Abstract: A method was developed for the direct determination of brilliant blue, ponceau 4R and tartrazine in jelly by capillary electrophoresis. The effects of several factors, such as pH value, type and concentration of running buffer, separation voltage on the separation of the synthetic pigments were investigated to find optimum conditions. The best separation among brilliant blue, ponceau 4R and tartrazine was achieved within 6 min under the following conditions: a mixture of 5 mmol/L Na2HPO4 and 5 mmol/L Na2B4O7 (pH＝8.5) as running buffer, separation voltage 18 kV, and detection wavelength 255 nm. The method has been used to determine some commercial jellies with satisfying results and recovery rates between 85% and 110%.

Key words: capillary electrophoresis, pigment, jelly