胆甾醇和链甾醇在混合溶剂中溶解度的NRTL-SAC和COSMO-RS预测

使用两个热力学模型NRTL-SAC和COSMO-RS预测胆甾醇和链甾醇在混合溶剂中的溶解度,并以实验数据为计算基准,通过平均相对偏差(ARD)评价模型的预测效果。为填补溶解度数据空白,采用静态法结合高效液相色谱法(HPLC)测定了298.2 K下两种甾醇分别随混合溶剂组成变化的溶解度。NRTL-SAC对两种甾醇的溶解度预测在满意范围,最大ARD为50.58%。COSMO-RS预测结果非常不理想。通过改进,输入一个298.2 K时的实验值预测同一混合溶剂组成下随温度变化的溶解度,结果预测值与实验值吻合得较好,胆甾醇和链甾醇在(正己烷+乙醇)混合溶剂中,总的ARD分别从80.57%和82.30%降为12.77%和21.32%。上述结果表明,只需少量实验数据的NRTL-SAC和只需一个实验数据的COSMO-RS(ref)可用于两种甾醇溶解度的预测,为工业分离纯化过程中的溶剂快速筛选提供重要的理论依据。

Solubility prediction for cholesterol and desmosterol in mixed solvents via NRTL-SAC and COSMO-RS

Solubility of cholesterol and desmosterol in mixed solvents was predicted via two thermodynamic models,NRTL-SAC and COSMO-RS.With experimental data as the basis,average relative deviation(ARD)was used to evaluate the prediction effects of the models.To fill the blank of solubility data,the solubilities of two sterols at 298.2 K in mixed solvent with different compositions were determined using the static method combined with high performance liquid chromatography(HPLC).The ARDs by NRTL-SAC for two sterols in mixed solvents are less than 50.58%.The prediction results by COSMO-RS are extremely dissatisfied,but the predicted values satisfactorily agree with the experimental values by using an experimental datum.The total ARDs for cholesterol and desmosterol in n-hexane + ethanol mixed solvents decrease to 12.77% and 21.32% from 80.57% and 82.30%,respectively.The results show that NRTL-SAC from limited experimental data and COSMO-RS with only one experimental datum can be used for solubility prediction for two sterols,and are useful in rapid selection of suitable solvents for industrial separation and purification processes.