Diamondoid and biomarker characterization of oils from the Llanos Orientales Basin, Colombia

Quantitative analysis of diamondoids in crude oils using gas chromatography–triple quadrupole mass spectrometry

“…The MDLs and MQLs of diamondoids obtained by the SIM-GC-MS, which fall in the range of 0.23-2.53 and 0.78-8.44 lg/g oil, respectively, are 4-66 times higher than those of GC-MS-MS (Table 3). The MQLs of target analytes obtained by the GC-MS-MS method, ranging from 0.08-0.37 lg/g oil, are lower than the diamondoid baseline concentrations previously reported (Dahl et al, 1999;Springer et al, 2010). Therefore, these results demonstrate that GC-MS-MS has sufficient sensitivity for the determination of diamondoids even after sample dilution, whereas with the GC-MS method, samples with low concentrations of diamondoids (at ppm and sub-ppm levels) need to be concentrated prior to analysis to reach MQLs.…”

“…During previous quantification of diamondoids, cyclopentadecane, deuterated n-alkanes or diamondoids were usually used as internal standards (Wingert, 1992;Dahl et al, 1999;Schulz et al, 2001;Wei et al, 2006a;Springer et al, 2010). To simplify, however, relative response factors (RRF) of each diamondoid to the corresponding internal standards were generally assumed to be one.…”

“…To simplify, however, relative response factors (RRF) of each diamondoid to the corresponding internal standards were generally assumed to be one. In addition, the relative response factors of a diamondoid kit (including A, 1-MA, 2-MA, 1-EA, 2-EA, 1,3-DMA, 1-E-3-MA and 1,3,5-TMA) relative to deuterated n-alkanes (n-dodecane-d 26 and n-hexadecane-d 34 ) and five adamantanes (A, 1-MA, 2-MA, 2-EA, and 1,3-DMA) relative to the d 16 -adamantane have been used for quantification of diamondoids by GC-MS (Wang et al, 2006;Azevedo et al, 2008;Springer et al, 2010). In this study, calibration curves of response factors for ten diamondoid standards (i.e., A, 1-MA, 1,3-DMA, 1,3,5-TMA, 2-MA, 1-EA, 1-E-3-MA, 2-EA, D and 1-MD) were obtained by the GC-MS-MS and GC-MS analyses.…”

Composition of Diamondoids in Oil Samples From the Alpine Foreland Basin, Austria: Potential as Indices of Source Rock Facies, Maturity and Biodegradation

“…However, higher maturity would lead to cracking of major oil constituents (as well as biomarkers) and enrichment of diamondoids (i.e. the progressive concentration of diamondoids during cracking of less stable hydrocarbons), as described by Dahl et al (1999) and later observed by Azevedo et al (2008), Springer et al (2010 and Zhang et al (2015). In the present data, no correlation was observed in a cross-plot (Fig.…”

The origin and evolution of adamantanes and diamantanes in petroleum

“…At later maturation stages, the yield gradually increases in the range 2.0-2.7% EasyRo, and then rapidly decreases at >2.7% EasyRo; these data suggest that the diamondoid method of Dahl et al (1999) is probably not feasible for assessing the extent of oil cracking at high maturity stages, and that this method should be limited to maturity stages <2.0% EasyRo. Additionally, the baseline concentration of 3-+ 4-methyldiamantanes is approximately 47 ppm for the Tarim oil, which is remarkably higher than that of other basin oils (Dahl et al, 1999;Springer et al, 2010). Differences between the analytical procedures used to obtain the measurements may be a major factor accounting for the different results (as well as differences between the study areas).…”