Secondary Organic Aerosol from Aqueous Reactions of Green Leaf Volatiles with Organic Triplet Excited States and Singlet Molecular Oxygen

详细信息    查看全文

• 作者：Nicole K. Richards-Henderson ; Andrew T. Pham ; Benjamin B. Kirk ; Cort Anastasio
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：January 6, 2015
• 年：2015
• 卷：49
• 期：1
• 页码：268-276
• 全文大小：371K
• ISSN：1520-5851

文摘

Vegetation emits a class of oxygenated hydrocarbons - the green leaf volatiles (GLVs) - under stress or damage. Under foggy conditions GLVs might be a source of secondary organic aerosol (SOA) via aqueous reactions with hydroxyl radical (OH), singlet oxygen (¹O₂*), and excited triplet states (³C*). To examine this, we determined the aqueous kinetics and SOA mass yields for reactions of ³C* and ¹O₂* with five GLVs: methyl jasmonate (MeJa), methyl salicylate (MeSa), cis-3-hexenyl acetate (HxAc), cis-3-hexen-1-ol (HxO), and 2-methyl-3-butene-2-ol (MBO). Second-order rate constants with ³C* and ¹O₂* range from (0.13鈥?2) 脳 10⁸ M^鈥? s^鈥? and (8.2鈥?0) 脳 10⁵ M^鈥? s^鈥? at 298 K, respectively. Rate constants with ³C* are independent of temperature, while values with ¹O₂* show significant temperature dependence (E_a = 20鈥?6 kJ mol^鈥?). Aqueous SOA mass yields for oxidation by ³C* are (84 卤 7)%, (80 卤 9)%, and (38 卤 18)%, for MeJa, MeSa, and HxAc, respectively; we did not measure yields for other conditions because of slow kinetics. The aqueous production of SOA from GLVs is dominated by ³C* and OH reactions, which form low volatility products at a rate that is approximately half that from the parallel gas-phase reactions of GLVs.