溶剂诱导相变萃取法用于高效液相色谱-质谱分析的血浆样品前处理

在匀相的乙腈-水体系中添加一种疏水但与乙腈互溶的有机溶剂(如氯仿), 能诱导乙腈-水体系分相, 基于此现象建立了一种血浆样品处理方法溶剂诱导相变萃取(SIPTE). 与传统的液-液萃取法相比, 该法最大的优势为新形成的有机相为乙腈(仅含少量氯仿), 与常用的反相C₁₈柱兼容, 能直接进行高效液相色谱-质谱分析. 此外, 通过减少乙腈及氯仿的用量还可实现样品的自动浓缩. 本文通过测定血浆中尼群地平, 验证了该方法的有效性. 使用反相C₁₈柱, 以V(乙腈)∶V(水)=70∶30(含20 mmol/L甲酸铵)为流动相, 尼莫地平为内标, ESI正离子模式下选择离子监测(SIM)测定了血浆中尼群地平的浓度. 实验所得的线性、精密度和准确度结果良好, 表明所建立的方法灵敏、准确、简单、快速, 可用于药物代谢动力学研究.

Solvent Induced Phase Transition Extraction Method for High Performance Liquid Chromatography-Mass Spectrometry Analysis of Plasma Samples of Pretreatment

Hydrophobic solvent such as chloroform can be used as modifier to induce phase separation of the acetonitrile aqueous mixture. Capitalizing on this phase transition phenomenon, a novel approach, named solvent induced phase transition extraction(SIPTE), was proposed to extract drug in plasma. SIPTE is superior to conventional liquid-liquid extraction(LLE) as the recovered acetonitrile solution can be directly injected into the RP-LC system, which greatly simplifies the sample preparation procedure. Furthermore, the proposed SIPTE is excellent due to the function of automatically preconcentrating the sample. Nitrendipine was used as the test drug to design and validate the SIPTE method. Nitrendipine was separated on a RP-C18 column, using acetonitrile/water containing 20 mmol/L of ammonium formate(70∶30, volume ratio) as the mobile phase. Nimodipine was selected as the internal standard for the quantification purpose. The obtained good linear, accuracy and precision results prove that the SIPTE method is sensitive and accurate enough to be used for pharmacokinetic study.