Large-Surface Carbon Film Electrode - A Simple Sensor for Voltammetric Determination of Electrochemically Reducible Organic Compounds
Abstract
A newly developed large-surface carbon film electrode (LS-CFE) based on a microcrystalline natural graphite-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 center dot 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 mu mol l(-1), with limits of quantification (L(Q)s) of 2.3 mu mol l(-1) and 1.8 mu mol 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 mu mol l(-1).