A comparison between PIXE and ICP-AES measurements of metals in aerosol particulate collected in urban and marine sites in Italy

PIXE and ICP-AES techniques are largely used in atmospheric aerosol studies. Since PIXE is able to provide the total elemental concentrations, while ICP-AES results depend on the extraction conditions, parallel PIXE and ICP-AES measurements of Fe, Al, Cu, Pb, Mn, Cr, Ni, V, As on PM10 and PM2.5 samples were compared. Two extraction procedures were applied to samples from 5 sites at different anthropization level in Italy: a “weak” extraction (HNO3 at pH = 1.5) and a “strong” extraction (micro-wave oven in HNO3 and H2O2 – following EU rules).The amount of the metal extracted in the different conditions resulted to be strongly dependent on the sampling site, on the main sources of the particle (crustal or anthropic) containing the metal and on the sampled size class.