PYROLYSIS-GAS CHROMATOGRAPHY MASS-SPECTROMETRY IN THE ANALYSIS OF ASPHALTENES

A study on the flash pyrolysis of asphaltenes using gas chromatography /mass spectrometry is reported. Six n-heptane-precipitated asphaltene samples, characterized by elemental analysis and nuclear magnetic reso nance (NMR), were selected because of their different compositions. By considering the main pyrolysis products some structural parameters we re worked out. The results obtained from the pyrolysis data were compa red to those deriving from elemental analysis and NMR. In spite of the severe thermal treatment (650-degrees-C for 20 s) undergone by the as phaltenes, the pyrolysis products qualitatively reflect structural dif ferences shown in the original samples by NMR (a non-destructive techn ique).