RESOLUTION OF THE OPTICAL ISOMERS OF DANSYL AMINO-ACIDS BY REVERSED PHASE LIQUID-CHROMATOGRAPHY WITH OPTICALLY-ACTIVE METAL CHELATE ADDITIVES

The technique of ligand exchange chromatography through addition of lipophilic metal chelates to the mobile phase of a reversed phase column has been extended to the separation of the optical isomers of dansyl amino acids using an optically active metal chelate. Remarkably high α values approaching 2.0 are achieved while maintaining high performance conditions. It is hypothesized that the metal center, in addition to imposing a rigid environment at the exchange site, also induces proton loss from the sulfonamide group of the dansyl derivatives, since retention and selectivity are strongly dependent upon pH and the metal ion selected. Stereoisomeric selectivity is shown to be dependent upon the particular dansyl amino acid and the optically active metal chelate employed. © 1979, American Chemical Society. All rights reserved.