麻黄生物碱类化合物电喷雾电离质谱

采用电喷雾离子阱质谱(ESI-MS)法，研究了麻黄生物碱类化合物的质谱行为及分子结构与裂解规律间的关系．样品通过直接进样，进行一级质谱正负离子全扫描(扫描范围m／z：50～800)和选择性离子二级质谱分析(扫描范围m／z：50～200)．流动相：甲醇一水(50：50V/V)，流速：0．2mL／min，离子源喷雾电压：4．5kV；毛细管温度：200℃，鞘气流速：40个单位．结果显示，该类化合物在电喷雾电离一级质谱中易得到质子产生正离子，并有部分自发丢失小分子H20的碎片产生．应用碰撞诱导解离(CID)技术得到的二级质谱显示，麻黄生物碱侧链氮原子比较活跃，质谱碰撞容易失去连接在N原子上的取代基团，特征性丢失为CH2、CH4、NH4、NH2等中性碎片．一级、二级质谱图适宜作为麻黄生物碱提取物特征图谱，实验结果可应用于麻黄生物碱类化合物的结构分析研究，并为麻黄药材有效成分的鉴定提供了一种快速、准确的检测方法．

The electrospray ionization- mass spectra of alkaloid in Herba Ephedrae

Alkaloids in Herba Ephedrae are analysed by ESI-ITMS detector to study their relationship between molecular structure and MS behaviors .Samples (dissolved in mathanol) are directly infused into the MS detector by autosampler,then analysed in two modes:MS and MS/MS full scan modes.The results show that in MS detection ,alkaloids are easily to get H~+ and become positive ions in electrospray ionization procedure.In MS/MS collision induced detection,substitutes linked to the atom N is most likely to dissociate in neutral fragment forms of CH_2,CH_4,NH_4 and NH_2. The characteristics of the alkaloids mass specctra will be helpful to further study their molecular struture,and offer a new,quick method to identify the Herba Ephedrae medicinal materials.