Cyclodextrin-mediated chiral separations via capillary zone electrophoresis /
| Main Author: | |
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1993.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | In the secondary chemical equilibria-assisted electrophoretic separation of the enantiomers of monoprotic chiral weak electrolytes, the effective mobilities, the resulting mobility ratios and peak resolutions were predicted using a model based on multiple competing equilibria. The model was tested with chiral weak adds and bases and two types of cyclodextrin host molecules, namely, β-cyclodextrin and hydroxypropyl β-cyclodextrin. According to the model, three classes of separation are possible as a result of the selective complexation of the nondissociated forms of the enantiomers with the cyclodextrin host (Type I), the selective complexation of the dissociated forms of the enantiomers with the cyclodextrin (Type II), and the selective complexation of both the dissociated and nondissociated forms of the enantiomers with the cyclodextrin (Type III). Model parameters can be readily derived from three separate sets of experiments: one in background electrolytes of varying pH values without cyclodextrin additives, one with varying cyclodextrin concentrations at a pH value that is dose to the pK[a] of the solute, and one with varying cyclodextrin concentrations at a pH value where the solute is completely charged. The model reveals that in some cases successful chiral electrophoretic separations can only be achieved under entirely non-intuitive conditions, considering the coulombic nature of the electrophoretic process, and its predictions facilitate the development of useful optimization strategies for all three types of separations. |
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| Item Description: | Vita. "Major subject: Chemistry." |
| Physical Description: | xix, 187 leaves : illustrations ; 28 cm |
| Bibliography: | Includes bibliographical references. |