矩形截面毛细管电泳和二维分离

在石英单晶表面制成矩矩截面毛细管柱中进行电泳实验。由于矩形柱比圆形柱有更大散热侧面积且石英单晶的导热性能远无于熔融石英，所以可施加较高的场强，不仅提高了柱效，而且缩矩了分离时间。两相交的通道之间形成自然连接，可实现二维分离，并消除死体积。

Capillary Electrophoresis on Rectangular Channels and Two-Dimensional Separation

A capillary electrophoresis(CE) system with rectangular cross-sectional columns fabricated on monocrystal quartz plate is investigated. Because of its high surface-to-volume ratio and excellent heat conductivity of quartz, rectangular capillary is extremely efficient at dissipating heat as compared to conventional circular capillaries. Comparative study showed that much higher electric field strength can be applied to this system without bubble forma- tion. The effectiveness of this planar capillary electrophoresis has been demonstrated by comparing the separation of two solutes in phosphate buffer with rectangular and circular columns of same cross-sectional area. In addition, injection by micro injector can eliminate sample biasing and increase reproductivity. A simple manifold of rectangular flow channels is fabricated on quartz substrate. By use of electroosmotic pumping it is possible to control the direction of fluid flow in the manifold of intersecting channels to realize two-dimensional separation. The main factors causing band-broadening in capillary electrophoresis are longitudinal diffusion, injection delay time and wall absorption. In some cases the wall absorption makes the most contribution.