Chiroptical detection during liquid chromatography 7: The rotation angle/absorbance ratio of chiral molecules. Its possible use for on-line analysis during preparative separations of enantiomers

The rotation angle/absorbance ratios C+=α+/A+ and C−=α−/A−, determined via detection by a polarimeter and a photometer, were checked for the first time with reference to their use for on-line analysis during preparative separations. For this purpose, (+)-, (−)- and (±)-carvones were investigated by liquid chromatography (LC) on microcrystalline tribenzoylcellulose. It turned out that the ratios C+ and C− depend only slightly upon concentration (Table 1). Overlapped peaks of enantiomers were successfully submitted to computer deconvolution (e.g. Fig. 2, bottom). A procedure for on-line analysis during preparative LC is proposed.