Institute of Atmospheric Environment and Pollution Control, School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China.
Center of Analysis and Measurement, Hefei University of Technology, Hefei, 230009, People's Republic of China.
Environ Sci Pollut Res Int. 2018 Nov;25(31):31091-31100. doi: 10.1007/s11356-018-3091-y. Epub 2018 Sep 5.
The photochemical oxidation of di-n-butyl phthalate (DBP) by OH radicals from nitrous acid (HONO) in atmospheric hydrometeors was explored by two techniques, steady-state irradiation, and laser flash photolysis (LFP). The effects of atmospheric liquid parameters on DBP transformation were systematically evaluated, showing that DBP does not react with HONO directly and OH-initiated reactions are crucial steps for consumption and transformation of DBP. Two reaction channels are operative: OH addition and hydrogen atom abstraction. The overall rate constant for the reaction of DBP with OH is 5.7 × 10 M s, and its specific rate constant for addition is 3.7 × 10 M s determined by using laser flash photolysis technique. Comparing the individual reaction rate constant for aromatic ring addition with the total rate constant, the majority of the OH radicals (about 65%) attack the aromatic ring. The major transformation products were identified by GC-MS, and the trends of their yields derived from both ring addition and H-abstraction with time are discussed. These results provide important insights into the photochemical transformation of DBP in atmospheric hydrometeors and contribute to atmospheric aerosol chemistry.
亚硝酸（HONO）中的羟基自由基（OH 自由基）对邻苯二甲酸二丁酯（DBP）的光化学氧化作用，通过两种技术，稳态辐照和激光闪光光解（LFP）进行了研究。系统地评估了大气液体参数对 DBP 转化的影响，结果表明 DBP 不会与 HONO 直接反应，而 OH 引发的反应是 DBP 消耗和转化的关键步骤。存在两种反应途径：OH 加成和氢原子摘取。DBP 与 OH 的反应的总速率常数为 5.7×10^-11 M s^-1，其加成的特定速率常数为 3.7×10^-11 M s^-1，这是通过使用激光闪光光解技术确定的。将芳香环加成的个别反应速率常数与总速率常数进行比较，大多数 OH 自由基（约 65%）攻击芳香环。通过 GC-MS 鉴定了主要的转化产物，并讨论了它们的产率随时间从环加成和 H 提取的趋势。这些结果为大气水相中 DBP 的光化学转化提供了重要的见解，并为大气气溶胶化学做出了贡献。
