液-质联用法测定人血浆中磷霉素的浓度及其应用

The method for determination of fosfomycin in human plasma by LC-MS/MS and its application

目的:建立人血浆中磷霉素的高效液相色谱-串联质谱测定方法。方法:50μL血浆中加入50μL内标溶液(福多司坦),250μL甲醇,漩涡混匀;离心取30μL上清液,与100μL注射用水混匀,取20μL进行LC-MS/MS分析。采用UltramateTM XB-CN分析柱(150mm×4.6mm,5μm),以甲醇-5mmol.L-1醋酸铵溶液(10∶90)为流动相,流速0.7mL.min-1,柱温22℃,进样量20μL。采用API4000型三重四极杆串联质谱仪,负离子方式检测;扫描方式为多反应监测,用于定量分析的离子反应分别为m/z137→m/z79(磷霉素)和m/z178→m/z91(福多司坦)。结果:血浆中磷霉素在0.10～12.0mg.L-1范围内线性关系良好(r=0.996 3),最低检测限为0.10mg.L-1。该方法的日内和日间精密度均小于10.6%。血浆中低、中、高3种浓度的绝对回收率(n=5)分别为95.4%,95.9%,91.6%。结论:本研究中的检测方法操作简单,灵敏,准确,重复性好,适用于该药的临床药动学研究。

OBJECTIVE To develop a liquid chromatographic/tandem mass spectrometric method for determination of fosfomycin in human plasma. METHODS 50μL fudosteine （IS solution, 1.00 mg·L^-1 ） and 50μl plasma were mixed and deproteinized with 250μL methanol, then 30 μL of the supernatant were further mixed with 100 μL water, and a 20μL aliquot of mixture was injected for the LC/MS/MS analysis. Chromatographic separations were carried out on a 4. 6 mm× 100 mm Ultramate TM XB-CN column, The isocratic mobile phase, methanol 5 mmol L 1 ammonium acetate （10：90） was run at a flow rate of 0. 7 mL min^-1 at room temperature. An API 4000 tandem mass spectrometer as detector was operated in the negative ion mode. Multiple reaction monitoring using the precursor to product ion combinations of m/z 137→79 and m/z 178→91 was performed to quantify fosfomycin and fudosteine, respectively. RESULTS The linear range of concentration was 0. 10 - 12. 0 mg·L^-1. The lower limit of quantification was 0. 100 mg·L^-1. The intra-day and inter-day relative standard deviation was less than 10. 6%. The absolute recoveries of low, medium and high concentration were 95.4%,95.9%,91.6%. CONCLUSION This method is simple, sensitive, accurate and reproducible. It is suitable for pharmacokinetic study of fosfomycin calcium.