King, Joshua Matthew Philip;
(1994)
A study of techniques for the assessment and control of performance in preparative scale liquid chromatographic separations.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
In this study techniques have been developed to control the performance of preparative scale liquid chromatographic separations. Analysis of chromatograms has been carried out to determine how the individual components comprising the chromatogram overlap with one another, A mathematical model, consisting of one template function to describe the elution profile of each individual component, has been developed to describe the chromatogram and has been successfully applied to chromatographic data generated by a cation exchange of hen egg white. Parameters for the functions have been obtained by use of a directed search optimisation algorithm and results compared with those obtained by scanning SDS polyacrylamide gels of column fractions. The effect of the size of the difference between the actual and predicted chromatograms on the accuracy of the description of the separation gained has been investigated in terms of the subsequent effect on the quality of possible control decisions made. Fuzzy logic techniques have been applied to interpret information obtained from chromatogram analysis in order to identify the position of the product within the overall chromatogram. Sources of failure related to either chromatographic phenomena or to mathematical features of the fuzzy method have been investigated. Finally control actions which may be made using the information obtained from chromatogram analysis and product identification are investigated. In order to simplify the visualisation of control decisions the chromatograms have been transformed into fractionation diagrams, allowing the optimum fraction, in terms of purity and productivity, to be selected. Consideration is also given to when re-optimisation of separation is appropriate by calculating possible improvements to purity and productivity of the product fraction. This requires the use of the fractionation diagram and additional information gained off-line about the retention behaviour of individual components.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | A study of techniques for the assessment and control of performance in preparative scale liquid chromatographic separations |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Thesis digitised by ProQuest. |
| Keywords: | Applied sciences; Fuzzy logic; Liquid chromatographic separations |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10098707 |
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