薄层色谱法鉴别大黄饮片真伪

目的建立一种以土大黄苷为检测指标,定性鉴别中药大黄饮片真伪的薄层色谱(TLC)方法。方法以甲醇为提取溶剂,用超声波提取的方法制备供试品溶液,以硅胶G板为固定相,苯-甲酸乙酯-甲酸-甲醇(30:10:0.1:15)为展开剂展开,紫外光(365 nm)下检视。结果华北大黄和河套大黄两种伪品大黄饮片的薄层色谱中检出土大黄苷,正品大黄饮片中未检出;对市售的10批大黄饮片进行TLC鉴别,有50%检出土大黄苷成分。结论该方法操作简便、结果准确、专属性强,可用于大黄饮片的真伪鉴别,有一定的应用价值。

Identification of Rhei Radix et Rhizoma by TLC

Objective To establish a method for identification of Rhei Radix et Rhizoma by thin layer chromatography （TLC）,using ponticin as detection index.Methods Sample solution was prepared by ultrasonic extraction,using methanol as extraction solvent.Silica gel G was used as stationary phase,with benzene-ethyl formate-formic acid-methanol（30∶10∶0.1∶15） as developing solvent.The chromatogram was inspected under ultraviolet light（365nm）.Results Rhaponticin was detected by TLC in two fakes incuding Rheum franzenbachii Munt.and Rheum hotaoense C.Y.Cheng et Kao,and wasn＇t detected in certified products.Rhaponticin was also detected in 50 ％ of commercially available products.Conclusion This method is simple,accurate and with high specificity.It can be used for identification of Rhei Radix et Rhizoma.