气候变化领域集成服务门户(CCPortal): Heterogeneous OH oxidation of isoprene-epoxydiol-derived organosulfates: Kinetics; chemistry and formation of inorganic sulfate

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DOI	10.5194/acp-19-2433-2019
	Heterogeneous OH oxidation of isoprene-epoxydiol-derived organosulfates: Kinetics; chemistry and formation of inorganic sulfate
	Lam H.K.; Kwong K.C.; Poon H.Y.; Davies J.F.; Zhang Z.; Gold A.; Surratt J.D.; Chan M.N.
发表日期	2019
ISSN	16807316
起始页码	2433
结束页码	2440
卷号	19 期号:4
英文摘要	Acid-catalyzed multiphase chemistry of epoxydiols formed from isoprene oxidation yields the most abundant organosulfates (i.e., methyltetrol sulfates) detected in atmospheric fine aerosols in the boundary layer. This potentially determines the physicochemical properties of fine aerosols in isoprene-rich regions. However, chemical stability of these organosulfates remains unclear. As a result, we investigate the heterogeneous oxidation of aerosols consisting of potassium 3-methyltetrol sulfate ester (C 5 H 11 SO 7 K) by gas-phase hydroxyl (OH) radicals at a relative humidity (RH) of 70.8 %. Real-time molecular composition of the aerosols is obtained by using a Direct Analysis in Real Time (DART) ionization source coupled to a highresolution mass spectrometer. Aerosol mass spectra reveal that 3-methyltetrol sulfate ester can be detected as its anionic form (C 5 H 11 SO 7 - ) via direct ionization in the negative ionization mode. Kinetic measurements reveal that the effective heterogeneous OH rate constant is measured to be 4:74±0.2×10 -13 cm 3 molecule-1 s -1 with a chemical lifetime against OH oxidation of 16.2±0.3 days, assuming an OH radical concentration of 1:5×10 6 molecules cm -3 . Comparison of this lifetime with those against other aerosol removal processes, such as dry and wet deposition, suggests that 3-methyltetrol sulfate ester is likely to be chemically stable over atmospheric timescales. Aerosol mass spectra only show an increase in the intensity of bisulfate ion (HSO 4 - ) after oxidation, suggesting the importance of fragmentation processes. Overall, potassium 3-methyltetrol sulfate ester likely decomposes to form volatile fragmentation products and aqueous-phase sulfate radial anion (SO 4 - ). SO 4 - subsequently undergoes intermolecular hydrogen abstraction to form HSO 4 - . These processes appear to explain the compositional evolution of 3-methyltetrol sulfate ester during heterogeneous OH oxidation. © Author(s) 2019.
语种	英语
scopus关键词	aerosol; atmospheric chemistry; chemical composition; hydroxyl radical; isoprene; oxidation; physicochemical property; reaction kinetics; sulfate
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144619
作者单位	Earth System Science Programme, Faculty of Science, Chinese University of Hong Kong, Hong Kong, Hong Kong; Department of Chemistry, UC Riverside, Riverside, United States; Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, United States; Institute of Environment, Energy and Sustainability, Chinese University of Hong Kong, Hong Kong, Hong Kong
推荐引用方式 GB/T 7714	Lam H.K.,Kwong K.C.,Poon H.Y.,et al. Heterogeneous OH oxidation of isoprene-epoxydiol-derived organosulfates: Kinetics; chemistry and formation of inorganic sulfate[J],2019,19(4).
APA	Lam H.K..,Kwong K.C..,Poon H.Y..,Davies J.F..,Zhang Z..,...&Chan M.N..(2019).Heterogeneous OH oxidation of isoprene-epoxydiol-derived organosulfates: Kinetics; chemistry and formation of inorganic sulfate.Atmospheric Chemistry and Physics,19(4).
MLA	Lam H.K.,et al."Heterogeneous OH oxidation of isoprene-epoxydiol-derived organosulfates: Kinetics; chemistry and formation of inorganic sulfate".Atmospheric Chemistry and Physics 19.4(2019).