Li Xiang, Danell Ryan M, Brinckerhoff William B, Pinnick Veronica T, van Amerom Friso, Arevalo Ricardo D, Getty Stephanie A, Mahaffy Paul R, Steininger Harald, Goesmann Fred
1 Center for Space Science and Technology, University of Maryland , Baltimore County, Baltimore, Maryland, USA.
Astrobiology. 2015 Feb;15(2):104-10. doi: 10.1089/ast.2014.1203. Epub 2015 Jan 26.
Evidence from recent Mars missions indicates the presence of perchlorate salts up to 1 wt % level in the near-surface materials. Mixed perchlorates and other oxychlorine species may complicate the detection of organic molecules in bulk martian samples when using pyrolysis techniques. To address this analytical challenge, we report here results of laboratory measurements with laser desorption mass spectrometry, including analyses performed on both commercial and Mars Organic Molecule Analyzer (MOMA) breadboard instruments. We demonstrate that the detection of nonvolatile organics in selected spiked mineral-matrix materials by laser desorption/ionization (LDI) mass spectrometry is not inhibited by the presence of up to 1 wt % perchlorate salt. The organics in the sample are not significantly degraded or combusted in the LDI process, and the parent molecular ion is retained in the mass spectrum. The LDI technique provides distinct potential benefits for the detection of organics in situ on the martian surface and has the potential to aid in the search for signs of life on Mars.
近期火星任务的证据表明，近地表物质中存在高达1 wt%水平的高氯酸盐。当使用热解技术时，混合高氯酸盐和其他氯氧化合物可能会使在大量火星样本中检测有机分子变得复杂。为应对这一分析挑战，我们在此报告激光解吸质谱的实验室测量结果，包括对商用仪器和火星有机分子分析仪（MOMA）实验模型仪器所做的分析。我们证明，在选定的加标矿物基质材料中，通过激光解吸/电离（LDI）质谱检测非挥发性有机物不会受到高达1 wt%高氯酸盐的抑制。样品中的有机物在LDI过程中不会显著降解或燃烧，并且母分子离子保留在质谱中。LDI技术为在火星表面原位检测有机物提供了明显的潜在优势，并且有可能有助于寻找火星上的生命迹象。
