Abstract：
we developed an effective protein precipitation method for determination of levamlodipine in human plasma using LC-MS/MS. Sample extraction was carried out by using liquid-liquid extraction in 96-well plate format. (S)-Amlodipine-d4 was used as internal standard (IS). The chromatographic separation was achieved using Philomen Chiral MX (2) column (3 μm, 2.1 × 100 mm). Mobile phase A was comprised of Acetonitrile (ACN), Mono ethanol amine (MEA) and Iso-Propyl alcohol (IPA) (1000:1:10, v/v/v), Mobile phase B was IPA-ACN (2:1, v/v). The flow rate was 0.4 mL/min. The total run time of each sample was 4.0 min with gradient elution. LC-MS/MS spectra were generated in positive ion mode, and multiple reaction monitoring (MRM) was used to detect the following transitions: m/z 409.20 → 238.15 for levamlodipine and 415.25 → 240.20 for (S)-Amlodipine-d4 (the IS). The method was linear from 50 to 10000 pg/mL（R2＝0.9988489）,and the lower limit of quantification (LLOQ) was 50 pg/mL. This method was applied to a bioequivalence study of levamlodipine.
摘要：
我们开发了一种使用LC-MS/MS测定人血浆中左旋氨氯地平的有效蛋白沉淀方法。通过在96孔板格式中使用液-液提取进行样品提取。(S)-氨氯地平-d4用作内标(IS)。采用Philomen手性MX(2)柱(3μm,2.1×100毫米)。流动相A由乙腈（ACN）组成，单乙醇胺（MEA）和异丙醇（IPA）（1000：1：10，v/v/v），流动相B是IPA-ACN(2:1,v/v)。流速为0.4mL/min。使用梯度洗脱,每个样品的总运行时间为4.0分钟。以正离子模式产生LC-MS/MS谱,多反应监测（MRM）用于检测以下转变：左旋氨氯地平的m/z409.20→238.15，（S）-氨氯地平-d4（IS）的m/z415.25→240.20。方法线性范围为50-10000pg/mL（R2＝0.9988489）,定量下限(LLOQ)为50pg/mL。该方法用于左旋氨氯地平的生物等效性研究。
