DETERMINATION OF GLYCEROL CONCENTRATIONS AND GLYCEROL ISOTOPIC ENRICHMENTS IN HUMAN PLASMA BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

An analytical method is presented to determine glycerol concentrations and stable isotope tracer enrichments in human plasma after intraveno us tracer infusion in a single analytical run, using gas chromatograph y coupled to mass spectrometry. The method uses an internal standard, which is also a stable isotope labeled form of glycerol. Three substan ces were tested as model compounds viz, [2-C-13]glycerol, and [1,2,3-C -13(3)]glycerol, and [1,1,2,3,3-H-2(5)]glycerol. Any combination of tw o can be used (one as internal standard, one as tracer), even if overl apping of the mass spectra occurs, The method is precise (recovery of spiked glycerol and tracer are, respectively, 99.7 and 99.8%) and repr oducible (intraassay variation <1.5%, interassay variation <6%) and ne eds only a small amount of plasma (100 mu l). (C) 1998 Academic Press.