石油醚索氏提取除杂,甲醇索氏提取杜仲藤中各部位的总黄酮含量,所得提取液用甲醇定量稀释至100 mL,分取1.0 mL于10 mL容量瓶中,并在碱性溶液中与铝(Ⅲ)反应后在510 nm波长处测定所生成络合物的吸光度.用芦丁作标准制作校准曲线,其回归方程为C=0.096 69 A-0.000 763,相关系数为0.999 3.按此方法分析了杜仲藤样品,测得茎中总黄酮量为93.0 mg·g-1(n=6,相对标准偏差为1.62%),叶中为96.4 mg·g-1(n=6,相对标准偏差为0.44%).

The sample was extracted with methanol by refluxing at 80 ℃ in a Soxhlet′s extractor after removal of its impurities by refluxing with petroleum ether under the same condition.The extract was diluted to 100 mL in a volumetric flask with methanol,an aliquot of 1 mL was transferred to a 10 mL volumetric flask and the flavonoids were determined by its reaction with Al(Ⅲ) in an alkaline solution.Absorbance of the complex formed was measured at 510 nm.Rutin was used as standard in the preparation of calibration curve,the linearity of which was shown by the linear regression equation of C(mg·L-1)=0.096 69 A-0.000 763 (r=0.999 3).In applying the proposed method to analysis of Parabarium micranthum,93.0 mg·g-1 (n=6,RSD=1.62%) of flavonoids were found in the stems,and 96.4 mg·g-1 (n=6,RSD=0.44%) were found in the leaves.