Abstract: A sensitive and rapid capillary electrophoresis method was set up for the determination of glutamine and glutamate in microbial fermented liquid after derivatized by Fmoc-Cl. The optimum derivatizing conditions were obtained and a suitable electrolyte consisting of 0.1 mol/L boracic-borax buffer (pH8.0) was selected with UV detection at 214 nm. The applied voltage was set at 15 kV. The two amino acids and the internal standard mandelic acid were completely separated and detected respectively by the method in 16 min. The relative standard derivations (RSD) are better than 1.14 % for migration time with 0.79 % peak area. The detection limits for Gln and Glu are 86μmol/L and 169μmol/L, respectively. The proposed method is successfully applied to the determination of amino acids in microbial conversion solution and the recoveries are in the range of 96.7%～99. 3 % for Gln and 95.9 %～97.9 % for Glu.

Key words: glutamine, glutamate, capillary electrophoresis, Fmoc-Cl, derivatization