Aleksandra Lelevic has obtained her PhD at the University Claude Bernard Lyon 1 in Lyon, France. Her thesis was carried out in IFP Energies Nouvelles and Institute of research on catalysis and the environment of Lyon and was focused on the use of the two-dimensional gas chromatography coupled with vacuum ultraviolet detection for the characterization of complex petrochemical samples.
Gas oils GOs analysis is essential for production process control, in order to meet quality standards, render these products safer for the environment and support research for alternative fuels. GOs quantitative analysis can be commonly achieved by employing two-dimensional comprehensive gas chromatography with flame ionisation detection GCGCFID in combination with identification templates. However, in order to perform quantification for families which coelute in GCGC analysis, such as olefins and naphthenes or monoaromatics and polynaphthenes, prefractionation of gas oil before GCGC analysis is necessary. Recent introduction of the Vacuum ultraviolet VUV detector provided new possibilities in GOs analysis, as this detector can discern between the majority of hydrocarbon families thus possibly rendering the gas oil prefractionation unnecessary. Additionally, it can perform quantification according to Beer-Lamberts law provided that VUV relative response factors RRFs are known. The purpose of this work is to report, for the first time, VUV RRFs for numerous hydrocarbons according to their family and their carbon number ca. 160 in GOs, permitting to perform direct quantification of hydrocarbons in GOs without prefractionation. VUV RRFs were measured by using a GCGC-VUVFID dual detection set-up in which FID was employed as a quantitative reference. In order to obtain VUVRRFs representative for any gas oil, a set of 14 GOs with different origins was employed. Both VUV RRFs averaged in 125-240 nm range and spectral VUVRRFs reference spectra were obtained. It was demonstrated that VUV RRFs are similar between employed GOs allowing their universal use. Obtained RRFs were used to perform hydrocarbons quantification for a light cycle oil LCO by GCGCVUV, with olefins and naphthenes being quantified through spectral decomposition. Good comparability with results obtained by prefractionation was observed demonstrating the great interest of the GCGCVUV approach for the detailed and rapid analysis of hydrocarbons in gas oils.