmospheric aerosols, and also discussed the experimental methods, photochemical aging, size distributions, sources, and transformation processes as well as diagnostic ratios of these organic acids. Based on the analyses and comparisons of dicarboxylic acids and related compounds in urban, marine and polar areas, we suggested that continental aerosols were mainly associated with anthropogenic e- missions, such as fossil fuel combustion, biomass burning, meal cooking and plastic waste burn- ing; whereas marine aerosols were not only affected by outflows from continental areas, biogenic unsaturated fatty acids and biogenic semi-volatile organics emitted from the surface ocean, but al- so attributed to the photochemical oxidation of related precursors during the long-range atmosphere- ic transport. In addition, we discussed the compound specific stable carbon isotopic analyses of diacids, oxoacids and ct-dicarbonyls. The isotopic composition of diacids was a powerful tool to investigate the photochemical aging processes of atmospheric aerosols. At last, the relationship between the long-distance transport of aerosol and the stable carbon isotope composition of diacids and related compounds was also illustrated in this paper.