Abstract

Trace analysis of Cd and Pb at surface modified thick film graphite electrode with Bi nanopowder has been carried out using square-wave anodic stripping voltammetry (SWASV) technique. Bi nanopowder synthesized by gas condensation (GC) method showed the size of 50sim100 nm with BET surface area, A_BET=6.8m2g-l. For a strong adhesion of the Bi nanopowder onto the screen printed carbon paste electrode, nafion solution was added into Bi-containing suspension. From the SWASV, it was found that the Bi nanopowder electrode exhibited a well-defined responses relating to the oxidations of Cd and Pb. The current peak intensity increased with increasing concentration of Cd and Pb. From the linear relationship between Cd/Pb concentrations and peak current, the sensitivity of the Bi nanopowder electrode was quantitatively estimated. The detection limit of the electrode was estimated to be 0.15µg/l and 0.07µg/l for Cd and Pb, respectively, on the basis of the signal-to-noise characteristics (S/N=3) of the response for the 1.0µg/l solution under a 10 min accumulation.

• Keywords: Bi nanopowder electrode;Gas condensation method;Cadmium;Lead;Square wave anodic stripping voltammetry;