The aim of the European Space Agency's ExoMars rover mission is to search for potential traces of present or past life in the swallow subsurface (2 m depth) of Mars. The ExoMars rover mission relies on a suite of analytical instruments envisioned to identify organic compounds with biological value (biomarkers) associated with a mineralogical matrix in a highly oxidative environment. We investigated the feasibility of detecting basic organics (linear and branched lipid molecules) with Raman laser spectroscopy, an instrument onboard the ExoMars rover, when exposed to oxidant conditions. We compared the detectability of six lipid molecules (alkanes, alkanols, fatty acid, and isoprenoid) before and after an oxidation treatment (15 days with hydrogen peroxide), with and without mineral matrix support (amorphous silica rich vs. iron rich). Raman and infrared spectrometry was combined with gas chromatography-mass spectrometry to determine detection limits and technical constraints. We observed different spectral responses to degradation depending on the lipid molecule and mineral substrate, with the silica-rich material showing better preservation of organic signals. These findings will contribute to the interpretation of Raman laser spectroscopy results on cores from the ExoMars rover landing site, the hydrated silica-enriched delta fan on Cogoon Vallis (Oxia Planum).

中文翻译：

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通过拉曼光谱检测氧化环境中潜在的脂质生物标志物及其对ExoMars 2020-拉曼激光光谱仪仪器性能的影响。

欧洲航天局ExoMars火星漫游者任务的目的是在火星的吞噬地下（深度2 m）中寻找当前或过去生命的潜在痕迹。ExoMars漫游者任务依赖于一套分析工具，该工具可在高度氧化的环境中识别与矿物学基质相关的具有生物学价值的有机化合物（生物标记）。我们研究了暴露在氧化剂条件下的ExoMars流浪者车载拉曼激光光谱仪（拉曼激光光谱仪）检测基本有机物（线性和分支脂质分子）的可行性。我们比较了在有和没有矿物质基质支持（富含无定形二氧化硅和富含铁的情况下）的氧化处理（使用过氧化氢15天）之前和之后六个脂质分子（烷烃，链烷醇，脂肪酸和类异戊二烯）的可检测性。拉曼光谱和红外光谱与气相色谱-质谱联用，以确定检测限和技术限制。我们观察到了取决于脂质分子和矿物质底物的不同的降解降解光谱响应，富含二氧化硅的材料显示出更好的有机信号保存。这些发现将有助于解释ExoMars流浪者着陆点上的岩心上的拉曼激光光谱结果，这是在Cogoon Vallis（Oxia Planum）上的富含水合二氧化硅的三角扇。富含二氧化硅的材料可以更好地保留有机信号。这些发现将有助于解释ExoMars流浪者着陆点上的岩心上的拉曼激光光谱结果，这是在Cogoon Vallis（Oxia Planum）上的富含水合二氧化硅的三角扇。富含二氧化硅的材料可以更好地保留有机信号。这些发现将有助于解释ExoMars流浪者着陆点上的岩心上的拉曼激光光谱结果，这是在Cogoon Vallis（Oxia Planum）上的富含水合二氧化硅的三角扇。