Management of the migration order of enantiomers in capillary electrophoresis and its influence on the analytical characteristics of the method

The main aim of this thesis is to use the potential of Capillary Electrophoresis (CE) as one of the important methods for studying enantioselective intermolecular interactions and for this purpose the use of chiral selectors, cyclodextrins. We use cyclodextrins as chiral selectors due to some significant factors, their structure is quite well studied, they are transparent in UV-range, and they have distinct NMR signals, which help determine the structure of the formed complex. Cyclodextrins are used in various fields, such as analytical, supramolecular chemistry, and the pharmaceutical industry. From a general point of view, cyclodextrins are used to improve water solubility, mask taste and smell, and overcome formulation problems of hydrophobic drugs. In this research, we used CE to check out the mechanisms of enantioselective complex formation between cyclodextrins and the test substance. We have confirmed once again that CE is the most sensitive method for detecting weak enantioselective effects. The utilization of CE allowed us to discover aspects of the enantioselective intermolecular interaction process. Capillary Electrophoresis is an electrokinetic method of separation of mixtures used to separate chiral substances. It’s not only a powerful technique for the analytical separation of enantiomeric mixtures but also allows us to examine such delicate mechanisms of (enantioselective) intermolecular interactions that cannot be learned by other methods. We can also use other physicochemical methods with it: X-ray structural analysis, nuclear magnetic resonance spectroscopy, mass spectrometry, and molecular modeling. If compared with different methods of separations, for instance, liquid and gas chromatography, CE has the major advantage as high plate numbers and operation in a single phase, it allows for easy adjustment of enantiomer migration order (EMO), short method development time, increase the selectivity, we can catch sight of enantioselective effects, which is not able to notice by other methods, etc. This method's supremacy is also economy and environmental friendliness since it doesn’t require dangerous organic solvents. Another predominant superiority of CE is extremely high separation efficiency. This facilitates carrying-off separation even when the selectivity is equal to 1.01.

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