Computer-generated isotope model achieves experimental accuracy of filiation for position-specific isotope analysis

TitleComputer-generated isotope model achieves experimental accuracy of filiation for position-specific isotope analysis
Publication TypeJournal Article
Year of Publication2019
AuthorsGoldman MJacob, Vandewiele NM, Ono S, Green WH
JournalChemical Geology
Volume514
Pagination1 - 9
ISSN0009-2541
KeywordsAutomated mechanism generation, Degeneracy, Enrichment, Isotopologue, Kinetic isotope effect, Symmetry
Abstract

Position-specific isotope analysis (PSIA) can aid in understanding the origins of molecules. Destructive PSIA requires a model to track isotope substitution through reaction pathways. We present a general method based on the Reaction Mechanism Generator software to construct quantitative kinetic models with atom-specific isotope tracking and kinetic isotope effects during thermal decomposition of model compounds. A propane mechanism produced with this method is compared to experiments. Without tuning kinetic or thermodynamic parameters to experimental data, the mechanism replicated, within experimental uncertainty, the relationship between the parent molecule's position-specific values and the fragments' enrichments. These isotope-specific models can serve as an in silico platform to quantitatively assess secondary isotopic reactions which can scramble position-specific enrichments, design and optimize experimental conditions, and test feasibility of PSIA for new compounds. The proposed methodology creates new opportunities for applications in isotope analysis for a range of chemical compounds.

URLhttp://www.sciencedirect.com/science/article/pii/S0009254119300865
DOI10.1016/j.chemgeo.2019.02.036