High resolution molecular organic geochemistry assessment of Brazilian lacustrine crude oils

Uncommon steranes in Brazilian marginal crude oils: Dinoflagellate molecular fossils in the Sergipe-Alagoas Basin, Brazil

“…Biomarker parameters were calculated using GC×GC-TOFMS analyses of terpanes (m/z 191), 25-norhopanes (m/z 177), steranes (m/z 217, 218), diasteranes (m/z 217, 259), C 30 tetracyclic polyprenoid (TPP, m/z 259), isoprenoids (m/z 183), and β-carotane (m/z 125). Tricyclic (Trn, where Tr = tricyclic terpane and n = carbon number), tetracyclic (TeTn, where TeT = tetracyclic terpane and n = carbon number), and pentacyclic terpanes were identified based on mass spectra and elution order relative to structured chromatograms, similar to previously described works (Oliveira et al, 2012;Soares et al, 2013;Casilli et al, 2014;Kiepper et al, 2014).…”

“…Consequently, high resolution analytical techniques, such as comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS), have been applied in biomarker analyses of crude oils Casilli et al, 2014), evaluation of biodegradation (Silva et al, 2011;Soares et al, 2013;Li et al, 2014), assessment of depositional paleoenvironments (Oliveira et al, 2012;Kiepper et al, 2014;Zhang et al, 2015) and study of unresolved complex mixtures (Tran et al, 2010;Eiserbeck et al, 2012;Weng et al, 2015). The purpose of this work is to use GC×GC-TOFMS of steranes, alkyl steranes and other biomarkers in crude oil samples from the Sergipe-Alagoas Basin in order to better describe the source rock depositional environments for the oils.…”

Organofacies and paleoenvironment of lower Carboniferous mudstones (Dishuiquan Formation) in Eastern Junggar, NW China

“…This aromatic carotenoid was first identified in the Green River Shale (Murphy et al, 1967). β-Carotane was later found in numerous sedimentary rocks and crude oils (Bechtel et al, 2012;Brocks and Schaeffer, 2008;Casilli et al, 2014;Jiang and Fowler, 1986;Sousa Júnior et al, 2013). The compound is also reported in the upper Permian oil shale from Southern Junggar (Carroll, 1998).…”

Analyzing hydrocarbon fractions in crude oils by two-dimensional gas chromatography/time-of-flight mass spectrometry under reversed-phase column system

“…When integrated with time-of-flight mass spectrometry (GC Â GC/TOFMS), it is one of the most effective methods for separating complex mixtures [6][7][8][9][10]. This technique is useful because it offers a large amount of information that is difficult to obtain by conventional one-dimensional GC [11][12][13][14][15].…”