血清总同型半胱氨酸候选参考测量程序(液相色谱串联质谱法)的建立及性能评估

Establishment and performance evaluation of candidate reference measurement procedure for serum total homocysteine by liquid chromatography-tandem mass spectrometry

目的建立一种基于液相色谱串联质谱(LC-MS/MS)技术的血清总同型半胱氨酸(Hcy)候选参考测量程序并对其性能进行评价。方法采用一种简单的蛋白沉淀方法对血清样本进行前处理,然后采用LC-MS/MS定量检测总Hcy,参照美国临床实验室标准化协会(CLSI) C62-A文件和C50-A文件对建立的候选参考方法进行线性、检测限与定量限、基质效应、精密度、正确度等基本分析性能验证。结果 LC-MS/MS检测总Hcy的线性范围为0.5～200.0μmol/L。定量限和检测限分别为0.31 nmol/g、0.06 nmol/g。3种不同比例(1∶1、80∶20、20∶80)的血清与溶液混合物的相对基质效应分别为1.94%、1.91%、1.78%。批内、批间变异系数(CV)分别为<2%和<1%。3种浓度(30.58、49.21、65.42 nmol/g)的加标样本平均加标回收率分别为99.8%、100.2%、100.8%。测定NIST SRM 1950标准物质的结果偏移<1%。样本处理后分别在室温[(23±2)℃]和自动进样器(温度为10℃)中放置24 h,检测结果均非常稳定。结论成功建立了基于LC-MS/MS技术的血清总Hcy候选参考测量程序。该参考测量程序准确度高、精密度好,能够用于常规临床检验方法的量值溯源,保证测定结果的准确性。

Objective To establish a candidate reference measurement procedure for serum total homocysteine(Hcy)by liquid chromatography-tandem mass spectrometry(LC-MS/MS),and to evaluate its analytical performance.Methods Samples were prepared by a simple protein precipitation method,and LC-MS/MS was used to determine serum total Hcy quantitatively.According to the Clinical and Laboratory Standards Institute(CLSI)C62-A and C50-A documents,the performance,including linearity,limit of detection,limit of quantitation,relative matrix effect,precision and trueness,was evaluated.Results The linear range of total Hcy by LC-MS/MS was 0.5-200.0μmol/L.The limit of quantitation and limit of detection were 0.31 nmol/g and 0.06 nmol/g,respectively.The relative matrix effects were 1.94%,1.91%and 1.78%for sera and solution mixtures in 3 different ratios(1∶1,80∶20 and 20∶80).The within-run and between-run coefficients of variation(CV)were<2%and<1%.The average recovery rates of 3 levels(30.58,49.21 and 65.42 nmol/g)were 99.8%,100.2%,100.8%,respectively.The bias of NIST standard reference material(SRM)1950 was<1%.After the samples were processed,they were placed at room temperature[(23±2)℃]and autosampler(10℃)for 24 h,and the results were stable.Conclusions The candidate reference measurement procedure for serum total Hcy by LC-MS/MS has been established,and it has good accuracy and precision,which can be used for measurement traceability.