SFC and SFC hyphenated techniques in petroleum industry

Owing to the high complexity of the matrices to be investigated, petroleum industry has to face a tough analytical challenge when a detailed characterization is required or not. It can be the case for different reasons such as to reach for the specifications of final fuels and products, to improve and evaluate the effectiveness of processes or additives, to monitor the ageing of fuels and lubricants...The implementation of chromatographic techniques has long been mandatory to reach for the highest selectivity and resolution capabilities. However, true analysis of petroleum matrices requires the highest level of resolution whatever the technique being implemented. This is the reason why multi-dimensional chromatographic techniques have been used for a long time for the analysis of hydrocarbon groups (SAR, PIONA...) for example. More recently, comprehensive two-dimensional techniques, mainly comprehensive 2D Gas Chromatography (GCxGC) have shown their effectiveness for reaching a higher level of resolution of petroleum and related matrices while the profits of supercritical fluid chromatography (SFC) are still subject of debates. Whatever the separation technique, the hyphenation of mass spectrometry should not be underestimated for the identification of compounds of interest or even for quantitative analysis.

Thus, this presentation will review petroleum and related applications of SFC including historical and "registered" methods and more prospective techniques such as heart-cutting possibilities for hydrocarbon group separation by SFC, detailed and selective separations using various column configuration and selective detection, hyphenation to GCxGC and High Temperature GCxGC for improving detailed analysis. Application to various cuts or fractions will be presented, including vacuum distillates, some biofuels and additives. In some cases, data obtained will be used to show the complementarity of techniques. Trends for hyphenation of SFC with separation techniques involving a dense fluid, including SFCxSFC will be discussed too.