title: Consequences of a maximum existing in the dependence of separation selectivity on concentration of cyclodextrin added as chiral selector in capillary zone electrophoresis.
abstract: The maximum in the dependence of the separation selectivity on the concentration of cyclodextrin may be utilized for the determination of the mean value of host-guest interaction constants of the separated enantiomers. For the hosting of N-t-BOC-DL-tryptophan by beta-cyclodextrin, the mean value of these constants, found by drop line estimated from the cyclodextrin concentration corresponding at the maximum, is 350 L.mol-1. The separation at this concentration of cyclodextrin offers the highest resolution in the shortest separation time. It is shown that commonly used simple preliminary experiments, testing the capability of a cyclodextrin to resolve chiral compounds, and based on relatively high cyclodextrin concentrations, may easily lead to incorrect conclusions in cases of enantiomers strongly interacting with the cyclodextrin used.
authors.affiliation: Institute of Analytical Chemistry, Czech Academy of Sciences, Brno.
authors.forename: R
authors.initials: R
authors.lastname: Vespalec
authors.forename: S
authors.initials: S
authors.lastname: Fanali
authors.forename: P
authors.initials: P
authors.lastname: Bocek
mesh_terms: D003505:Cyclodextrins / Q000737:chemistry*; D004586:Electrophoresis / Q000295:instrumentation / Q000379:methods*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014364:Tryptophan / Q000737:chemistry*
chemical_list: D003505:Cyclodextrins; D014364:Tryptophan