title: Development of a matrix-based candidate reference material of total homocysteine in human serum.
abstract: We developed and evaluated a candidate serum reference material to help improve clinical routine measurement, and to provide traceability of the measurement results. D8-Homocystine, dithiothreitol, and acetonitrile were used as an internal standard, the reducing agent, and the protein precipitating agent, respectively. A triple quadrupole mass spectrometer with an electrospray ionization source was used for monitoring the transitions (m/z 140.0 → 94.0, 136.0 → 90.0) in multiple-reaction-monitoring mode. We used a calibration model relying on bracketing and gravimetric measurements to give SI-traceability and higher accuracy to serum value assignments. The method was evaluated for accuracy using NIST Standard Reference Material SRM1955. The results of the three concentrations (1, 2, and 3) of total homocysteine in human serum samples were determined by an isotope-dilution liquid chromatography-tandem mass spectrometry method; tHcy 1 is 28.8 ± 1.1 μmol/L, tHcy 2 is 17.93 ± 0.57 μmol/L, and tHcy 3 is 14.38 ± 0.46 μmol/L. Graphical abstract The workflow diagram.
authors.affiliation: Division of Chemical Metrology and Analytical Science, National Institute of Metrology, Beijing, 100029, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Division of Chemical Metrology and Analytical Science, National Institute of Metrology, Beijing, 100029, China. songdw@nim.ac.cn.
authors.forename: Dewei
authors.initials: D
authors.lastname: Song
authors.affiliation: Division of Chemical Metrology and Analytical Science, National Institute of Metrology, Beijing, 100029, China.
authors.forename: Bei
authors.initials: B
authors.lastname: Xu
authors.affiliation: Division of Chemical Metrology and Analytical Science, National Institute of Metrology, Beijing, 100029, China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Li
authors.affiliation: Division of Chemical Metrology and Analytical Science, National Institute of Metrology, Beijing, 100029, China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Dai
authors.affiliation: Beijing Aerospace General Hospital, Beijing, 100076, China.
authors.forename: Baorong
authors.initials: B
authors.lastname: Chen
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D006710:Homocysteine / Q000097:blood* / Q000737:chemistry*; D006801:Humans; D012016:Reference Values; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D006710:Homocysteine
keywords: Homocysteine; Human serum; Isotope dilution mass spectrometry; Reference material