Capillary electrophoresis ionic

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). 

Friedl, W., Reijenga, J. C., and Kenndler, E., Ionic strength and charge number correction for mobilities of multivalent organic anions in capillary electrophoresis, /. Chromatogr. A, 709, 163, 1995. 

Shimizu, T. and Kenndler, E., Capillary electrophoresis of small solutes in linear polymer solutions Relation between ionic mobility, diffusion coefficient and viscosity, Electrophoresis, 20, 3364, 1999. 

Capillary electrophoresis offers several useful methods for (i) fast, highly efficient separations of ionic species (ii) fast separations of macromolecules (biopolymers) and (iii) development of small volume separations-based sensors. The very low-solvent flow (l-10nL min-1) CE technique, which is capable of providing exceptional separation efficiencies, places great demands on injection, detection and the other processes involved. The total volume of the capillaries typically used in CE is a few microlitres. CE instrumentation must deliver nL volumes reproducibly every time. The peak width of an analyte obtained from an electropherogram depends not only on the bandwidth of the analyte in the capillary but also on the migration rate of the analyte. 

Parameters that should be tested in HPLC method development are flow rate, column temperature, batch and supplier of the column, injection volume, mobile phase composition and buffer pH, and detection wavelength [2], For GC/GLC methods, one should investigate the effects of column temperature, mobile phase flow rate, and column lots or suppliers [38], For capillary electrophoresis, changes in temperature, buffer pH, ionic strength, buffer concentrations, detector wavelength, rinse times, and capillaries lots and supplier should be studied [35, 36], Typical variation such as extraction time, and stability of the analytical solution should be also evaluated [37],... 

Factors Affecting Ionic Migration. Effect of Temperature. pH and Ionic Strength. Electro-osmosis. Supporting Medium. Detection of Separated Components. Applications of Traditional Zone Electrophoresis. High-performance Capillary Electrophoresis. Capillary Electrochromatography. Applications of Capillary El ectrochromatography. ... 

M. Vaher, M. Koel and M. Kaljurand, Non-aqueous capillary electrophoresis in acetonitrile using ionic-liquid buffer electrolytes. Chromatographia Supplement, 53 (2001) 302-306. 

Wang, J., M. Pumera, and G. Collins. A chip-based capillary electrophoresis-contactless conductivity microsystem for fast measurements of low-explosive ionic components. Analyst 127, 719-723 (2002). 

The first work on pKa determination by zone electrophoresis using paper strips was described by Waldron-Edward in 1965 (15). Also, Kiso et al. in 1968 showed the relationship between pH, mobility, and p/C, using a hyperbolic tangent function (16). Unfortunately, these methods had not been widely accepted because of the manual operation and lower reproducibility of the paper electrophoresis format. The automated capillary electrophoresis (CE) instrument allows rapid and accurate pKa determination. Beckers et al. showed that thermodynamic pATt, (pATf) and absolute ionic mobility values of several monovalent weak acids were determined accurately using effective mobility and activity at two pH points (17). Cai et al. reported pKa values of two monovalent weak bases and p-aminobenzoic acid (18). Cleveland et al. established the thermodynamic pKa determination method using nonlinear regression analysis for monovalent compounds (19). We derived the general equation and applied it to multivalent compounds (20). Until then, there were many reports on pKa determination by CE for cephalosporins (21), sulfonated azo-dyes (22), ropinirole and its impurities (23), cyto-kinins (24), and so on. 

H Nishi. Enantiomer separation of basic drugs by capillary electrophoresis using ionic and neutral polysaccharides as chiral selectors. J Chromatogr A 735 345-351, 1996. 

Y Mrestani, RHH Neubert. Non-ionic micellar affinity capillary electrophoresis for analysis of interactions between micelles and drugs. J Pharm Biomed Anal 24 637-643, 2001. 

Qin, W., and Li, S.F.Y., Determination of ammonium and metal ions by capillary electrophoresis-potential gradient detection using ionic liquid as background electrolyte and covalent coating agent, ]. Chromatogr. A., 1048, 253-256,2004. 

Berthier, D., Varenne, A., Gareil, R, Digne, M., Lienemann, C.-P, Magnac, L., and Olivier-Bourbigouc, H., Capillary electrophoresis monitoring of halide impurities in ionic liquids. Analyst, 129,1257-1261, 2004. 

Ionic liquids as background electrolyte additives in capillary electrophoresis... 

Stalcup, A. M. and Cabovska, B., Ionic liquids in chromatography and capillary electrophoresis, J. Liq. Chromatogr. Relat. Technol, Tl, 1443-1459,2004. 

Chen, X. and Qi, S., The capillary electrophoresis based on ionic liquids, Current Anal. Chem., 2, 411-419,2006. 

Vaher, M., Koel, M., and Kaljurand, M., Ionic liquids as electrolytes for nonaqueous capillary electrophoresis. Electrophoresis, 23, 426-430, 2002. 

Francois, Y., Zhang, K., Varenne, A., and Gareil, R, New integrated measurement protocol using capillary electrophoresis instrumentation for the determination of viscosity, conductivity and absorbance of ionic liquid-molecular solvent mixtures. Anal. Chim. Acta, 562,164-170, 2006. 

Jiang, T.-F., Gu, Y.-L., Liang, B., Li, J.-B., Shi, Y.-R, and Ou, Q.-Y., Dynamically coating the capillary with l-alkyl-3-methylimidazolium based ionic liquids for separation of basic proteins by capillary electrophoresis. Anal. Chim. Acta, 479, 249-254, 2003. 

Yu, L., Qin, W., and Li, S. F. Y, Ionic liquids as additives for separation of benzoic acid and chlorophenoxy acid herbicides by capillary electrophoresis. Anal. Chim. Acta, 547,165-171,2005. 

Laamanen, R.-L., Busi, S., Lahtinen, M., and Matilainen, R., A new ionic liquid dimethyldinonylammonium bromide as a flow modifier for the simultaneous determination of eight carboxylates by capillary electrophoresis, /. Chromatogr. A, 1095, 164-171, 2005. 

Marszalt, M. R, Markuszewski, M. J., and Kaliszan, R., Separation of nicotinic acid and its structural isomers using l-ethyl-3-methylimidazolium ionic liquid as a buffer additive by capillary electrophoresis, ]. Pharm. Biomed. Anal., 41, 329-332,2006. 

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