摘要
本文是为了考察中药材的分析方法和寻找提取新技术而进行研究。常规中草药质量控制的分析方法采用超声处理、索氏提取和水蒸气蒸馏提取,本研究采用具有精密压力控制的微波萃取仪,探讨微波提取金银花中主要有效成分的特点。本研究采用具有精确压力和温度控制的微波萃取仪,购买市售的中药饮片金银花,根据本研究建立的微波辅助提取和参考药典2005版推荐的超声波提取两种方法提取金银花中的主要有效成分绿原酸,考察了不同的微波辐射功率和提取时间对提取率的影响。最终选定本仪器的微波辅助提取的优化参数为:用35%乙醇作溶剂,固液比1:30,微波功率60%(最大功率850W),设定压力0.10MPa,恒压时间1min。超声波提取优化参数为:用35%乙醇作溶剂,固液比1:40,功率100%(最大功率300W),提取时间40min。分别用紫外可见分光光度法和高效液相色谱法来对微波辅助提取和超声波提取在优化条件下的提取效果进行比较。对比不同提取方法的检测结果显示:用微波法对金银花中绿原酸进行提取的提取率明显高于超声波提取。其中,用紫外可见分光光度法测得结果显示微波提取的提取率比超声波高30%左右,而用高效液相色谱法测得结果中微波提取的提取率更是比超声波高出近1倍。实验证明微波辅助提取金银花中的主要成分绿原酸不仅是一种高效快捷样品前处理方法而且提取率远高于超声波处理技术。
It was studied on the Chinese herbal medicines analysis in order to search for a new extraction technology.The conventional herbal quality testing and analysis is used to be implemented by water decoction,ultrasonic extraction,Soxhlet extraction or steam distillation extraction.At here,the characteristics of extracting the active ingredient chlorogenic acid from the flos lonicerae japonicae were investigated by using a closed-vessel microwave assisted extraction(MAE) apparatus with a precise pressure controlling unit. The MAE method was contrasted with the ultrasonic extraction method which is recommended by the Pharmacopoeia version 2005.By the MAE method the major parameters that influence the extraction efficiency were optimized at 35%Ethanol,1:30 solid/liquid ratio,60%microwave power(the full power is 850W),0.10 MPa pressure in the extraction vessels,1 min holding time.By the ultrasonic extraction,35% Ethanol,1:40 solid/liquid ratio,100%ultrasonic power(the full power is 300W),40 min extraction time were chosen. The extraction was determined by UV-Vis spectrophotometer and HPLC with a PDA 2996 detector.It shows that the extraction yield of MAE was remarkable higher than ultrasonic extraction.By the extraction result,MAE was about 30%more efficient than ultrasonic extraction if the UV-Vis spectrophotometer was used to detect.And if it was detected by using the HPLC-PDA 2996 detector the MAE was even reaches to about 100%more efficient than ultrasonic extraction.So the MAE was proven to be a rapid and reliable method to extract chlorogenic acid from the flos lonicerae japonicae.
