Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 330-338).

Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 268-281).

Electrophoretic separations have been demonstrated for over a century resulting in methods being devised to separate a variety of compounds, mainly of biological origin. Only in the past twenty-five years has capillary electrophoresis (CE) emerged as a viable technique, with a variety of different separation methods being reported. One draw back of CE is its inability to separate neutral compounds, hence alternative methods have been developed to facilitate this. This study investigated Capillary Electrochromatography (CEC), one of the techniques that can be used to separate neutral compounds, in which a capillary column is packed with a stationary phase designed for liquid chromatography. Separation is determined by interactions between the solutes and the stationary phase, with the flow being driven by electroosmosis. Initial work involved the development of an in-house packing method for CEC columns. The method developed, which was a pressure driven system using a Shandon HPLC packer, proved to be successful. The reliability of the retaining frit and the nature of the packing material were major factors in column performance. Once the column fabrication process had been developed, the experimental conditions for CEC in the Prince Technology CE instrument were optimised. The results showed that in many respects the system responded as a traditional LC system would, with changes in buffer compositions, stationary phase and, in this case, EOF etc. all producing definite and reproducible changes in the separation of the test mixture. Variations in sample loading technique were investigated and a simple method developed to improve the peak efficiencies and resolution of analytes, by focussing them on the head of the column. Once the experimental conditions were established, a series of applications were undertaken with differing results. The applications included studies of a series of polyaromatic Hydrocarbons (PAH), a test mixture of small molecules, with different polarities, prostaglandins and nicotine metabolites. Separation of the PAH and test mixtures were successful and corroborated some of the observations made while studying the experimental conditions for CEC. Separation of the prostaglandin mixture was unsuccessful; this was not totally unexpected due to the similarity in their structures. Study of the nicotine metabolites allowed a comparison of CZE with CEC, however due to limited availability sample the work was not fully completed. Despite this, the study did indicate that both methods showed promise, but required further development.

A theoretical model of continuous gas chromatography using one disk rotating on top of a stationary plate is described. A disk chromatograph was designed and built. Experimental results obtained with this apparatus are reported. Both flexible disks and solid disks with springy -supports were used. The flexible disks were found to be unsuitable. Reproducible chromatographic peaks were obtained using the solid disks with air as the carrier gas and either helium or natural gas as the sample. The angular position of the peak was found to increase with the disk diameter and with the height of the hub to which the rotating disk was mounted. For a given disk diameter and a given hub position, the angular position of the peak (θ) could be fitted by the following equations: (1) θ = k₁ω a (2) θ = k3 [formula omitted] where ω is the speed of rotation, V is the volumetric flowrate of the carrier gas, a and k₁ are constants for a given V, and b and k₃ are constants for a given ω. Attempts to achieve chromatographic separations of hydrocarbon mixtures did not succeed. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Gas chromatography (GC) is a technique that includes all chromatographic processes in which a substance to be analyzed is in the gaseous state or is converted into such a state. Miniaturized GCs are in high demand due to their portability, ability to operate in the field, low power requirements and low material cost. The focus of this thesis is on the development, testing and applications of portable analytical instruments, specifically miniature gas chromatographs. In the first chapter, two portable gas chromatograph prototypes are described; including a miniature GC and an auto sampling GC. The second chapter describes student experiment development that incorporates mini GCs into the academic chemistry curriculum and focuses on teaching principles of chromatography or use a gas chromatograph as a tool. The third chapter focuses on development, testing and application of a portable auto sampling prototype GC to aid in the production of biofuels.

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Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 140-153). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--Oregon State University, 2004. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. John G. Dorsey, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed Sept. 19, 2005). Document formatted into pages; contains xxii, 154 pages. Includes bibliographical references.

Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. John G. Dorsey, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed Jan. 19, 2005). Includes bibliographical references.