丹参提取过程动力学研究:模型建立及关键工艺参数考察

该研究以Fick第一扩散定律、分配平衡来表示丹参药材宏观层面内、外传质过程,建立传质模型,并将药材比表面积融合在传质阻力中,从而有效避免了药材形状不规则问题,扩大了模型适用范围。同时进一步将传质模型与酚酸降解动力学模型结合,建立丹酚酸B、紫草酸和丹参素的提取动力学模型。将模型应用于丹参提取过程研究,敏感性分析结果表明,在最大提取率(320 min)附近,模型预测相对误差在5%以内,模型预测性能较好。不同工艺参数考察结果表明,搅拌会显著加快丹酚酸B传质速率;溶剂倍量对丹酚酸B传质和降解无明显影响;温度的倒数与传质阻力对数值线性关系良好,决定系数为0.996,温度与传质阻力符合阿伦尼乌斯公式。研究结果表明,在较高提取温度(358 K以上)下,紫草酸和丹参素浓度变化受传质影响较弱,只需考虑降解对其浓度变化的影响。该研究为中药提取的工艺优化和质量控制提供了基础。

Study on extraction kinetics of Salviae Miltiorrhizae Radix et Rhizoma:model establishment and investigation of critical process parameters

In this study,Fick′s first law and partition equilibrium were used to represent the internal and external mass transfer processes of Salviae Miltiorrhizae Radix et Rhizoma at the macroscopic level,and a mass transfer model was established.The specific surface area was integrated into the mass transfer resistance,which effectively avoided the irregular shape of medicinal materials and expanded the application scope of the model.Meanwhile,the mass transfer model was further combined with the kinetic model of salvia-nolic acid degradation to establish the extraction kinetic models of salvianolic acid B,lithospermic acid and Danshensu.The model was applied to study the extraction process of Salviae Miltiorrhizae Radix et Rhizoma.According to the sensitivity analysis results,the relative error of the model prediction was within 5%near the maximum extraction rate(320 min),and the prediction performance of the model was good.According to the investigation results of different process parameters,stirring could significantly accelerate the mass transfer rate of salvianolic acid B,while the mass transfer resistance and degradation rate constant were not affected by solvent-to-solid ratio.The linear relationship between the reciprocal of temperature and the logarithm of mass transfer resistance was good(R2=0.996),indicating that the temperature and mass transfer resistance conformed to Arrhenius formula.In addition,we also found that the concentration changes of lithospermic acid and Danshensu were weakly affected by mass transferwhen the extraction temperature was higher than 358 K.This study has provided the basis for the process optimization and quality control of traditional Chinese medicine extraction.