Metals concentrations in transitional and coastal waters by ICPMS and voltammetry analysis of spot samples and passive samplers (DGT)

This study investigates the relationships among Ni, Cd and Pb's different chemical forms determined by different methodologies in coastal and transitional waters across a broad geographical scale. Concentrations were measured in spot samples and through passive sampling (DGT). High variability of metal concentrations was found among sampling sites and methodologies due to natural water fluctuations rather than to a given metal or method. Total dissolved metal concentrations in spot samples were lower than the EQS-WFD values. The labile fractions of Cd and Pb, measured in spot samples by Anodic Stripping Voltammetry and by DGT-ICPMS, were highly correlated. Similar labilities were found for Cd, while for Pb, the ASV labile fraction was asymptotic to 50% lower. These results reflect the pool of mobile and labile species available towards each technique kinetic window, and they seem not to be affected by discrete sampling flaws.

Automated summary

This study investigates the relationships among different chemical forms of Ni, Cd, and Pb in coastal and transitional waters across a broad geographical scale. The concentrations of metals vary greatly among sampling sites and methodologies, mainly due to natural water fluctuations. The labile fractions of Cd and Pb in spot samples are highly correlated, with Pb's labile fraction significantly lower than Cd's.