Micellar electrokinetic capillary principle

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... 

CE has many separation modes that are beneficial to protein impurity analysis. Within the many thousands of potential protein impurities in a recombinant product there will be several that have only minor physicochemical differences from the drug product. The application of different CE modes can potentially resolve these impurities. CE methods can be divided into four principle modes that are applicable to recombinant protein impurity analysis capillary zone electrophoresis, capillary isoelectric focusing, capillary gel electrophoresis, and micellar electrokinetic capillary chromatography. Each mode will be discussed briefly. Since the technology is so young and still very exploratory, CE methods are developed empirically for specific separations. It is difficult to provide standard protocols for CE impurity analysis. Instead, protocols that can be used as a starting point for impurity analysis will be provided as well as the citation of examples of impurity analyses from the literature to provide additional sources of protocols for interested readers. 

Different separation mechanisms, which determine selectivity, can be exploited in hpce by appropriate choice of operating conditions. There are four principle modes of operation (table 4.22) and it should be noted that in only one, micellar electrokinetic capillary chromatography (mecc), is it possible to separate neutral species from one another. 

What is the principle of micellar electrokinetic capillary chromatography How does it differ from capillary zone electrophoresis ... 

Micellar electrokinetic chromatography performed in capillaries is a separation technique combining some of the operational principles of micellar liquid chromatography and capillary zone electrophoresis. This technique was termed micellar electrokinetic capillary chromatography (MECC) by Burton et al. [79]. MECC uses the addition of a surface-active agent in the working electrolyte, which creates new possibilities for electrophetic separations. 

Subsequently four different CE modes are described in the sections Capillary Zone Electrophoresis, Capillary Gel Electrophoresis, Capillary Isoelectric Focussing, and Micellar Electrokinetic Chromatography (MEKC), respectively. The fundamental principles of the specific separation modes are briefly explained, using appropriate equations where required. In Table 3 all equations are listed. In addition, the influence of both instrumental parameters and electrolytic solution parameters on the optimization of separations is described. 

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. 

Fig. 3 Schematics of the separation principle of MEKC. Source From Micellar electrokinetic chromatography, in Capillary Electrophoresis TechnologyP ...

Foret, F. Kivankova, L. Boek, P. Principles of capillary electrophoretic techniques Micellar electrokinetic chromatography. In Capillary Zone Electrophoresis, Radola, B.J., Ed. VCH Weinheim, 1993 67-74. 

Owing to its outstanding high-performance separation potential also capillary electrophoresis has been employed in different modes and with different detection methods for separation and determination of MC. Both capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC), which employs a surfactant above the critical micelle concentration to separate neutral and uncharged molecules based on electromigration principle, have been employed for determination of... 

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