Simultaneous determination of TBHQ and BHA on a MWNT-Brij® 35 modified electrode in micellar media

Abstract

A voltammetric method for the simultaneous detection and quantification of tert-butylhydroquinone (TBHQ) and butylated hydroxyanisole (BHA) was developed using a multi-walled carbon nanotube (MWNT)-Brij® 35 modified glassy carbon electrode in Brij® 35 micellar medium. Significant improvements of TBHQ and BHA voltammetric characteristics were observed on the modified electrode. Electrochemical oxidation of TBHQ and BHA is a diffusion-controlled process that is confirmed by the linear dependence of peak currents on υ^1/2 with R² = 0.9983 and 0.9901, respectively, and involves two electrons corresponding to the formation of p-quinones. Under conditions of differential pulse voltammetry, a linear dynamic range of 1.0–1000 μmol L⁻¹ for TBHQ and 0.50–7.50 and 10.0–750 μmol L⁻¹ for BHA were obtained with the detection limits of 0.26 and 0.15 μmol L⁻¹, respectively. The approach developed was successfully applied for the quantification of TBHQ and BHA in linseed oil samples with recoveries from 99% to 103% after a simple and rapid extraction with Brij® 35 micellar medium.