The integrated CE-ED microchip system was described previously [36]. The CE microchip was placed in a laboratory-built Plexiglas holder for housing the separation chip and electrochemical detector, allowing convenient replacement. The holder consisted of a sample, running buffer, and unused reservoirs. Short pipette tips were cut and inserted into the fluidic ports of the various reservoirs on the glass chip for providing solution contact between the channel on the chip and the corresponding reservoir on the chip holder. Platinum wires were inserted into the compartments to provide the electrical contacts to a highvoltage power supply. A home-made high voltage power supply, with an adjustable voltage range between 0 and +4000 V, was used for controlling the injection and separation. The amperometric detector, placed in the waste reservoir, at the separation channel outlet, consisted of an Ag/AgCl wire reference electrode, a platinum wire counter electrode, and a screen-printed carbon working electrode.