title: Study of plasma induced chemistry by DC discharges in CO2/N2/H2O mixtures above a water surface.
abstract: The chemistry induced by atmospheric pressure DC discharges above a water surface in CO(2)/N(2)/H(2)O mixtures was investigated. The gaseous mixtures studied represent a model prebiotic atmosphere of the Earth. The most remarkable changes in the chemical composition of the treated gas were the decomposition of CO(2) and the production of CO. The concentration of CO increased logarithmically with the increasing input energy density and an increasing initial concentration of CO(2) in the gas. The highest achieved concentration of CO was 4.0 +/- 0.6 vol. %. The production of CO was crucial for the synthesis of organic species, since reactions of CO with some reactive species generated in the plasma, e. g. H* or N* radicals, were probably the starting point in this synthesis. The presence of organic species (including the tentative identification of some amino acids) was demonstrated by the analysis of solid and liquid samples by high-performance liquid chromatography, infrared absorption spectroscopy and proton-transfer-reaction mass spectrometry. Formation of organic species in a completely inorganic CO(2)/N(2)/H(2)O atmosphere is a significant finding for the theory of the origins of life.
authors.affiliation: Ecole Centrale Paris, Laboratoire EM2C CNRS UPR 288, Grande Voie des Vignes, 92290, Châtenay-Malabry, France. mario.janda@em2c.ecp.fr
authors.forename: Mario
authors.initials: M
authors.lastname: Janda
authors.forename: Marcela
authors.initials: M
authors.lastname: Morvova
authors.forename: Zdenko
authors.initials: Z
authors.lastname: Machala
authors.forename: Imrich
authors.initials: I
authors.lastname: Morva
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D002248:Carbon Monoxide / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry*; D013058:Mass Spectrometry; D008956:Models, Chemical; D009584:Nitrogen / Q000737:chemistry*; D000069497:Origin of Life; D011312:Pressure; D014867:Water / Q000737:chemistry*
chemical_list: D005609:Free Radicals; D014867:Water; D002245:Carbon Dioxide; D002248:Carbon Monoxide; D009584:Nitrogen