Organic nitrate aerosol formation via NO3 + biogenic volatile organic compounds in the southeastern United States
Organic nitrate aerosol formation via NO3 + biogenic volatile organic compounds in the southeastern United States
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美国东南部通过NO₃与生物源挥发性有机化合物形成有机硝酸盐气溶胶
DOI：
10.5194/acp-15-13377-2015
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发表时间：
2015-01-01
影响因子：
6.3
通讯作者：
Fry, J. L.
中科院分区：
文献类型：
--
作者：
Ayres, B. R.;Allen, H. M.;Fry, J. L.
在阿拉巴马州中部进行的南方氧化剂和气溶胶研究（2013年夏季的SOAS活动）期间，对氧化剂、生物源挥发性有机化合物（BVOCs）和有机硝酸盐进行的气相和气溶胶相测量表明，硝酸根自由基（NO₃）与单萜的反应导致了显著的二次气溶胶形成。活动期间，NO₃与萜烯的累积损失与气相和气溶胶有机硝酸盐浓度的增加相关。通过气溶胶质谱法和热解离激光诱导荧光测量，NO₃自由基消耗与有机硝酸盐气溶胶形成的相关性表明，气溶胶相单萜硝酸盐的摩尔产率为23 - 44%。通过化学电离质谱法（CIMS）观测到的化合物与预测的NO₃与BVOCs反应的损失相关，并且表明C₁₀H₁₇NO₅（可能是一种过氧硝酸酯）是一种主要的被纳入气溶胶的硝酸氧化萜烯产物。观察到的类似异戊二烯产物C₅H₉NO₅在气溶胶相中占总有机硝酸盐的比例不到1%，并且相关性表明它主要是异戊二烯经硝酸氧化后的气相产物。在SOAS期间，有机硝酸盐占NOᵧ收支的30% - 45%。还对无机硝酸盐进行了监测，结果表明在粗模态矿物粉尘增加的情况下，HNO₃的吸收产生硝酸盐气溶胶质量负荷的速率与通过NO₃ + BVOCs产生有机硝酸盐的速率相当。
Gas- and aerosol-phase measurements of oxidants, biogenic volatile organic compounds (BVOCs) and organic nitrates made during the Southern Oxidant and Aerosol Study (SOAS campaign, Summer 2013) in central Alabama show that a nitrate radical (NO3) reaction with monoterpenes leads to significant secondary aerosol formation. Cumulative losses of NO3 to terpenes are correlated with increase in gas- and aerosol- organic nitrate concentrations made during the campaign. Correlation of NO3 radical consumption to organic nitrate aerosol formation as measured by aerosol mass spectrometry and thermal dissociation laser-induced fluorescence suggests a molar yield of aerosol-phase monoterpene nitrates of 23-44 %. Compounds observed via chemical ionization mass spectrometry (CIMS) are correlated to predicted nitrate loss to BVOCs and show C10H17NO5, likely a hydroperoxy nitrate, is a major nitrate-oxidized terpene product being incorporated into aerosols. The comparable isoprene product C5H9NO5 was observed to contribute less than 1% of the total organic nitrate in the aerosol phase and correlations show that it is principally a gas-phase product from nitrate oxidation of isoprene. Organic nitrates comprise between 30 and 45% of the NOy budget during SOAS. Inorganic nitrates were also monitored and showed that during incidents of increased coarse-mode mineral dust, HNO3 uptake produced nitrate aerosol mass loading at a rate comparable to that of organic nitrate produced via NO3 + BVOCs.