SEPARATION OF NAPHTHALENE-2,3-DICARBOXALDEHYDE-LABELED AMINO-ACIDS BY HIGH-PERFORMANCE CAPILLARY ELECTROPHORESIS WITH LASER-INDUCED FLUORESCENCE DETECTION

Analysis of amino acids derivatized by reaction with naphthalene-2,3-dicarboxaldehyde (NDA) was investigated using high-performance capillary electrophoresis (HPCE) combined with laser-induced fluorescence detection. Of the HPCE modes, capillary zone electrophoresis, micellar electrokinetic chromatography and cyclodextrin (CD)-modified micellar electrokinetic chromatography (CD-MEKC) were applied to the separation of these amino acid derivatives. CD-MEKC allowed separation in less than 30 min and proved to be effective for chiral separation in some cases. A detection limit of 0.8 amol was obtained for NDA-labelled leucine at a signal-to-noise ratio of 2.