Determination of Lead Traces by Stripping Voltammetry Using Ti(N,C) Working Electrodes

Abstract

Electrochemical stripping techniques still attract considerable attention for trace metal analysis and for measuring several important organic compounds, due to their unique capabilities of pre-concentrating the analytes at the electrode surface and associated favourable low limits of detection. In this work it is reported for the first time that the Ti(N0,1C0,9), Ti(N0,4C0,6) and Ti(N0,5C0,5) working disc electrodes, a „mercury-free” sensors, offers surprisingly good analytical performance and some valuable properties. The analytical applicability of the Ti(N,C) electrode was confirmed in determination of lead(II) traces in synthetic solutions both with and without surfactants, in certified reference material and in natural water samples. The effects of dissolved oxygen, acids, anions and metal ions were investigated for the Ti(N,C) electrode. Newly prepared and not activated electrode usually cannot be polarized. Therefore, to use the electrode as a voltammetric sensor, its electrochemical activation is required. Composition of conditioning electrolyte and procedures of the electrodes activation were optimized. The fabrication and the response performance of the investigated electrodes were described in the paper. The voltammetric data were associated with the structural characterization of the electrode surface using scanning electron microscopy (SEM) and transmition electron microscopy (TEM).