Seasonal variability of formaldehyde production from photolysis of rainwater dissolved organic carbon
Seasonal variability of formaldehyde production from photolysis of rainwater dissolved organic carbon
复制标题
雨水溶解有机碳光解产生甲醛的季节变化
DOI：
10.1016/j.atmosenv.2010.06.044
复制
发表时间：
2010
影响因子：
5
通讯作者：
J. Willey
中科院分区：
文献类型：
--
作者：
M. Southwell;Jeremy D. Smith;G. Avery;R. Kieber;J. Willey
在模拟太阳光条件下，对美国北卡罗来纳州威尔明顿13次降水过程中雨水中甲醛（HCHO）的光化学产生进行了测定。在所有辐照样品中，甲醛浓度均增加，而在黑暗对照中未观察到变化。HCHO的光生速率与溶解有机碳（DOC）有很强的相关性，这表明HCHO来自雨水DOC的直接或间接光解。相对于地表沃茨的报道，较高的光生速率（0.03-2.9μMh−1）表明雨水DOC在HCHO产生方面比地表沃茨更对光不稳定。生长季节的HCHO光生速率（1.0±1.0μMh−1）高于非生长季节（0.08±0.05μMh−1），即使将速率标准化为DOC（6.8±3.6μMh− 1 mM C− 1 vs 1.8±1.0μMh− 1 mM C−1）。较高的生长季节率可能与DOC组成的季节差异有关，这可以通过雨水样品每单位碳的荧光差异来证明。照射雨水的C18提取物也产生甲醛，但在较低的利率相比，相应的全雨样品，这表明雨水中的dichloryllic成分发挥作用，在甲醛的光合作用。我们的研究结果表明，雨水DOC的光解产生大量的甲醛，并可能其他低分子量的有机化合物，可能增加其反应性和生物利用度。
Photochemical production of formaldehyde (HCHO) was measured in rainwater from 13 precipitation events in Wilmington, North Carolina, USA under conditions of simulated sunlight. HCHO concentrations increased in all samples irradiated with no changes observed in dark controls. HCHO photoproduction rates were strongly correlated with dissolved organic carbon (DOC) suggesting HCHO was derived from direct or indirect photolysis of rainwater DOC. The higher photoproduction rates (0.03–2.9μMh−1) relative to those reported for surface waters suggests that rainwater DOC is more photolabile in terms of HCHO production than surface waters. HCHO photoproduction rates were higher in growing season (1.0±1.0μMh−1) compared to non-growing season (0.08±0.05μMh−1) even when rates were normalized for DOC (6.8±3.6μMh−1mM C−1versus 1.8±1.0μMh−1mM C−1). The higher growing season rate may be related to seasonal differences in the composition of DOC as evidenced by differences in fluorescence per unit carbon of rainwater samples. Irradiation of C18 extracts of rainwater also produced HCHO, but at lower rates compared to corresponding whole rain samples, suggesting that hydrophyllic components of rainwater play a role in HCHO photoproduction. Our results indicate that photolysis of rainwater DOC produces significant amounts of HCHO, and possibly other low molecular weight organic compounds, likely increasing its reactivity and bioavailability.
影响因子：
5
作者：
Matsumoto, K;Kawai, S;Igawa, M
通讯作者：
Igawa, M