Determination of mannose and fructose in human plasma using deuterium labelling and gas chromatography/mass spectrometry.

We used gas chromatography/mass spectrometry to measure mannose and fructose in human blood plasma. The plasma samples were treated with sodium borodeuteride. Characteristic ion fragments for (1-d)mannitol, (2-d)mannitol and (1-d,2-13C)mannitol were selected for use in sugar fragmentography and to build an algorithm for calculation of the sugar concentrations. The analytical recovery of mannose and fructose and the precision of the mannose assay were satisfactory. The measurement of fructose was marked by poor precision, which was accounted for, at least in part, by the low fructose content of the plasma samples. The method may prove useful in profiling monosaccharides in biological fluids. The method leans on the measurement of polyols but it can also provide auxiliary information on the occurrence of aldoses and ketoses.