杜仲叶中绿原酸的浸出动力学

Leaching Kinetics of Chlorogenic Acid from Eucommia ulmoides Leaves

采用有机溶剂对杜仲叶中绿原酸进行浸提,用高效液相色谱法对绿原酸进行定性定量分析,考察了液固比、乙醇浓度、温度和时间对绿原酸浸出率的影响,并对绿原酸浸出过程进行了动力学模拟.结果表明,绿原酸浸出的最优条件为乙醇浓度60%(?),液固比10 m L/g,在60℃下提取40 min,该条件下绿原酸的浸出率达90.21%.乙醇浸提杜仲叶中绿原酸符合内扩散动力学模型,表观活化能Ea=11.46 k J/mol.

Ethanol solution was employed as a solvent for extracting chlorogenic acid（CGA） from Eucommia ulmoides leaves, and HPLC was used to determine the concentration of CGA in the extraction liquid. The process variables, such as the ratio of liquid to solid, the ethanol concentration, the extraction temperature and extraction time, were investigated in detail. The optimum parameters were as follows： ratio of liquid to solid of 10 m L/g, ethanol concentration of 60%（φ）, extraction temperature of 60 ℃ and extraction time of 40 min. Under the optimum conditions, the extraction yield of CGA reached up to 90.21%. The infusion rates of CGA at different temperatures were measured and the rate constants of infusion were calculated and obtained. The results indicated that the extraction of CGA in ethanol solution was controlled by internal diffusion. The extracting process was satisfied with the internal diffusion kinetic model, and the apparent activation energy was 11.46 k J/mol.