Advances in analytical chemistry enabling compound-specific isotope measurements have brought about a decade of exploration into the δ13C signatures of n-alkanes and fatty acids formed as important components of plant leaf waxes, soils, sediments and organic aerosols. However, our knowledge of their sources and transport processes in heavily polluted urban aerosols in China is still limited. In this study, we investigate the seasonal variation in stable carbon isotopic composition of n-alkanes and fatty acids in urban aerosols from Beijing. The result showed that 13C-depletion in C29 n-alkane was observed during an extreme rainfall event, during which the inflow of air masses were originated from lower latitude regions. Higher concentrations of 13C-enriched C23 n-alkane in winter together with the air mass trajectories suggested that the Beijing aerosols were affected by the air masses transported from the southern regions. Higher C24/FA ratios with 13C-enrichment occurred as influenced by southerly air masses and lower C24/FA ratios with 13C-depletion was observed with northerly air masses in fall and winter. Our study demonstrated that typical specific markers, such as C23 n-alkane, C29 n-alkane and C24:0 fatty acid, could record the characteristics and isotopic signals of fossil and non-fossil sources in urban aerosols.
The supplementary cover of ACS earth and space chemistry?
This work from Prof. Pingqing Fu’s group in Tianjin University and collaborators from Chinese Academy of Sciences, etc., has been recently published on ACS earth and space chemistry, and is selected as the supplementary cover article for the current issue.
Lujie Ren#, Wei Hu, Juzhi Hou, Linjie Li, Siyao Yue, Yele Sun, Zifa Wang, Xiaodong Li, Chandra Mouli Pavuluri, Shengjie Hou, Cong-Qiang Liu, Kimitaka Kawamura, Robert Mark Ellam, and Pingqing Fu*.2019. Compound-Specific Stable Carbon Isotope Ratios of Terrestrial Biomarkers in Urban Aerosols from Beijing, China. ACS earth and space chemistry. DOI: 10.1021/acsearthspacechem.9b00113.
Link to the article: https://pubs.acs.org/doi/10.1021/acsearthspacechem.9b00113
