New Microsystem of Capillary Electrophoresis with Amperometric Detection / 分析化学

ABSTRACT

We have made a cheap microsystem of capillary electrophoresis with a new method, integrating the electrodes, injection channel, separation channel, buffer reservoirs and detection cell on a polymethylmethacrylate (PMMA) chip. Using an integrated micro carbon fiber disk electrode as the working electrode in three electrodes system, 1 × 10-4 mol/L dopamine (DA) could be detected with end-column amperometric detection. The reproducibility was good. Peak current was 6.73 nA、theoretical plate numher was 71300/m and height equivalent of one theoretical plate height was 14.0 μm for 1 × 10-4 mol/L DA. The limit of detection was 3.6× 10-8mol/L and the linear range was extended from 5 × 10-7 mol/L to 1 × 10-4 mol/L for DA. 1 × 10-4 mol/L catechol (CA) and 5× 10- 5 mol/L DA were also separated completely with R. = 10.1.