TiC Working Electrode. Voltammetric Characteristics and Application for Determination of Lead Traces by Stripping Voltammetry

• Published in: Electroanalysis (New York, N.Y.) N.Y.), 2008-08, Vol.20 (15), p.1655-1664
• Main Authors: Baś, B., Piech, R., Niewiara, E., Ziemnicka, M., Stobierski, L., Kubiak, W. W.
• Format: Article
• Language: English
• Subjects: Lead; Mercury-free electroanalysis; Stripping voltammetry; Titanium carbide; Trace analysis; Underpotential deposition
• ISSN: 1040-0397; 1521-4109
• DOI: 10.1002/elan.200804229

The TiC working electrode was tested as a novel, potential electrode for anodic stripping voltammetric determination of lead(II) ions traces. To demonstrate the practical applicability of the TiC electrode, an underpotential deposition/dissolution (UPD) phenomena system in electrolyte without removal of oxygen was tested. The electrode was constructed be means of mounting a TiC disk (Ø=3.5 mm) in a resin body. Three compositions of TiC were tested differing in stoichiometry, namely TiC0.6, TiC0.8, and TiC1.0. The key problem is the method of electrochemical activation of the TiC electrode. No or improperly activated electrode is not polarized and is unsuitable as a voltammetric sensor. The TiC electrode was used for the determination of Pb2+ in concentrations ranging from 1 to 100 nM. The instrumental parameters, composition of supporting electrolyte and procedures of the electrode activation were optimized. The repeatability of DP ASV runs in synthetic solutions covering the entire concentration range is better than 3%. The calibration curve is characterized by a correlation coefficient of at least 0.999. The detection limit was 2 nM for an electrodeposition time of 30 s. The method enables determination of Pb2+ in the presence of, among the others, high excesses of Cd, Cu, In, Sb, Se, and Tl ions as well as surfactants, Triton X‐100 and humic acids. The analysis of Pb2+ in synthetic solutions with and without surfactants, certified reference material and natural water samples have been performed. The voltammetric data were associated with the structural characterization of the electrode surface using scanning electron microscopy (SEM) and X‐ray fluorescence spectroscopy (XRF).