PREPARATION OF METHYLATED BETA-CYCLODEXTRIN-BONDED STATIONARY PHASES AND CHROMATOGRAPHIC EVALUATION FOR CHIRAL SEPARATION

A native and two types of methylated beta-cyclodextrin(CD)-bonded stat ionary phases have been prepared and their ability to separate enantio mers of eight 2,4-dinitrophenyl amino acids was investigated by revere d-phase high performance liquid chromatography. When heptakis(3-O-meth yl)-beta-CD bonded stationary phase was compared with the native beta- CD stationary phase, increased enantioselectivity and peak resolution were observed for aromatic amino acids. Effects of organic modifier co ntent and pH of the mobile phase on retention and enantioselectivity f or the analytes were examined to optimize mobile phase conditions. The elution order of racemates of all analytes on both the native and hep takis(3-O-methyl)-beta-CD bonded stationary phases was D before L enan tiomer. The structural features of the analytes on retention, enantios electivity and peak resolution were examined and discussed.