New Solvents for Space Missions: Utility for Life Detection Instruments and Notable Terrestrial Applications

Mark      A. Sephton; Richard      W. Court; Alexander      O. Baki; Mark      R. Sims; David      Cullen

Abstract

Instruments designed to test for signs of life on Mars must have operational simplicity and efficiency. One example is the Life Marker Chip being developed to fly on the forthcoming European Space Agency ExoMars mission. Target organic compounds include both polar and non polar molecules and, prior to our patented discovery, no solvent had been tested which effectively extracted both types of molecule in a fashion which was compatible with antibodybased detectors. We have compared the extraction efficiency of water-based solvents alongside conventional organic solvents to determine their suitability for extracting organic mixtures on space missions. Using a range of hydrocarbon standards and a Mars regolith simulant (JSC Mars-1) we have concluded that a water-methanol mix with 1.5 to 2.5 g/L of polysorbate 80 represents the most suitable solvent with extraction efficiencies that can achieve up to approximately 30% of that using conventional organic solvents (assuming 100% efficiency with 93:7 (vol:vol) dichloromethane:methanol mixtures). The surfactant solution will also provide solutions to terrestrial problems, one of which is explored in the patented work.

Keywords: Life detection, organic compounds, extraction, Life Marker Chip, ExoMars, surfactants, Polysorbate, sonication, gas chromatograph, Spin-offs, polyoxyethylene