Nonaqueous electrophoresis, effects

Two effects which may be encountered during nonaqueous electrophoresis are space charge conditions and electrohydrodynamics (EHD). When an electric field is applied across a uniformly dispersed colloid the macroscopic charge density is zero and the field is uniform at the time of application. As the separation of opposite polarity charges occurs, a net internal... 

The effect of an additive (Brij 35) on the mobilities of different porphyrins (photodynamic anticancer drugs) was studied in a nonaqueous capillary electrophoresis system based on a 1 1 complexation model (118). 

Miller, J. L., Shea, D., and Khaledi, M. G., Separation of acidic solutes by nonaqueous capillary electrophoresis in acetonitrile-based media. Combinated effects of deprotonation and heteroconjugation, ]. Chromatogr. A, 888,251-266, 2000. 

Electrophoresis in nonaqueous media may be an effective means of separating polyhydroxy compounds from mixtures which would otherwise be difficult to resolve. Subsequent separation of salt from carbohydrate could then be accomplished by means of ion-exchange techniques. 

Ma, H. et al. Hydrogen-bond effect and ion-pair association in the separation of neutral calix[4]pyrroles by nonaqueous capillary electrophoresis. J. Chromatogr. A. 2008,1188, 57-60. 

A scale that would enable us to compare the acidity in all solvents could be based on the transfer activity coefficient on the proton (see the entry Capillary Electrophoresis in Nonaqueous Media). The effect of the solvent of any species can be expressed in the same way as for the proton by this concept and applied to all particles involved in the thermodynamic equilibrium. 

Problems encountered with CE include poor solubility of fatty acids in aqueous solutions and the unavailability of sensitive modes for aliphatic acids. This is often counteracted by nonaqueous capillary electrophoresis (NACE) with indirect detection. NACE-1A (indirect absorbance) is a simple, sensitive, and effective technique for the determination of fatty acids using i-PrOH and 40% acetonitrile (as organic modifier) and HIQSA... 

Fillet M., Servais A.C., Crommen J., Effects of background electrolyte composition and addition of selectors on separation selectivity in nonaqueous capillary electrophoresis. Electrophoresis, 24, 1499-1507 (2003). 

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