液相色谱-质谱法测定雷公藤浸膏中4种倍半萜类生物碱含量

目的建立一种灵敏、可靠的雷公藤浸膏中4种倍半萜类雷公藤生物碱含量的高效液相色谱-质谱检测方法。方法雷公藤浸膏样品经氯仿溶解后用稀盐酸（2.0 mol·L~（-1））提取,Waters Oasis.MCX小柱进行净化,以0.05%（V/V）醋酸-醋酸铵溶液（5 mmol·L~（-1））/乙腈（45/55,V/V）为流动相,采用Zorbax SB C_（18）柱（250mm×4.6mm,5μm）分离,应用高效液相色谱/大气压化学电离正离子选择离子监测模式（SIM）测定,雷公藤春碱、雷公藤定碱、雷公藤吉碱和雷公藤次碱的定量离子分别为m/z874、884、858和868。结果 4种雷公藤生物碱的绝对回收率为86.5%～96.0%,质量浓度在1.0～200.0μg·L~（-1）内具有良好线性,批内RSD〈7.4%,批间RSD〈9.3%,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4种倍半萜类雷公藤生物碱含量的检测。

Determination of four sesquiterpene alkaloids in Tripterygium wilfordii hook.F.extracts by liquid chromatography coupled with mass spectrometry

AIM To develop a sensitive and accurate method for the determination of four sesquiterpene alkaloids in Tripterygium wilfordii hook.F.extracts by high-performance liquid chromatography coupled with mass spectrometry （LC/MS）.METHODS After the sesquiterpene alkaloids in Tripterygium wilfordii hook.F.extracts were dissolved by chloroform and extracted by hydrochloric acid solution（2.0 mol·L~（-1））,the sample was cleaned by solid-phase extraction （SPE） using Oasis MCX cartridges.The separation was performed on a Zorbax SB C_（18） column（250 mm×4.6 mm,5μm）using the mobile phase consisting of 0.05%（V/V） acetic acid-ammonium acetate（5 mmol·L~（-1））/acetonitrile（45/ 55,V/V）.Detection was carried out by a positive atmospheric pressure chemical ionization mass spectrometry（APCI- MS） in the selected ion monitoring（SIM） mode with the protonated molecular ions m/z 874M ＋ H]~＋,m/z 884 M ＋ H]~＋,m/z 858M ＋ H]~＋ and m/z 868M ＋ H]~＋ for wilfortrine,wilfordine,wilforgine and wilforine,respectively. RESULTS Calibration curve was linear within the range of 1.0 - 200.0μg·L~（-1）,and the extraction recoveries were from 86.5%to 96.0%.The intra-day RSD were less than 7.4%,the inter-day RSD were less than 9.3%,and the limits of quantification were 1.0μg·kg~（-1） for the four sesquiterpene alkaloids.CONCLUSION This method is found to be simple,sensitive,little interferential and can be used for the determination of the sesquiterpene alkaloids in Tripterygium wilfordii hook.F.extracts.