Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: ideas and perspectives 02 Jun 2020

Submitted as: ideas and perspectives | 02 Jun 2020

Review status
This preprint is currently under review for the journal BG.

Ideas and perspectives: Same Carbon Different Elements – An Insight into Position-Specific Isotope Patterns Within a Single Compound

Yuyang He1, Xiaobin Cao2,3, and Huiming Bao2,3,4 Yuyang He et al.
  • 1Institute of Mechanics, Chinese Academy of Sciences, No.15 Beisihuanxi Road, Beijing 100190, PR China
  • 2International Center for Isotope Effects Research, Nanjing University, Nanjing 210023, P. R. China
  • 3School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, PR China
  • 4Department of Geology and Geophysics, Louisiana State University, E235 Howe Russell Kniffen, Baton Rouge, LA 70803

Abstract. It is expected that information on the source, reaction pathway, and kinetics of an organic compound can be obtained from its position-specific isotope compositions or intramolecular isotope distribution (Intra-ID). To retrieve the information, we could use its equilibrium Intra-ID as a reference for understanding the observed Intra-IDs. Historically, observed, apparently close-to-equilibrium carbon Intra-ID had prompted an open debate on the nature of biosystem and specifically the pervasiveness of reversible biochemical reactions. Much of the debates remain unresolved, and the discussion has not clearly distinguished two states of equilibrium: (1) the equilibrium among the bond-breaking/forming positions in reactant and product, and (2) the equilibrium among all carbon positions in a compound. For an organic molecule with multiple carbon positions, equilibrium carbon Intra-ID can be attained only when a specific reaction is in equilibrium and the sources of each position are also in equilibrium with each other. An Intra-ID provides limited information if the sources and pathways are both unconstrained. Here, we elaborate on this insight using examples of the Intra-IDs of hydroxyl-bearing minerals, N2O, and acetic acid. Research effort aiming at calibrating position-specific equilibrium and kinetic isotope fractionation factors for defined processes will help to interpret Intra-IDs of a compound accurately and fully.

Yuyang He et al.

Interactive discussion

Status: open (until 14 Jul 2020)
Status: open (until 14 Jul 2020)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Yuyang He et al.

Yuyang He et al.


Total article views: 197 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
156 39 2 197 0 1
  • HTML: 156
  • PDF: 39
  • XML: 2
  • Total: 197
  • BibTeX: 0
  • EndNote: 1
Views and downloads (calculated since 02 Jun 2020)
Cumulative views and downloads (calculated since 02 Jun 2020)

Viewed (geographical distribution)

Total article views: 123 (including HTML, PDF, and XML) Thereof 123 with geography defined and 0 with unknown origin.
Country # Views %
  • 1



No saved metrics found.


No discussed metrics found.
Latest update: 07 Jul 2020
Publications Copernicus
Short summary
Different carbon sites in a large organic molecule has different isotope composition. We realized that different carbon sites may not have chance to exchange isotopes at all. The lack of appreciation of this notion might be blamed for an unsettled debate on the thermodynamic state of an organism. Here we demonstrated using minerals, N2O, and acetic acid that the dearth of exchange among different carbon sites renders them as independent as if they were different elements in organic molecules.
Different carbon sites in a large organic molecule has different isotope composition. We...