Certification of Creatinine in a Human Serum Reference Material by Gas Chromatography/Mass Spectrometry and Liquid Chromatography/Mass Spectrometry

Published

July 3, 2007

Author(s)

Nathan G. Dodder, Susan S. Tai, Lorna T. Sniegoski, Michael J. Welch

Abstract

Background: To meet recommendations given by the Laboratory Working Group of the National Kidney Disease Education Program (NKDEP) for improving serum creatinine measurements, the National Institute of Standards and Technology (NIST) developed Standard Reference Material (SRM) 967: Creatinine in Frozen Human Serum. SRM 967 is intended for use by laboratories and in vitro diagnostic manufacturers for the calibration and evaluation of routine clinical methods.Methods: The SRM was produced from two serum pools with different creatinine levels. The concentrations were certified using a definitive isotope-dilution gas chromatography/mass spectrometry (GC/MS) method and an isotope-dilution liquid chromatography/mass spectrometry (LC/MS) method. The LC/MS method is a potential higher-order Reference Measurement Procedure.Results: The GC/MS mean concentrations ( standard deviation) were: 0.758 0.006 mg/dL for Level I and 3.914 0.018 for Level II. The LC/MS results were: 0.747 0.002 mg/dL for Level I and 3.918 0.009 mg/dL for Level II. There was a 1.4 % difference between the mean Level I GC/MS and LC/MS measurements, and a 0.10 % difference between the mean Level II GC/MS and LC/MS measurements. The results from the two methods were combined to give the certified concentrations and expanded uncertainties. (continued page 3)Conclusions: The certified concentration ( expanded uncertainty) of SRM 967 was 0.753 0.021 mg/dL for Level I (a value close to the diagnostically important concentration and recommended laboratory measurement performance goal of 1 mg/dL) and 3.916 0.083 mg/dL for Level II (a concentration corresponding to a patient with chronic kidney disease).

Citation

Clinical Chemistry

Volume

53

Pub Type

Journals

Keywords

creatinine, gas chromatography/mass spectrometry, human serum reference material, liquid chromatography/mass spectrometry, SRM 967

Citation

Dodder, N. , Tai, S. , Sniegoski, L. and Welch, M. (2007), Certification of Creatinine in a Human Serum Reference Material by Gas Chromatography/Mass Spectrometry and Liquid Chromatography/Mass Spectrometry, Clinical Chemistry (Accessed April 26, 2024)