Electroanalytical Determination of Cadmium(II) and Lead(II) Using an Antimony Nanoparticle Modified Boron-Doped Diamond Electrode

We report the simultaneous electroanalytical determination of Pb2+ and Cd2+ by linear sweep anodic stripping voltammetry (LSASV) using an antimony nanoparticle modified boron doped diamond (Sb-BDD) electrode. Sb deposition was performed in situ with the analytes, from a solution of 1 mg L-1 SbCl3 in 0.1 M HCl (pH 1). Pb2+ inhibited the detection of Cd2+ during simultaneous additions at the bare BDD electrode, whereas in the presence of antimony, both peaks were readily discernable and quantifiable over the linear range 50-500 mu g L-1. Ex situ AFM characterization of the BDD electrode after Sb deposition showed a distribution of nanoparticles ranging from 3 to 110 nm in height, and 8.5 to 506.5 nm in diameter across the electrode surface, which corresponded well to the low mass of Sb expected on the BDD with respect to the voltammetric data.