Mode-filtered light capillary electrophoresis (CE) was developed for capillary electrochromatography (CEC) by applying annular columns of different size (250, 320, and 530 mum),and a bovine serum albumin (BSA)-modified chiral stationary phase. BSA was encapsulated on the pretreated surface of an optic fiber and the inner wall of a capillary using sol-gel technique with a resultant larger active stationary phase area. The coating was examined by atomic force microscopy (AFM) and Fourier transform infrared (FT-IR). The separation of DL-tryptophan (10 mM) was investigated under different voltage/current conditions.