Method development for determination of sudan red in food using electrochemical technique

Abstract

To develop a method for analysis synthetic azo dye compound (sudan I, sudan II, sudan III, and sudan IV) in food sample. The electrochemical analysis was investigated using cyclic voltammetry at glassy carbon and CNT modified glassy carbon electrodes. It was found that four sudan dyes provided well-defined cyclic voltammogram at both electrodes. The amperometric waveform parameters were optimized at GC electrode by FIA system. The significantly low detection limits of 0.01, 0.10, 0.025, and 0.01 ppm for sudan I, sudan II, sudan III and sudan IV were obtained, respectively. High performance liquid chromatography with amperometric detection was investigated for separation and quantitative determination of four sudan dyes. Comparison experiments were carried out using GC and CNT modified GC electrodes. The chromatography was performed using a commercially available Innertsil C18 column, with the optimum conditions: acetonitrile and 20 mM acetate buffer (90:10; %v/v) at flow rate I, mL min-1. Sudan dyes were detected at 0.95 and 0.85 V at GC and CNT modified GC electrodes, respectively. The linear concentration ranges of four sudan dyes were 0.01 to 150.0 and 0.005 to 25.0 ppm at GC and CNT modified GC electrode, respectively. The recoveries were in the ranges of 93.74 to 104.56 and 93.98 to 104.09% at GC and CNT modified GC electrodes, respectively with %RSD < 10%. The proposed method was further applied to analyse soft drink and chilli sauce samples. The results from proposed method gave the acceptable percent recovery values.