Zhu Hailin, Luo Jinwen
Department of Applied Chemistry, Xiasha Campus, Zhejiang Sci-Tech University, Hangzhou, China.
J Pharm Biomed Anal. 2005 Sep 1;39(1-2):268-74. doi: 10.1016/j.jpba.2005.02.024. Epub 2005 Apr 7.
A fast and sensitive method of coupled high-performance liquid chromatography-electrospray tandem mass spectrometry for the assay of lorazepam in human plasma was developed. Plasma samples were simply treated with acetonitrile to precipitate and remove proteins and the isolated supernatants were directly injected into the HPLC/MS/MS system. Chromatographic separation was performed on a Zorbax C(18) (100 x 2.1 mm I.D.) column with a 65:35 (v/v) mixed solution of acetonitrile and 10mM aqueous formic acid being used as mobile phase. With diazepam as an internal standard, quantification was performed by selected reaction ion monitoring of the transitions of m/z 321--> m/z 275 for lorazepam and m/z 285--> m/z 193 for the internal standard. The assay was validated in the concentration range of 0.71-71.3 ng/ml in human plasma. A detection limit of 0.10 ng/ml for lorazepam was achieved, and inter- and intra-run precisions of better than 4.4% (R.S.D.) were observed. The developed method has been successfully applied for pharmacokinetic study of the drug in man.
建立了一种快速灵敏的高效液相色谱-电喷雾串联质谱联用方法用于测定人血浆中的劳拉西泮。血浆样品只需用乙腈处理以沉淀并去除蛋白质，分离出的上清液直接注入HPLC/MS/MS系统。色谱分离在Zorbax C(18)（100×2.1 mm内径）柱上进行，以乙腈和10mM甲酸水溶液的65:35（v/v）混合溶液作为流动相。以地西泮为内标，通过对劳拉西泮的m/z 321→m/z 275和内标的m/z 285→m/z 193的选择反应离子监测进行定量。该测定法在人血浆0.71 - 71.3 ng/ml的浓度范围内得到验证。劳拉西泮的检测限达到0.10 ng/ml，批间和批内精密度均优于4.4%（相对标准偏差）。所建立的方法已成功应用于该药物在人体的药代动力学研究。
