Liquid chromatographic enantiomer separation of N-phthaloyl protected α-amino acids on coated and immobilized chiral stationary phases derived from polysaccharide derivatives

Liquid chromatographic enantiomer separation of N-phthaloyl (PHT) protected alpha-amino acids on several coated and immobilized chiral stationary phases (CSPs) derived from polysaccharide derivatives was performed. The coated CSP of Chiralpak AD showed more or less enantioseparation than the covalently bonded CSP of Chiralpak IA with the same chiral selector of amylose tris(3,5-dimethylphenylcarbamate). However, the coated Chiralcel OD showed greater enantioseparation than the covalently bonded Chiralpak IB with the same chiral selector of cellulose tris(3,5-dimethylphenylcarbamate). Among all examined CSPs, Chiralcel OD afforded the greatest performance for enantiomer resolution of alpha-amino acids and, therefore, all analytes enantiomers were baseline separated on Chiralcel OD. The chromatographic method developed in this study was usefully applied for determination of the enantiomeric purity of commercially available alpha-amino acids analytes.