Conference
Isotopologues of organic molecules: method developments and applications
May 25th 2022 @ 10 AM
Place: Room GR C2 495 Ecole Polytechnique Fédérale de Lausanne, CH1015 Lausanne
Prof. Alexis Gilbert is an Assistant Professor in the Department of Earth and Planetary Sciences at Tokyo Institute of Technology and is a Fellow of the NASA Astrobiology Institute.
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Abstract / Stable isotope analysis of light elements (2H, 13C, 15N, 18O, 34S) provides detailed information regarding the origin and history of organic molecules. The heavy/light ratios are traditionally measured on simple gases arising from conversion of the molecule to be analyzed: H2 for 2H analysis, CO2 for 13C, N2 for 15N, etc. While universally used, conventional methods result in a loss of information on the isotope distribution within molecules, thus omitting a large portion of available information. Isotope substitution within a molecule can occur at different positions or involve more than one heavy isotope and leads to a set of molecular species called isotopologues. Recent years have seen the development of several methodologies for the precise measurement of isotopologues of organic molecules and have documented an ability to trace the origin of a given molecule in a way that is fundamentally different from traditional analyses. This presentation will review the recent methodological developments for the analysis of doubly-substituted (‘clumped’) and position-specific isotopologues of organic molecules as well as the application in food authentication, biogeochemistry and astrobiology.