以吡啶类β-环糊精衍生物为毛细管气相色谱固定相,对3种含2个手性中心的拟除虫菊酸衍生物——2,2-二甲基-3-甲酰基-环丙烷羧酸甲酯、菊酸甲酯和二氯菊酸甲酯,进行了色谱分离研究。实验结果显示,这3种拟除虫菊酸甲酯在同一根色谱柱上均获得较好的手性拆分结果。同时,利用热力学方法探讨了色谱分离机理,证明3种拟除虫菊酸甲酯在固定相上的色谱保留及手性识别均为焓驱动过程,且存在熵焓补偿效应。
Three kinds of pyrethroic acid methyl esters with two chiral centers, 2, 2-dimethyl-3-formacyl cyclopropanecarboxylic acid methyl ester, 2, 2-dimethyl-3- (2-methyl-propenyl) cyclopropan- ecarboxylic acid methyl ester and 3- ( 2, 2-dichloroethenyl ) -2, 2-dimethyl cyclopropanecarboxylic acid methyl ester, were investigated on capillary gas chromatography by using synthesized pyridylβ- cyclodextrin derivative as stationary phase. The results showed that three compounds were well enanti- oseparated each other. The thermodynamic parameters of the analytes were further evaluated and the enantioseparation mechanism was investigated. The result indicated that the enantioseparation of three pyrethroic acid methyl esters was enthalpy controlling process in the examined temperature range, and the enthalpy-entropy compensation effect was existed in the course of chiral recognition.