An evaluation of the Jasco CD-995: a detector for the simultaneous measurement of chemical and enantiomeric purity.

An evaluation of the use of the Jasco CD-995 in conjunction with achiral high-performance liquid chromatography (HPLC) for the determination of the enantiomeric purity of various SB compounds is described. The Jasco CD-995 is the first commercially-available detector specifically designed for the on-line monitoring of circular dichroism (CD) at a fixed wavelength. Predecessors such as the OR-990 from Jasco and other manufacturers use optical rotation as the detection principle. The results demonstrate that where enantiomeric purity is required to be controlled at levels greater than 99% w/w it is unlikely that the use of the CD-995 with achiral HPLC will compare with the sensitivity of enantio-selective HPLC and capillary electrophoresis (CE). In contrast, where the control of enantiomeric purity is required at levels less than 99% w/w good agreement can be achieved between the CD-995 with achiral HPLC and these techniques. Furthermore, the ability of the CD-995 in such situations to monitor ordinary UV absorbance and CD facilitates the simultaneous measurement of chemical and enantiomeric purity. The benefits in terms of "faster, information-rich analyses" are clear.