电色谱塔板高度方程的考察  

Confirmation of the Plate Height Equation in Electrochromatography

作　　者：姬磊[1] 戴朝政[1] 张维冰[2] 

机构地区：[1]中国科学院成都有机化学研究所,四川成都610041 [2]中国科学院大连化学物理研究所,辽宁大连116011

出　　处：《色谱》2003年第2期131-134,共4页Chinese Journal of Chromatography

摘　　要：对电色谱塔板高度方程正确与否进行了验证。对于电色谱塔板高度方程的若干影响因素如色谱柱结构参数、毛细管内半径r0、保留因子k、扩散系数Dm以及脱附速率常数kd对柱效率的影响进行了实验考察,并将实验数据与借助计算机计算的结果加以对比。从而得出结论:我国色谱理论工作者提出的电色谱塔板高度方程成立。由于该方程合理地考虑到各种影响溶质谱带展宽的因素,因此可以为毛细管电色谱过程的柱型设计、条件优化提供理论上的指导。The plate height equation in capillary electrochromatography: H=2γDmu+2λdpu1/3u1/3+ω(Dm/dp)1/3+2ku(1+k)2kd+θ′k2dp2uDm(1+k)2+r02ku12(1+k)Dr+3+Kr02-2α+b(1+k)T2 has been developed based on the HorvathLin model. The equation has been verified by computer simulation as well as experimental results. In experiments, the effects of some factors, such as column structure parameters, the internal radius of the column r0, the retention factor k, the diffusion coefficients and Joule heating on the efficiency of capillary electrochromatography were studied. It is found that the column efficiency can be improved in the column with bigger interstitial space since the radial diffusion coefficient, Dr, increases accordingly. The Joule effect is found to contribute to the plate height very significantly and it drastically reduces the efficiency of column when the radial temperature difference between the center of tube and the tube wall becomes too high. The axial dispersion of the eluate in the interstitial space and the intraparticle diffusion resistance to mass transfer are found to influence the column efficiency mostly when molecular diffusivity, Dm, is small. Therefore, the radial diffusion process has the most important contribution to the plate height. A larger rate of kd is found to accelerate the distribution equilibrium of solute between the mobile phase and the stationary phase, which leads to a better column efficiency. The plate height equation is useful for the design of the column structure and for the optimization of separation conditions.

关 键 词：毛细管电色谱 塔板高度方程 色谱过程动力学 径向扩散 轴向扩散 柱效 焦耳热 

分 类 号：O657.8[理学—分析化学] O658.9[理学—化学]