A LC-MS/MS method to simultaneously profile 14 free monosaccharides in biofluids.

Monosaccharides are important players in cell metabolism and potential biomarkers. An effective tool to quantify monosaccharides is required in basic research and healthcare. In this study, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay that could simultaneously quantify 14 free monosaccharides and evaluated its performance according to clinical guidance. The LC-MS/MS step separated and quantified 14 monosaccharides with 6 min. The coefficient of variation at the lower limit of quantification was less than 20% for each analyte. The R square values from linear regression analyses were all greater than 0.995. The validated assay was employed to profile free monosaccharides in conditioned media from cell culture and patient sera from glucose tolerance test. Both LO2 cells and HEK293 cells consumed D-glucosamine, D-glucose and produced D-glucuronic acid, N-acetyl-D-glucosamine. Additionally, LO2 cells produced D-mannose and L-fucose, whereas HEK293 cells consumed D-mannose. In patient sera from glucose tolerance test, the level of D-glucose increased significantly after glucose intake, but the levels of other monosaccharides didn't. In conclusion, the LC-MS/MS assay we developed for 14-monosaccharide profiling met clinical requirements. The monosaccharide profiling results showed the distinct monosaccharide metabolism between liver and kidney cells, and the ignorable diet effect on 6 serum monosaccharides.