Chemical characterization of aerosol collected at Mt. Yulong in wintertime on the southeastern Tibetan Plateau

In order to evaluate the chemical composition of aerosol on the southeastern Tibetan Plateau, aerosol samples were acquired at Mt. Yulong during January to February, 2010. Eighteen elements (Al, Si, P, S, Ca, Ti, K, Cr, Mn, Fe, Ni, Zn, As, Br, Ba, Pb, Sb and Cu) and major water-soluble ions (SO ₄ ^2-, NO ₃ ^-, Cl ^-, Na ⁺, NH ₄ ⁺, K ⁺, Mg ²⁺, and Ca ²⁺) were detected. The results show that Ca, Fe, Al, Si, S, K and Ti are major elements which mainly originate from crustal material, while SO ₄ ^2- and Ca ²⁺ are the dominant anion and cation in the samples, respectively. Results of ion analysis indicate that our samples are alkaline and that the main compounds present are CaCO ₃, (NH ₄) ₂SO _4, and CaSO ₄. The enrichment factors (EFs) determined for As, Br, Ca, Cu, S, Pb and Zn are greater than 10; in particular, EFs for As and Br are above 100. However, the high EF for As could be caused by crustal sources because the high level of As enrichment can be found commonly on the Tibetan Plateau. Analyses including Scanning Electron Microscope (SEM) observations, EF determinations, backward trajectories and correlation coefficients reveal that Al, Fe, Ca, Ti, Mn, Fe, K and Mg ²⁺ mainly originate from crustal sources; Pb, Br, Cu, Ni, Zn and Sb come mainly from traffic-related emissions; and biomass burning influences Cl ^-, Br, S and P.