Surface modification of porous graphite has been studied in detail by liquid chromatography. The non-polar nature of the graphite provides the basis for adsorptive modification by which the graphite surface is either deactivated or functionized. While the elimination of geometric heterogeneity is achieved by adsorption of trace polyaromatic compounds, the specialist in selectivity is conferred to the graphite by a monolayer coating of modifiers. A number of strategies are used for different purposes. These include dynamic coating, insoluble coating and cross-linked coating. The chromatographic properties of the modified materials are evaluated in terms of efficiency, selectivity and stability. With the exception for cross-linked coating, the modified materials show performances better than those of the original graphite. Applications to adsorption, ion exchange, chiral and exclusion chromatography are demonstrated. These new packings are found particularly useful in the separation of inorganic anions, amino acid and hydroxy acid enantiomers. They give excellent peak symmetry and long term stability. The mechanisms of retention on the graphite based materials are characterised and discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:663444 |
| Date | January 1992 |
| Creators | Wan, Quian-Hong |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/13187 |
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