The Establishment, Evaluation, and Validation of Operating and Working Parameters for an Analytical Method to quantify Polyphenolic Compounds using an Electrochemical Apparatus

Abstract

Polyphenols have health-beneficial antitumorigenic and antioxidative effects. This project evaluated the spectroelectrochemical responses to polyphenols for the development of an analytical polyphenolic method using an electrochemical apparatus. Operating parameters of 0.5 V and 1000 seconds were chosen after evaluations of cyclic voltammograms and durational response. Linearity was measured (R2: 0.96, caffeic acid; 0.94, protocatechuic acid; 0.93, gallic acid; over concentration range 0.5 - 5.0 mM), as were effects of ion strength (no baseline effect by buffer less than 1.0 M), and solvent composition (influence detected in non-aqueous solutions). Effects of ascorbic or monohydroxyphenolic acid on polyphenolic determinations by the electrochemical apparatus were compared to determinations by the Folin Ciocalteu (FC) method. Ascorbic acid exerted significant interference on electrochemical and FC measurements. Monohydroxyphenolic acids did not interfere with electrochemical polyphenol measurements, but significantly interfered with FC quantifications. This electrochemical apparatus may offer potential for the development of a quantitative assay for polyphenols.