Principles of Capillary Electrophoresis

Electrophoresis in glass capillaries was first described by J. W. Jorgenson in 1981, 9 

Capillary electrophoresis provides unprecedented resolution. When we conduct chromatography in a packed column, peaks are broadened by three mechanisms in the van Deemter equation (23-33) multiple flow paths, longitudinal diffusion, and finite rate of mass transfer. An open tubular column eliminates multiple paths and thereby reduces plate height and improves resolution. Capillary electrophoresis reduces plate height further by knocking out the mass transfer term that comes from the finite time needed for solute to equilibrate 

Palcic, and N. J. Dovichi. Instrumentation for Chemical Cytometry, Anal. Chem. 2000, 72,672.] 

Multiple path term Mass transfer term 

When an ion with charge q (coulombs) is placed in an electric field E (V/m), the force on the ion is qE (newtons). In solution, the retarding frictional force is /uep, where ncp is the velocity of the ion and/is the friction coefficient. The subscript ep stands for electrophoresis. The ion quickly reaches a steady speed when the accelerating force equals the frictional force  

---

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... 

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. 

Gersten D. Gel Electrophoresis of proteins Essential Techniques Series. New York John Whey 8 Sons, 1996. Harris DC. Principles of capillary electrophoresis. In Harris DC. Quantitative chemical analysis. New York ... 

Describe the principles of capillary electrophoresis. What are its advantages ... 

The theoretical principles of capillary electrophoresis are closely related to those of electrophoresis. In electrophoresis the velocity of an ion is related to its electrophoretic mobility (Me) as follows ... 

Hgure 2 Schematic representation of the principles of capillary electrophoresis and electroosmotic flow. 

Microchips offer various possibilities for the performance of analytical assays they comprise a capillary system, to which electric fields can be applied, which is the principle of capillary electrophoresis (CE). Thus, capillary electrophoretic separation assays can be transferred to microchips leading to the accelerated separation of compounds, in particular of carbohydrates, amino acids, peptides, proteins, and nucleic acids. In Table 3, some representative assays are summarized with special emphasis on the practical applications. 

The boom in microanalysers started aroimd 1994. Laborious sample treatment procedures and other peripheral operations were performed in reactor columns connected upstream or downstream from the central part. Highly efficient instruments, like a miniature mass spectrometer, became available. Amperometric detectors became the standard device for flow systems since they could be miniaturized easily. They are foimd primarily in liquid chromatographic /i-TASs as well as in such systems which work on the principle of capillary electrophoresis. 

---