Abstract: A hybrid microfluidic system produced by coupling a microfabricated glass chip with conventional silica capillary for UV absorbance detection was developed. The system has proved to be robust, and easily fabricated at a low cost. The effects of sample loading and separation field strength on plate number, migration time and signal response were observed in the optimization studies. The reproducibility was examined by using benzoic acid as a model sample and following similar behavior as for complete photolithographically produced glass chip systems. The results showed that the reproducibility is good and the RSD(n=11) was only 1.5% for benzoic acid. The performance of the system was demonstrated by separating sulphamethoxazole(SMZ) and trimethoprim(TMP) in sulphatrim tablets within 70 s. The detection limits were comparable to those obtained with a commercial capillary electrophoresis instrument.

Key words: Microfluidic chip-silica capillary hybrid system, Microfluidic capillary electrophoresis, UV detection