CATHODIC STRIPPING VOLTAMMETRY OF VANADIUM BASED ON ADSORPTIVE ACCUMULATION OF ITS SOLOCHROME VIOLET RS COMPLEX AT THE STATIC MERCURY DROP ELECTRODE

A very sensitive electrochemical stripping procedure for vanadium is reported. Accumulation is achieved by controlled adsorption of the vanadium/solochrome violet RS complex on the static mercury drop electrode. Optimal experimental parameters found include an accumulation potential of -0.22 V, solochrome violet RS concentration of 2.0 x 10(-6)M, and a differential pulse stripping mode. After 5 minutes preconcentration, a detection limit near 1.7 x 10(-10) M vanadium is obtained. The response is linear over the 0-21 mug1(-1) concentration range, and the relative standard deviation (at the 11.2 mug1(-1) level) is 3.8%. The possible interference by other trace ions are investigated. Simultaneous determination of vanadium with molybdenum and cadmium is illustrated. The merits of this procedure are demonstrated in the analysis of sea and river waters.