Bismuth Film Electrode in Metal Complexation Studies: Stripping Analysis of the Pb(II)-, Cd(II)-, and Zn(II)-Binding with Phthalate

摘要

The possibilities of bismuth film electrode for complexation studies by anodic stripping voltammetry (ASV) and constant current stripping chronopotentiometry (CCSCP) are tested for Pb(II), Cd(II), and Zn(II) in the presence of phthalate. In all cases, labile complexes are detected. The regular signals obtained for the Pb(II)-phthalate system allow an accurate determination of stability constants by means of the DeFord-Hume method. As for Cd(II)-ions, the two overlapping signals usually present in the absence of ligands suffer a similar evolution with the addition of phthalate. Then, the use of an intermediate potential between both signals allows a reasonable estimation of stability constants. In contrast, the two overlapping signals obtained for Zn(II) behave in a quite irregular way in the presence of phthalate, thus hindering any quantitative analysis of the formed complexes.