Methods for the selective determination and quantification of 10 synthetic phenolic antioxidants (SPA) in jet and diesel fuels have been developed. The analytical procedure involves no sample preparation and uses direct injection of the diluted parent fuel into the GC column. Gas chromatography with both triple quadrupole and quadrupole time-of-flight mass spectrometry was used to quantify synthetic phenolic antioxidants in the range of 0.1−20 mg/L. Precision was in the range of 3− 9%. The method is demonstrated to be rugged and robust and, since no extraction is required, does not require estimation of extraction efficiencies. It is generally suited to volatile SPA compounds included in jet and diesel fuel specifications. The method is appropriate for the estimation of SPA in fresh and in-service middle distillate fuels stored on military bases and tankers or in use on aviation or naval platforms.

No abstract

No abstract

Thermal stressing experiments on a modified surrogate fuel and synthetic paraffinic kerosene (SPK) have been carried out under both static and dynamic conditions at 140 °C. In order to characterize the oxidation products, some key degradation compounds were monitored throughout the stressing experiment. Products resulting from ring closure reactions were also identified in the surrogate fuel and the SPK, with the identification of iso-benzofuranone and alkyldihydrofuranones. Furanones were quantified using gas chromatography−mass spectrometry (GC-MS) with high-performance liquid chromatography (HPLC) prefractionation. The formation of these furanones indicates that dynamic stressing promotes a reactivity that has only been reported at either higher temperatures or longer residence times.