CE Zone Electrophoresis

The electrolyte concentration in the separation electrolyte solution should be higher than that of the sample to avoid local potential gradients, which give uneven migration and zone asymmetry. 

The cLODs and cLOQs in zone CE (not lower than about 10 M) are generally higher than in LC because of the short optical path (50-100pm) and small injection volumes (2-20 nl). However, CE with UV detection has become a valuable technique in pharmaceutical analysis of small molecules. 

The high efficiency obtainable in a short time makes this technique an important tool for main component assays, impurity determinations, enantiomeric separations, and identity confirmation. These applications do not require very low detection limits and can mostly be carried out using the sample introduction methods mentioned in Section 6.4.1. Enantiomer separation is obtained by adding to the electrolyte solution a complex-forming compound, for example, cyclodextrins, which give different complex formation with the two forms. 

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