POLAROGRAPHY AND STRIPPING VOLTAMMETRY OF METAL-POLYCARBOXYLATE COMPLEXES - THE CU(II)-POLYACRYLATE SYSTEM

A systematic study of the voltammetric behavior of Cu(II) in the prese nce of polyacrylic acid (PAA) was carried out by means of sampled dire ct current polarography (DCP), normal pulse polarography (NPP), differ ential pulse polarography (DPP), reverse pulse polarography (RPP), cyc lic voltammetry (CV), and differential pulse anodic stripping voltamme try (DPASV). Background currents due to PAA, and probably anodic oxida tion of the Hg in this potential region, hinder the study of the Cu(II ) reduction. Results obtained seem to indicate the lability of the Cu/ PAA complex. Distorted DPASV signals are obtained for Cu(II) in the pr esence of PAA, which are explained on the basis of the change of the l igand-to-metal ratio during the different steps of the electrodic proc ess. Titrations of Cu(II) with partially neutralized PAA allow the det ermination of the apparent formation constant K of the Cu/PAA complex system.