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Field observations of C2 and C3 organosulfates and insights into their formation mechanisms at a suburban site in Hong Kong.
Wang, Yuchen; Liang, Shumin; Le Breton, Michael; Wang, Qiong Qiong; Liu, Qianyun; Ho, Chin Hung; Kuang, Bin Yu; Wu, Cheng; Hallquist, Mattias; Tong, Rongbiao; Yu, Jian Zhen.
Affiliation
  • Wang Y; College of Environmental Science and Engineering, Hunan University, Hunan, China; Division of Environment and Sustainability, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China.
  • Liang S; Department of Chemistry, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China.
  • Le Breton M; Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
  • Wang QQ; Department of Chemistry, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China.
  • Liu Q; Division of Environment and Sustainability, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China.
  • Ho CH; Division of Environment and Sustainability, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China.
  • Kuang BY; Department of Chemistry, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China.
  • Wu C; Division of Environment and Sustainability, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China; Institute of Mass Spectrometer and Atmospheric Environment, Jinan University, Guangzhou, China.
  • Hallquist M; Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
  • Tong R; Department of Chemistry, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China.
  • Yu JZ; Division of Environment and Sustainability, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China; Department of Chemistry, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China. Electronic address: jian.yu@ust.hk.
Sci Total Environ ; 904: 166851, 2023 Dec 15.
Article in En | MEDLINE | ID: mdl-37673264
ABSTRACT
Organosulfates (OSs) are formed from volatile organic compounds (VOCs) and their oxidation products in the presence of sulfate particles. While OSs represent an important component in secondary organic aerosol, the knowledge of their formation driving force, mechanisms, and environmental impact remain inadequately understood. In this study, we report ambient observations of C2-3 oxygenated VOCs derived OSs (C2-3 OSs) at a suburban location of Hong Kong during autumn 2016. The C2-3 OSs, including glycolaldehyde sulfate (GS), hydroxyacetone sulfate (HAS), glycolic acid sulfate (GAS), and lactic acid sulfate (LAS), were quantified/semi-quantified using offline liquid chromatography-mass spectrometry analysis of aerosol filter samples. The average sum concentration of C2-3 OSs was 36 ng/m3. Correlation analysis revealed that sulfate, surface area, and liquid water content were important factors influencing C2-3 OS formation. Online measurement with an iodide High-Resolution Time-of-Flight Chemical-Ionization Mass Spectrometer (HR-ToF-CIMS) coupled with the Filter Inlet for Gases and AEROsols (FIGAERO) was also conducted to monitor C2-3 OSs, and their potential oxygenated VOC precursors in both gas- and particle-phase, and aerosol acidity tracer simultaneously. Our measurements support that glycolaldehyde/glyoxal, hydroxyacetone, glycolic acid/glyoxal, and lactic acid/methylglyoxal are likely precursors for GS, HAS, GAS, and LAS, respectively. Additionally, we found strong correlation between C2-3 OSs and H3S2O8-, a marker for aerosol acidity, providing field observational evidence for acid-catalyzed formation of small OSs. Based on both online and offline measurements, acid-catalyzed formation mechanisms in particle/aqueous phase are proposed. Specifically, the unique structure of adjacent carbonyl and hydroxyl groups in the C2-3 oxygenated VOC precursors can facilitate the formation of (1) a five-member ring intermediate via intramolecular hydrogen bond to react with sulfur trioxide through heterogenous reaction or (2) cyclic sulfate intermediate via particle-phase reaction with sulfuric acid to generate C2-3 OSs. These proposed mechanisms provide an alternative pathway for the liquid-phase production of C2-3 OSs.
Key words

Full text: 1 Collection: 01-internacional Database: MEDLINE Language: En Journal: Sci Total Environ Year: 2023 Document type: Article Affiliation country: China

Full text: 1 Collection: 01-internacional Database: MEDLINE Language: En Journal: Sci Total Environ Year: 2023 Document type: Article Affiliation country: China