HR: 11:35h
AN: A52A-06    [Abstracts]
TI: An investigation for unexpected high yield of peroxides from isoprene through aqueous phase ozonolysis
AU: * Wang, H
EM: whhsli@pku.edu.cn
AF: The State Key Laboratory of Environmental Simulation and Pollution control, College of Environmental Sciences and Engineering, Peking University, Yiheyuan Road 5, Beijing, 100871, China
AU: Chen, Z
EM: zmchen@pku.edu.cn
AF: The State Key Laboratory of Environmental Simulation and Pollution control, College of Environmental Sciences and Engineering, Peking University, Yiheyuan Road 5, Beijing, 100871, China
AU: Hua, W
EM: huawei315@163.com
AF: The State Key Laboratory of Environmental Simulation and Pollution control, College of Environmental Sciences and Engineering, Peking University, Yiheyuan Road 5, Beijing, 100871, China
AU: Jie, C
EM: jie.chongyu@gmail.com
AF: The State Key Laboratory of Environmental Simulation and Pollution control, College of Environmental Sciences and Engineering, Peking University, Yiheyuan Road 5, Beijing, 100871, China
AB: It has recently become evident that isoprene, the atmosphere's most abundant non-methane hydrocarbon, and its oxidation products can considerably result in formation of secondary organic aerosols (SOA) through the acid- catalyzed aqueous phase reaction with hydrogen peroxide. However, the peroxide source in the atmospheric aqueous process is unclear. The present study revealed a potentially important route to the formation of aqueous peroxides, including hydrogen peroxide and hydroxylmethyl hydroperoxide, from the aqueous phase ozonolysis of isoprene. In this study, the atmospheric aqueous phase ozonolysis of isoprene at different pHs and temperatures were studied with the method of laboratory simulation. The major products, including peroxides and carbonyl compounds, were well-characterized, with a measured carbon balance approaching 100%, and the detailed reaction mechanisms were proposed. Most strikingly, peroxides have been found in the aqueous phase ozonolysis of isoprene with unexpected high yields. Considering the huge amount of isoprene in the atmosphere, we suggest that the aqueous phase ozonolysis of isoprene and its first-generation oxidation products may contribute a considerable and even the main source of oxidants to the atmospheric aqueous phase. This means that isoprene and its oxidation products can be transformed into SOA by peroxides provided from their aqueous phase ozonolysis reactions, even if there is no other peroxide source.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting