Laboratoire Génie des Procédés et Matériaux, CentraleSupélec, University Paris-Saclay, Gif-sur-Yvette, France.
LATMOS/IPSL, UVSQ Université Paris-Saclay, Sorbonne Université, CNRS, Guyancourt, France.
Astrobiology. 2021 Sep;21(9):1137-1156. doi: 10.1089/ast.2020.2393.
-butyldimethylsilyl--methyltrifluoroacetamide (MTBSTFA), mixed with the solvent -dimethylformamide (DMF), is used as a derivatizing reagent by the Sample Analysis at Mars (SAM) experiment onboard NASA's Curiosity rover and will soon be utilized by the Mars Organic Molecule Analyzer experiment onboard the ESA/Roscosmos Rosalind Franklin rover. The pyrolysis products of MTBSTFA, DMF, and the MTBSTFA/DMF mixtures, obtained at different temperatures, were analyzed. Two different pyrolysis modes were studied, flash pyrolysis and ramp pyrolysis (35°C/min), to evaluate the potential influence of the sample heating speed on the production of products in space chromatographs. The effect of the presence of calcium perchlorate on the pyrolysis products of MTBSTFA/DMF was also studied to ascertain the potential effect of perchlorate species known to be present at the martian surface. The results show that MTBSTFA/DMF derivatization should be applied below 300°C when using flash pyrolysis, as numerous products of MTBSTFA/DMF were formed at high pyrolysis temperatures. However, when an SAM-like ramp pyrolysis was applied, the final pyrolysis temperature did not appear to influence the degradation products of MTBSTFA/DMF. All products of MTBSTFA/DMF pyrolysis are listed in this article, providing a major database of products for the analysis of martian analog samples, meteorites, and the analysis of martian rocks and soils. In addition, the presence of calcium perchlorate does not show any obvious effects on the pyrolysis of MTBSTFA/DMF: Only chloromethane and TBDMS-Cl (chloro-tertbutyldimethylsilane) were detected, whereas chlorobenzene and other chlorine-bearing compounds were not detected. However, other chlorine-bearing compounds were detected after pyrolysis of the Murchison meteorite in the presence of calcium perchlorate. This result reinforces previous suggestions that chloride-bearing compounds could be reaction products of martian samples and perchlorate.
-叔丁基二甲基硅基-甲基三氟乙酰胺（MTBSTFA）与溶剂二甲基甲酰胺（DMF）混合，被 NASA 的好奇号漫游车上的样品分析（SAM）实验用作衍生试剂，很快也将被 ESA/俄罗斯航天局罗莎琳德·富兰克林漫游车上的火星有机分子分析仪实验所采用。分析了在不同温度下获得的 MTBSTFA、DMF 和 MTBSTFA/DMF 混合物的热解产物。研究了两种不同的热解模式，即闪热解和斜坡热解（35°C/min），以评估样品加热速度对空间色谱仪中产物生成的潜在影响。还研究了高氯酸钙的存在对 MTBSTFA/DMF 热解产物的影响，以确定已知存在于火星表面的高氯酸盐对热解产物的潜在影响。结果表明，在使用闪热解时，MTBSTFA/DMF 衍生化应在 300°C 以下进行，因为在高温热解温度下形成了许多 MTBSTFA/DMF 的产物。然而，当应用类似于 SAM 的斜坡热解时，最终热解温度似乎不会影响 MTBSTFA/DMF 的降解产物。本文列出了 MTBSTFA/DMF 热解的所有产物，为分析火星模拟样品、陨石和火星岩石和土壤提供了主要的产物数据库。此外，高氯酸钙的存在对 MTBSTFA/DMF 的热解没有显示出任何明显的影响：仅检测到氯甲烷和 TBDMS-Cl（氯叔丁基二甲基硅烷），而未检测到氯苯和其他含氯化合物。然而，在存在高氯酸钙的情况下对默奇森陨石进行热解后，检测到了其他含氯化合物。这一结果进一步证实了以前的建议，即含氯化合物可能是火星样品和高氯酸盐的反应产物。
