Abstract: A novel microchip-based capillary electrophoresis system, based on the micro-electrode end-col-umn electrochemical detection, is described.Afixed guide tube was aligned accurately with the outlet ofthe separation channel to achieve the proper and reproducible alignment of microelectrode with the channel.Such a design permits easy and rapid replacement of different material microelectrodes or modified elec-trodes, obviating the disadvantages of permanent attachment of the detector.Using the homemade 7 μmcarbon-fiber microdisk electrodes and 30 μm Pt microdisk electrodes, a performance of separating neuro-transmitters, with good precision and submicromolar detection limits, demonstrated the versatility, sim-plicity, low-cost and high-sensitivity advantages of this new detector.

Key words: Microchip-based capillary electrophoresis, Electrochemical detection, Microdisk electrodes, Neurotransmitters