呋塞米血药浓度测定方法的建立及应用

Determination of furosemide in human plasma and its application in renal failure patients

目的建立三重串联四极杆液质联用仪测定人血浆中呋塞米含量的方法，并初步应用于临床。肾衰竭患者的血药浓度监测。方法采用液质联用仪（LCfMS／MS）检测，血浆样品采用乙酸乙酯进行萃取，通过ESI负离子分析模式，MRM扫描方式，得到呋塞米（328．9—284．9）及内标双氯芬酸钠（293．9—249．9）的TIC谱图。结果呋塞米血浆样品在12．8～5120ng／ml浓度范围内线性关系良好，最低定量限为12．8ng／ml，提取回收率在70％-83％范围内，无明显基质效应影响。日内、日间精密度良好，相对标准差（RSD）均〈10％。处理前后的血浆样品在经过常温（避光）及冷冻放置后，稳定性良好，RSD均〈15％。随机选取5名肾衰竭患者静脉推注40mg呋塞米进行实际测定，推注后0．5h和2h的血药浓度分别在2．34～4．94mg/L和0．71一1．83mg／L范围内。结论该方法灵敏、稳定，具有临床应用价值。

Objective The aim of this study was to establish a three tandem quadrupole LC/MS/MS method for determination of furosemide in human plasma which can be used to monitor the concentration of therapeutic drug in renal failure patients. Methods Ethyl acetate was employed to pretreat the plasma sample. The TIC spectrum of furosemide （328.9→284.9） and diclofenac sodium （293.9-→249.9, internal standard） were obtained by using the mode of MRM scan in negative ion analysis model. Five renal failure patients were chosen to monitor the drug concentration in plasma at different time points after the methodology validation. Results The calibration curve of furosemide was linear at the range of 12.8-5 120 ng/mL, with the lowest limit of quantification of 12.8 ng/mL. The recovery of this extraction method was 70%-83%, with no obvious matrix effect. The intra-day and inter-day precisions expressed as the relative standard deviation （RSD） for less than 10%. The stability of furosemide met the analysis requirements （RSD〈15%） before and after the pretreatment of plasma sample, no matter the placed environment was room temperature or frozen. Five renal failure patients with intravenous injection of 40 mg furosemide were selected randomly. The concentration was 2.34-4.94 mg/L and 0.71 ---1.83 mg/L at 0.5 h and 2 h after intravenous injection. Conclusion This method was sensitive, stable, and of great value in clinical applications.