Background: Several GC and HPLC methods have been proposed for the separation of aldose enantiomers. Keywords: 2-polyhydroxyalkyl-thiazolidine-4(R)-carboxylic acids (3-nitrophenyl)methyl esters, enantioseparation, HPLC-UV, L-cysteine (3-nitrophenyl)methyl ester, monosaccharides.