Simultaneous Voltammetric Determination of Ascorbic Acid and Sulfite in Beverages Employing a Glassy Carbon Electrode Modified with Carbon Nanotubes within a Poly(Allylamine Hydrochloride) Film

Abstract

AbstractA glassy carbon electrode modified with functionalized multiwalled carbon nanotubes within a poly(allylamine hydrochloride) film was used for the simultaneous voltammetric determination of ascorbic acid and sulfite. The anodic peak potentials of ascorbic acid and sulfite oxidation at a MWCNTs‐PAH/GCE were found to be 0.005 V and 0.327 V (vs. Ag/AgCl (3.0 M KCl)), respectively by cyclic voltammetry, whereas at a GCE were 0.278 V and 0.722 V. Using linear sweep voltammetric technique, the obtained analytical curves were linear in the ascorbic acid and sulfite concentration range from 5.0 to 200.0 µM, with detection limits of 3.0 and 3.5 µM for ascorbic acid and sulfite, respectively. The proposed method was successfully used for the simultaneous determination of ascorbic acid and sulfite in fruit juices.