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建立了一种高通量液相色谱-串联质谱技术检测干血点（ DBS）中同型半胱氨酸（ homocycteine，Hcy）的方法。以 DBS为样本，homocystine-D8为同位素内标，二硫苏糖醇（ DTT ）为蛋白结合态 Hcy 的还原剂，使用含0.1％（ v／v）甲酸、0.05％（ v／v）三氟乙酸的乙腈溶液萃取。整个前处理过程使用自动移液平台及96孔板实现高通量自动化操作。处理后的样本经过 Phenomenex CN柱分离，使用多反应监测模式进行 LC-MS／MS 分析。结果表明：Hcy的检出限为0.12μmol／L（ S／N=3），定量限为0.46μmol／L（ S／N=10）。Hcy 在1.16~148.00μmol／L 范围内线性关系良好，R2=0.994。Hcy 的平均回收率为（103.0±4.97）％~（112.0±2.13）％，日内相对标准偏差（ RSD）为1.9％~4.6％，日间 RSD为1.5％~7.1％。DBS 样本在不同温度（-4、-20、22和37℃）下储存不同时间（0、1、2、3、4、5、6、14天）后的稳定性试验显示样本总体 RSD﹤15％，经前处理后的样本在48 h内的稳定性试验显示样本总体 RSD﹤5％。该方法与传统生化分析方法的相关性好（ R2=0.9818，n=47）。

A high-throughput method to measure homocysteine( Hcy ) in dried blood spots ( DBS) by liquid chromatography-tandem mass spectrometry ( LC-MS/MS ) was established. The DBS sample processing includes adding homocystine-D8 as internal standard,dithiothreitol ( DTT)as reducing agent for bound Hcy forms,acetonitrile containing 0. 1%( v/v)formic acid and 0. 05%( v/v)trifluoroacetic acid for Hcy extraction. This procedure was carried out in a 96-well plate format in an automated liquid handling platform to facilitate high-throughput analysis. The processed samples were separated on a Phenomenex CN column and quantitated by LC-MS/MS in multiple reaction monitoring( MRM)mode. The limit of detection was 0. 12μmol/L( S/N=3)and the limit of quantification was 0. 46 μmol/L( S/N=10). The linear range was 1. 16-148. 00 μmol/L ( R2 = 0. 994 ). The average recoveries were ( 103. 0 ± 4. 97 )% -(112. 0±2. 13)%. The intra-day relative standard deviations( RSDs)were 1. 9%-4. 6% and the inter-day RSDs were 1. 5%-7. 1%. DBS sample stability was confirmed by measuring same DBS samples stored for 0,1,2,3,4,5,6 and 14 days at -4,-20,22 and 37 ℃,and an overall sample RSD﹤15% was found under each temperature. Processed sample stability within 48 hours was also confirmed with an overall sample RSD﹤5%. The comparison of this method with conventional biochemistry assay was made by measuring 47 blood samples both in an automa-ted biochemistry analyzer( samples in plasma form)and with the LC-MS/MS method( samples in DBS form),which showed excellent correlation(R2=0. 982).