Capillary electrophoresis basic principles

F. BressoUe, M. Audran, T.-N. Pham, and J-J. Vallon, Cyclodextrins and enantiomeric separations of drugs by liquid chromatography and capillary electrophoresis Basic principles and new developments, J. Chro-matogr. B 657 303 (1996). 

Capillary electrochromatography-mass spectrometry (CE-MS), 4 641 Capillary electrodes, 14 27 Capillary electrophoresis (CE), 4 602-603, 631-633 6 385 9 751-752 antibody based columns with, 6 402 chiral additives, 6 77-79 applications, 4 641 basic principles, 4 606-609 detectors, 4 634-635 for DNA analysis, 4 636-637 flow profiles generated, 4 608 instrumentation, 4 633 as microfluidic assay technique,... 

Methods development starts with a relatively high number of techniques to characterize and test samples. The number of protocols is often reduced once the critical parameters and the methods that identify them have been defined. The analyst must evaluate the initial techniques with respect to their purposes. If the goal is to generate research data, the practicality of the method and its limitations are not of primary concern if the goal is to use the technique as part of a test procedure, it has to be evaluated in terms of its potential to meet full validation. Critical procedures (e.g., release testing) that cannot be validated will bring a project to an expensive halt. For these reasons, this chapter provides basic principles as well as limitations of capillary electrophoresis (CE) as applied to the analysis of real biopharmaceutical molecules. 

The word electrokinetic implies the joint effects of motion and electrical phenomena. We are interested in the electrokinetic phenomena that originate the motion of a liqnid within a capillary tube and the migration of charged species within the liquid that surrounds them. In the first case, the electrokinetic phenomenon is called electroosmosis whereas the motion of charged species within the solution where they are dissolved is called electrophoresis. This section provides a brief illns-tration of the basic principles of these electrokinetic phenomena, based on text books on physical chemistry [7-9] and specialized articles and books [10-12] to which a reader interested to stndy in deep the mentioned theoretical aspects should refer to. 

Capillary Electrochromatography. Capillary electrochromatography (CEC) is a hybrid technique that works on the basic principles of capillary electrophoresis and chromatography [41], This mode of chromatography is used on either packed or tubular capillaries/columns. The packed column approach was introduced by Pretorius et al. [60] in 1974, while open tubular CEC was presented by Tsuda et al. [61] a decade later. In 1984 Terabe et al. [62] introduced another modification in liquid chromatography, micellar electrokinetic capillary... 

BASIC PRINCIPLES AND THEORY OF CAPILLARY GEL ELECTROPHORESIS OF BIOPOLYMERS... 

The next four chapters discuss the basic principles underlying operation and method development of the most common electrodriven analytical techniques CE, capillary isoelectric focusing (cIEF), capillary gel electrophoresis (CGE), and affinity capillary electrophoresis (ACE). Weinberger presents a comprehensive approach for method development in CE with an emphasis on small-molecule applications. This is followed by Kilar s chapter describing the principles of and method development in cIEF, as well as recent innovations... 

This chapter introduces the basic concepts and principles of capillary electrophoresis (CE), presenting some background on electrophoresis and capillary electrophesis and describing the components of the system. The two main types of CE, capillary zone and micellar electrokinetic electrophoresis, are described, and a selection strategy, based on the two types of separation, electrophoretic migration and electroosmosis, is presented. 

The purpose of this article was to provide the reader with a basic understanding of capillary electrophoresis and to describe how a technique such as MEKC uses basic principles of chromatography to perform separations which are not possible electrophoretically. As the applications for electrokinetic chromatography rapidly expand, the future direction will develop on two fronts ... 

Peterson, J. R. Mohammad, A., Eds. Basic Principles and Modes of Capillary Electrophoresis, Humana Press Totowa (NJ), 2001. 

Capillary electrophoresis is the generic name for a family of related techniques which have their origin in capillary zone electrophoresis (CZE) and are capillary gel electrophoresis (CGE), capillary isoelectric focusing (CIEF), miscellar electrokinetic capillary chromatography (MECC) and capillary isotachophoresis (CITE). Though the techniques differ significantly in principle of operation they can be carried out largely on the same basic instrumentation. 

Capillary zone electrophoresis is not only the simplest form of CE, but also the most commonly utilized. Discussion of this mode permits the presentation of a generic design for the instrumentation for CE. The addition of specialized reagents to the separation buffer readily allows the same instrumentation to be used with the other modes mentioned in the previous section addition of surfactants with MEKC, ampholines for CIEF and a sieving matrix (linear polymers, entangled matrices) for CGE. The discussion on CZE in the following subsections allows for analysis of some of the basic principles governing analyte separation by this technique. 

Capillary electrophoresis, although carried out in a capillary tube, is not fundamentally a chromatographic technique. It evolved somewhat tenuously from the traditional gel electrophoresis and, as the separation procedure differs considerably from chromatography, the basic principles involved in an electrophoretic separation will be briefly described. 

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