Soluble and particulate metals in the Adige River

The concentrations of 10 metals (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) were monitored over a 1-year period in the waters of the lower Adige River. Concentrations in the dissolved and particulate phases were measured, thus constructing a database on metal variability. The concentrations of Cd, Cr, Cu, Mn, Ni, and Pb in these water samples are too low to be directly determined by flame atomic absorption spectrometry or (graphite furnace atomic absorption spectrometry (GFAAS). In this work Cd, Co, Cu, Mn, Ni, Pb, and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS) or GFAAS after on-line preconcentration and following solvent elution with a flow injection analysis system (FIAS). The eluted samples were also dried in a vacuum container and restored to a small volume with concentrated HNO3 and Milli-Q water for analysis by ICP-MS or GFAAS. The concentrations of soluble Cd, Fe, and Mn and particulate As, Cr, Cu, Pb, and Zn are well correlated with seasonal variability (P < 0.01). Dissolved As and Fe are well correlated (P < 0.01), and with respect to the particulate phase, good correlations are observed between Pb, Cd, and Cu. (C) 1998 Academic Press.