Molecularly imprinted polymer as chiral selector for enantioseparation of amino acids by capillary gel electrophoresis

A capillary electrophoresis method for the enantioseparation of D,L-aromatic amino acids using molecularly imprinted polymer as chiral selector has been developed. Methacrylic acid was used as functional monomer and ethylene glycol dimethacrylate (EDMA) as crosslinking monomer. The molecularly imprinted polymer was packed in capillaries by incorporating with acrylamide gel. The composition of the polymerization mixtures affects the separation factor to some extent. The molar ratio of cross-linker to functional monomer to print molecule was 20:4:1, which gives the best separation for aromatic amino acid enantiomers by using L-phenylalanine anilide (L-pheAN) as print molecule. Under the same conditions, however, separation of D,L-phenylalanine using L-phenylalanine as print molecule is poorer than that using L-pheAN. Polymer particles (less than or equal to 5 mu m) were supported by 6 % acrylamide and 5 % bisacrylamide gel in the capillary. The effects of organic solvents, electrophoretic buffer and pH on separation were also investigated.