Large-Surface Carbon Film Electrode – A Simple Sensor for Voltammetric Determination of Electrochemically Reducible Organic Compounds

Page: 264

H. Šmejkalová and V. Vyskočil

Charles University in Prague, Faculty of Science, University Research Centre UNCE " Supramolecular Chemistry" , Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry, Prague

 

A newly developed large-surface carbon film electrode (LS-CFE) based on a microcrystalline natural graphi-te–polystyrene composite film was used to study the electrochemical behavior of 4-nitrophenol (4-NP) using DC voltammetry (DCV) and differential pulse voltammetry (DPV). Voltammetic behavior of 4-NP was investigated in dependence on the pH of the used Britton-Robinson buffer. As optimum pH values for the voltammetric determination of 4-NP at the LS-CFE in the cathodic potential region, the pH values 6.0 (for DCV) and 7.0 (for DPV) were chosen. The determinations of 4-NP at the LS-CFE (at a concentration of the analyte of 1•10–4 mol l–1) showed a good repeatability for both voltammetric techniques used (RSD 2.2 % for DCV and 0.4 % for DPV). Under optimum conditions, the calibration dependences of 4-NP were measured in the concentration range from 1 to 100 μmol l–1, with limits of quantification (LQs) of 2.3 μmol l–1 and 1.8 μmol l–1 for DCV and DPV, respectively. The applicability of the newly developed methods for the determination of 4-NP was verified on the model samples of drinking and river water, with LQs in the range from 1 to 2 μmol l–1.

 

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