MICROMACHINING OF CAPILLARY ELECTROPHORESIS INJECTORS AND SEPARATORS ON GLASS CHIPS AND EVALUATION OF FLOW AT CAPILLARY INTERSECTIONS

A capillary electrophoresis system with a sample injector has been integrated on a 1 X 2 cm planar glass chip by use of micromachining techniques. Separation of three amino acids was achieved in the device within 4 s. A maximum of 6800 theoretical plates was obtained with 470 V between injection and detection points. Electric fields of 2500 V/cm and power dissipation of 2.3 W/m did not result in Joule heating effects due to the thermal mass and conductivity of the glass chips. Leakage at channel intersection points was found to arise from convective as well as diffusion effects. Methods of device fabrication are presented.