密闭式微波系统的微波辅助萃取动力学模型

从Fick扩散定律出发,利用电磁场增强扩散的理论,建立了微波辅助萃取(MAE)动力学模型,对影响MAE的温度、萃取时间、颗粒大小、微波功率等因素进行了模拟研究.除功率有些偏差外,其它参数的模拟结果与实验结果十分接近.实验和模型结果还表明,MAE条件下的白藜芦醇(Res)的扩散系数与模拟条件下的扩散系数比普通加热回流的扩散系数提高了20倍.这更进一步说明了MAE是通过增强目标化合物在基体内扩散速度的一个萃取过程.

A Kinetic Model for Microwave-Assisted Extraction under Closed Vessel Condition

Based on the Fick's diffusion law and using the electromagnetic-enhanced diffusion theory, a kinetic model has been developed for microwave-assisted extraction (MAE) under closed vessel condition. The effects of irradiation temperature and time, the microwave power and particle size on MAE were modeled. Except for the power, the experimental and modeling data of MAE were closed to each other and their diffusion coefficients of resveratrol were almost the same, indicating that the model developed was reasonable. Experimental data also revealed that the diffusion coefficients obtained by the MAE was enhanced by a factor of 20 in comparison with those obtained by the conventional reflux heating,this further demonstrates that the diffusion of target compound from the sample matrix is enhanced during the MAE process.