Optimization of salidroside extraction using ultrasonic-microwave synergistic extraction by response surface methodology

Based on the root of salidroside from Rhodiola as raw material, with ethanol as solvent, the method of ultrasonic-microwave synergistic extraction technology was adopted to optimize the extraction process of salidroside from Rhodiola in terms of the yield. On the basis of single factor experiments, the optimum conditions for the extraction of salidroside were obtained by center-united experiment design with three factors and three levels. According to quadratic regression analysis, influencing process factors were identified. And response surface together with contour were firstly graphed with extraction rate as the response value. On the analysis of significance and interaction of various factors, it could be concluded that the optimum extraction technology of salidroside by ultrasonic-microwave synergistic extraction was as follows:volume fraction of ethanol was 70%, the ratio of material to solvent of 1∶20, ultrasonic time of 20min, microwave time of 10min, microwave power400W.Under these conditions extracting for 3 times, the yield of the salidroside was 2.21%.