| The enantiomeric resolution of four β2-agonists,namely mabuterol,bambuterol,clenbuterol and clenproperol,was studied on Pikle type α-Burke-2 chiral stationary phase.Factors affecting the enantioresolution,such as type and concentration of the salts additives, content of organic solvents and column temperature were investigated.The optimal separation conditions were as follows:mobile phase:dichloromethane-ethanol（19∶1）containing 5 mmol/L ammonium acetate,flow rate:2.0 mL/min,column temperature:20 ℃.Under the above conditions,the enantiomers of clenbuterol and clenproperol were successfully separated with resolutions of 1.78 and 1.68,respectively.The enantiomers of bambuterol and mabuterol were partly separated with resolutions of 1.00 and 1.25,respectively.The thermodynamic parameters of four β2-agonists on α-Burke-2 chiral stationary phase were calculated,the enantioselectivity was proved to be enthalpocally controlled.The chiral recognition mechanism was discussed,π-π interaction and hydrogen binding between α-Burke-2 chiral stationary phase and β2-agonists were confirmed to be the interactions responsible for the chiral discrimination. |