高效液相色谱串联质谱法测定人血浆中硫辛酸

目的: 建立LC-MS/MS法测定人血浆中硫辛酸浓度,并对口服0.2 g硫辛酸分散片后的药代动力学进行研究. 方法: 血浆样品以萘普生为内标,经乙腈沉淀蛋白后进行LC-MS/MS分析.采用高效液相分离系统,色谱柱为Venuseil XPB C₁₈柱(150 mm×2.1 mm,5 μm),流动相为乙腈-10 mmol·L^-1醋酸铵-甲酸(80:20:0.2);采用质谱检测系统,ESI离子源,负离子模式,多反应监测(MRM)方式监测m/z 205→m/z 171(硫辛酸)和m/z 229→m/z 170(萘普生,内标). 结果: 建立的LC-MS/MS法在2.500~5 000 ng·mL^-1质量浓度范围内,硫辛酸色谱响应与质量浓度相关性良好,定量下限为2.500 ng·mL^-1;批内及批间精密度RSD均小于7%,准确度在96.5%~101.6%.12名受试者单次服用0.2 g硫辛酸分散片后AUC_0-t为(1 816±885.6)ng·mL^-1·h,AUC_0-∞为(1 837±879.6)ng·mL^-1·h,C_max为(3 432±2 410)ng·mL^-1,t_max为(0.45±0.44)h,t_1/2为(0.45±0.18)h,MRT为(0.73±0.31)h,CL为(133.2±66.63)L·h^-1,V_d为(85.60±50.98)L. 结论: 本测定方法灵敏准确,适用于人血浆中硫辛酸浓度的测定及其药代动力学研究.

Objective: To develop a sensitive and specific LC-MS/MS method for determination of lipoic acid in human plasma and to study its pharmacokinetic feature in healthy volunteers after a single dose of 0.2 g lipoic acid dispersible tablets. Methods: After adding naproxen as the internal standard,plasma was deproteinized with acetonitrile.The analyte was isocratically eluted on a Venuseil XPB C₁₈ column(150 mm×2.1 mm,5 μm)with acetonitrile-10 mmol·L^-1ammonium acetate-formic acid(80:20:0.2)by LC-MS/MS with negative ionization.Ions monitored in the multiple reaction monitoring(MRM)mode were m/z 205→m/z 171 for lipoic acid and m/z 229→m/z 170 for naproxen(IS). Results: The linear range of the standard curve of lipoic acid was from 2.500 ng·mL^-1to 5 000 ng·mL^-1.The lower limit of quantitation(LLOQ)of lipoic acid was 2.500 ng·mL^-1 and RSD of intra- and inter-batch precisions was less than 7%,and the accuracy was between 96.5%-101.6%.The analysis showed AUC_0-t was(1 816±885.6)ng·mL^-1·h,AUC_0-∞(1 837±879.6)ng·mL^-1·h,C_max(3 432±2 410)ng·mL^-1,t_max(0.45±0.44)h,t_1/2(0.45±0.18)h,MRT(0.73±0.31)h,CL(133.2±66.63)L·h^-1,V_d(85.60±50.98)L in 12 volunteers after a single dose of 0.2 g lipoic acid dispersible tablets. Conclusion: The established LC-MS/MS method is highly sensitive and accurate,which is suitable for the pharmacokinetic study of lipoic acid in human plasma.