Abstract: Achiral stationary phase(CSP) was prepared by coating cellulose tris(3,5-dimethylphenylcarbamate) onto aminopropylated spherical silica gel.The enantioselective separation of a series of biphenyl dialkyl dicarboxylates(DDBs) with antihepatitis activity was chromatographed for the first time on the CSpOf the six DDBs investigated, five could be directly resolved via normal phase mode HPLC.The effect of alcohol modifiers in mobile phase was investigated.The mobile phases used in the study were composed of hexane modified with two homologous series of alcohols: methanol ethanol mixtures(1:1, molar ratio), ethanol, 1-propanol, 1-butanol, 1-pentanol and 2-propanol,2-butanol,2-pentanol, and tert butanol.It was found that the retention time and the separation factors of DDBs on the CSPwere dramatically influenced by the kinds of alcohols in mobile phase.The results of the study indicate that alcohol in the mobile phase not only competes for chiral bondings sites with chiral solutes but can also alter the steric environment of the chiral cavities on the CSPby binding to achiral sites at or near the chiral cavity.The purpose of this paper is to demonstrate that better chiral resolution can be obtained via a change of alcohol modifiers in mobile phase

Key words: Enantiomer separation, Alcoholic modifier, Cellulose based CSP, Biphenyl dialkyl dicarboxylates