Abstract: Chiral resolutions of felodipine (FEL) were compared using two cellulose tris(4-methyl benzoate) stationary phases, Chiralcel OJ-R and Chiralcel OJ-H. The effects of the mobile phase and the column temperature on the retention and separation were compared. Using n-hexane/2-propanol (90:10, v/v) as mobile phase, the FEL can be enantioseparated. There are transition temperatures in the van’t Hoff plots of the two columns. In the higher temperature region the enantioseparation was enthalpy controlled, and in the lower temperature region it was entropy controlled. The higher temperature was good for the resolution of FEL enantiomers even though the selectivity was change with maximum value at 19 ℃ for OJ-R and 14 ℃ for OJ-H. The two columns showed similar mechanism in the FEL chiral separation.

Key words: chiral separation, chiral stationary phase, felodipine , high performance liquid chromatography (HPLC)