摘要目的 建立同位素稀释液相色谱串联质谱(isotope dilution chromatography tandem mass spectrometry,ID-LC/MS)测定人血清同型半胱氨酸(Hcy)参考方法,并运用于临床实验室室间质评(external quality assessment,EQA)样本靶值的确立.方法 参照国际检验医学溯源联合委员会(the Joint Committee for Traceability in Laboratory Medicine,JCTLM)推荐方法,建立本实验室Hcy参考方法,并对所建方法的精密度、正确度、特异性、残留、基质效应等进行评估,并将建立的参考方法用于上海地区2018年度第二次EQA样本Hcy靶值的确立.结果 该方法3 d 3批次检测12.5μmol/L和37.4μmol/L样本,批间CV分别为1.03％和2.10％,精密度较好;检测美国国家标准和技术研究院(National Institute of Standards and Technology,NIST)标准参考物质(standard reference material,SRM)1955均在规定的不确定度范围内;无基质效应和携带污染.2018年第二次EQA数据显示国产试剂组均值低于参考方法赋值结果,进口试剂组均值高于参考方法赋值结果.结论 建立的ID-LC/MS/MS测定血清Hcy参考方法精密度、正确度、特异性均较好,无分析物残留,有望在临床实验室Hcy测定的量值溯源中发挥一定作用.

abstractsObjective To establish a reference measurement procedure for the determination of human serum homocysteine by isotope dilution high performance liquid chromatography-tandem mass spectrometry (ID-LC/MS/MS), and to apply it to establish sample target values for external quality assessment (EQA) in clinical laboratories. Methods The reference method of Hcyquantification in our laboratory was establishedaccording to the method recommended by the Joint Committee for Traceability in Laboratory Medicine (JCTLM). The precision, trueness, specificity, residue and matrix effect of the method were evaluated. The reference method was applied to establish Hcy target values for samples of the second EQA in Shanghai of 2018. Results The method detects 12.5μmol/L and 37.4μmol/L samples in three batches in three days, and the CV between batches is 1.03％and 2.10％, respectively. The measured values of Standard reference material (SRM) 1955 of National Institute of Standards and Technology (NIST) were within the specified uncertainty range. No matrix effect and carryover were observed. The second EQA data in 2018 showed that the average value of domestic reagent group was lower than that of reference method, and that of imported reagent group was higher than that of reference method. Conclusion Thereference measurement procedure of ID-LC/MS/MS was successfully established to determine the human serum homocysteine. It is expected to play a role in tracing the quantities of Hcy in clinical laboratories.