Separation of mandelic acid and its derivatives with new immobilized cellulose chiral stationary phase.

A new liquid chromatographic method has been developed for the chiral separation of the enantiomers of mandelic acid and their derivatives 2-chloromandelic acid, 4-hydroxymandelic acid, 4-methoxymandelic acid, and 3,4,5-trismethoxymandelic acid. The enantiomers were separated by a CHIRALPAK(®) IC (250 mm×4.6 mm, 5 µm). Mandelic acid, 4-methoxymandelic acid, and 3,4,5-trismethoxymandelic acid were baseline resolved (resolution factor (RS)=2.21, RS=2.14, and RS=3.70, respectively). In contrast, the enantioselectivities between CHIRALPAK(®) IC and 2-chloromandelic acid and 4-hydroxymandelic acid investigated were low. By comparing the chromatographs of mandelic acid enantiomers and mandelic acid spiked with (R)-mandelic acid, it was determined that the first effluent was (R)-mandelic acid.