Comparison of monomeric and polymeric amino acid based surfactants for chiral separations

To better understand chiral recognition with polymeric amino acid based sur factants, the chromatographic performance of 18 monomeric and polymeric sur factants were compared for chiral analytes with various charge states and h ydrophobicities. In this study, four amino acids (glycine, L-alanine, L-val ine, and L-leucine) were chosen, and all possible combinations of the chira l single aminoacid and dipeptide surfactants were synthesized. The results indicate that polymeric surfactants usually provide better chiral resolutio n for enantiomers of lorazepam, temazepam, 1,1 ' -bi-2-naphthol, and propra nolol as compared to monomeric surfactants. In contrast, monomers perform b etter for chiral recognition of the 1,1 ' -bi-2-naphthyl-2,2 ' -diyl hydrog enphosphate enantiomers. (C) 2001 Elsevier Science BN. All rights reserved.