Abstract: L-Glutamic acid (Glu) racemization research is of great importance for the preparation of optical pure D-Glu. In the present work, we studied L-Glu racemization reaction through Schiff base intermediate by using capillary array electrophoresis (CAE) with 532 nm laser-induced confocal fluorescence detection. The racemization products were labeled by carboxytetramethylrhodamine succinimidyl ester (TAMRA) and analyzed in a 100 mmol/L Tris-borate buffer (pH 10) system containing 2 mmol/L β-CD by CAE. Under this condition, the TAMRA-Glu enantiomer can be completely separated. The influences of the type and dosage of the aldehyde, organic acids, as well as the water content in the reaction system on the racemization were examined in detail, and L-Glu was racemized quickly in the presence of 0.2 molar ratio of L-Glu to salicylaldehyde (as the catalyzer) in acetic acid containing 20%(v/v) water.

Key words: L-glutamic acid (Glu), racemization , capillary array electrophoresis (CAE)