ADSORPTIVE DIFFERENTIAL-PULSE VOLTAMMETRIC DETERMINATION OF TRACE AMOUNTS OF RUTHENIUM

An electrochemical technique for the convenient determination of trace amounts of ruthenium was developed, based on the adsorptive accumulation of Ru(II)-salicylaldehyde thiosemicarbazone on the surface of a hanging mercury drop electrode, followed by the reduction of the adsorbed complex during the cathodic scan. The adsorptive differential-pulse voltammetric curve exhibited a well-defined cathodic peak at -0.750 V versus a saturated calomel electrode. Cyclic voltammetry was used to characterize the interfacial and redox behaviour. The optimum analytical conditions for the determination of ruthenium, for the working range 5-80 ng cm-3, were etablished. A statistical evaluation of the experimental results is reported. The method was applied to the determination of ruthenium in synthetic solutions of various compositions as well as in catalysts.