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Title: High performance liquid chromatography : theory and applications
Author: Abid, F. M.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1987
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A detailed study was undertaken of both the individual and combined effects of pH, temperature and flow rate on the retention volumes of underivatised amino acids. The relative merits of 3-dimensional S-window diagrams to locate the optimum conditions for the separation of amino acids on a stationary phase comprising 5μ ODS has been successfully performed. The enthalpies of retention of transfer from stationary phase to mobile phase for the amino acids have been measured from the chromatographic data. An isocratic study of the separation of phenylthiohyddation (PTH) amino acids using a 3μ MOS Hypersil reverse phase column was performed by the pre-column derivatisation method. Subsequently, a more detailed investigation was made of the various factors which control the separation, viz. pH, temperature and eluent composition. The conditions for optimum separation were located by constructing, with the aid of a computer, a 3-dimensional S-window diagram. The enthalpy of transfer from stationary phase to mobile phase and the entropy of the process were evaluated from the chromatographic data. A new pre-column derivatisation method for the separation of amino acids by gradient elution was established using an ODS column; this was applied to the analysis of amino acids extracted from mammalian tissue. The retention behaviour of PTH-amino acids was studied on a mixed stationary phase comprising silica bonded to alkylcynanide and octyl silica in the ratio of 60:40, w/w. This factor has an important bearing on the solute retention selectivity of the column. It was found that the selectivity of the acidic and basic PTH-amino acids could be precisely controlled by adjusting the packing percentage and mobile phase composition, suggesting that the mixed phase technique could be profitably exploited for analytical purposes. HPLC group type analyses of oil samples, normally requiring more sophisticated and time consuming methods of analysis, were performed using normal and reverse phase columns of different materials. The separated fraction has been identified by mass spectrometry, and the results obtained have been of some assistance in an investigation relating to poorly combustable oil. Finally, an extended and modified LC theory has been proposed, and a new modified approach which relates the inverse corrected retention volume (1/VR) and volume fraction composition of polar solvent component (φB) has been established for a polar component variation of 0 to 100% . The results indicate good agreement between the theoretical and experimental values for all systems displaying a non-linear relationship between 1/VR and φB.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available