With comprehensive two-dimensional gas chromatography linked to time-of-flight mass spectrometry(GC × GC-TOFMS),ten light hydrocarbon(LH) compounds were qualitatively and quantitatively studied in light hydrocarb...With comprehensive two-dimensional gas chromatography linked to time-of-flight mass spectrometry(GC × GC-TOFMS),ten light hydrocarbon(LH) compounds were qualitatively and quantitatively studied in light hydrocarbons(LHs) components of crude oils.For significant differences in the concentrations of 3-isoproyltoluene(3-iPT),4-isoproyltoluene(4-iPT) and 2-isoproyltoluene(2-iPT) in crude oils,and the 2-iPT probably derived mainly from similar skeleton monocyclic terpenoids via dehydrogenation and aromatization,the ratios of(3+4)-/2-iPT(iPTr),3-/2-iPT(iPTr1) and 4-/2-iPT(iPTr2) are proposed to distinguish the organic matter origin of crude oils.Relatively higher iPTr(>8.0),iPTr1(>7.0) and iPTr2(>4.0) values indicate that crude oils are sourced from the co-contribution of lower aquatic organisms,bacteria,algae,and terrestrial higher plants,whereas lower iPTr(<5.0),iPTr1(<3.0),iPTr2(<2.0) values suggest that crude oils originated from terrestrial higher plants.The iPTr,iPTr1,and iPTr2 values show notable distinction which is mainly controlled by 2-iPT concentrations,while the concentrations of 3-iPT and 4-iPT have similar distribution range in all studied oils.The 2-iPT depleted in marine oils from the Tarim Basin and lacustrine oils from the Beibuwan Basin is less than 0.30 mg/g LHs,whereas 2-iPT enriched in swamp oils from the Tarim Basin is greater than 0.50 mg/g LHs.The iPTr,iPTr1,and iPTr2 ratios and 2-iPT concentrations can be used to distinguish the organic matter origin of crude oils,especially for light oils and condensates with low concentrations of biomarkers.展开更多
基金supported by the National Science and Technology Major Project(No.2016ZX05003-002-004)the National Natural Science Foundation of China(Nos.41072105,41872147,41503029)the National Key Research and Development Program of China(No.2017YFC0603102)。
文摘With comprehensive two-dimensional gas chromatography linked to time-of-flight mass spectrometry(GC × GC-TOFMS),ten light hydrocarbon(LH) compounds were qualitatively and quantitatively studied in light hydrocarbons(LHs) components of crude oils.For significant differences in the concentrations of 3-isoproyltoluene(3-iPT),4-isoproyltoluene(4-iPT) and 2-isoproyltoluene(2-iPT) in crude oils,and the 2-iPT probably derived mainly from similar skeleton monocyclic terpenoids via dehydrogenation and aromatization,the ratios of(3+4)-/2-iPT(iPTr),3-/2-iPT(iPTr1) and 4-/2-iPT(iPTr2) are proposed to distinguish the organic matter origin of crude oils.Relatively higher iPTr(>8.0),iPTr1(>7.0) and iPTr2(>4.0) values indicate that crude oils are sourced from the co-contribution of lower aquatic organisms,bacteria,algae,and terrestrial higher plants,whereas lower iPTr(<5.0),iPTr1(<3.0),iPTr2(<2.0) values suggest that crude oils originated from terrestrial higher plants.The iPTr,iPTr1,and iPTr2 values show notable distinction which is mainly controlled by 2-iPT concentrations,while the concentrations of 3-iPT and 4-iPT have similar distribution range in all studied oils.The 2-iPT depleted in marine oils from the Tarim Basin and lacustrine oils from the Beibuwan Basin is less than 0.30 mg/g LHs,whereas 2-iPT enriched in swamp oils from the Tarim Basin is greater than 0.50 mg/g LHs.The iPTr,iPTr1,and iPTr2 ratios and 2-iPT concentrations can be used to distinguish the organic matter origin of crude oils,especially for light oils and condensates with low concentrations of biomarkers.
