DIESEL FUEL MARINE AND SEDIMENT ANALYSIS - SUPERCRITICAL AMMONIA EXTRACTION AND DIRECT FLUID INJECTION MASS-SPECTROMETRY

The technique of direct fluid injection-mass spectrometry has been applied to the characterization of the polar components of diesel fuel marine. Two fractionation schemes involving alumina and silica column chromatography were used for initial separation into four fractions. DFI-m. s. with ammonia chemical ionization was used to provide selective detection of the more polar DFM components. Results were also obtained for supercritical ammonia extraction of the insoluble fuel sediments formed by aging the DFM samples and for the highly polar components adsorbed on silica particles during column fractionation. The results show that DFI-m. s. allows a rapid evaluation of the molecular weight distribution of the polar components in these fuels, including the most polar materials which are not amenable to conventional extraction and analysis methods.