Voltammetric Sensor for the Determination of TBHQ in Coconut Oil

Abstract

A sensitive voltammetric method for the determination of tert-butylhydroquinone (TBHQ), a widely used synthetic phenolic antioxidant in oils and fats, using multiwalled carbon nanotube modified gold electrode (MWCNT/GE) was developed. In 0.10 M phosphate buffer solution (PBS) of pH 2, TBHQ gave redox peaks at E pa = 258 mV and E pc = 228 mV on MWCNT/GE. Diffusion-controlled electrooxidation of TBHQ was found to be perfectly reversible with the involvement of two electrons and two protons. The anodic peak currents varied linearly with concentrations of TBHQ in the range 4.0 × 10−6 to 1.00 × 10−4 M. The limit of detection achieved for the developed sensor was 3.20 × 10−8 M (5.31 ng mL−1). Developed sensor was used for the determination of TBHQ in commercially available coconut oil. The results obtained from the developed method were in good agreement with the standard method (HPLC-UV).