The Use of Chemical Bleaching and Thin-layer Chromatographic Methods for the Detection and Identification of Sudan-III Dye in Adulterated Palm Oil

Abstract

The deleterious effect of consuming azo dye adulterants in palm oil is well documented including cancer. The presence of Sudan-III dye in palm oil cannot be detected by mere visual inspection. This study was aimed at developing a simple, cheap and convenient protocol for detection and identification of Sudan-III and other azo dyes in adulterated palm oil. The results revealed that the refractive index could be used to screen for azo dye adulteration in palm oil samples as the parameter increases with increasing concentration of Sudan-III dye in palm oil and were statistically different ((p<0.05) from crude unadulterated palm oil samples. Analytical thin layer chromatography and chemical bleaching using 20% v/v each of concentrated sulphuric acid and 30% hydrogen peroxide in palm oil was effective in detecting Sudan III dye adulteration in concentrations of 10mg/L and above.