目的:建立人外周血单核细胞(hPBMCs)内齐多夫定三磷酸化物(ZDV—TP)的固相萃取-液相色谱-串联质谱(SPE—LC—MS/MS)测定方法,并将其应用于临床试验中ZDV—TP在hPBMCs内浓度的测定。方法:hPBMCs样本采用强阴离子交换固相萃取小柱实现ZDV—TP与齐多夫定(ZDV)、齐多夫定-磷酸化物(ZDV—MP)和齐多夫定二磷酸化物(ZDV—DP)的分离后,加入酸性磷酸酶将其去磷酸化为等物质的量的齐多夫定原药。去磷酸化后的样本经HLB固相萃取小柱脱盐处理后,采用Agi—lent XDB—C18色谱柱,以0.2%甲酸水溶液-甲醇为流动相进行等度洗脱。采用ESI正离子模式检测,离子监测方式为MRM,用于定量分析的离子反应分别为m/z267.9-m办126.8(ZDV)和m/z247.9→m/z120.8(替硝唑,内标)。结果:ZDV—TP在0.1125~82.05ng·mL-1(每106个细胞含ZDV—TP0.06~43pmol),范围内线性良好(r=0.9971),定量下限为0.1125ng·mL-1。日内及日间精密度(RSD)均小于9.0%,回收率和基质效应均符合生物样本的测定要求。结论:本文所建立的方法灵敏度高,专属性强,且成功应用于临床试验中ZDV在hPBMCs内的ZDV—TP的测定。
Objective:To develop a method for the determination of zidovudine triphosphate (ZDV-TP) in human peripheral blood mononuclear cells (hPBMCs) using solid phase extraction (SPE) and liquid chromatography-tan- dem mass spectroscopy(LC-MS/MS) , and apply it to quantitate ZDV-TP concentrations in hPBMCs. Methods: By performing a salt gradient anion exchange SPE, ZDV-TP was isolated from zidovudine (ZDV) , zidovudine monophosphate(ZDV-MP), and zidovudine diphosphate (ZDV-DP). Isolated ZDV-TP was dephosphorylated with acid phosphatase to its parent drug from ZDV, which was then desalted by HLB SPE cartridges. The separation of the analytes was achieved on a Phenomenex Gemini-Cls column with 0.2% formic acid solution and methanol as the mo- bile phase. ZDV was detected by an electrospray ionization tandem mass spectroscopy in the multiple-reaction-mo- nitoring positive mode. The precursor-product ion transitions monitored were m/z 267.9-126. 8 for ZDV and m/z 247.9-120. 8 for tinidazole (internal standard). Results:The calibration curve of ZDV-TP was established over the range of 0. 112 5-82. 05 ng . mL-1 ( r = 0. 997 1 ). The lower limit of quantification (LLOQ) was 0. 112 5 ng. mL-1.The intra-and inter-day precisions(RSDs) were less than 9.0%. The average extraction recoveries and the matrix effects were satisfied with the requirements of biological sample measurement. Conclusion: The established method was sensitive and reliable, and has been successfully used for the ZDV-TP concentration quantitation in hPBMCs.