Environment context.Oxygenated organic compounds are active constituents in ambient aerosols, affecting their hygroscopic properties and other interactions with water. We have measured 29 oxygenated organic compounds, together with inorganic ions and other major aerosol constituents, in ambient samples collected under various synoptic conditions in Hong Kong. These composition profiles of water-soluble matter provide valuable data for modelling and theoretical studies of aerosol–water interactions.
Abstract. This study reports a comprehensive dataset of oxygenated compounds, inorganic ions and other major aerosol constituents in fine particulate matter (2.5 μm) in the urban atmosphere of Hong Kong in periods of different synoptic weather conditions during 2003–05. The oxygenated compounds quantified include C2–C10 dicarboxylic acids, C3–C9 ketoacids and C2–C3 dicarbonyls, their combined concentrations accounting for 3.2–18.2% of water-soluble organic carbon on a carbon mass basis. Six C2 and C3 oxygenated compounds, namely oxalic acid, malonic acid, glyoxylic acid, pyruvic acid, glyoxal, and methyl glyoxal, dominate this suite of oxygenated compounds, accounting for 75% of the total quantified oxygenated species. Good correlations were observed among most of the quantified oxygenated compounds, suggesting that a relatively stable abundance distribution exists under varying synoptic conditions. These composition profiles provide a comprehensive dataset for use in modelling and theoretical studies of aerosol–water interactions, secondary aerosol formation pathways, and speciated organic mass distributions.