High-performance capillary electrophoretic analysis of synthetic food colorants

A high-performance capillary electrophoresis method with diode-array detection has been developed for analysis of synthetic food colorants. The influence of buffer composition on the separation of the food colorants was examined, as were the effects of alpha-, beta- and gamma-cyclodextrins on analyte migration behavior. Eight food colorants were completely separated within 10 min using pH 9.5 borax - NaOH buffer containing 5 mM beta-cyclodextrin. Experimental results indicate that the relative standard deviations of analyte migration times were < 0.88% under the optimized separation condition. Correlation coefficients of the linear calibration plots of the analytes exceeded 0.998. The method was suitable for determination of the quantities of synthetic food colorants in ice cream bars and fruit soda drinks.