A novel electrochemical detection scheme for channel electrophoresis has been developed. A microfabricated array of individually addressed microelectrodes has been used as a site-specific amperometric detector for continuous separations in a buffer-filled rectangular channel. Continuous separations of picomole quantities of dopamine and catechol by channel electrophoresis with this new defection scheme have been demonstrated. Dopamine, an electroactive neurotransmitter, has been continuously monitored for 60 min with the electrochemical array detector. The new detection technique should allow dynamic chemical events in volume-limited microenvironments (i.e. single cells) to be examined with channel electrophoresis.