Viscosity Zone electrophoresis

The mobilities of alkylpyridines were modeled and predicted in capillary zone electrophoresis.35 The model predicted that compounds adopt a preferred orientation, and additionally predicted mobilities of structural isomers to within 4%, a higher degree of accuracy than can be obtained from simple considerations of van der Waal s radius. Quantitative prediction of the mobilities of some pyridines, such as alkenylpyridines, was not possible. Mobilities of small solutes in capillaries filled with oligomers of ethylene glycol were related to solution viscosity and the diffusion coefficient.36... 

Since all electrophoretic mobility values are proportional to the reciprocal viscosity of the buffer, as derived in Chapter 1, the experimental mobility values n must be normalized to the same buffer viscosity to eliminate all other influences on the experimental data besides the association equilibrium. Some commercial capillary zone electrophoresis (CZE) instruments allow the application of a constant pressure to the capillary. With such an instrument the viscosity of the buffer can be determined by injecting a neutral marker into the buffer and then calculating the viscosity from the time that the marker needs to travel through the capillary at a set pressure. During this experiment the high voltage is switched off. 

Capillary zone electrophoresis (CZE) is the most simple and widely used mode in CE. Separations take place in an open-tube, fused silica capillary under the influence of an electric field. The velocity of the analytes is modified by controlling the pH, viscosity, or concentration of the buffer, or by changing the separation voltage. The electroosmotic flow is often used in this mode to improve resolution or to shorten analysis times. 

Capillary zone electrophoresis (CZE), also known as free-solution CE, is the most widely used mode of CE essentially because of its versatility. Protein separation in CZE is based on the differential electrophoretic mobility of the analytes. This mobility is primarily dependent on a protein s size and net charge, the charge-to-mass ratio. Solvent properties that influence the size and charge of a protein include pH, ionic strength, viscosity, and dielectric constant.67 Manipulation of these properties, most notably pH, dictates the selectivity in CZE. Maximizing the charge difference between two proteins via pH modification optimizes their separation. 

There are several practical applications involving interactions between starch and saccharides. For example, starch-derived sugars are used as plasticizers for starch.956 Thus, the addition of potato starch to sugar syrup increases the solution viscosity to a level where it retains gas bubbles and is suitable for producing froths.957 Agaran, starch, and swollen Sephadex G-200 form a mixed support for zone electrophoresis.958 A plywood of improved strength resulted from the blending of an aqueous solution of... 

The use of SDS is not always without drawbacks. One of the most important is encountered when the sample is rich in DNA. A terrible viscosity results, which can hamper the electrophoresis process. Moreover, some protein classes (e.g. glycoproteins) bind SDS poorly and are thus poorly separated in the subsequent electrophoresis. In such cases, it is advisable to use cationic detergents. They are usually less potent than SDS, so that a urea-detergent mixture must be used for optimal solubilization (MacFarlane 1989). Moreover, electrophoresis in the presence of cationic detergents must be carried out at a very acidic pH, which is not technically simple but still feasible (MacFarlane 1989). This technique has however gained recent popularity as a double zone electrophoresis method able to separate even membrane proteins (Hartinger et al. 1996), and showing more separation power than SDS electrophoresis alone. 

LC, liquid chromatography GC, gas chromatography E, extraction F, filtration CZE, capillary zone electrophoresis 8°, eluotropic value Rl, refractive index dzs Ci density BP, boiling point tj, viscosity , dielectric constant. 

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