Zhang, Gui-Hua, Fu, Ke-Qin, Xi, Jiang-Bo, Chen, Wei, Tang, Sheng, and Bai, Zheng-Wu
Highlights • Ten chiral selectors (CSs) applied for HPLC analysis were synthesized with chitosan. • Some selectors showed very high separation ability and mobile phase tolerability. • The CS with 4-OCF 3 displayed strong separation ability as the one with 3,5-diCl. • Structure-property relationship of the selectors was observed and discussed. • Separation ability of the selectors could be recovered by n -hexane/THF or pure THF. Abstract In order to screen chiral selector structure and find structure-property relationship, ten chitosan 3,6-bis(phenylcarbamate)-2-(cyclopropylformamide)s were synthesized from which corresponding chiral stationary phases were prepared. Enantioseparation capability and mobile phase tolerability of the chiral stationary phases were evaluated. The chiral selectors with 3-chloro-4-methylphenyl, 4-chlorophenyl, 3-chlorophenyl, 3,5-dichlorophenyl and 4-trifluoromethoxyphenyl groups demonstrated powerful enantioseparation capability. Enantioseparation capability was found to be dependent on a match between the substituent at C2 and the one attached to phenyl group at C3/C6 of glucose unit in the chitosan derivatives. Moreover, the tolerability tests revealed that the developed chiral stationary phases were highly tolerable to pure ethyl acetate, pure acetone and n -hexane/tetrahydrofuran of various ratios. In addition, n -hexane/tetrahydrofuran was found to be a modifier to adjust suprastructure of the chitosan derivatives, resulting in an improvement or restoration in enantioseparation. This observation implies n -hexane/tetrahydrofuran may make a damaged chiral selector restore its enantioseparation capability. [ABSTRACT FROM AUTHOR]