Abstract: A method was developed for the rapid determination of auramine O in yellow croaker by microchip capillary electrophoresis with contactless conductivity detection. Effects of the type and concentration of buffer, separation voltage and injection time on the separation and detection were investigated, and the optimal analysis conditions were obtained in the buffer solution of 5.0 mmol/L lactate(pH=3.29) at the separation voltage of 1.8 kV, where auramine O could be separated and determined within 1.0 min. The linear range of the concentration of auramine O is from 5.0 mg/L to 100.0 mg/L, and the limit of detection is 0.2 mg/kg(S/N=3).The method was used for the analysis of auramine O in the yellow croaker satisfactorily.

Key words: Microchip capillary electrophoresis, Contactless conductivity detection, Auramine O