Micro-ion Traps for Detection of (Pre)-Biotic Organic Compounds on Comets

Comets are currently believed to be a mixture of interstellar and nebular material. Many of the volatiles in comets are attributed to interstellar chemistry, because the same species of carbonaceous compounds are also observed in ices in interstellar molecular (ISM) clouds. Comets are thus likely to be a relatively pristine reservoir of primitive material and carbonaceous compounds in our solar system. They could be a major contributor to the delivery of prebiotic organic compounds, from which life emerged through impacts on early Earth. Mass spectrometers are very powerful tools to identify unknown chemicals, and much progress bas been made in miniaturizing mas spectrometers for space applications. Most miniatu rized mass spectrometers developed to date, however, are still relatively large, power hungry, complicated to assemble, and would have significant impact on space flight vehicle total payload and resource allocations

Detection and Quantification of Nitrogen Compounds in Martian Solid Samples by the Sample Analysis at Mars (SAM) Instrument Suite

The Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) Curiosity Rover detected both reduced and oxidized nitrogen-bearing compounds during the pyrolysis of surface materials from three sites at Gale Crater. Preliminary detections of nitrogen species include NO, HCN, ClCN, CH3CN, and TFMA (trifluoro-Nmethyl-acetamide). On Earth, nitrogen is a crucial bio-element, and nitrogen availability controls productivity in many environments. Nitrogen has also recently been detected in the form of CN in inclusions in the Martian meteorite Tissint, and isotopically heavy nitrogen (delta N-15 approx +100per mille) has been measured during stepped combustion experiments in several SNC meteorites. The detection of nitrogen-bearing compounds in Martian regolith would have important implications for the habitability of ancient Mars. However, confirmation of indigenous Martian nitrogen bearing compounds will require ruling out their formation from the terrestrial derivatization reagents (e.g. N-methyl-N-tert-butyldimethylsilyl-trifluoroacetamide, MTBSTFA and dimethylformamide, DMF) carried for SAM's wet chemistry experiment that contribute to the SAM background. The nitrogen species we detect in the SAM solid sample analyses can also be produced during laboratory pyrolysis experiments where these reagents are heated in the presence of perchlorate, a compound that has also been identified by SAM in Mars solid samples. However, this does not preclude a Martian origin for some of these compounds, which are present in nanomolar concentrations in SAM evolved gas analyses. Analysis of SAM data and laboratory breadboard tests are underway to determine whether nitrogen species are present at higher concentrations than can be accounted for by maximum estimates of nitrogen contribution from MTBSTFA and DMF. In addition, methods are currently being developed to use GC Column 6, (functionally similar to a commercial Q-Bond column), to separate and identify unretained compounds such as NO, N2O, and NO2, which are difficult to detect by EGA-MS due to mass interferences at 30, 44 and 46, respectively. Here we present evolved gas analysis-mass spectrometry (EGA-MS) and gas chromatography mass spectrometry (GC-MS) data on the identification and quantification of these nitrogen-bearing compounds, and suggestions for their origin

The Search for Nitrates on Mars by the Sample Analysis at Mars (SAM) Instrument

Planetary models suggest that nitrogen was abundant in the early Martian atmosphere as N2 but it was lost by sputtering and photochemical loss to space, impact erosion, and chemical oxidation to nitrates. A nitrogen cycle may exist on Mars where nitrates, produced early in Mars' history, may have been later decomposed back into N2 by the current impact flux. Nitrates are a fundamental source of nitrogen for terrestrial microorganisms, and they have evolved metabolic pathways to perform both oxidation and reduction to drive a complete biological nitrogen cycle. Therefore, the characterization of nitrogen in Martian soils is important to assess habitability of the Martian environment, particularly with respect to the presence of nitrates. The only previous mission that was designed to search for soil nitrates was the Phoenix mission but N-containing species were not detected by TEGA or the MECA WCL. Nitrates have been tentatively identified in Nakhla meteorites, and if nitrogen was oxidized on Mars, this has important implications for the habitability potential of Mars. Here we report the results from the Sample Analysis at Mars (SAM) instrument suite aboard the Curiosity rover during the first year of surface operations in Gale Crater. Samples from the Rocknest aeolian deposit and sedimentary rocks (John Klein) were heated to approx 835degC under helium flow and the evolved gases were analyzed by MS and GC-MS. Two and possibly three peaks may be associated with the release of m/z 30 at temperatures ranging from 180degC to 500degC. M/z 30 has been tentatively identified as NO; other plausible contributions include CH2O and an isotopologue of CO, 12C18O. NO, CH2O, and CO may be reaction products of reagents (MTBSTFA/DMF) carried from Earth for the wet chemical derivatization experiments with SAM and/or derived from indigenous soil nitrogenated organics. Laboratory analyses indicate that it is also possible that <550degC evolved NO is produced via reaction of HCl with nitrates arising from the decomposition of perchlorates. All sources of m/z 30 whether it be martian or terrestrial will be considered and their implications for Mars will be discussed

Amino Acids in Antarctic Micrometeorites

International audienc

Search for organic molecules on Mars with the Gas Chromatograph-Mass Spectrometer of the Sample Analysis at Mars experiment onboard the MSL 2011 Curiosity rover

In past times, life might have emerged under Martian conditions milder than the present ones, and left some remnants at the surface. Even if this did not happen, prebiotic molecules may have been preserved in the soil, and they might be similar to those that prevailed on the Earth surface some 3.5 to 4 billion years ago. NASA's MSL2011 rover Curiosity will explore the surface and subsurface of Mars, seeking traces of prebiotic or biological activity. Organic signatures are among the main signatures of interest in this frame, and they will be among the main targets of the Gas Chromatograph Quadrupole Mass Spectrometer (GC-QMS) which constitutes the core of the Sample Analysis at Mars (SAM) analytical laboratory, developed by the NASA/GSFC in collaboration with the University of Paris (Fr) and the JPL. The main goal of this instrumentation is indeed to determine molecular abundances and isotopic ratios of organic molecules present in the collected samples, by analyzing gases either sampled from the atmosphere, or obtained from soil processing, either by physical heating or chemical reactions. In order to prepare for the interpretation of the data obtained in situ with the GCQMS of SAM, and due to the complexity of this instrumentation, a number of calibrations are required to determine the exact behaviour of each part of this instrumentation, that is required to correctly treat the signal and obtain a correct interpretation of it. In order to prepare the SAM-GC in situ results treatment and interpretation, it is necessary: (1) to determine the instrument ability to detect targets molecules under the instrument operating conditions and (2) to create data bases to help for the identification and quantification of the molecules that could be detected with SAM. With this aim we first selected molecules which might be analyzed with SAM-GC using the following criteria: (1) abundance at the Mars surface (2) astrobiological interest, (3) formation during the sample preparation. Then we characterized these target molecules with laboratory instrumentation using discrete spare components of the GC flight model ; in a second step, we used a SAM-GC spare model, in a vacuum chamber roughly reproducing the environmental conditions inside the Curiosity rover. A following step will be to carry out similar experiments with the whole SAM testbed located at the NASA/GSFC. This paper will present an overview of the analytical capabilities of the GC-QMS, with a focus on the GC part, relying on the calibration described previously. In addition, we will present analyses done on Atacama soil samples, Mars soil analogue, to get an evaluation of the SAM GC performances with a natural sample

Search for organic molecules on Mars with the Gas Chromatograph-Mass Spectrometer of the Sample Analysis at Mars experiment onboard the MSL 2011 Curiosity rover

In past times, life might have emerged under Martian conditions milder than the present ones, and left some remnants at the surface. Even if this did not happen, prebiotic molecules may have been preserved in the soil, and they might be similar to those that prevailed on the Earth surface some 3.5 to 4 billion years ago. NASA's MSL2011 rover Curiosity will explore the surface and subsurface of Mars, seeking traces of prebiotic or biological activity. Organic signatures are among the main signatures of interest in this frame, and they will be among the main targets of the Gas Chromatograph Quadrupole Mass Spectrometer (GC-QMS) which constitutes the core of the Sample Analysis at Mars (SAM) analytical laboratory, developed by the NASA/GSFC in collaboration with the University of Paris (Fr) and the JPL. The main goal of this instrumentation is indeed to determine molecular abundances and isotopic ratios of organic molecules present in the collected samples, by analyzing gases either sampled from the atmosphere, or obtained from soil processing, either by physical heating or chemical reactions. In order to prepare for the interpretation of the data obtained in situ with the GCQMS of SAM, and due to the complexity of this instrumentation, a number of calibrations are required to determine the exact behaviour of each part of this instrumentation, that is required to correctly treat the signal and obtain a correct interpretation of it. In order to prepare the SAM-GC in situ results treatment and interpretation, it is necessary: (1) to determine the instrument ability to detect targets molecules under the instrument operating conditions and (2) to create data bases to help for the identification and quantification of the molecules that could be detected with SAM. With this aim we first selected molecules which might be analyzed with SAM-GC using the following criteria: (1) abundance at the Mars surface (2) astrobiological interest, (3) formation during the sample preparation. Then we characterized these target molecules with laboratory instrumentation using discrete spare components of the GC flight model ; in a second step, we used a SAM-GC spare model, in a vacuum chamber roughly reproducing the environmental conditions inside the Curiosity rover. A following step will be to carry out similar experiments with the whole SAM testbed located at the NASA/GSFC. This paper will present an overview of the analytical capabilities of the GC-QMS, with a focus on the GC part, relying on the calibration described previously. In addition, we will present analyses done on Atacama soil samples, Mars soil analogue, to get an evaluation of the SAM GC performances with a natural sample

Preservation of organic matter on Mars by sulfur

International audienceDeltaic-lacustrine mudstones at Pahrump Hills, Gale Crater, Mars yielded a variety of sulfur-containing volatiles upon heating to 500-860°C, as detected by the Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover. The detection of organosulfur compounds comprising thiophenes, dimethylsulfide and thiols by gas chromatography-mass spectrometry and evolved gas analyses, together with aromatic and other hydrocarbon molecules with distributions specific to the sample (i.e., not from the SAM background) indicate that some or all of these organic fragments released at high temperatures are indigenous to the mudstones. The organosulfur compounds are most likely derived from sulfur organics in the sediments. However, there is a possibility that sulfurization of some organic fragments occurred in the oven. On Earth, sulfurization of organic matter is a key process that aids preservation over geological time-scales. This is because it reduces reactive functional groups and adds cross links between small unstable molecules thereby converting them into recalcitrant macromolecules. Sulfurization of organic materials prior to deposition and during early diagenesis may have been a key mechanism responsible for organic matter preservation in the Murray formation mudstones. Sulfur-bearing organics have also been observed in carbonaceous meteorites and there is indication of their presence in the Tissint martian meteorite. A quantitative assessment of organosulfur compounds relative to their non-organic counterparts will be presented for the Murray formation mudstones analyzed by SAM and meteorites analyzed in the laboratory under similar analytical conditions

Potential sources of by-products generated by the Tenax® trap of SAM

International audienceSample Analysis at Mars (SAM) experiment onboard the Curiosity rover onboards a Gas Chromatography (GC) coupled to a Mass Spectrometer (MS).To adapt on the nature of a sample to the analytical devices used, a sample preparation and gas processing system implemented with (a) a pyrolysis system, (b) wet chemistry: MTBSTFA and TMAH (c) the hydrocarbon trap (silica beads, Tenax® TA and Carbosieve G) and the injection trap (Tenax® GR composed of Tenax® TA and 30% of graphite) are used to concentrate volatiles released from the sample prior to GC-MS analysis [1]. This study investigates all the potential sources of by-products (artifacts and backgrounds) generated by the Tenax® trap itself and all the by-products coming from the interaction of Tenax® with the derivatizing agent MTBSTFA and martian perchlorates

Potential sources of by-products generated by the Tenax® trap of SAM

International audienceSample Analysis at Mars (SAM) experiment onboard the Curiosity rover onboards a Gas Chromatography (GC) coupled to a Mass Spectrometer (MS).To adapt on the nature of a sample to the analytical devices used, a sample preparation and gas processing system implemented with (a) a pyrolysis system, (b) wet chemistry: MTBSTFA and TMAH (c) the hydrocarbon trap (silica beads, Tenax® TA and Carbosieve G) and the injection trap (Tenax® GR composed of Tenax® TA and 30% of graphite) are used to concentrate volatiles released from the sample prior to GC-MS analysis [1]. This study investigates all the potential sources of by-products (artifacts and backgrounds) generated by the Tenax® trap itself and all the by-products coming from the interaction of Tenax® with the derivatizing agent MTBSTFA and martian perchlorates