STUDY ON THE SENSITIVE AND SELECTIVE ADSORPTION VOLTAMMETRY OF VANADIUM WITH ANTIPYRYLAZO-III (APA-III)

The sensitive and selective adsorption voltammetric determination of t he vanadium(V)-antipyrylazoIII complex in HAc-NaAc solution is investi gated. The V-complex is strongly adsorbed onto a stationary Hg-electro de and is reduced at a potential more negative than that corresponding to the reduction of its ligand. The conditions for determining vanadi um are investigated and the mechanism of the reduction peak of the van adium complex is discussed, as also the influence of foreign ions on t he determination of vanadium. An at least 20-fold excess of foreign io ns does not cause any interference. The detection limit is 4 x 10(-10) mol/l V with 3 min enrichment time.