Owing to environmental and economical problems arising from an increasing consumption of fossil fuel (greenhouse gas emission, climate change, high price of oil) government policies are mandating the development of new sources of energy to replace either totally or partially fossil fuels.Products resulting from the vegetable oil transformation, or more generally from the biomass represent today a credible alternative as a renewable source of energy, without additional carbon dioxide emission.In order to perform an efficient upgrade of those materials to transportation fuels using refming process, it is highly desirable to unravel their composition.In particular, the access to the detailed molecular characterization of the oxygenated derivatives is a critical issue to understand the conversion process and to estimate the difficulties of transformation of these products.