Mass spectrometric study of aged benzene secondary organic aerosol in the presence of dry ammonium sulfate
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- 作者：Mingqiang Huang ; Jiahui Zhang ; Shunyou Cai…
- 刊名：Journal of Atmospheric Chemistry
- 出版年：2016
- 出版时间：September 2016
- 年：2016
- 卷：73
- 期：3
- 页码：329-344
- 全文大小：1,466 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Earth sciences
Meteorology and Climatology
Atmospheric Protection, Air Quality Control and Air Pollution - 出版者：Springer Netherlands
- ISSN：1573-0662
- 卷排序：73
文摘
Inorganic seed particles have relatively large surface area, and play an important role in the formation and aging of secondary organic aerosol (SOA). The effects of dry (NH4)2SO4 which is the most commonly found in urban atmosphere on the aged benzene SOA were qualitatively studied utilizing aerosol laser time-of-flight mass spectrometer (ALTOFMS) coupled with Fuzzy C-Means (FCM) clustering algorithm in this study. Experimental results indicated that nitrophenol, oxocarboxylic acid, epoxide products are the predominant components in the aged benzene SOA in the presence of low concentration (about 10 μg m−3) of dry (NH4)2SO4. These aged products are the same as the previously obtained aged benzene SOA without (NH4)2SO4 seed aerosol, indicating that low concentration of dry (NH4)2SO4 acts just as the nucleation or condensation center of the SOA, and do not affect the chemical composition of SOA. However, 1 H-imidazole, 1 H-imidazole-2-carbaldehyde, hydrated 1 H-imidazole-2-carbaldehyde, 2,2′-biimidazole, hydrated N-glyoxal substituted 1 H-imidazole, N-glyoxal substituted hydrated 1 H-imidazole-2- carbaldehyde, hydrated mono glyoxal substituted hydrated 1 H-imidazole-2-carboxaldehyde, mono glyoxal substituted 2,2-biimidazole and hydrated glyoxal dimer substituted imidazole which are formed from ammonium ion reaction with glyoxal are the major particulate products in the aged benzene SOA in the presence of high concentration (about 100 μg m−3) of dry (NH4)2SO4. The retention of water on the dry (NH4)2SO4 particles creates ammonium ion, which can promote the formation of high-molecular-weight (HMW) products through multiphase reactions such as hydration and polymerization of aldehydes form from OH-initiated oxidation of benzene.KeywordsBenzeneSecondary organic aerosolAmmonium sulfateSeed aerosolLaser desorption/ionizationAging mechanism