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Novel solvent systems for in situ extraterrestrial sample analysis

By Richard W. Court, Alexander O. Baki, Mark R. Sims, David C. Cullen and Mark A. Sephton

Abstract

The life marker chip (LMC) is being designed to test for the chemical signature of life in the soil and rocks of Mars. It will use an antibody array as part of its detection and characterisation system and aims to detect both polar and non-polar molecules at the sub-ppm to tens of ppb level. It is necessary to use a solvent to transfer organic compounds from the Martian samples to the LMC itself, but organic solvents such as dichloromethane or hexane, commonly used to dissolve non-polar molecules, are incompatible with the LMC antibodies. Hence, an aqueous-based solvent capable of dissolving the biomarkers that might exist in the soil or rocks of Mars is required. Solvent extractions of a Martian soil analogue, JSC Mars-1, spiked with a range of standards show that a 20:80 (vol:vol) mixture of methanol and water is incapable of extracting compounds insoluble in water. However, addition of 1.5 mg ml−1 of the surfactant polysorbate 80 produces extraction efficiencies of the aliphatic standards, hexadecane and phytane, equal to 25–30% of those produced by the common organic solvent mixture 93:7 (vol:vol) dichloromethane:methanol. Extraction of squalene and stigmasterol using the polysorbate solution is less efficient but still successful, at 5–10% of the efficiency of 93:7 dichloromethane:methanol. Such aliphatic compounds with occasional functional groups represent the compound classes to which most fossil organic biomarkers belong. The polysorbate solution did not extract the aromatic compounds pyrene and anthracene with great efficiency. A solvent of 20:80 methanol:water with 1.5 mg ml−1 polysorbate 80 is therefore capable of selectively extracting aliphatic biomarkers from Martian samples and transferring them to the antibody sites on the life marker chip

Topics: Mars, ExoMars, Extraterrestrial life, Astrobiology
Publisher: Elsevier
Year: 2010
DOI identifier: 10.1016/j.pss.2010.07.004
OAI identifier: oai:dspace.lib.cranfield.ac.uk:1826/4765
Provided by: Cranfield CERES
Journal:

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Citations

  1. (2004). Detection of methane in the atmosphere of Mars.
  2. (2008). Extraterrestrial nucleobases in the Murchison meteorite. doi
  3. (2009). H2O at the Phoenix landing site. doi
  4. (2004). In situ evidence for an ancient aqueous environment at Meridiani Planum, doi
  5. (1998). JSC Mars-1: a Martian soil simulant, doi
  6. (2002). Organic compounds in carbonaceous meteorites. doi
  7. (2010). Organic geochemistry and the exploration of Mars.
  8. (1976). Search for organic compounds on the surface of Mars, doi
  9. (2007). Searching for life on Mars: Selection of molecular targets for ESA's Aurora ExoMars mission. doi
  10. (1996). The delivery of organic matter from asteroids and comets to the early surface of Mars. doi
  11. (2005). The specific molecular identification of life experiment (SMILE). doi
  12. (2008). The Urey instrument: An advanced in situ organic and oxidant detector for Mars exploration. doi

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