Abstract
In this work, we report a study of electrode surface fouling due to phenols oxidation which considered being a major problem for the electrochemical study of phenols. Thus, Bisphenol A (BPA) was selected as model analyte in this study. Indeed, the products of its oxidation block the active surface area of the electrode and thus decreasing the electrochemical signal. Several parameters affecting this problem were investigated during this work such as the choice of the electrochemical analysis technique, the carbon material brand, the concentration of BPA, the temperature, the pH of the supporting electrolyte and the addition of Tween 20. Indeed, the optimization of these parameters has reduced significantly the electrode fouling problem and increased sensitivity. A comparative study of the analytical performance of several electrochemical carbonaceous paste electrodes based on graphite, carbon black, multiwall carbon nanotubes and glassy carbon to quantify BPA at low concentration levels was performed. The oxidation current intensity was proportional to the concentration of BPA within a concentration range from 1 mu M to 16 mu M in the presence of Tween 20. The limits of detection (LOD) obtained values were comprised between 0.12 mu M and 0.8 mu M for all tested electrodes. The carbon black paste electrode and the conventional carbon paste electrode were found to be the most sensitive electrodes towards BPA determination in presence of Tween 20. (C) 2017 Elsevier B.V. All rights reserved.