VOLTAMMETRIC DETERMINATION OF VANADIUM WITH ADSORPTIVE PRECONCENTRAION OF THE PYROCATECHOL VIOLET COMPLEX

A sensitive stripping voltammetric procedure for trace measurements of vanadium in aqueous samples is reported. The method is based on the i nterfacial accumulation of the vanadium pyrocatechol complex onto the hanging mercury drop electrode, followed by reduction of the adsorbed complex. The limit of detection is 0.1nM vanadium after a 3 min collec tion with a stirred solution at pH 4.7. The procedure is selective wit h respect to other metals and has been applied in analyzing various sa mples.