Preconcentration and voltammetric determination of palladium (II) at sodium humate modified carbon paste electrodes

A chemically modified carbon paste electrode was prepared by incorporating appropriate amounts of sodium humate(NaA). Palladium(II) was selectively accumulated in a solution of Britton-Robinson(B-R) buffer (pH 2.8) onto the electrode surface in open circuit mode. The subsequent electrochemical measurement was carried out by cyclic voltammetry (CV) and linear sweep anodic stripping voltammetry (LSASV) in a supporting electrolyte of 1.0 M HCl. The obtained oxidation currents (I_pa1 and L_pa2) were proportional to the Pd(II) concentration in the range of 4.7 × 10^–6 - 9.4 × 10^–8 M. The developed method was applied to the quantitative determination of palladium in real samples. Received: 6 March 1998 / Revised: 3 June 1998 / Accepted: 3 July 1998