Department of Hospital Pharmacy, Erasmus University Medical Center, 's-Gravendijkwal 230, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.
J Chromatogr B Analyt Technol Biomed Life Sci. 2010 Mar 1;878(7-8):675-81. doi: 10.1016/j.jchromb.2010.01.037. Epub 2010 Jan 29.
A sensitive and specific method using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of levetiracetam (LEV) in plasma of neonates. A plasma aliquot of 50 microl was deproteinized by addition of 500 microl methanol which contained 5 microg/ml UCB 17025 as an internal standard. After centrifugation, 50 microl of supernatant was diluted with 1000 microl of 0.1% formic acid-10 mM ammonium formate in water (pH 3.5) (mobile phase solution A) and 2 microl was injected onto the UPLC-system. Compounds were separated on a Acquity UPLC BEH C(18) 2.1 mm x 100 mm column using gradient elution with mobile phase solution A and 0.1% formic acid in methanol (mobile phase solution B) with a flow rate of 0.4 ml/min and a total runtime of 4.0 min. LEV and the internal standard were detected using positive ion electrospray ionization followed by tandem mass spectrometry (ESI-MS/MS). The assay allowed quantification of LEV plasma concentrations in the range from 0.5 microg/ml to 150 microg/ml. Inter-assay inaccuracy was within +/-2.7% and inter-assay precision was less than 4.5%. Matrix effects were minor: the recovery of LEV was between 97.7% and 100%. The developed method required minimal sample preparation and less plasma sample volume compared to earlier published LC-MS/MS methods. The method was successfully applied in a clinical pharmacokinetic study in which neonates received intravenous administrations of LEV for the treatment of neonatal seizures.
建立了一种灵敏、特异的超高效液相色谱-串联质谱法（UPLC-MS/MS），用于检测新生儿血浆中的左乙拉西坦（LEV）。取 50μl 血浆，加入 500μl 甲醇，内含 5μg/ml UCB 17025 作为内标，沉淀蛋白。离心后，取 50μl 上清液用 1000μl 0.1%甲酸-10mM 甲酸铵水溶液（pH3.5）（流动相溶液 A）稀释，取 2μl 注入 UPLC 系统。采用 Acquity UPLC BEH C18（2.1mm×100mm）柱，以流动相溶液 A 和 0.1%甲酸甲醇溶液（流动相溶液 B）为梯度洗脱，流速 0.4ml/min，总运行时间 4.0min，分离各化合物。LEV 和内标采用正离子电喷雾电离串联质谱（ESI-MS/MS）检测。该法可定量检测 0.5μg/ml 至 150μg/ml 范围内的 LEV 血浆浓度。批间准确度在±2.7%范围内，批间精密度小于 4.5%。基质效应较小：LEV 的回收率在 97.7%至 100%之间。与早期发表的 LC-MS/MS 方法相比，该方法所需的样品制备和血浆样品量更少。该方法成功应用于一项临床药代动力学研究，研究中新生儿接受 LEV 静脉给药治疗新生儿癫痫。
