【摘要】 研究建立了血清中尿素测定的新方法,以尿素同位素标记物(Urea-13C,15N2)为内标,样品用乙腈沉淀蛋白。以ZORBAXRX-SIL色谱分离柱,V(乙腈):V(水)=95:5为流动相,使用电喷雾三重四极杆串联质谱的多重反应监测模式(Multiple Reaction Monitoring,MRM)测定,以及同位素稀释的括号法进行定量。所建立的液相色谱同位素稀释串联质谱法(ID-LCMS/MS)对于分析血清尿素的批内、批间RSD分别为0.21%～0.85%、0.05%～0.38%,回收率为97.9%～102.3%,采用美国国家标准和技术研究院(NIST)的血清标准物质SRM909b进行了方法确证,测定结果与标准值的相对偏差小于0.5%且在其定值范围内。更多还原

【Abstract】 A candidate reference measurement procedure for urea in human serum involving ID-LCMS/MS has been developed and evaluated.Isotope labeled urea (Urea-13C,15N2) as the internal standard was added to a serum sample.The serum samples were treated with acetonitrile to deproteinate by precipitation.Separation was performed on a ZORBAX RX-SIL column using an isocratic mobile phase of acetonitrile:water=50:50,(V:V).An Agilent tandem mass spectrometer equipped with an electrospray ionization source operated in multiple reaction monitoring (MRM) mode was utilized,and the results of determination were calculated from peak ratios by the bracketing method based on the theory of isotope dilution analysis.The results of the ID-LCMS/MS method for the analysis of urea in human serum samples are as follows:the within-run RSD ranged from 0.21% to 0.85%,between-run RSD ranged from 0.05% to 0.38% and recoveries ranged between 97.9% and 102.3%.The results for the analysis of the certified reference material SRM909b (Level I) showed a bias less than 0.5%,which is within the uncertainty range in the certificate of SRM909b.更多还原