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An international assessment of the metrological equivalence of higher-order measurement services for creatinine in serum

Published

Author(s)

Johanna Camara, Katrice A. Lippa, David L. Duewer, Hugo H. Gasca-Aragon, Blaza Toman

Abstract

Background: The CCQM-K80 Key Comparison directly assessed the equivalence of many of the world’s higher-order value-assigned materials (HOVAMs) for creatinine in human serum. This 2009 international study compared the certified values and uncertainties of the materials using measurements made under repeatability conditions. Methods: The study evaluated 17 materials submitted by six national metrology institutes (NMIs). The creatinine quantity in these materials ranged from 3 mg/kg to 57 mg/kg (about 0.3 mg/dL to 6 mg/dL or 30 nmol/L to 500 nmol/L). All materials were stored and prepared according the specifications provided by the participating NMIs. Samples were processed and analyzed under repeatability conditions by one analyst using isotope-dilution liquid chromatography-mass spectrometry in two measurement campaigns. The certified values and repeatability measurements were compared using uncertainty-weighted generalized distance regression. Results: The instrumental repeatability relative standard deviation was 1.2 %. The measurement design required assessment of within-unit and between-campaign variability in addition to measurement repeatability. At a 95 % level of confidence, the certified values for all 17 materials agreed to within their assigned uncertainties. Conclusion: CCQM-K80 demonstrated the metrological equivalence of the currently available HOVAMs for creatinine in human serum and of the creatinine measurement services provided by the participating NMIs.
Citation
Analytical and Bioanalytical Chemistry
Volume
403

Keywords

creatinine, reference material, international comparison

Citation

Camara, J. , Lippa, K. , Duewer, D. , Gasca-Aragon, H. and Toman, B. (2012), An international assessment of the metrological equivalence of higher-order measurement services for creatinine in serum, Analytical and Bioanalytical Chemistry, [online], https://doi.org/10.1007/s00216-012-5869-y (Accessed February 27, 2024)
Created April 2, 2012, Updated November 10, 2018