目的建立高灵敏度的LC-ESI-MS/MS测定人血浆中氨氯地平浓度的方法。方法血浆样品经氢氧化钠溶液碱化,乙醚液-液萃取后进行分析。色谱柱COSMOSIL C₁₈柱(2.0mm×150mm,5μm),流动相甲醇-水-甲酸(60∶40∶0.1),流速0.25mL·min^-1,通过电喷雾离子化四极串联质谱,以选择离子反应监测(SRM)扫描方式进行检测。用于定量分析的监测离子分别为m/z409→238(氨氯地平)和m/z237→194(内标,卡马西平)。结果回收率为86%～95%,线性范围为0.1～6μg·L^-1,定量下限为0.1μg·L^-1,检测限为0.01μg·L^-1,应用此法测定了20名健康受试者交叉口服5mg氨氯地平剂量的试验制剂和参比制剂后的血药浓度经时过程。结论该法具有更高的灵敏度,适用于测定口服低剂量药物后人血浆中氨氯地平的浓度。

OBJECTIVE To develop a sensitive and specific LC-ESI-MS/MS method for the determination of amlodipine in human plasma.METHODS Amlodipine and internal standard carbamazepine were extracted from plasma with ether after being alkalized by NaOH, then separated on a COSMOSIL C₁₈ column. The mobile phase consisted of methanol-water-formic acid(60∶40∶0.1), at the flow rate of 0.25 mL·min^-1. A Finnigan TSQ tandem mass spectrometer equipped with electrospray ionization source was used as detector and was operated in the positive ion mode. Selected reaction monitoring(SRM)using the precursor →product ion combinations of m/z409 → 238 and m/z237→194 was used to quantify amlodipine and internal standard, respectively.RESULTS The recoveries of amlodipine were 86%～95%. The standard curve was linear in the range of 0.1～6 μg·L^-1.The limit of quantification was below 0.1 μg·L^-1 and the limit of detection was below 0.01 μg·L^-1.The method was successfully used in the determination of amlodipine in plasma of 20 male volunteers after oral administration of 5 mg amlodipine test and reference tablets by the random two-way cross-over design . CONCLUSION The method is proved to be suitable for the determination of amlodipine in human plasma after oral administration of low dosage,which offers advantage of much greater sensitivity over the previously reported methods.