Chen, L.Zhao, Y.Gao, F.Garland, M.CHEMICAL & ENVIRONMENTAL ENGINEERING2014-06-172014-06-172003-07Chen, L., Zhao, Y., Gao, F., Garland, M. (2003-07). Determination of enantiomeric excess using the ultraviolet-circular dichroism and the high-performance liquid chromatography-circular dichroism methods. Applied Spectroscopy 57 (7) : 797-804. ScholarBank@NUS Repository. https://doi.org/10.1366/00037020332210288900037028https://scholarbank.nus.edu.sg/handle/10635/66520Two useful numerical methods using ultraviolet (UV) and circular dichroism (CD) spectroscopies are proposed to determine enantiomeric excess (e.e). An algorithm is also proposed to generate self-consistent pure R and S enantiomer reference spectra. After all pure reference spectra are generated, a simulated annealing algorithm is applied to minimize the mismatch between the experimental spectra and the spectra after a least-squares fit. Optimal factors for R and S enantiomers are then used to determine e.e. The ultraviolet-circular dichroism (UV-CD) method uses the combined UV and CD spectra in a composite form, while the high-performance liquid chromatography (HPLC)-CD method only employs the CD spectra with the total concentrations of R plus S enantiomers provided by HPLC using a non-chiral stationary phase. Both methods were successfully tested on mixtures with known composition and then applied to real experimental data (unknown compositions). Compared with the UV-CD method, the results show that excellent results are more readily obtained using the HPLC-CD method. With the systems studied, the latter usually provided outstanding estimations of e.e with low error percentages.Enantiomeric excessEnantiomersHigh-performance liquid chromatography-circular dichroismHPLC-CDPure reference spectraSimulated annealingUltraviolet-circular dichroismUV-CDArticle000184358600011