Complexation, adsorption and reduction of palladium-dimethylglyoxime: Analytical considerations

RAMÍREZ SILVANA A.; GABRIEL GORDILLO

Global Journal of Analytical Chemistry

Simplex Academic Publishers

Lugar: Tamil Nadu; Año: 2010 vol. 1 p. 59 - 67

0976-5514

Electroanalysis offers an interesting tool for palladium quantification by using adsorptive strippingvoltammetry of Pd-dimethylglioxime complex on mercury. Here we show that complexation kinetics andsolubility in the homogeneous phase, in addition to surface concentration, are relevant analytical aspects to beconsidered. Complexation kinetics is first order in both Pd(II) and the ligand (k = 15 s-1 M -1). This determines thechemical equilibration time after each metal addition: for example when using 1 × 10-4 M dimethylglioxime anon- negligible chemical equilibration time ca. 1 hour should be considered. The upper limit of the linear range isdetermined by two factors: complex solubility in the solution (ca. 2.5 M) and surface concentration. The lattershould develop a redox charge lower than 30 C cm-2.