Molecular
structure of heavy petroleum could be investigated by
the composition of its ruthenium ion catalyzed oxidation (RICO) products.
However, the interpretation of the results was not comprehensive due
to the limited compositional information obtained solely by gas chromatography
(GC) analysis. In this study, a semiquantitative method based on electrospray
ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry
(FT-ICR MS) was established and applied for the molecular characterization
of RICO products. Thousands of polar compounds were detected by negative-ion
ESI FT-ICR MS in the RICO products of the Canadian oil sands bitumen
derived asphaltenes. Besides alkyl carboxylic acids, naphthenic acids
with one to five naphtha rings, nitrogen- and sulfur-containing carboxylic
acids, and acidic compounds with multioxygen atoms were observed.
The upper carbon number limit of alkyl moieties connected to the aromatic
cores of the asphaltenes was found up to 60, which is much higher
than the results derived from GC analysis. Normal and isomer alkyl
carboxylic acids, as well as naphthenic acids, were quantitatively
analyzed separately. The quantitative results of alkyl carboxylic
acids from ESI FT-ICR MS agreed well with the GC results. The FT-ICR
MS results indicate that additional compositional information could
be obtained from RICO analysis. In addition, the method is instructive
for the development of quantitative analysis technology for petroleum
molecular characterization based on ESI FT-ICR MS
