Stable carbon isotopic composition of low‐molecular‐weight dicarboxylic acids and ketoacids in remote marine aerosols
Stable carbon isotopic composition of low‐molecular‐weight dicarboxylic acids and ketoacids in remote marine aerosols
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DOI：
10.1029/2005jd006466
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发表时间：
2006-04
影响因子：
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通讯作者：
Haobo Wang;K. Kawamura
中科院分区：
文献类型：
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作者：
Haobo Wang;K. Kawamura
[1]测定了西太平洋和南大洋（35°N ~ 65°S）海洋气溶胶中C2 ~ C9二元羧酸（DCAs）和部分酮酸的稳定碳同位素组成（δ 13 C）。平均而言，草酸（平均值为-16.8‰）、己二酸（-17.2‰）和乙醛酸（-17.6‰）的δ 13 C较重，而马来酸（-24.2‰）、甲基丙二酸（-23.6%o）和邻苯二甲酸（-23.1‰）的δ 13 C较低。草酸的δ 13 C值差异很大（-27至-7%o），从中纬度向赤道逐渐增加。丙二酸、琥珀酸和己二酸的δ 13 C也有类似的纬度变化趋势。然而，邻苯二甲酸、马来酸和乙醛酸没有观察到这种趋势。我们认为，向赤道的δ 13 C增加与光化学老化的空气质量，其中动力学同位素效应的光化学降解的DCA可能是重要的。一些饱和DCA的δ 13 C差异也发现从中纬度到赤道增加。
[1] We determined stable carbon isotopic composition (δ 13 C) of C 2 to C 9 dicarboxylic acids (DCAs) and some ketoacids in the marine aerosols from the western Pacific and Southern Ocean (35°N to 65°S). On average, oxalic (mean, -16.8‰), adipic (-17.2‰), and glyoxylic (-17.6‰) acids showed heavier δ 13 C, whereas maleic (-24.2‰), methylmalonic (-23.6%o), and phthalic (-23.1‰) acids were more depleted in 13 C. Oxalic acid presented very diverse δ 13 C values (-27 to -7%o), which increased from midlatitudes toward the equator. A similar latitudinal trend of δ 13 C was also found for malonic, succinic, and adipic acids. However, such a trend was not observed for phthalic, maleic, and glyoxylic acids. We suggest that the δ 13 C increase toward the equator is associated with photochemically aged air masses, in which kinetic isotope effects for photochemical degradation of DCAs may be important. Differences in δ 13 C of some saturated DCAs were also found to increase from midlatitudes to the equator.