RESUMO
A pepsin modified poly (glycidyl methacrylate-ethyleneglycol dimethacrylate)(poly (GMA-EDMA)) capillary monolith (32 cm ×75 μm,22cm effective lenth)was applied in exploring the interaction between nefo-pam enantiomers and bovine serum albumin (BSA),mode of frontal analysis was selected to measure the binding constant,number of binding sites and the location of binding sites of BSA to both nefopam enantiomers.The opti-mal CEC conditions obtained were a running buffer consisted of 15 mmol /L ammonium acetate at pH 5.5,separa-tion voltage 5.0 kV,detection wavelength 215 nm,injection 10 kV ×6 s,solvent of samples consisted of 50 mmol/L ammonium acetate at pH 7.4.The results indicated that the monolith could provide a satisfactory resolution between the two enantiomers plateaus,BSA in the binding system didn′t disturb the separation or determination of nefopam enantiomers in electrochromatography.The frontal analysis demonstrated that BSA has only one binding site with both enantiomers,the binding constants (K)were 443 L/mol and 527 L/mol,respectively,and the dis-placement experiments indicated that binding site of both isomers to BSA molecule was the Sudlow siteⅡ.