The Use of 13C NMR Spectroscopy and Comprehensive Two-dimensional Gas Chromatography, GC×GC, for Identification of Compounds Involved in Diesel Fuel Oxidative Behavior
An approach has been proposed combining one dimensional inverse gated 13C NMR spectroscopy and a comprehensive two dimensional gas chromatography (GC×GC) to analyze diesel fuels prior and after oxidation under the standard conditions. Classes of hydrocarbons present before and after oxidation have been identified and quantified. A decrease in aromatic iso- and n-paraffinic hydrocarbons and an increase in the total saturated hydrocarbons have been observed after oxidation. In that respect NMR spectroscopy has potential to be used as standard method for determination of oxidation stability. Furthermore, GC×GC has been applied to identify compounds involved in the formation of sediments during oxidation. Obtained results have shown that hydrocarbon composition, especially the normal paraffin content play a role in the formation of sediments in these distillate fuels. This is important since sediments may influence the quality of diesel fuels.