title: Analysis of organic sulfur compounds in atmospheric aerosols at the HKUST supersite in Hong Kong using HR-ToF-AMS.
abstract: Organic sulfur compounds have been identified in ambient secondary organic aerosols, but their contribution to organic mass is not well quantified. In this study, using a high-resolution time-of-flight aerosol mass spectrometer (AMS), concentrations of organic sulfur compounds were estimated based on the high-resolution fragmentation patterns of methanesulfonic acid (MSA), and organosulfates (OS), including alkyl, phenyl, and cycloalkyl sulfates, obtained in laboratory experiments. Mass concentrations of MSA and minimum mass concentrations of OS were determined in a field campaign conducted at a coastal site of Hong Kong in September 2011. MSA and OS together accounted for at least 5% of AMS detected organics. MSA is of marine origin with its formation dominated by local photochemical activities and enhanced by aqueous phase processing. OS concentrations are better correlated with particle liquid water content (LWC) than with particle acidity. High-molecular-weight OS were detected in the continental influenced period probably because they had grown into larger molecules during long-range transport or they were formed from large anthropogenic precursors. This study highlights the importance of both aqueous-phase processing and regional influence, i.e., different air mass origins, on organic sulfur compound formation in coastal cities like Hong Kong.
authors.affiliation: †Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Dan Dan
authors.initials: DD
authors.lastname: Huang
authors.affiliation: ‡Division of Environment, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Yong Jie
authors.initials: YJ
authors.lastname: Li
authors.affiliation: ‡Division of Environment, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Berto P
authors.initials: BP
authors.lastname: Lee
authors.affiliation: †Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.|‡Division of Environment, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Chak K
authors.initials: CK
authors.lastname: Chan
mesh_terms: D000336:Aerosols / Q000032:analysis*; D001272:Atmosphere / Q000737:chemistry*; D002947:Cities; D006723:Hong Kong; D013058:Mass Spectrometry / Q000379:methods*; D008970:Molecular Weight; D009930:Organic Chemicals / Q000032:analysis*; D013431:Sulfates / Q000032:analysis; D013457:Sulfur Compounds / Q000032:analysis*; D013472:Sunlight; D013997:Time Factors
chemical_list: D000336:Aerosols; D009930:Organic Chemicals; D013431:Sulfates; D013457:Sulfur Compounds