毛细管电泳-电喷雾-质谱-质谱分离鉴定粉防己生物碱

Separation and identification of alkaloids in Stephania tetrandra by capillary electrophoresis electrospray-MS/MS

目的 以非水毛细管电泳对粉防己甲醇提取物中的生物碱进行分离,并利用在线电喷雾离子阱质谱得到的准分子离子及碎片信息对其进行鉴定。方法 使用未涂层毛细管(86cm×75μmID,紫外检测器距进样端21cm),50mmol·L^(-1)醋酸铵-4％HAc-甲醇溶液为运行缓冲液,分离电压为25kV。质谱接口为同轴鞘液接口;电喷雾电压为4.5kV。铝毛细管温度为170℃;鞘液组成为60％异丙醇-39％水-1％HAc,鞘液流速为5μL·min^(-1)。MS-MS的碰撞能量为30％,所要求的最小信号计数为1×10~5。结果与结论 毛细管电泳-质谱及质谱-质谱联用技术对粉防己甲醇提取物中生物碱进行了分离鉴定,比传统的根据迁移时间或淌度定性更加准确,可用于研究中药复杂成分。

Aim To establish a method for separation and identification of alkaloids in Stephania tetrandra S. Moore methanol extracts by using non-aqueous capillary electrophoresis interfaced with electrospray ionization ion trap mass spectrometry. Methods The molecular ions or adducts of alkaloids and fragments of specific parent ions were used for the identification. An uncoated capillary (86 cm×75 μm ID, on-line UV detection occurred at 21 cm from the inlet of the capillary) was used. Ammonium acetate (50 mmol·L^(-1)containing 4% HAc in methanol was used as the running buffer; separation voltage was 25 kV. A coaxial sheath flow interface was used as the CE-MS interface; the electrospray voltage was 4.5 kV; the temperature of aluminium capillary was 170℃;60% isopropanol-39% water-1% HAc was used as the sheath liquid with the flow rate of 5 μL·min^(-1); the collision energy of MS-MS was set at 30% and the least ion counts was 1×10~5. Results and conclusion The alkaloids in Stephania tetrandra S. Moore methanol extracts were separated and identified by CE-ESI-MS/MS. The proposed method is of high accuracy and can be used for the investigation of traditional Chinese medicine.