1999 Volume 15 Issue 1 Pages 35-40
A simple method has been developed for the voltammetric determination of Ga(III). In a 50 mM Mo(VI)-0.2 M HCl-40%(v/v) CH3CN system, Ga(III) reacts directly with Mo(VI) to form a 12-molybdogallate(III) complex. The yellow Keggin complex undergoes a two-step reduction to the mixed-valence heteropoly-blue species at the glassy carbon (GC) electrode. The 1st voltammetric reduction current depends linearly on the Ga(III) concentration in the range of 5×10-5 - 1×10-3 M. Common metal ions including Al(III) and In(III) at 100-fold concentrations caused no interference. The effect of organic solvents on the formation of the Keggin complexes prepared so far is also discussed.