Octakis-6-sulfato-γ-cyclodextrin as additive for capillary electrokinetic chromatography of dibenzoazepines: Carbamazepine, oxcarbamazepine and their metabolites
✍ Scribed by Ettore Marziali; Maria Augusta Raggi; Natalja Komarova; Ernst Kenndler
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 130 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0173-0835
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✦ Synopsis
Single isomer octakis-(2,3-dihydroxy-)6-sulfato-gamma-cyclodextrin used as pseudostationary phase of the background electrolyte interacts with dibenzo[b,f]azepines (consisting of a condensed 3-ring system) and forms negatively charged complexes. Hydroxygroups in position 2 and 3 at carbamazepine increase the extent of interaction, whereas substitution by oxygen at position 10 and/or 11 reduces it. The complex constants for the analytes are ranging from few tens L/mol (10-hydroxycarbamazepine, 10,11-dihydroxycarbamazepine, 10,11-epoxycarbamazepine, oxcarbazepine) to several hundreds L/mol (carbamazepine, 2-hydroxycarbamazepine, 3-hydroxycarbamazepine), and are much larger than those of the analytes with octakis-(2,3-dimethyl-)-6-sulfato-gamma-cyclodextrin. Full enantiomeric separation of the chiral metabolites of carbamazepine and oxcarbazepine is obtained at octakis-(2,3-dihydroxy-)-6-sulfato-gamma-cyclodextrin concentrations of about 10 mM (3 mM borate buffer, pH 8.5). Compared to heptakis-6-sulfato-beta-cyclodextrin, selectivity differs and stereoselectivity is more pronounced.