A rapid analytical method for monitoring the enantiomeric purity of chiral molecules synthesized in ionic liquid solvents
Article first published online: 24 JAN 2012
Copyright © 2012 Wiley Periodicals, Inc.
Volume 24, Issue 3, pages 201–208, March 2012
How to Cite
Zhao, Q., Twu, P. and Anderson, J. L. (2012), A rapid analytical method for monitoring the enantiomeric purity of chiral molecules synthesized in ionic liquid solvents. Chirality, 24: 201–208. doi: 10.1002/chir.21983
- Issue published online: 16 FEB 2012
- Article first published online: 24 JAN 2012
- Manuscript Accepted: 19 OCT 2011
- Manuscript Revised: 17 OCT 2011
- Manuscript Received: 1 SEP 2011
- National Science Foundation (Analytical and Surface Chemistry Program in the Division of Chemistry and the Separation and Purification Processes Program in the Chemical, Environmental, Bioengineering, and Transport Systems Division). Grant Number: CHE-0748612
Choose one or more boxes to highlight terms.
- ionic liquids;
- solid-phase microextraction;
- chiral gas chromatography;
- asymmetric synthesis;
- enantiomeric excess determination
Ionic liquids (ILs) have been widely used as reaction solvents in asymmetric synthesis due to their interesting physical and chemical properties. However, monitoring reactant-to-product conversion and the enantiopurity of formed stereoisomers often involves a tedious extraction step before chromatographic analysis. In this study, a rapid and sensitive sampling method using headspace solid-phase microextraction (SPME) coupled to chiral gas chromatography was developed for the “on-line” analysis of chiral molecules in the IL solvent. Three different SPME sorbent coatings, namely polydimethylsiloxane, polyacrylate, and a polymeric ionic liquid-based fiber, were examined in this study. The analytical performance of the developed method was evaluated in terms of reproducibility, slope of calibration curve, linear range, calibration linearity, and the determination of detection limits. The SPME method was successfully applied in the determination of enantiomeric excess from selected mixtures of chiral molecules. A preliminary study was performed using an “on-fiber” derivatization approach revealing that the stereoisomers extracted by the SPME fiber can be efficiently derivatized using a short “on-fiber” derivatization step. The developed SPME method eliminates the need of sequestering the reaction, separating the compounds of interest from the IL solvent, and the addition of a derivatizing reagent. Chirality, 2012. © 2012 Wiley Periodicals, Inc.