液相色谱-串联质谱法测定人血浆中乙胺丁醇的浓度

Concentration determination of ethambutol in human plasma by LC-MS/MS

目的建立液相色谱-串联质谱(LC-MS/MS)测定人血浆中乙胺丁醇浓度的方法。方法采用Lichrospher CN(4.6mm×250mm,5μm)色谱柱;流动相为乙腈-水(含0.1%甲酸)(15:85,V/V),流速为1.0mL·min-1;通过LC-MS/MS,电喷雾离子化(ESI)法,以选择反应监测方式进行检测;检测离子为m/z205.1→m/z115.9(乙胺丁醇),m/z166.0→m/z148.0(伪麻黄碱,内标)。结果本法中乙胺丁醇最低定量限为0.02052mg·L-1,线性范围为0.02052～6.156mg·L-1,回收率>75%,日内及日间RSD均<15%。结论LC-MS/MS法操作简便、灵敏度高,可用于乙胺丁醇临床血药浓度测定。

AIM To establish a method of LC-MS/MS for the determination of ethambutol in human plasma. METHODS The chromatographic separation was performed on Lichrospher CN （4.6 mm× 250 mm, 5 μm） chromatographic colunm with a mobile phase consisted of acetonitrile-water （contained 0. 1% formic acid） （15 ： 85, V/V） at a flow-rate of 1.0 mL.min^-1. Finnigan TSQ tandem mass spectrometer equipped with electronic spray ionization source （ESI） was used as detector, operated in the positive ion mode and acted as selected reaction monitoring （SRM）. The detection ions of ethambutol were consisted of m/z 205.1 → m/z 115.9 （ethambutol）, and m/z 166.0 → m/z 148.0 （pseudoephedrine, IS）. RESULTS The assay for ethambutol was linear in range over 0.020 52 - 6.156 mg.L^-1 with a lower limit quantitation of 0.020 52 mg.L^-1. Intra- and inter-day precision of RSD was less than 15%. The recovery of ethambutol was 77.0% - 83.0% and relative deviation of stability was less than 15%. CONCLUSION This method of LC-MS/MS is simple, highly sensitive and suitable for clinical pharmacokinetics or bioequivalence studies.