Organosulfates which have been discovered in secondary organic aerosols are important constituents of PM_2.5 in the atmosphere. Formed through anthropogenic activities and biogenic emissions, they have negative impacts on not only human health but also global climate change. Based on major precursors in different atmospheric environments, i.e., biogenic volatile organic compounds isoprene and α-/β-pinene in forest (clean area), anthropogenic polycyclic aromatic hydrocarbons in urban (polluted area), and biogenic and anthropogenic mixed sources carbonyls in areas affected by both vegetation and human activities, we elaborated systematically the categories and structures of organosulfates and their photooxidation formation pathway under various atmospheric conditions with different atmospheric oxidants in the presence of SO₂/H₂SO₄. Then, relevant literatures have been reviewed as much as possible and the concentration levels in PM_2.5 in reported areas worldwide aresummarized. Moreover, up-to-date analytical techniques are described, as well as their benefits and drawbacks. Finally, impact factors of organosulfates formation are discussed. At the end of context, several issues are proposed which need to be addressed urgently, and future research directions in organosulfates are also prospected.
Contents
1 Introduction
2 The categories and formation mechanisms of OS
2.1 Forest (clean area)
2.2 Urban (polluted area)
2.3 Mixture areas affected by both vegetation and human activities
3 The concentration levels of OS
4 Analytical techniques
5 Impact factors
6 Conclusion