LC-MS法同时测定雷公藤浸膏中雷公藤新碱和雷公藤碱戊含量

目的建立一种灵敏、准确的雷公藤浸膏中雷公藤新碱和雷公藤碱戊含量的LC-MS法。方法雷公藤浸膏样品经氯仿溶解后用稀盐酸（2．0mol·L“）溶液提取，上清液移人Oasis。MCX固相萃取小柱进行净化，然后样品在ZorbaxPlusRRHDC18柱（50innl×2．1mm，1．8μm）上，以醋酸铵缓冲液[0．05％醋酸一酸酸铵溶液（5mmol·L-1）]-乙腈（30：70）为流动相进行分离，应用LC—MS法，在大气压化学电离正离子选择离子监测模式（SIM）下测定，雷公藤新碱和雷公藤碱戊的定量离子分别为m／z806和m／z779。结果雷公藤新碱和雷公藤碱戊的绝对回收率为87．0％-97．5％，在含量1．0—200．0μg·kg-1内均具有良好线性，日内RSD均〈9．8％，日间RSD均〈14．7％，定量检出限均为1．0μg·kg-1。结论本方法简便、灵敏、干扰少、特异性好，可用于雷公藤浸膏中雷公藤新碱和雷公藤碱戊含量的监测。

Determination of contents of euonine and wilforidine in Tripterygium wilfordii hook. F. extract by liquid chromatography coupled with mass spectrometry

AIM To establish a sensitive and accurate method for the determination of contents of trace euonine and wilforidine in Tripterygium wilfordii hook. F. extract by liquid chromatography coupled with mass spectrometry （LC- MS）. METHODS After the alkaloids in Tripterygium wilfordii hook. F. extract was dissolved by chloroform and ex- tracted by hydrochloric acid solution （2.0 mol L-1）, the supernatant was cleaned by the solid-phase extraction （SPE） using Oasis MCX cartridges. The separation was performed on a Zorbax Plus RRHD C18 column（50 mm × 2.1 mm, 1.8 μm）using a mobile phase consisting of 0.05 % acetic acid-ammonium acetate （5 mmol L- 1 ）.acetonitrile （30 ： 70）. Detection was carried out by a positive atmospheric-pressure chemical ionization mass spectrometry （APCI-MS） in the se- lected ion monitoring （SIM） mode with the protonated molecular ions m/z 806 [M ＋ H]＋ and m/z 779 [M ＋ H]＋ for euonine and wilforidine, respectively. RESULTS Calibration curves were linear within the range of 1.0 - 200.0 μg kg- 1, and the extraction recoveries were from 87.0 % to 97.5 %. The intra-day RSD was less than 9.8 %, the inter-day RSD was less than 14.7 %, and the limits of quantification （LOQ） were 1.0 μg kg-l for the two alkaloids. CONCLU- SION This method is found to be simple, sensitive and little interferential, and can be used for the determination of trace euonine and wilforidine in Tripterygium wilfordii hook. F. extract.