Characterization of organosulfates in atmospheric aerosols at Four Asian locations

Organosulfates have recently been observed in ambient atmospheres as a component of aerosol organic matter. This study presents the first characterization of organosulfates in Asia and demonstrates their ubiquity and chemical diversity, yet minor contribution to fine particulate mass. Organosulfates were characterized in ambient aerosol by ultra-performance liquid chromatography and high-resolution mass spectrometry, which allowed for experimental determination of molecular formulas and estimation of atmospheric abundance. Aerosols were analyzed from four sites spanning urban and remote locations, including Hanimaadhoo, Maldives, Gosan, Korea, Singapore, and Lahore, Pakistan. Semi-quantitative analysis yielded average estimates of OS accounting for less than 1% of PM2.5 mass, 2.3% of organic carbon, and 3.8% of total sulfate. The majority of the observed compounds were attributed to biogenic secondary organic aerosol from isoprene or monoterpenes. New organosulfates are also reported.

► We characterize organosulfates in Asian aerosol for the first time.
► Organosulfates are minor contributors to particulate mass and carbon.
► More than 20 individual organosulfate species were observed.
► Most species were consistent with biogenic secondary organic aerosol.
► Other species were unique to a season or location.