Study on Chiral Selective Inclusion and Retention Characteristics of cis-trans Isomers and Enantiomers of Sertraline with HP-β-CD as a Mobile Phase Modifier
HP-β-环糊精对盐酸舍曲林异构体手性选择包合和色谱保留行为影响的研究

The effect of the inclusion complex formation of cis-trans isomers and enantiomers of sertraline with added hydroxypropyl-beta-cyclodextrin (HP-beta-CD) in the reversed-phase high performance liquid chromatographic (RP-HPLC) mobile phase on the retention and selectivity has been investigated. Graphs of 1/k vs HP-beta-CD] in different experimental conditions gave good linear relationships, indicating the stoichiometry ratio of 1:1. The binding constants between HP-beta-CD and cis-trans isomers and enantiomers of sertraline were calculated by using the liquid chromatographic retention values. Meanwhile, the influences of pH value, buffer ionic strength, concentration of organic modifier and temperature on the binding constant have been studied in detail. Quantitative equations were obtained for the correlations between the binding constants and the above influencing parameters. On the other hand, the thermodynamic parameters of the inclusion complexes were determined for the four inclusion complexes. The study characterized the chiral recognition selectivity between sertraline isomers and HP-beta-CD. It was demonstrated that the chiral selectivity values were in the same sequence as delta(j,i) deltaH and delta(j,i) deltaS and opposite order against the binding constants of inclusion complexes. Both enthalpic and entropic terms were negative for cis-trans isomers and enantiomers of sertraline. It was confirmed that enthalpy-driven separations occurred in consistency with the results. The influence of temperature on retention behavior showed that the process of inclusion was exothermic, in consistency with the calculated thermodynamic parameters.