Direct separation of the enantiomers of (±)-metoprolol tartrate on impregnated TLC plates withD-(−)-tartaric acid as a chiral selector

A method for chromatographic separation of the enantiomers of (+/-)-metoprolol tartrate (+/- MeT) employing a chiral mobile phase additive (CMPA) is described. By using silica gel plates previously impregnated with the mobile phase (ethanol-water, 70 + 30, v/v) containing D-(-)-tartaric acid as chiral selector, direct separation of the enantiomers of +/- MeT was achieved. The results of experiments with different concentrations of D-(-)-tartaric acid (5.8, 11.6, and 23 mmol L-1) revealed that the best resolution of the enantiomers of +/- MeT was achieved with 11.6 mm D-(-)-tartaric acid in both the mobile phase and the impregnation solution, at 25 2 degrees C.