Microelectrodes based on porphyrins for the determination of ascorbic acid in pharmaceutical samples and beverages

Abstract

Different porphyrins were used for the design of seven carbon paste and seven diamond paste based microelectrodes, which were employed for the determination of ascorbic acid in pharmaceutical and beverages samples using differential pulse voltammetry (DPV). The limits of detection lie between 1.1 × 10-14and 5.1 × 10-7M while the sensitivities were between 3.07 pA/M and 1285.18 A/M. Ascorbic acid was recovered reliable from pharmaceutical and beverages samples in percentages higher than 92.00% and 91.50%, respectively. The surface of the microelectrodes can easily be renewed by simple polishing, obtaining a fresh surface ready for use in a new assay.