Sequential voltammetric determination of mercury(II) and toxic metals in environmental bio-monitors: application to mussels and clams

This article reports the sequential voltammetric determination of Hg(II) and Cu(II) at gold electrode (GE), and of Cu(II), Pb(II), Cd(II), Zn(II) at hanging mercury drop electrode by square wave anodic stripping voltammetry in mussels and clams, possible environmental bio-monitors. The analytical procedure was verified by the analysis of standard reference materials: oyster tissue NBS-SRM 1566a, mussel tissue BCR-CRM 278 and cod muscle BCR-CRM 422. Precision and accuracy, expressed as relative standard deviation and relative error, respectively, were always less than 6%. Then, the analytical procedure was transferred and applied to mussels and clams sampled in two lagoon ecosystems connected with Adriatic Sea (Italy): the Goro Bay, located in the Po river mouth area and the lagoon ecosystem located in proximity to Ravenna. A critical comparison with spectroscopic measurements is also discussed.