Separation of the enantiomers of dansyl-DL-amino acids by normal-phase TLC on plates impregnated with a macrocyclic antibiotic

Direct racemic resolution of dansyl-DL-amino acids has been accomplished by normal-phase TLC on silica gel plates impregnated with vancomycin (0.34 mM), a macrocyclic antibiotic, as chiral selector. The mobile phases enabling successful resolution of most of the racemic dansyl amino acids were acetonitrile -0.5 M NaCl(aq), 10 + 4 and 14 + 3 (v/v). Spots were detected by use of a fixed dual-wavelength (lambda = 254 nm) ultraviolet light. The minimum amount detected was 2.1 mu g.