Investigating organic molecules in MSL's SAM Wet Chemistry experiments using de novo mass spectrometry interpretation

• Main Authors: Chou, L, Malespin, C, Mcadam, A, Glavin, D, Millan, Maëva, Freissinet, Caroline, Szopa, Cyril, Williams, A, J, Lewis, J, Eigenbrode, J, Teinturier, S, Bonnet, Jean-Yves, Prats, B, Brinckerhoff, W, Johnson, S, S, Mahaffy, P
• Other Authors: NASA Goddard Space Flight Center (GSFC), Georgetown University Washington (GU), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Florida Gainesville (UF), Goddard Earth Sciences and Technology and Research (GESTAR), NASA-Universities Space Research Association Washington (USRA), Telespazio France, eINFORMe inc.
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2023
• Subjects: [SDU]Sciences of the Universe [physics]; Yellowknife
• Online Access: https://insu.hal.science/insu-04484749; https://insu.hal.science/insu-04484749/document; https://insu.hal.science/insu-04484749/file/2886-LPI2023.pdf

International audience Introduction: For the past decade, the Sample Analysis at Mars (SAM) instrument suite onboard the Mars Science Laboratory (MSL) Curiosity Rover has served as a critical payload for characterizing the chemical composition of Mars, helping to elucidate its past and present geochemical environments and habitability [1,2]. The SAM instrument suite includes evolved gas analysis (EGA) and pyrolysis-gas chromatography (pyro-GC), coupled to mass spectrometry (MS), all of which has been used to conduct in situ chemical characterization of Martian sediments. While SAM can detect a wide range of volatile organic compounds via thermal volatilization, it was also designed to extract and analyze less volatile and more polar organic molecules by derivatization using two wet chemistry reagents: N-methyl-N-(tertbutyl-dimethylsilyl) trifluoroacetamide in dimethyl formamide (MTBSTFA:DMF 4:1) and tetramethylammonium hydroxide (TMAH) in methanol [3]. Polar compounds such as amino acids, fatty acids, or nucleobases are some of the important astrobiological targets that can be revealed by SAM wet chemistry experiments. To date, SAM has conducted several MTBSTFA derivatization experiments on Mars, three of which were full cup derivatization experiments, and three others were "opportunistic derivatization" (OD) experiments using MTBSTFA vapor that leaked into SAM's Sample Manipulation System earlier in the mission [4]. Those experiments were conducted on samples Curiosity obtained from Yellowknife Bay (sample: Cumberland OD x2), Bagnold Dunes (Ogunquit Beach), Vera Rubin ridge (Rock Hall OD), and the Glen Torridon region (Glen Etive and Mary Anning) of Gale crater. In those MTBSTFA wet chemistry experiments, several high mass and high abundance compounds were tentatively identified based on mass fragmentation patterns and supporting evidence from SAM-like pyro-GC-MS laboratory analyses. These compounds likely resulted from the derivatization reaction of possible MTBSTFA byproducts (e.g., silanol) with MTBSTFA ...