Soluble of metals within TSP in Shanghai

The dissolution of metals within aerosol particles is meaningful to evaluate the bioavailability and mobility of metals. Total suspended particles (TSP) samples were collected in Shanghai. We extracted the water soluble and acid soluble (pH=2) metals by the mini-recirculation-leach-system and measured their concentrations by the high resolution inductively coupled plasma mass spectrometry. The dissolution kinetics were rapid, the maximum solubility of metals could be reached in a few minutes. Overall, the average water-soluble concentrations were low for Co, Cr, Cd, V and Ni, median for Cu, Pb and Mn and high for Fe, Al, Zn and Mg. Combine the soluble metal concentrations with the back trajectory, the original air mass had significant impacts on water soluble metal concentrations. The water solubility and acid solubility were different for various metals, the water solubility of Fe was the lowest (2.0%), others followed an order: Al, Cr, V, Pb, Co, Ni, Cu, Cd, Mn, Mg, Zn. The metals' solubility was increased with the decrease of the solvent pH value. While the chemical speciation of metals was the internal cause of metals' solubility, the metals' ionic potential and the water solubility was negatively correlated.