Source Identification and Seasonal Variations of Carbonaceous Aerosols in Beijing—A Stable Isotope Approach
Carbonaceous aerosols constitute an important part of atmospheric particles in urban areas. Within this study, total carbon (TC) was investigated in total suspended particulates (TSP) and fine particles (PM2.5) collected in the megacity Beijing, China. Beside mass and TC concentrations, also stable C isotopes were analyzed by isotope ratio mass spectrometry (IR-MS) coupled to an element analyzer (EA). Carbon isotope ratios (δ13C) can serve as a fingerprint for source identification, because different source materials have characteristic δ13C values.
The δ13C values in 2008 varied from − 28.2 to − 25.0‰ for PM2.5 and from − 25.5 to − 22.3‰ for TSP samples. In order to gain more information about potential source material, the δ13C values of different source samples from Beijing were analyzed, such as sand from desert regions, construction material, topsoil, or coal. The isotopic C ratio was lowest in summer and highest in spring and winter. The lower δ13C values during summer are caused by a higher share of natural organic C collected, whereas higher δ13C values during the other seasons correlate with higher TC concentrations from anthropogenic and geogenic sources.
KeywordsTotal Suspended Particle Isotope Ratio Mass Spectrometry Carbon Isotope Ratio Source Apportionment Gobi Desert
This study was funded by the German Research Foundation (DFG) under grant STU 169/32-1,2. Laboratory analyses were carried out at the Institute of Mineralogy and Geochemistry (IMG), Karlsruhe Institute of Technology (KIT), Germany. The authors express their special gratitude to the technical staff at IMG for their support. The authors also thank all colleagues in China at CRAES and CUG for collecting the filter samples.
- 11.Norra S, Schleicher N, Stüben D, Chai F, Chen Y, Wang S (2010) Assessment of aerosol concentration sampled at five sites in Beijing from 2005 till 2007. In: Rauch S et al (eds) Highway and urban environment, alliance for global sustainability bookseries 17. Springer, pp 133–140Google Scholar
- 17.Schleicher N, Norra S, Dietze V, Yu Y, Fricker M, Kaminski U, Chen Y, Cen K (2011) The effect of mitigation measures on size distributed mass concentrations of atmospheric particles and black carbon concentrations during the Olympic Summer Games 2008 in Beijing. Sci Total Environ 412–413, 185–193Google Scholar
- 18.Schleicher N, Norra S, Chen Y, Chai F, Wang S (2012) Efficiency of mitigation measures to reduce particulate air pollution—a case study during the Olympic Summer Games 2008 in Beijing, China. Sci. Total Environ 427–428, 146–158Google Scholar