Limits...
Diamondoid characterization in condensate by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry: The Junggar Basin of Northwest China.

Li S, Hu S, Cao J, Wu M, Zhang D - Int J Mol Sci (2012)

Bottom Line: However, they are very difficult to separate and accurately quantify by conventional geochemical methods due to their low abundance in oil.It not only separates the compounds that coelute in conventional GC-MS (e.g., 4, 8-dimethyl-diamantane and trimethyl-diamantane) but also allows the identification of compounds that were not previously detected (e.g., trimethyl-diamantane (15A)).The diamondoid indexes indicate that a representative condensate from Well DX 10 is highly mature with equivalent Ro being approximately 1.5%.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Tectonics and Petroleum Resources (China University of Geosciences), Ministry of Education, Wuhan 430074, China; E-Mails: hushzh@cug.edu.cn (S.H.); zdm2007@cug.edu.cn (D.Z.).

ABSTRACT
Diamondoids in crude oil are useful for assessing the maturity of oil in high maturation. However, they are very difficult to separate and accurately quantify by conventional geochemical methods due to their low abundance in oil. In this paper, we use comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) to study the compounds in condensates from the Junggar Basin of northwest China and address their geological and geochemical applications. GC×GC-TOFMS improves the resolution and separation efficiency of the compounds. It not only separates the compounds that coelute in conventional GC-MS (e.g., 4, 8-dimethyl-diamantane and trimethyl-diamantane) but also allows the identification of compounds that were not previously detected (e.g., trimethyl-diamantane (15A)). A reversed-phase column system improves the separation capabilities over the normal phase column system. The diamondoid indexes indicate that a representative condensate from Well DX 10 is highly mature with equivalent Ro being approximately 1.5%.

Show MeSH

Related in: MedlinePlus

Real second-dimensional chromatogram (a) and GC×GC-TOFMS contour plot (b) of adamantanes identified in the condensate from Well DX 10 by GC×GC-TOFMS analysis under normal phase column system. The compounds are listed in Table 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC3472753&req=5

f1-ijms-13-11399: Real second-dimensional chromatogram (a) and GC×GC-TOFMS contour plot (b) of adamantanes identified in the condensate from Well DX 10 by GC×GC-TOFMS analysis under normal phase column system. The compounds are listed in Table 1.

Mentions: The molecular formula of adamantanes is CnH2n−4 and the carbon number ranges from C10 to C14. Adamantanes were identified by characteristic fragment ions of m/z 136, 135, 149, 163, 177 and 191 (C10 to C13; Figure 1a). In the first-dimensional chromatogram, some adamantanes overlap with chain isoparaffins, such as nC11 and No.2 adamantane (Figure 1a). This leads to inaccurate quantitative analysis of adamantanes. In contrast, in GC×GC-TOFMS analysis, adamantanes can be effectively separated, although they have the same or similar first-dimensional retention time (Figure 1b). The carbon number of adamantanes that were identified in the condensate from Well DX 10 ranged from C10 to C14.


Diamondoid characterization in condensate by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry: The Junggar Basin of Northwest China.

Li S, Hu S, Cao J, Wu M, Zhang D - Int J Mol Sci (2012)

Real second-dimensional chromatogram (a) and GC×GC-TOFMS contour plot (b) of adamantanes identified in the condensate from Well DX 10 by GC×GC-TOFMS analysis under normal phase column system. The compounds are listed in Table 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472753&req=5

f1-ijms-13-11399: Real second-dimensional chromatogram (a) and GC×GC-TOFMS contour plot (b) of adamantanes identified in the condensate from Well DX 10 by GC×GC-TOFMS analysis under normal phase column system. The compounds are listed in Table 1.
Mentions: The molecular formula of adamantanes is CnH2n−4 and the carbon number ranges from C10 to C14. Adamantanes were identified by characteristic fragment ions of m/z 136, 135, 149, 163, 177 and 191 (C10 to C13; Figure 1a). In the first-dimensional chromatogram, some adamantanes overlap with chain isoparaffins, such as nC11 and No.2 adamantane (Figure 1a). This leads to inaccurate quantitative analysis of adamantanes. In contrast, in GC×GC-TOFMS analysis, adamantanes can be effectively separated, although they have the same or similar first-dimensional retention time (Figure 1b). The carbon number of adamantanes that were identified in the condensate from Well DX 10 ranged from C10 to C14.

Bottom Line: However, they are very difficult to separate and accurately quantify by conventional geochemical methods due to their low abundance in oil.It not only separates the compounds that coelute in conventional GC-MS (e.g., 4, 8-dimethyl-diamantane and trimethyl-diamantane) but also allows the identification of compounds that were not previously detected (e.g., trimethyl-diamantane (15A)).The diamondoid indexes indicate that a representative condensate from Well DX 10 is highly mature with equivalent Ro being approximately 1.5%.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Tectonics and Petroleum Resources (China University of Geosciences), Ministry of Education, Wuhan 430074, China; E-Mails: hushzh@cug.edu.cn (S.H.); zdm2007@cug.edu.cn (D.Z.).

ABSTRACT
Diamondoids in crude oil are useful for assessing the maturity of oil in high maturation. However, they are very difficult to separate and accurately quantify by conventional geochemical methods due to their low abundance in oil. In this paper, we use comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) to study the compounds in condensates from the Junggar Basin of northwest China and address their geological and geochemical applications. GC×GC-TOFMS improves the resolution and separation efficiency of the compounds. It not only separates the compounds that coelute in conventional GC-MS (e.g., 4, 8-dimethyl-diamantane and trimethyl-diamantane) but also allows the identification of compounds that were not previously detected (e.g., trimethyl-diamantane (15A)). A reversed-phase column system improves the separation capabilities over the normal phase column system. The diamondoid indexes indicate that a representative condensate from Well DX 10 is highly mature with equivalent Ro being approximately 1.5%.

Show MeSH
Related in: MedlinePlus