Capillary electrophoresis resolution

Jamali, B., and Lehmann, S. (2004). Development and validation of a high-resolution capillary electrophoresis method for multi-analysis of ragaglitazar and arginine in active pharmaceutical ingredients and low-dose tablets. /. Pharm. Biomed. Anal. 34(3), 463—472. 

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... 

McCord BR, Jung JM, Holleran E (1993a) High resolution capillary electrophoresis of forensic DNA using a non-gel sieving buffer. J Liquid Chromatogr 16 1963-1981. 

It is a feature of current developments in mass spectrometry that this method of analysis can be coupled or interfaced with other techniques. The interfacing may in fact be with further MS equipment (MS/MS), or with various separation techniques such as high-performance liquid chromatography (LC/MS), gas chromatography (GC/MS), electrophoresis, particularly high-resolution capillary electrophoresis (CE/ MS), and biomolecular interaction analysis (BIA/MS) (Krone 1997). 

Another MS-based technique has been used in an attempt to determine the normal peptides present in bodily fluids. Peptides present in a normal urine sample were separated by high-resolution capillary electrophoresis (CE). A peptide pattern was established by analyzing the mass spectra from 18 samples (W3). The patterns contained ion peaks from 247 peptides (out of more than 1000 detected) that were present in more than 50% of the samples. The data was compared to five samples from patients with renal disease and impaired renal function. An alternative pattern was evident for samples from diseased individuals with additional ion peaks in the spectra and the absence of previously observed peaks. Even though a small number of samples were analyzed, valuable information about biological samples was obtained rapidly, illustrating the significance of MS. 

Khandurina, J. and Guttman, A. High resolution capillary electrophoresis of oligosaccharide structural isomers. Chromatographia, 62, S37, 2005. 

Hjerten, S., Valtcheva, L., Elenbring, K., and Liao, J. L. Fast, high-resolution (capillary) electrophoresis in buffers designed for high field strengths. Electrophoresis 16, 584,1995. 

Capillary Electrophoresis. Capillary electrophoresis (ce) or capillary 2one electrophoresis (c2e), a relatively recent addition to the arsenal of analytical techniques (20,21), has also been demonstrated as a powerful chiral separation method. Its high resolution capabiUty and lower sample loading relative to hplc makes it ideal for the separation of minute amounts of components in complex biological mixtures (22,23). 

Capillary Electrophoresis. Capillary electrophoresis (ce) is an analytical technique that can achieve rapid high resolution separation of water-soluble components present in small sample volumes. The separations are generally based on the principle of electrically driven ions in solution. Selectivity can be varied by the alteration of pH, ionic strength, electrolyte composition, or by incorporation of additives. Typical examples of additives include organic solvents, surfactants (qv), and complexation agents (see Chelating agents). 

The heating effect is the limiting factor for all electrophoretic separations. When heat is dissipated rapidly, as in capillary electrophoresis, rapid, high resolution separations are possible. For electrophoretic separations the higher the separating driving force, ie, the electric field strength, the better the resolution. This means that if a way to separate faster can be found, it should also be a more effective separation. This is the opposite of most other separation techniques. 

This chapter will first cover the nature of electrophoretic separations, especially those concerning capillary electrophoresis. Comprehensive multidimensional separations will then be defined, specifically in terms of orthogonality and resolution. The history of planar and non-comprehensive electrodriven separations will then be discussed. True comprehensive multidimensional separations involving chromatography and capillary electrophoresis will be described next. Finally, the future directions of these multidimensional techniques will be outlined. 

E. M. Benson, A. J. Tomlinson and S. Nayloi, Time course analysis of a microsomal incubation of a therapeutic dmg using preconcenti ation capillary electrophoresis (Pc-CE) , 7. High Resolut. Chromatogr. 17 671-673 (1994). 

Enantioresolution in capillary electrophoresis (CE) is typically achieved with the help of chiral additives dissolved in the background electrolyte. A number of low as well as high molecular weight compounds such as proteins, antibiotics, crown ethers, and cyclodextrins have already been tested and optimized. Since the mechanism of retention and resolution remains ambiguous, the selection of an additive best suited for the specific separation relies on the one-at-a-time testing of each individual compound, a tedious process at best. Obviously, the use of a mixed library of chiral additives combined with an efficient deconvolution strategy has the potential to accelerate this selection. 

The extraordinary complexity of human genes and their products has encouraged the development of extremely high-resolution analytical methods.75 Capillary electrophoresis is competitive with slab gel methods, with resolution up to the order of about 1,000 base pairs for sequencing, sizing, and detection of mutation. Reversed phase HPLC is useful for restriction digest mapping and MALDI-MS up to about 1000 base pairs. 

Kilar, E and Hjerten,S., Fast and high resolution analysis of human serum transferrin by high performance isoelectric focusing in capillaries, Electrophoresis, 10, 23, 1989. 

Camilleri, P., Harland, G. B., and Okafo, G., High resolution and rapid analysis of branched oligosaccharides by capillary electrophoresis, Anal. Biochem., 230, 115,1995. 

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