RETENTION AND SELECTIVITY OF FLAVANONES ON HOMOPOLYPEPTIDE-BONDED STATIONARY PHASES IN BOTH NORMAL-PHASE AND REVERSED-PHASE LIQUID-CHROMATOGRAPHY

Three linear polymers of repeating amino acid units, or homopolypeptid es, have been individually covalently bonded to microparticulate silic a and evaluated for liquid chromatographic separations. The retention and selectivity of seven flavanones were investigated on these station ary phases and a structurally similar, commercially available referenc e stationary phase, Chiraspher. All three of the homopolypeptide stati onary phases retain solutes in the normal-phase made. The aromatic-con taining homopolypeptide stationary phases also retain solutes in the r eversed-phase mode. Selectivity values for the flavanones were higher in the normal-phase mode; chiral selectivity was observed for the amph iphilic homopolypeptide stationary phase in the reversed-phase mode. T he retention mechanism of each stationary phase is suggested based on the chemical nature and conformation of the corresponding homopolypept ide ligand.