STABLE-ISOTOPE DILUTION METHOD FOR THE DETERMINATION OF SERUM GLUCOSE USING FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRY

Isotope dilution mass spectrometry (IDMS) has been considered a reliable analytical method which can be used as a definitive method in clinical chemistry. In the present paper the IDMS method for serum glucose determination using off-line liquid chromatography/fast atom bombardment mass spectrometry (FABMS) has been developed. Uniformly labeled glucose was used as an internal standard and deproteinized serum samples were separated using high performance liquid chromatography (HPLC) under two different conditions and the collected glucose fraction was concentrated. Measurements were performed using standard FABMS with a glycerol matrix. Quantification was performed by measuring the peak intensity ratio of m/z 255 and 261 corresponding to (M+G+H-H2O)+ ions of unlabeled and labeled glucose in FAB mass spectra. Since a relatively large peak was observed in the blank spectrum, the blank was subtracted and finally about 1% precision was obtained.