高效液相色谱法同时测定杜仲中的几种多酚酸——超声助提及微波助提和热回流提取技术的比较

微波、超声波和热回流提取技术分别用于提取杜仲中的绿原酸、咖啡酸、没食子酸、原儿茶酸和香草酸，并用高效液相色谱进行分析.考察了提取时间和溶剂对提取效果的影响.结果表明：超声波助提和热回流提取分别需90 min和120 min才能达到最大提取，而微波助提仅需50 s就可达到.在微波助提和热回流提取中，水比甲醇提取效果要好，而在超声波助提过程中，用甲醇作溶剂获得的提取率比水高.3种提取方法的重现性均较好.综合来看，微波助提比超声波助提和热回流提取技术效果更好，更有利于杜仲中酚酸的提取.

Simultaneous Determination of Several Polyphenolic Acids in Eucommia Ulmodies by HPLC:Comparison of Microwave and Ultrasound-Assisted Extraction with Heat Reflux Extraction Techniques for the Extraction of Polyphenolic Acids

Microwave-and ultrasonics-assisted extraction(MAE and UAE) and heat reflux extraction(HRE) techniques were respectively used for simultaneous extraction of five polyphenolic acids,i.e.chlorogenic acid,caffeic acid,gallic acid,protocatechuic acid and vanillic acid,from Eucommia ulmodies.The influence of extraction time and solvent type on the extraction yields of compounds tested was investigated.The time that the highest extraction yields are obtained is 90 min and 2 h for UAE and HRE respectively;whereas MAE needs only 50 s.While water is shown to be a better solvent than methanol in MAE and HRE techniques for these polyphenolic acids,methanol produces a higher extraction yield than that obtained using water in UAE.The repeatabilities of the three extraction techniques were shown to be satisfactory.Due to the high extraction yields and the considerable saving of time,MAE was more effective than UAE and HRE techniques in the extraction of these polyphenolic acids from Eucommia ulmodies.