Characteristics and formation mechanisms of atmospheric organosulfates

Abstract

Atmospheric organosulfates refer to sulfate esters and their derivatives that have been identified in ambient secondary organic aerosol(SOA) samples. Recent laboratory and field studies show that organosulfates are derived from the reactions of particulate sulfates or sulfuric acid with compounds formed from hydroxyl radical(OH)/nitrate radical(NO3)/ozone(O3)-initiated reactions of isoprene, α-/β-pinene, and other monoterpenes and sesquiterpenes. Organosulfates can also be formed through reactive uptake of carbonyls such as glyoxal by particulate sulfates or sulfuric acid. Enhanced acidity of the sulfate seed particles favors the production of organosulfate. Hydrolysis of organosulfates is slow unless in a highly acidic solution. Offline electrospray ionization mass spectrometry(ESI-MS) and online aerosol mass spectrometry(AMS) are useful methods to detect atmospheric organosulfates.