Supercritical fluid chromatography hyphenated with twin comprehensive two-dimensional gas chromatography for ultimate analysis of middle distillates.
This paper reports the conditions of online hyphenation of supercritical fluid chromatography (SFC) with twin comprehensive two-dimensional gas chromatography (twin-GCxGC) for detailed characterization of middle distillates; this is essential for a better understanding of reactions involved in refining processes. In this configuration, saturated and unsaturated compounds that have been fractionated by SFC are transferred on two different GC x GC columns sets (twin-GCxGC) placed in the same GC oven. Cryogenic focusing is used for transfer of fractions into the first dimension columns before simultaneous GCxGC analysis of both saturated and unsaturated fractions. The benefits of SFC-twin-GC x GC are demonstrated for the extended alkane, iso-alkane, alkene, naphthenes and aromatics analysis (so-called PIONA analysis) of diesel samples which can be achieved in one single injection. For that purpose, saturated and unsaturated compounds have been separated by SFC using a silver loaded silica column prior to GC x GC analysis. Alkenes and naphthenes are quantitatively recovered in the unsaturated and saturated fractions, respectively, allowing their identification in various diesel samples. Thus, resolution between each class of compounds is significantly improved compared to a single GCxGC run, and for the first time, an extended PIONA analysis of diesel samples is presented.
Adam
Frédérick
F
IFP, Département Physique et Analyse, BP3, 69390 Vernaison, France.
Thiébaut
Didier
D
Bertoncini
Fabrice
F
Courtiade
Marion
M
Hennion
Marie-Claire
MC
D000473:Alkanes / Q000032:analysis; D000475:Alkenes / Q000032:analysis; D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods*; D025924:Chromatography, Supercritical Fluid / Q000295:instrumentation / Q000379:methods*; D003516:Cycloparaffins / Q000032:analysis; D004867:Equipment Design; D005742:Gasoline / Q000032:analysis*; D012680:Sensitivity and Specificity
D000473:Alkanes; D000475:Alkenes; D003516:Cycloparaffins; D005742:Gasoline