Enantiomeric Separation, Microorganism Studies And Determination Of Binding Constants Using Capillary Electrophoresis

Abstract

Enantiomeric separation of three series of compounds, including β-lactams, synthetic amino acids and ruthenium(II) polypyridyl complexes using different modes of capillary electrophoresis are discussed in this dissertation. Enantiomeric recognition mechanisms are explored by studying the effect of the structures of chiral selectors and analytes. Results indicated that the size correlation between the analyte and the cyclodextrin cavity size play an important role in enantioseparation. Effects of experimental parameters including chiral selector concentration, buffer additive type and concentration, run buffer pH and applied voltage are studied for optimization of the enantioseparations. A new class of chiral selectors, cyclofructans were developed and examined via capillary zone electrophoresis in both normal and reverse polarity mode. Superior enantioselectivity was observed for cationic compounds, especially primary amines and primary amino acids.Capillary electrophoresis also was studied as a technique for the fast analysis of microorganisms. Online preconcentration approaches in capillaries with greater internal diameters were investigated to improve the sensitivity and reliability for diluted microbial samples. Rapid detection of Candida albicans and/or bacteria in blood plasma by "sample-self focusing" using capillary elelctrophoresis-laser induced fluorescence within 10 mins was successfully achieved.Finally, a review was prepared on the estimation of apparent binding constants using capillary electrophoresis. It provides information on the fundamentals of binding and a summary of recent applications and advances of CE-based methods.