Synthesis of Nanocrystalline Bismuth and Its Application to the Detection of Trace Metals

Surface modified carbon strip electrode with Bi nanopowder was suggested for a simultaneous analysis of Zn, Cd, and Pb ions by a square wave anodic stripping voltammetry, and the influence of the modifying Bi mass and particle size on the trace metal response was investigated. The Bi nanopowders with various particle size distributions were synthesized by an optimization of the gas condensation condition, in which a refractory crucible was applied for the evaporation of volatile Bi, and then immobilized on the surface of a working electrode. The result of the stripping measurements shows that when the modifying mass and the particle size of the Bi powder were in the range of 2 to 5 mu g/cm(2) and less than 300 nm, respectively, a well-developed and reproducible stripping response was obtained. The proposed "mercury-free" carbon strip electrode, modified with Bi nanopowder, is conveniently usable and directly applicable to a trace metal analysis without a pre-deposition of Bi and complicated surface polishing steps.