Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2007. / In this thesis the main capillary electrodriven chromatographic techniques (i.e.
Capillary Electrochromatography CEC, Micellar Electrokinetic Chromatography
MEKC and Microemulsion Electrokinetic Chromatography MEEKC) were compared
in terms of column manufacturing, fundamental chromatographic performance,
and some applications were developed. The first stage of this thesis aimed at
developing improved packed and open tubular CEC columns. For the
manufacturing of packed CEC columns, the frit-burning step proved of critical
importance, together with the slow build-up of the packed bed. The making of
open tubular columns is a relatively simple, "one pot" sol-gel reaction taking
place in mild conditions. The nature of the gel and the resulting selectivity of the
column could easily be changed by changing the precursors.
In a second stage of this thesis the packed and open tubular CEC columns were
evaluated chromatographically and compared with the results obtained by MEKC
and MEEKC. All electrodriven separation techniques showed high efficiencies. The
selectivity proved easier to tune with sol-gel chemistry for the making of open
tubular columns. Resolution is acceptable for packed CEC, MEKC and MEEKC. For
peak capacity, CEC has the advantage of a practically non-limited elution time,
while MEKC and MEEKC suffer of the drawback of the existence of an elution
window which is limited in time by the elution of the micelles.
Some applications were developed in this study on open tubular CEC columns
and for the packed CEC columns. Various sugars derivatized with 9-
aminopyrene-1,4,6-trisulfonic acid (APTS) could be separated with open tubular
CEC, using an octyl, amino or cyano stationary phase. Open tubular columns
containing α, β and γ cyclodextrins attached to the stationary phase were
developed. This approach proved promising for the separation of positional
isomers. A method was developed for the analyses of a mixture of carbamates
and for several steroids with packed column CEC directly coupled with MS.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/1336 |
| Date | 12 1900 |
| Creators | Buica, Astrid Sorina |
| Contributors | Sandra, Pat, Crouch, Endrew, University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. |
| Publisher | Stellenbosch : University of Stellenboschv |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 4743462 bytes, application/pdf |
| Rights | University of Stellenbosch |
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