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Voltammetric determination of vanadium with adsorptive preconcentration 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 interfacial accumulation of the vanadium-pyrocatechol complex onto the hanging mercury drop electrode, followed by reduction of the adsorbed complex. The limit of detection is 0.1 nM vanadium after a 3 min collection with a stirred solution at pH 4.7. The procedure is selective with respect to other metals and has been applied in analysing various samples.