中文摘要：

采用乙醇回流提取法,以亚硝酸钠、硝酸铝、氢氧化钠为试剂,芦丁为对照,研究柳树叶中黄酮含量的测定。利用正交实验对柳树叶中黄酮含量测定方法进行优化。以乙醇浓度、回流时间、回流温度、料液比为因素,总黄酮显色液的吸光度为指标进行实验。得到的最佳条件为：乙醇浓度50%,料液比1∶30,回流时间为1h,回流温度为70℃,在最佳条件下的总黄酮含量为18.92mg/g。

英文摘要：

The extraction of flavonoids from willow leaves with ethanol as solvent,sodium nitrite,aluminium nitrate and sodium hydroxide as indicator and rutin as control was studied.The optimum conditions of extracting flavonoids from willow leaves were studied by orthogonal test using concentration of extracting solution,temperature,time and solid-liquid ratio as influencing factors.The content of flavonoids was determined by spectrophotometry.The optimum conditions obtained were as follows：the methanol concentration was 50%,the ratio of mass of raw material to the volume of solvent（solid-liquid ratio）was 1∶30,the refluxing time was 1hand the refluxing temperature was 70℃.Under these conditions the flavonoids were extracted efficiently and the extraction yield could reach 18.92mg/g.The method is simple,convenient,and can be applied to extract flavonids in large scale.