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(ll) was selectively accumulated in a solution of Britton-Robinson(B-R) buffer (pH 2.8) onto the electrode surface ill 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 x 10(-6) - 9.4 x 10(-8) M. The developed method was applied to the quantitative determination of palladium in real samples.