RETENTION, ENANTIOSELECTIVITY AND ENANTIOMERIC ELUTION ORDER OF PROPRANOLOL AND ITS ESTER DERIVATIVES ON AN ALPHA1-ACID GLYCOPROTEIN-BONDED COLUMN

The retention, enantioselectivity and enantiomeric elution order of racemic propranolol (PP) and its ester derivatives (O-acetyl, -propionyl, -butyryl and -valeryl PP) on an alpha-1-acid glycoprotein (AGP)-bonded column have been investigated by changing eluent composition (eluent pH, buffer concentration, type and content of organic modifier). The retention of these cationic solutes, PP and its ester derivatives, was influenced by eluent pH, ionic strength and organic modifier content. The enantioselectivity was dependent on eluent pH and type of organic modifier. Reversal of the enantiomeric elution order of ester derivatives of PP (O-propionyl- -butyryl) and - valeryl PP) occurred around eluent pH 6-7. These results suggest that chiral recognition or binding properties may be altered by the change in eluent composition, especially eluent pH and type of organic modifier.