HP-β-CD对苯基琥珀酸对映体色谱保留机制及拆分机理的研究  

Studies on the Retention and Separation Mechanisms of Phenylsuccinic Acid Enantiomers with HP-β-CD as Chrial Mobile Phase Additive in HPLC

作　　者：王钟辉[1] 满瑞林[1] 唐课文[1,2] 

机构地区：[1]中南大学化学化工学院,湖南长沙410083 [2]湖南理工学院化学化工系,湖南岳阳414000

出　　处：《分析测试学报》2009年第2期162-167,共6页Journal of Instrumental Analysis

基　　金：国家自然科学基金资助项目(20776038)

摘　　要：利用反相液相色谱(RP-HPLC)法,以羟丙基-β-环糊精(HP--βCD)为手性流动相添加剂,研究了苯基琥珀酸(PSA)对映体的色谱保留机制。苯基琥珀酸对映体达到基线分离的最佳色谱分离条件为:10 mmol/LHP--βCD,20%(体积分数)乙腈,0.05%(体积分数)三氟乙酸,pH 2.5,柱温25℃,流速1.0 mL/m in,进样量为20μL,检测波长为254 nm。该文建立了保留因子(k)与ce(HP--βCD)、ce(H+)、包结平衡常数以及苯基琥珀酸的解离常数的关系式,并结合实验对该关系式进行了验证。保留因子的倒数1/k对ce(HP--βCD)呈良好的线性关系,证明HP-β-CD与苯基琥珀酸对映体形成了包合比1∶1的包合物。在低酸度值下,包结平衡常数的计算结果显示,R-(-)-苯基琥珀酸与HP-β-CD所形成的包合物的包结平衡常数(162.5)比S-(+)-苯基琥珀酸(97.4)的大很多。手性拆分过程中热力学参数的计算结果表明,HP-β-CD对苯基琥珀酸对映体的分离过程主要是一个焓驱动的过程,包合过程是一个放热过程。通过比较手性选择体结构,探讨了HP-β-CD拆分苯基琥珀酸对映体的机理。研究表明,分子尺寸大小相匹配以及构象诱导作用大小不同可能是HP-β-CD拆分苯基琥珀酸对映体的主要因素。The chromatographic retention mechanism of phenylsuccinic acid （PSA） has been studied by reverse phase high performance liquid chromatography（RP-HPLC） with hydroxypropyl-β-cyclodextrin（HP-β-CD） as chiral mobile phase additive. The optimum chromatographic conditions for baseline separation of PSA were found to be as follows ： mobile phase ： 10 mmol/L HP-β-CD in 20% （ by volume） acetonitrile, trifluoroacetic acid（ pH 2.5, adjusted with triethylamine） ： 0. 05% , flow rate： 1.0 mL/min, column temperature： 25 ℃, injection volume： 20 μL and the detection wavelength： 254 nm. A mathematical model expressing the relationships of retention factor（k） with ce （HP-β-CD） and ce （ H ^＋ ） , inclusion complex constants and dissociation constants of PSA was established and examined by experiments. The results showed that the mathematical model could forecast on the separa- tion process. The plot of 1/k vs c, （HP-β-CD） showed a good linear relationship, indicating that the stoichiometric ratio of the complexes formed between PSA and HP-β-CD was 1 ： 1. The inclusion complex constants were calculated at low pH value and the thermodynamic parameters of inclusion complexes were determined. The results indicated that the constant of the inclusion complex formed between R-（ - ）-PSA and HP-β-CD was much higher than that of S-（ ＋ ）-PSA, and the separation of PSA enantiomers was an enthalpy-driven process, and the process of inclusion was exothermic process. In addition, the separation mechanism of PSA enantiomers with HP-β-CD was discussed by comparing the structure of cyclodextrins. The result indicated that the matching of the molecular size and the great difference of the effects of conformation induction may be the main factors for the separa- tion of PSA enantiomers by HP-β-CD.

关 键 词：HP-βCD 苯基琥珀酸对映体 拆分机理 保留机制 手性流动相添加剂 反相液相色谱 

分 类 号：O657.7[理学—分析化学]