Study of the reduction of palladium(II) on a mercury electrode in the presence of dimethylglyoxime

Abstract

The adsorptive behavior of Pd" ions in the presence of dimethylglyoxime (DMG) was investigated using voltammetric techniques. It was found that the bis-dimethylglyoximato palladium(ii) complex is adsorbed strongly between pH 3 and 5 and between the potentials 0 and -0.3 V (vs. Ag/AgCl). The peak current is proportional to the Pd-DMG surface concentration, and increases linearly with scan rate (Blog i,,/L?u = 0.97). The adsorptive stripping response was evaluated with respect to pH, the concentration of the electrolyte, the addition of surfactants and the preconcentration potential. From the results a general scheme for the reduction process is given.

Some Importante Parameters for Electrochemical Behaviour of Palladium (II) in the Presence of Chelate Ligand Dimethylglyoxime

“…Investigation of the reduction process of Pd-DMG complex [14] showed that the voltammetric peak height depends on pH , the concentration of DMG and buffer composition, the scan rate, and the presence of surface active substances [2].The adsorptive stripping response was evaluated with respect to the concentration of the supporting electrolyte and the preconcentration potential. The optimum concentration of the supporting electrolyte (acetate buffer) is 0.1 mol/L and the optimum pH value is 3.5 ± 0.5.…”

“…The optimum potential range for its accumulation is between 0 and -0.35 V with respect to the Ag/AgCl electrode [2,14]. Current response during the reduction of the Pd-DMG complex depends on their equilibrium concentration on the electrode surface [14].…”

“…Therefore, it is expected that the electroanalytical techniques analogous to the stripping method are advantageous in improving the quantitation of palladium(IT). Further increase in the sensitivity and the selectivity of advanced voltammetric methods, e.g., differential pulse polarography (DPP), square wave voltammetry (SWV) and stripping voltammetry (SV), can be achieved by a modification of the electrode [6][7][8] and/or an enhanced adsorption of the analyte [9][10][11][12][13][14].…”

“…On the basis of the data published by Wang and Varughese [10] and considering our previous investigations [2,14], we optimised some parameters of importance for adsorptive stripping voltammetry (AdSV). The determination of palladium(TJ) in different solid samples by this method is also presented herein.…”

Voltammetric Analysis of Trace Levels of Platinum Group Metals – Principles and Applications

“…Such a technique has been employed for the determination of several metals, but, considering only the platinum group metals, their voltammetric determination is limited to few but definite procedures, procedures, however prevalently addressed to single elements of the PGMs [68,69], so much so that, for example, the same supporting electrolyte may present, at the same potential, voltammetric signals relevant to two different PGMs, as Pt(II) and Ru(III) in the presence of 1-(2-pyridylazo-2-naphtol) as ligand [70]. Evidently, this goes against the peculiarity of the same technique, that permits to quantify simultaneously several metals carrying out single potential scans (possibility of multicomponent determination).…”