Determination of serum glucose by isotope dilution liquid chromatography tandem mass spectrometry

Abstract

Objective To develop a candidate reference method for the measurement of serum glucose based on isotope dilution liquid chromatography tandem mass spectrometry(ID-LC/MS/MS)Methods An internal standard [~(13)C_6]glucose was added to serum samples and equilibrated with endogenous glucose.Serum proteins were removed by a precipitation with anhydrous ethanol.Serum glucose and the internal standard were then reacted with 1-phenyl-3-methyl-5-pyrazolone and the formed derivatives were analyzed by liquid chromatography tandem mass spectrometry with multiple reaction monitoring(MRM).The method was calibrated with bracketing calibrators and serum glucose concentrations were calculated by comparing the peak area ratios of samples with that of the calibrators.Results The within-run,between-run and total coefficients of variation averaged 0.36%,0.47%and 0.61%,respectively.The analytical recoveries ranged from 99.0% to 100.9%.Results of analyzing the certified reference material SRM 965a showed an average biases of-0.20%.Conclusions An ID-LC/MS/MS method for measuring serum glucose has been developed.The method is highly precise and accurate and may be used as a candidate reference method. Key words: Blood glucose; Isotope dilution; Chromatography,liquid; Tandem massspeetrometrv