A convenient and validated enantiomer separation of chiral aliphatic amines as nitrobenzoxadiazole derivatives on polysaccharide-derived chiral stationary phases under simultaneous ultraviolet and fluorescence detection

A convenient method using a fluorogenic agent, 4-chloro-7-nitro-1,2,3-benzoxadiazole (NBD-Cl), was developed for enantiomer separation of chiral aliphatic amines including amino alcohols by normal high-performance liquid chromatography. The enantiomer separation of chiral aliphatic amines as NBD derivatives was performed on six covalently bonded and four coated-type polysaccharide-derived chiral stationary phases (CSPs) under simultaneous ultraviolet (UV) and fluorescence detection (FLD). Among the covalently bonded CSPs, Chiralpak IE showed the best enantiomer separation for most analytes. The other CSPs also showed good enantioselectivity except for Chiralpak IB. On the other hand, Chiralpak AD-H and Amylose-1 generally exhibited better enantiomer separation of NBD derivatized chiral amines among the coated CSPs. The developed analytical technique was also applied to determine the optical purity of commercially available (R)- and (S)-leucinol; the impurity was found to be 0.06%. The developed method was validated and proved to be an accurate, precise, sensitive, and selective method suitable for separation of chiral aliphatic amines as NBD derivatives under simultaneous UV and FLD.