Free-zone electrophoresis

Electrophoresis, Free Zone, Theory, Equipment, and Applications (Hjertte). 18 55... 

Capillary electrophoresis (CE) or capillary zone electrophoresis (CZE) is the technique most often employed in pesticide residue analysis. In its most basic form, free zone electrophoresis, a fused-silica capillary is filled with electrolyte (running buffer or background electrolyte). A potential is applied across the capillary and the cations... 

Zhu, M., Hansen, D.L., Burd, S., and Gannon, F., Factors affecting free zone electrophoresis and isoelectric focusing in capillary electrophoresis, /. Ckromatogr., 480, 311, 1989. 

Hjerten, S., Elenbring, K., Kilar, F., Liao, J.-L, Chen, A. J. C., Siebert, C. J., and Zhu, M.-D., Carrier-free zone electrophoresis, displacement electrophoresis and isoelectric focusing in a high-performance electrophoresis apparatus, /. Chromatogr., 403, 47, 1987. 

Hjerten, S. (1958). Free zone electrophoresis Preliminary note. Arkiv for Kemi 11, 151-152. 

Free solution electrophoresis (capillary zone electrophoresis). 

Teflon tubes and obtained separations with plate heights less than 10 pm. They also provided a theoretical basis for migration dispersion in free zone electrophoresis. 

Jorgenson, J. W., and Lukacs, K. D. (1981). Free-zone electrophoresis in glass capillaries. Clin. Chem. 

Mandrup, G. (1992). Rugged method for the determination of deamidation products in insulin solutions by free zone capillary electrophoresis using an untreated fused-silica capillary. J. Chromatogr. 604, 267—281. 

Separation is performed using free-zone electrophoresis, where the capillary is filled with a separating buffer at a defined pH and molarity. This buffer is also called a BGE. During separation, the polarity is set to cathodic or anodic mode, also called normal and reverse mode, depending on the charge of the molecule cation or anion. For anions, the capillary is usually dynamically coated with an electroosmotic flow (EOF) modifier to reverse the EOF and separate the analytes in the co-electroosmotic mode. 

S Hjerten. Free Zone Electrophoresis. Almquist and Wiksells, Uppsala, Sweden,... 

The second parameter influencing the movement of all solutes in free-zone electrophoresis is the electroosmotic flow. It can be described as a bulk hydraulic flow of liquid in the capillary driven by the applied electric field. It is a consequence of the surface charge of the inner capillary wall. In buffer-filled capillaries, an electrical double layer is established on the inner wall due to electrostatic forces. The double layer can be quantitatively described by the zeta-potential f, and it consists of a rigid Stern layer and a movable diffuse layer. The EOF results from the movement of the diffuse layer of electrolyte ions in the vicinity of the capillary wall under the force of the electric field applied. Because of the solvated state of the layer forming ions, their movement drags the whole bulk of solution. 

HJerten, Stellan, Free Zone Electrophoresis. Theory, Equipment and... 

Capillary Free-Zone Electrophoresis of Synthetic Polyelectrolytes... 

Zone electrophoresis is used extensively in modem research and clinical laboratories. In this technique, the components of the analyte mixture separate completely to form discrete zones, or bands, that may be stabilized by a support medium or may exist as free zones. The analyte solution is applied to the medium as a spot or band, and the electric field causes the initial band to separate into component bands through migration, as shown in Figure 9.4. 

BJ Compton. Electrophoretic mobility modeling of proteins in free zone capillary electrophoresis and its application to monoclonal antibody microheterogeneity analysis. J Chromatography 559 357-366, 1991. 

M.-D. "Carrier-free zone electrophoresis, displacement electrophoresis and isoelectric focusing in a high-performance electrophoresis apparatus" /. Chromatography. 1987, 403, pp 47-61. 

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