Abstract: A capillary zone electrophoretic (CZE) method for the separation of ten synthetic colorants such as acid red 92, patent blue V, uranine, acid red 1, indigo carmine, black BN, ponceau 6R, quinoline, amaranth, lemon yellow, and six preservatives including benzoic acid, sorbic acid, methyl paraben, ethyl paraben, propyl paraben, butyl paraben in beverages was developed. The effects of separation voltage, capillary temperature, pH and concentration of running buffer on the separation were investigated. A 46 cm×50 μm uncoated fused silica capillary was used with 70 mmol/L boric acid (pH 9.5) containing 4% (v/v) acetonitrile as background electrolyte solution. The detection wavelength was set at 220 nm, and the run voltage was 30 kV. The injection time was 5 s at 500 mPa and the temperature was 25 ℃. The linear relationship between the mass concentration and peak area for each of these analytes was obtained in the concentration range of 1~250 mg/L, with a correlation coefficient not less than 0.9938. The recoveries were between 95.8% and 108.7%. The method has been applied to the determination of food additives in real samples. The results showed that the method is simple, accurate, and suitable for the simultaneous determination of the sixteen food additives in beverage.

Key words: beverage, food additives, pigments, preservatives, capillary zone electrophoresis (CZE)