Fast analysis of domoic acid using microchip electrophoresis with laser-induced fluorescence detection

A fast and effective method was developed to detect domoic acid based upon microchip electrophoresis combined with laser-induced fluorescence detection. Through study of the gated injection process on the cross channel of the microchip, the low-voltage mode with relatively longer sample loading time was adopted to reduce the sample discrimination and improve the signal sensitivity. Fluorescein isothiocyanate was used as the derivatizing reagent for domoic acid. Under the optimized conditions, domoic acid was completely separated in 60 s with separation efficiency of 1.35 x 105 m(-1). The calibration curve was obtained in the range of 1.0 x 10(-9) to 1.0 x 10(-7) mol/L, and the detection limit reached 2.8 x 10(-10) mol/L. This developed method was successfully applied to analyze domoic acid in real samples.