Electrochemical determination of Sudan IV in food samples by using graphene-modified glassy carbon electrodes

Abstract

A simple and sensitive modified electrode was fabricated with graphene via the drop-casting method and applied for the electrochemical detection of Sudan IV. Cyclic voltammetry (CV) was used to investigate the electrochemical behaviors of Sudan IV in phosphate buffer solution (PBS). The experimental conditions such as determining medium, scan rate, and accumulation time were optimized for the determination of Sudan IV. The sensor has excellent performance associated with high sensitivity, a low detection limit (6.00 \times 10^{-8} M), and a wide linear range of 2.00 \times 10^{-7} M to 8.00 \times 10^{-5} M with a correlation coefficient as follows: i_{pc} (A) = 4.37 \times 10^{-6} + 0.35C, R = 0.9930. Under optimized conditions, the applicability of the method for rapid determination of Sudan IV was corroborated by analyzing food samples with recoveries from 96.8% to 99.2%, and the related RSD values were within the range of 1.51% to 3.78%. A simple extraction procedure using ethanol was applied for the extraction of Sudan IV from samples of chili powder and tomato sauce.