Volatile products of the two-step (400, 650°C) flash pyrolysis of Ivanovskoe asphaltite from Orenburg oblast, its asphaltenes, oils, and benzene and benzene-ethanol resins have been characterized by gas chromatography-mass spectrometry (GCMS) in the on-line mode. The "unresolvable complex mixture" of nonidentifiable compounds prevails at both temperatures. The compositions of identified compounds in the products obtained at 400 and 650°C substantially differ, especially, for resins and asphaltenes. At 650°C, the products for all the samples are characterized by the same set of compounds including homologues of alkanes; α-olefins; cyclohexanes; pregnanes and steranes, cheilanthanes and hopanes; hopenes; mono-, bi-, and tri- cyclic aromatic hydrocarbons; and benzo and dibenzothiophenes. This finding confirms that most of these compounds occur in the "bound" form as structural units of molecules of resinous-asphaltenic components of the natural asphaltite.
