一种连接石英毛细管的聚甲基丙烯酸甲酯电泳芯片的制作及其应用

利用模拟仿真软件模拟了死体积对于电泳分离的影响,并提出了一种实现聚甲基丙烯酸甲酯(Poly-methylmethacrylate,PMMA)电泳芯片与毛细管的最小死体积连接方法.将紫外吸收检测的检测窗口设计在石英毛细管上,使该PMMA芯片上的电泳分析可以直接采用紫外吸收检测器进行检测.利用该芯片对维生素B2进行了电泳分析,理论塔板数为73000/m;联磺甲氧苄啶片中的3种组分的分离度为4.5和1.9,3个峰迁移时间的RSD依次为1.0%,1.4%和1.0%,峰高的RSD依次为4.1%,3.0%和4.1%(n=5).

Fabrication and Applications of PMMA Electrophoresis Chips Connected to Fused-silica Capillaries

To connect a capillary with an electrophoresis chip, a dead volume was usually created due to a hole with a conical-shaped bottom formed by drilling into the edge of the chip after the capillary was inserted into the hole. The effects of the dead volume on the electrophoretic separation were simulated and evaluated by using a simulation software. A novel connecting PMMA electrophoresis chips to capillaries with the minimal dead volume was presented. A hole was drilled into the edge of the chip by using a 500 μm standard drill bit, then a home-made flattened drill bit was used to flatten the conical area, so a flattened-bottom hole was created, and a 375 μm-o.d. fused-silica capillary was inserted into the hole and fixed by using epoxy, which decreases the dead volume from 3.9 to 0.1 nL. The detecting point of the UV-absorption detection was put on the fused-silica capillary, so the electrophoresis on the PMMA chip could be directly detected by an UV-absorption detector. The electrophoretic analysis of vitamin B2 was performed on the chip, and the number of theoretical plates was 73 000/m; the electrophoretic separation of three components of sulfamethoxazole, sulfadiazine and trimethoprim tablet was also preformed, resolutions among these three components were 4.5 and 1.9, the relative standard deviations for migration time were 1.0%, 1.4% and 1.0%, and relative standard deviations for peak height were 4.1%, 3.0%, 4.1%, respectively(n=5).