SPE-LC-MS/MS法测定人外周血单核细胞内齐多夫定三磷酸化物

Determination of zidovudine triphosphate concentrations in human peripheral blood mononuclear cells by SPE-LC-MS/MS

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.