Seasonal and diurnal variations of particulate organosulfates in urban Shanghai, China
|Title||Seasonal and diurnal variations of particulate organosulfates in urban Shanghai, China|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Ma, Y, Xu, X, Song, W, Geng, F, Wang, L|
|Keywords||Fine particulate matter, Organosulfates, Secondary organic aerosols, Shanghai|
PM2.5 samples have been collected in urban Shanghai, China, during April (spring), July (summer), October (autumn) 2012, and January (winter) 2013, respectively. Seventeen organosulfates (OSs) derived from isoprene, α-/β-pinene, and presumably aromatic precursors were quantified using a high-performance liquid chromatogram coupled to a triple quadrupole mass spectrometer. During our sampling days, the total concentration of detected OSs ranged between 0.0209 and 60.8ngm-3 (sodium octyl sulfate and benzyl sulfate as standards). The seasonal average concentration of OSs was the highest (26.2ngm-3) in summer 2012 and the lowest (0.510ngm-3) in spring 2012, accounting for 0.471‰ and 0.00965‰ of the corresponding PM2.5 mass, respectively. Isoprene- and α-/β-pinene-derived OSs showed a clear seasonal fluctuation with a peak in summer, whereas OS derived from aromatic precursors was less variable in most seasons. The share of aromatic OS in the total measured OSs was the highest (63.5%) in winter 2013 and the lowest (2.94%) in summer 2012, suggesting that aromatic OS could serve as an important component of the OS species in urban Shanghai. In addition, a number of OSs demonstrated distinct diurnal profiles, reflecting diverse formation mechanisms with multiple atmospheric oxidants in an urbanized area like Shanghai. © 2013 Elsevier Ltd.