View article

Daily total suspended particulate (TSP), particle size smaller than 100μm and particle size smaller than 2.5μm (PM_2.5) aerosol samples were collected at two sites in Shanghai in four seasons from September 2003 to January 2005. Concentrations of the water-soluble ions (SO₄²⁻, NO₃⁻, Cl⁻, F⁻, PO₄³⁻, HCOO⁻, CH₃COO⁻, NO₂⁻, MSA, C₂O₄²⁻, NH₄⁺, Ca²⁺, Na⁺, K⁺, Mg²⁺) were measured for a total of 202 samples. Daily TSP and PM_2.5 mass concentrations ranged from 66.1 to 666.8μgm⁻³ and 17.8 to 217.9μgm⁻³, with annual average concentrations of 230.5 and 94.6μgm⁻³, respectively. The sum of ions contributed an average of 26% and 32% of TSP and PM_2.5 mass concentrations, respectively. In PM_2.5, the concentration of the major ions followed the order of SO₄²⁻>NO₃⁻>NH₄⁺>Cl⁻>Ca²⁺>K⁺, while in TSP was SO₄²⁻>NO₃⁻>Cl⁻>Ca²⁺>NH₄⁺>Na⁺. These major ions were mainly in the form of (NH₄ …