Voltammetric study of zinc(II) and lead(II) ions in the presence of alginate and pectin

Abstract

AbstractComplex formation of Zn(II) and Pb(II) with alginates and pectins was studied by normal‐pulse (NPP), reverse‐pulse (RPP), and differential‐pulse polarography (DPP), cyclic voltammetry (CV), and differential pulse anodic stripping voltammetry (DPASV). The systems appear to be labile on the different time scales of the various techniques. Adsorption of both polysaccharides, and the further induced adsorption of Zn(II) and Pb(II), are evidenced clearly by NPP. On the other hand, induced adsorption of metal ions is minimized under the RPP conditions. The reversibility of the redox couples Zn2+/Zn(Hg) and Pb2+/Pb(Hg) is not strongly affected by the presence of polysaccharides. Titrations of Zn(II) and Pb(II) with alginates or pectins were carried out by DPP and DPASV in order to determine formation constants, which was only found for the Zn(II)‐ion systems.