Cu(II) complexes of L-threonine, L-serine, and L-tartaric acid were prepared and used as ligand exchange reagents for enantiomeric resolution of some of the β-blockers (bisoprolol, metoprolol, and propranolol) and a β2-agonist (salbutamol). Impregnated thin-layer plates were prepared by spreading slurry of silica gel prepared in the solutions of each of the three ligand exchange reagents. The spots were detected with iodine. Effect of temperature on enantioresolution was also studied. The detection limits were found in the range 0.19–0.26 μg for each enantiomer. L-Ser proved to be a good ligand using a common mobile phase in each case.
R. Howe, R.G. Shanks, Nature (London) 210 (1966) 1336–1338.