Evaluation of modified cyclodextrins for chiral separations in gas chromatography and capillary electrophoresis

Sammanfattning: ABSTRACT

An evaluation of different derivatized cyclodextrins as chiral selectors for enantiomer separations has been performed with capillary electrophoresis and gas chromatography. Using gas chromatography, resolution of the enantiomers of atropisomeric PCB congeners, o,p-DDT and o,p-DDD was attempted on columns containing a mix of chiral selectors. Examinations of closely related cyclodextrins and the effect of different concentrations of these chiral selectors were executed.

A method for the determination of enantiomeric trace impurities by capillary electrophoresis was developed. This method consists of a simple and versatile scheme for reversing enantiomeric elution order. Enantiomer purity determination is most often done under overload conditions which lead to deformed peaks. When quantification of the impurity is performed the peaks ought to be fully resolved which can not be done if the minor peak appears on the tailing of a major peak. This can be avoided if the elution order of the enantiomers can be decided. A basic analyte, propranolol, and an acidic analyte, ibuprofen, were used as model substances.