紫外分光光度法及毛细管电泳法测定烷基酚与环糊精的包合常数

Measurement of Equilibrium Constants between β-Cyclodextrin and Alkylphenols by UV Spectrophotometry and Capillary Electrophoresis

β-环糊精(β-CD)具有独特的外部亲水、内部疏水的空心圆台结构,能分别与对特辛基酚(OP)和正壬基酚(NP)形成包合物。该文通过紫外分光光度法测定了β-CD与OP和NP的包合比及包合常数,实验结果表明,OP和NP与β-CD均形成1∶1的包合物,包合常数分别为71.06 L/mol和1 402.72 L/mol。同时采用毛细管电泳法测定了β-CD与OP和NP在10 mmol/L磷酸二氢钠-10 mmol/L硼砂-20 mmol/L胆酸钠缓冲溶液(p H 9.0)中的包合常数,采用双倒数法计算出β-CD与OP和NP的包合常数分别为68.20 L/mol,1 357.80 L/mol。经F检验和t检验判断,两种方法所测包合常数一致。

β-CD has a special large molecular cavity with an external hydrophilic and an internal hy- drophobic properties, and it could form inclusion complex with 4-tert-octylphenol（OP） and 4-n-non- ylphenol（NP）, respectively. In this paper, the stoichiometric ratios and the equilibrium constants between β-CD and the above two alkylphenols（APs） were determined by UV spectrophotometry. The results indicated that OP and NP both foITn inclusion complexes by a molar ratio of 1 ： 1 with β-CD, and the equilibrium constants were 71.06 L/mol and 1 402.72 L/mol, respectively. At the same time, the equilibrium constants between β-CD and APs were also studied by capillary electrophoresis under the conditions of 10 mmol/L sodium dihydrogen phosphate - 10 mmol/L sodium borate - 20 mmol/L sodium cholate（ pH 9. 0）. The double reciprocal was introduced to measure the equilibrium constants, and the values for OP and NP were 68.20 L/mol and 1 357.80 L/mol, respectively. Ac- cording to F test and t test, the equilibrium constants between ^-CD and APs obtained from two meth- ods have no difference.