Square-wave voltammetric determination of thallium using surface modified thick-film graphite electrode with Bi nanopowder

Trace analysis of thallium at surface modified thick-film graphite electrode with Bi nanopowder has been carried out using square-wave anodic stripping voltammetry (SWASV) technique. The Bi nanopowder electrode exhibited a well-defined response relating to the oxidation of TI. From the linear relationship between TI concentration and peak current, the sensitivity of the Bi nanopowder electrode was quantitatively estimated. The detection limit of TI was determined to be 0.03 mu g/L for 1.0 mu g/L TI solution under 10 min accumulation, which is lower than the reported values for a Bi film electrode. Furthermore, it is confirmed that EDTA addition effectively eliminates the Pb and Cd interferences in the course of TI determination by forming complexes with Pb2+ and Cd2+. (C) 2008 Elsevier B.V. All rights reserved.