title: Comparison of titania, zirconia, and silica stationary phases for separating diesel fuels according to hydrocarbon group-type by supercritical fluid chromatography.
abstract: Silica, zirconia, and titania columns were compared for their ability to separate diesel samples into saturates, mono-, di-, tri-, and polyaromatics by supercritical fluid chromatography (SFC) using pure CO(2) according to ASTM method D 5186-03. A titania column coupled in series to a silica column was found to provide the highest overall group-type resolutions based on 20 model compounds, with resolutions as high as 14.7 for saturates versus monoaromatics and 11.9 for monoaromatics versus diaromatics. An oilsands-derived Synfuel light diesel, a commercial Ontario diesel, and a heavy Shell Canada Ltd. diesel blending feedstock were studied on a titania-silica coupled column as well as on a conventional silica column. The Synfuel results were similar (within 0.5 mass%) on both the conventional bare silica column and the titania-silica coupled column. The heavier commercial diesel and diesel blending feedstock samples yielded different results on the titania-silica coupled column compared to the silica column alone, demonstrating the importance of achieving the highest possible resolutions when baseline separation of group-types is not obtained.
authors.affiliation: Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Canada.
authors.forename: Richard E
authors.initials: RE
authors.lastname: Paproski
authors.forename: Jean
authors.initials: J
authors.lastname: Cooley
authors.forename: Charles A
authors.initials: CA
authors.lastname: Lucy
mesh_terms: D025924:Chromatography, Supercritical Fluid / Q000295:instrumentation* / Q000379:methods*; D005410:Flame Ionization; D005742:Gasoline; D006838:Hydrocarbons / Q000302:isolation & purification*; D006841:Hydrocarbons, Aromatic / Q000302:isolation & purification; D012822:Silicon Dioxide / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D005742:Gasoline; D006838:Hydrocarbons; D006841:Hydrocarbons, Aromatic; C009495:titanium dioxide; D012822:Silicon Dioxide; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide