Determination of banned sudan dyes in chili powder by capillary electrophoresis

A simple and fast method, based on the use of micellar electrokinetic capillary chromatography in combination with UV detection, was developed for the determination of Sudan dyes (I, II, III and IV). The separation of a mixture of the four standards was achieved using a background electrolyte consisting of 5 mM borate (pH 9.3), 20 mM sodium dodecyl sulfate and 20% acetonitrile. Under optimized conditions, the four azo-dyes were baseline separated in 20 min with limits of detection ranging from 96 to 610 μg/L (S/N > 3). The applicability of the method for rapid screening and determination of Sudan dyes (I, II and III) was studied by analyzing spiked chili powder samples from India, Pakistan, Mexico, United States, Canada, and China.