Unprecedented Molecular Diversity Revealed in Meteoritic Insoluble Organic Matter: The Paris Meteorite’s Case

Grégoire Danger,Laurent Remusat,Carlos Afonso,Vassilissa Vinogradoff,Nathalie Carrasco,Jasmine Hertzog,Julien Maillard,Louis Le Sergeant D’Hendecourt,Alexander Ruf,Isabelle Schmitz-Afonso,Philippe Schmitt-Kopplin

doi:10.3847/psj/abb60f

Abstract

Abstract The insoluble organic matter (IOM) contained in carbonaceous chondrites has witnessed a diverse suite of processes possibly starting from the evolution of the parent molecular cloud down to the protosolar nebula and finally to asteroidal processes that occurred on the chondrites’ parent bodies. Laser desorption coupled with ultra-high-resolution mass spectrometry reveals that the IOM of the Paris meteorite releases a large diversity of molecules. Various molecular families ranging from hydrogenated amorphous carbon to CHNOS aromatic molecules were detected with heteroatoms (nitrogen, oxygen, and sulfur) mainly incorporated within aromatic structures. Molecules bearing nitrogen atoms present a significant variation in aromaticity. These unprecedented results allow the proposal that small molecules bearing heteroatoms could be trapped in the large macromolecular network of the IOM by hydrophobic interactions. This molecular diversity could originate from different sources, such as the soluble organic matter, the hydrothermal alteration inside the Paris’s parent body, or even generated during the IOM extraction procedure. It has to be noted that some of the molecular diversity may reflect fragmentation and rearrangement of the IOM constituents during the laser desorption ionization, although care was taken to minimize such damage.

Highlights

Carbonaceous chondrites (CCs) are fragments of primitive asteroids that are known to contain up to 6 wt.% of organic matter (OM) (Pearson et al 2006)
We report new results obtained from laser desorption ionization (LDI) coupled to an ultrahigh-resolution mass spectrometer (FT-ICR-MS) on a Paris insoluble organic matter (IOM)
The LDI-FT-ICR mass spectrum of the Paris IOM presents a large number of signals from which 14232 molecular formulas were assigned (Figure 1)

Summary

Introduction

Carbonaceous chondrites (CCs) are fragments of primitive asteroids that are known to contain up to 6 wt.% of organic matter (OM) (Pearson et al 2006). The insoluble organic matter (IOM) represents the major organic carbon component of CCs (75 to 95 wt.% of the total recovered organic matter) W.; Flynn 2006; Remusat 2015; Ruf et al 2018; Schmitt-Kopplin et al 2010; Sephton 2002). In particular the D/H ratio, indicate that it derives from precursors possibly originating from the interstellar medium or the cold regions of the outer solar system that were subsequently accreted on the CC parent bodies (Remusat et al 2010).

Methods

Results

Discussion

Conclusion