新型安培检测毛细管电泳微系统

New Microsystem of Capillary Electrophoresis with Amperometric Detection

将电极、６ｃｍ分离毛细管、缓冲池、检测池集成于８．４×５．０ｃｍ有机玻璃片上，制作了一个毛细管电泳微系统。以碳纤维微盘电极作为工作电极，采用三电极体系柱端检测了１×１０－４ｍｏｌ／Ｌ多巴胺（ＤＡ），具有良好的重现性，检测限３．６×１０－８ ｍｏｌ／Ｌ，线性范围５×１０－７～１×１０－４ｍｏｌ／Ｌ，并在该系统上分离了邻苯二酚（ＣＡ）和多巴胺的混合物。

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 x 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 number was 71300/m and height equivalent of one theoretical plate height was 14.0 mum for 1 x 10(-4) mol/L DA. The limit of detection was 3.6 x 10(-8) mol/L and the linear range was extended from 5 x 10(-7) mol/L to 1 x 10(-4) mol/L for DA. 1 x 10(-4) mol/L catechol (CA) and 5 x 10(-5) mol/L DA were also separated completely with R-s = 10.1.