Concentration and impacting factors of soluble nutrients in aerosols, Shanghai

To investigate the concentration and variation of soluble nutrients in the aerosols of Shanghai, 27 aerosol samples were collected from June 2007 to March 2009 in East China Normal University and analyzed for the soluble nutrients, including NO₃^- + NO₂^-, NH₄⁺, PO₄^3- and SiO₃^2-. By continuous leaching with Milli-Q water and hydrochloric acid (pH2), most of the nitrate/nitrite (94%) and ammonium (96%) could be leached in the first step, but the amount of silicate (34%) and phosphate (50%) dissolved in water was equal to or less than that in hydrochloric acid. Combine the nutrients concentration with the back trajectory, the origin and transportation process had significant impacts on aerosol nutrients concentration. The weight concentration for NO₃^- + NO₂^- and NH₄⁺ showed the highest value in land-sourced aerosols, but there were not much difference for PO₄^3- and SiO₃^2- in different types of aerosols. The volume-weighted concentration of all nutrients were influenced by both sources and precipitation and showed obvious seasonal characteristics, with higher concentration in Spring and Winter than in Summer and Autumn.