In order to alleviate the transport sector's reliance on oil, diversifying the liquid fuel supplies for the transportation field is of the upmost importance and recently, coal-derived liquids and upgraded bio-oils have sparked great interest as the new generation substitutes. However, these liquids have high oxygen contents and characterizing oxygenated compounds is crucial to monitor reaction mechanisms and optimize conversion conditions. Therefore, the objective of the Ph.D. was to develop powerful analytical systems to characterize oxygenated compound in coal and biomass oils. For this purpose comprehensive two-dimensional gas chromatography (GCxGC) was investigated and led to a breakthrough characterization of alcohols and phenols. Three other analytical tools were considered to unravel coal-derived liquids composition: High resolution mass spectrometry (FT-ICR/MS), 31P NMR and UV-visible spectroscopy. 70%w/w and 86%w/w of the oxygen content respectively in the naphtha and the gasoil cuts were identified and quantified. GC×GC optimization for oxygen speciation in upgraded bio-oils enabled the quantification of 60%w/w of the sample. As this technique does not offer enough resolution, a third dimension of separation involving supercritical fluid chromatography was integrated online prior GC×GC analysis (SFC-GCxGC). This system led to a detailed quantification of phenols, benzenediols, naphthols, and methoxyphenols in these matrices.Through these two products, theoretical considerations on orthogonality and on separation mechanisms governing GCxGC were deduced and presented in a third section
