研究哌甲酯(MPH)在人血浆中不稳定性,建立HPLC-MS/MS测定方法并运用于人体药代动力学研究。采用HPLC及LC-MS/MS法考察哌甲酯在醇、水、血浆中的稳定性及甲酸水溶液处理对哌甲酯降解的抑制作用。结果表明,于新鲜制备的人血浆样品(200μL)中立即加入2%甲酸水溶液10μL,能够抑制血浆中血浆酯酶的活性。以5 mmol·L-1醋酸铵水溶液(含0.1%甲酸)-甲醇(54∶46)为流动相;使用Sapphire C18柱进行分离。采用电喷雾离子源(ESI+)及多反应监测模式(MRM)进行检测,检测离子为m/z 234.2→84.1(MPH),m/z 260.3→183.1(普萘洛尔,内标)。哌甲酯血浆浓度测定线性范围为0.035~40 ng·mL-1;日内、日间精密度(RSD)均小于5%,准确度为±2%之内。应用此法研究了6名健康志愿者单剂量口服哌甲酯36 mg后药动学特点。所建方法能准确测定人血浆中哌甲酯的血药浓度,可用于哌甲酯的人体药动学研究。 To study the instability of methylphenidate (MPH) in human plasma, the HPLC-MS / MS method was established and applied to human pharmacokinetic study. The stability of methylphenidate in alcohol, water and plasma and the inhibitory effect of formic acid aqueous solution on the degradation of methylphenidate were investigated by HPLC and LC-MS / MS. The results showed that 10 μL of a 2% formic acid aqueous solution was immediately added to a freshly prepared human plasma sample (200 μL) to inhibit plasma esterase activity in plasma. Aqueous 5 mmol·L-1 ammonium acetate solution (containing 0.1% formic acid) -methanol (54:46) was used as the mobile phase. The separation was performed on a Sapphire C18 column. The electrospray ionization (ESI +) and multi-reaction monitoring (MRM) were used to detect the ions with m / z 234.2 → 84.1 (MPH) and m / z 260.3 → 183.1 (propranolol, internal standard). The linear range of the concentration of methylphenidate was 0.035-40 ng · mL-1. The intra- and inter-day precision (RSD) was less than 5% and the accuracy was within ± 2%. This method was used to study the pharmacokinetic characteristics of 36 healthy volunteers after a single oral dose of methylphenidate 36 mg. The established method can accurately determine the plasma concentration of methylphenidate in human plasma and can be used for human pharmacokinetic study of methylphenidate.