Date of Award
Doctor of Philosophy (PhD)
Isiah M. Warner
The research presented in this dissertation covers pseudo-stationary phase development for separations in electrokinetic chromatography (EKC). Micelles and cyclodextrins have traditionally served as the most popular pseudo-stationary phases (PSPs) used in EKC. However, the development and implementation of PSPs, which have improved properties over traditional ones, are necessary to extend the utility of electrokinetic chromatography. This dissertation covers research contributions, chapter by chapter, to the area of PSP development made by the author. In addition to this, Chapter 1 covers a brief history of chromatography and the fundamentals of capillary electrophoresis and EKC. The first pseudo-stationary phase developed was a modified poly (amido-amine) starburst dendrimer, diaminobutane dendrimer (DABD). The utility of DABD is demonstrated with the separation of a mixture of naphthalene derivatives and five neutral aromatic molecules in Part I of Chapter 2. Part II of Chapter 2 ventures into the development and implementation of chiral terminated poly-amide dendrimers for chiral separations. Anionic cyclodextrins are generally considered as traditional pseudo-stationary phases in EKC; however, cationic cyclodextrins are extremely rare. In Chapter 3, a novel hepta-substituted beta-cyclodextrin is introduced as a chiral selector for enantiomeric separation of non-steroidal anti-inflammatory drugs (NSAIDs) and phenoxypropionic acid herbicides (PPAHs). Separation parameters such as pH and concentration were found to have major influences on enantiomeric resolution of the NSAIDs and PPAHs. Results indicate that heptakis(6-methoxyethylarnine-6-deoxy)-beta-cyclodextrin performs exceptionally well for the enantiomeric resolution of NSAIDs and PPAHs. Chapter 4 of this dissertation focuses on a very different pseudo-stationary phase, a chiral polymeric surfactant (micelle polymer). Chiral recognition of two binaphthyl derivatives and three benzodiazepines was studied by use of polymeric surfactants in EKC. Four specific dipeptide terminated (multi-chiral) micelle polymers were synthesized for this study. In addition to the chiral separation study, the physicochemical properties (critical micelle concentration and specific rotation) of each polymer were investigated. The molecular weights of the various dipeptide terminated micelle polymers were also determined using analytical ultracentrifugation. These dipeptide terminated micelle polymers were designed to study the effect of the extra heteroatom at the polar head group of the micelle polymer for the enantiomeric separation of the binaphthyl derivatives and benzodiazepines.
Haynes, Judson Leroy III, "Development of Pseudostationary Phases for Separations in Electrokinetic Chromatography." (1999). LSU Historical Dissertations and Theses. 7087.