焦耳热效应对毛细管电泳中样品区带传输的影响

毛细管区带电泳过程中产生焦耳热效应会改变溶液的黏度,进而改变样品区带到达检测窗口的时间。建立了一个包含电势分布方程、连续性方程、动量方程、能量方程和样品组分迁移扩散方程的数学模型,应用有限元数值模拟的方法,对这些耦合的方程进行了求解。计算结构分析了在考虑和不考虑焦耳热的情况下样品组分区带的传输过程。结果表明,毛细管内径、对流换热系数及缓冲溶液浓度都会影响样品区带在毛细管中的运动速度,进而改变其到达检测窗口的时间。

Influence of Joule heating effects on sample band transport in capillary zone electrophoresis

Joule heating effect induced in capillary zone electrophoresis can change the buffer viscosity,thus changing the detection time of the sample plug.A mathematic model,including Poisson equation,NavierStokes equation,momentum equation,energy equation as well as electromigration and diffusion equation,was developed,and Finite Element Method was used to solve these equations simultaneously.The simulation results present the sample band transport process with and without considering the Joule heating effect.It shows that the capillary inner radius,heat transfer coefficient and buffer concentration have significant effect on the sample band transport velocity,thus changing the detection time for the sample band.