流动相组成和温度对衍生化b-环糊精键合固定相拆 分四种仲醇消旋体的影响

采用3,5-二甲苯基异氰酸酯衍生化β-环糊精键合固定相, 以正己烷-脂肪醇为流动相, 研究了脂肪醇结构及其浓度、柱温对2-苯基环己醇、2-萘基环己醇、4-三氟甲基-2-苯基环己醇以及3-(1-羟乙基)香豆素等四种仲醇手性拆分行为的影响. 当流动相中醇的摩尔浓度相同时, 异构体容量因子随脂肪醇碳链的增长而减小; 柱温升高, 异构体容量因子减小, 而分离因子增大. 用溶质的计量置换保留模型(SDM-R)和热力学理论对此现象进行了解释.

Influences of Composition of Mobile Phase and Temperature on the Enantioseparation of Four Kinds of Secondary Alcohols on Derived β-Cyclodextrin Bonded Stationary Phase

Four kinds of secondary alcohols, 2-phenylcyclohexanol, 2-(4-trifluoromethylphenyl)-cyclohexanol, 2-(2-naphthalenyl)-cyclohexanol and 3-(1-hydroxyethyl)coumarin, were directly resolved on N- (3,5-dimethylphenyl)carbamate-substituted 6-O-β-cyclodextin bonded silica stationary phase by a normal- phase system with n-hexane-alcohol as a mobile phase. The influences of temperature, structure and concentration of the alcohol in the mobile phase on the separation of the four investigated solutes were investigated. It was found that the capacity factors for each diastereomer decreased either with increasing carbon number of alcohol or temperature while selectivity factor increased with temperature at the same molar concentration of alcohol, for which the reason was explained with a stoichiometric displacement model for retention and thermodynamic theory.