Electrochemical determination of resveratrol in the dietary supplements at a boron-doped diamond electrode in the presence of hexadecyl trimethyl ammonium bromide using square-wave adsorptive stripping voltammetry

Abstract

A sensitive electroanalytical methodology for the determination of resveratrol is presented for the first time using adsorptive stripping voltam­metry at a bare boron-doped diamond (BDD) electrode. In cyclic voltammetry, resveratrol shows one irreversible and an adsorption-controlled oxidation peak at a BDD electrode. The voltammetric results indicated that in the presence of hexadecyl trimethyl ammonium bromide, the BDD electrode remarkably enhanced the oxidation of resveratrol, which leads to an improvement in the peak current with a shift of the peak potential to more positive values. Using the square-wave stripping mode, the compound yielded a well-defined voltam­metric response in 0.1 M nitric acid solution containing 100 µmol L-1 hexa­decyl trimethyl ammonium bromide at 0.74 V (vs. Ag/AgCl), after 60 s accu­mulation at the open-circuit condition. A linear calibration graph was obtained in the concentration range 0.025 to 60.0 μg mL-1, with a detection limit of 0.0063 μg mL-1. The applicability of the proposed method was verified by analysis of resveratrol in commercial dietary supplements.