State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510 640, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Environ Sci Technol. 2021 Apr 20;55(8):4553-4564. doi: 10.1021/acs.est.1c00874. Epub 2021 Mar 30.
Methoxyphenols are an important class of compounds emerging from biomass combustion, and their reactions with ozone can generate secondary organic aerosols in the atmosphere. Here, we use a vertical wetted wall flow tube reactor to evaluate the effect of ionic strength on the heterogeneous reaction of gas-phase ozone (O) with a liquid film of -vanillin (-VL) (2-hydroxy-3-methoxybenzaldehyde), as a proxy for methoxyphenols. Typical for moderately acidic aerosols, at fixed pH = 5.6, the uptake coefficients (γ) of O on -VL ([-VL] = 1 × 10 mol L) increase from γ = (1.9 ± 0.1) × 10 in the absence of NaSO to γ = (6.8 ± 0.3) × 10 at = 0.2 mol L, and then, it decreases again. The addition of NO ions only slightly decreases the uptakes of O. Ultrahigh-resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) reveals that the formation of multicore aromatic compounds is favored upon heterogeneous O reaction with -VL, in the presence of SO and NO ions. The addition of NO ions favors the formation of nitrooxy (-ONO) or oxygenated nitrooxy group of organonitrates, which are components of brown carbon that can affect both climate and air quality.
甲氧基酚是一类源自生物质燃烧的重要化合物，它们与臭氧的反应可以在大气中生成二次有机气溶胶。在这里，我们使用垂直湿壁流管反应器来评估离子强度对气相臭氧 (O) 与香草醛 (-VL) (2-羟基-3-甲氧基苯甲醛) 液相膜之间非均相反应的影响，香草醛是甲氧基酚的一种代表。在固定 pH = 5.6 的情况下，对于典型的中等酸性气溶胶，在没有 NaSO 的情况下，O 在 -VL 上的吸收系数 (γ) 为 γ = (1.9 ± 0.1) × 10 ，而在 = 0.2 mol L 时，γ 增加到 γ = (6.8 ± 0.3) × 10 ，然后再次下降。添加 NO 离子只会略微降低 O 的吸收。超高效分辨率电喷雾电离傅里叶变换离子回旋共振质谱 (FT-ICR MS) 表明，在存在 SO 和 NO 离子的情况下，O 与 -VL 的非均相反应有利于多核芳香族化合物的形成。添加 NO 离子有利于形成亚硝酰基 (-ONO) 或含氧亚硝酰基的有机硝酸盐，它们是棕色碳的组成部分，会影响气候和空气质量。
