Liquid chromatographic separation of the enantiomers of N-fluorenylmethoxycarbonyl α-amino acids on a covalently bonded type polysaccharide-derived chiral stationary phase under fluorescence detection

The liquid chromatographic enantiomer separation of N-fluorenylmethoxycarbonyl (FMOC) α-amino acids was performed using a covalently immobilized CSP (Chiralpak IB) with cellulose tris(3,5-dimethylphenylcarbamate) as a chiral selector under fluorescence detection. Several mobile phases with acid additives were used to show the effect of the reversed mobile phase on the chromatographic parameters of the separation and resolution factors. In this study, we observed that the enantioseparation of investigated FMOC α-amino acids on Chiralpak IB using 90% MeOH/water with 10 mM methanesulfonic acid as an additive in the reversed mobile phase (α = 1.18 - 2.31; Rs = 1.20 - 9.08) was significantly greater than that using other mobile phases including the conventional normal mobile condition. Owing to higher sensitivity and selectivity in fluorescence detection than in UV detection, this analytical method using the reversed phase mode is expected to enlarge their application of enantiomer resolution.