中文摘要：

目的优选麻黄中麻黄碱的最佳提取工艺。方法水煎法获得麻黄药材总提取物,反相高效液相色谱-电喷雾-飞行时间串联质谱选择离子对法测定总提物中麻黄碱的含量,正交设计优选最佳提取工艺。结果方法检测限为0.05μg·mL-1,线性范围为0.005～0.5mg·mL^-1;麻黄碱最佳提取工艺为：加30倍量水,75℃加热40min,提取4次。结论该检测方法灵敏、准确,可用于复杂体系中麻黄碱的测定;水煎法经济、绿色、无污染,可作为麻黄碱等生物碱类物质的提取方法。

英文摘要：

Objective To optimize the extraction conditions of ephedrine in Ephedra sinica.Methods The extracts of Ephedra sinica were obtained by water decoction.Reversed high performance liquid chromatography-electrospray-time of flight tandem mass spectrometry（HPLC-ESI-TOF-MS） was used to determine the concentration of ephedrine in extracts through selected ion mode.Orthogonal design was employed to optimize the extraction procedure.Results The limit of detection was 0.05 μg·mL-1.The peak area and the concentration of ephedrine gave a linear relationship in the range of 0.005-0.5 mg·mL-1.The best method for extracting ephedrine in Ephedra sinica was water decoction.Using this approach,the optimized conditions were as follows：the process of 30 folds water,a value of 75 ℃ for heating temperature,a repeatability of 4 times and 40 min for each time.Conclusion HPLC-ESI-TOF-MS was proved to be sensitive,accuracy and suitable to determine ephedrine in complex matrix.Water decoction has the properties of being economic,environment friendly and having no pollution.It will probably be an alterative for extracting alkaloids such as ephedrine.