Harnessing electrical forces for separation. Capillary zone electrophoresis, isoelectric focusing, field-flow fractionation, split-flow thin-cell continuous-separation and other techniques.
Harnessing electrical forces for separation. Capillary zone electrophoresis, isoelectric focusing, field-flow fractionation, split-flow thin-cell continuous-separation and other techniques.
复制标题
利用电力进行分离。
DOI：
10.1016/s0021-9673(01)84277-1
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Giddings,JC
中科院分区：
文献类型：
--
作者：
Giddings,JC
20年前首次提出的一个简单分析表明，场驱动分离（如电泳）的有效性（用最大理论塔板数（N）表示）由两种能量的无量纲比给出，其中−Δμ ex是带电物质的电势能降，RT是热能（R是气体常数，T是绝对温度）。量-Δμ exis是作用在物质上的力F和分离路径长度X的乘积。电泳，其中oftenN 106，可以直接追溯到巨大幅度的电力F.本文探讨了几种不同的手段，利用这些强大的力量分离，包括毛细管区带电泳，凝胶电泳，等电聚焦，电场流分馏和分流薄连续分离细胞的基本原理。值得注意的是，发现上述方程及其相关方程描述了所有这些不同电驱动系统的近似性能。影响系统的分辨能力和分离速度的因素得到解决;从这些考虑中出现了一些广泛的优化标准。不同方法的能力进行了比较，使用数值例子。
A simple analysis, first presented twenty years ago, showed that the effectiveness of a field-driven separation like electrophoresis, as expressed by the maximum number of theoretical plates (N), is given by the dimensionless ratio of two energies in which −Δμextis the electrical potential energy drop of a charged species andRTis the thermal energy (Ris the gas constant andTis the absolute temperature). Quantity −Δμextis the product of the forceFacting on the species and the path lengthXof separation. The exceptional power of electrophoresis, for which oftenN≈ 106, can be traced directly to the enormous magnitude of the electrical forceF.This paper explores the fundamentals underlying several different means for utilizing these powerful forces for separation, including capillary zone electrophoresis, gel electrophoresis, isoelectric focusing, electrical field-flow fractionation and split-flow thin continuous separation cells. Remarkably, the above equation and its relatives are found to describe the approximate performance of all these diverse electrically driven systems. Factors affecting both the resolving power and separation speed of the systems are addressed; from these considerations some broad optimization criteria emerge. The capabilities of the different methods are compared using numerical examples.