Free and sulfur-bound biomarkers in the Maikop Stratum bitumen from Azerbaijan

The hydrocarbon composition of the bitumen isolated from the Maikop Stratum rock from Northern Azerbaijan was thoroughly studied by the techniques of gas-liquid chromatography and gas chromatography-mass spectrometry. Along w ith the study of biomarkers from the free aliphatic fraction, the compositi on of biomarkers occurring as sulfur compounds in the aromatic and polar fr actions of the bitumen was investigated. The sulfurized hydrocarbon structu res of the aromatic and polar fractions were studied by means of Raney nick el reductive desulfurization reactions. In addition, organosulfur biomarker s of the 5-methyl-2-alkylthiophene series were detected. in which the radic als in the 2-position were derived from either normal or isoprenoid alkanes .