Sensitive enantioseparation by transient trapping-cyclodextrin electrokinetic chromatography

Area of Science:

• Analytical Chemistry
• Separation Science
• Chiral Analysis

Background:

• Chiral analysis is crucial in pharmaceuticals for distinguishing enantiomers.
• Existing methods often lack sufficient sensitivity for trace chiral compound detection.
• Capillary electrophoresis (CE) offers high separation efficiency but can be limited by sensitivity.

Purpose of the Study:

• To develop a highly sensitive chiral analysis method using capillary electrophoresis.
• To improve the preconcentration and enantioseparation of chiral compounds.
• To apply the method for pharmaceutical analysis and enantiomeric excess determination.

Main Methods:

• On-line sample preconcentration based on transient trapping was integrated with cyclodextrin electrokinetic chromatography (CDEKC).
• Partial introduction of a micellar solution before electrokinetic injection facilitated preconcentration and enantioseparation.
• The method was tested using (R),(S)-1-aminoindan as a model analyte and applied to other pharmaceutical compounds.

Main Results:

• Achieved up to 240-fold enhancement in peak intensity and 100-fold improvement in limit of detection for (R),(S)-1-aminoindan.
• Successfully resolved five chiral analytes simultaneously with 40- to 160-fold sensitivity enhancements.
• Demonstrated sensitive detection of (R)-chlorpheniramine enantiomeric excess (43 ppb in 5 ppm (S)-chlorpheniramine).

Conclusions:

• Transient trapping-CDEKC provides a highly sensitive approach for chiral analysis in capillary electrophoresis.
• The method offers effective preconcentration and enantioseparation for pharmaceutical compounds.
• This technique is applicable for both enantioseparation and enantiomeric excess determination with significant sensitivity gains.