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JOURNAL OF GEOPHYSICAL RESEARCH,
VOL. 112,
G04S11,
10 PP., 2007
doi:10.1029/2006JG000329
Organic amine biomarker detection in the Yungay region of the Atacama Desert with the Urey instrument
Department of Chemistry, University of California, Berkeley, California, USA
Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California, USA
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
Astrobiology Laboratory, Leiden Institute of Chemistry, Leiden, Netherlands
Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California, USA
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
Department of Chemistry, University of California, Berkeley, California, USA
The Urey in situ organic compound analysis instrument, consisting of a subcritical water extractor (SCWE) and a portable microchip capillary electrophoresis instrument called the Mars Organic Analyzer (MOA), was field tested in the Atacama Desert, Chile, in June 2005. Soil samples from the most arid Yungay region were collected, biomarkers were extracted by the SCWE, and organic amine composition and amino acid chirality analysis was performed by the MOA. Samples collected from the top 1 cm of duracrust soil but shielded from the ambient environment by rocks were compared to the exposed duracrust. The shielded duracrust yielded amines and amino acids ranging from 50 to 100 ppb, while amino acid signals from the exposed duracrust were below blank levels. Samples from buried gypsum deposits located directly above a water flow channel contained amino acids ranging from 13 to 90 ppb. Chiral analysis revealed D/L ratios of 0.39 ± 0.08 and 0.34 ± 0.07 for alanine/serine and 0.78 ± 0.06 for aspartic acid, indicating significant racemization of biologically produced amino acids. On the basis of the D/L ratios, we estimate sample ages ranging from 103 to 105 years. These results demonstrate the successful field testing of the Urey instrument, as well as the detection of biomarkers from past terrestrial life in one of the most arid and Mars-like regions on Earth.
Received 28 September 2006; accepted 6 April 2007; published 22 August 2007.
Citation: (2007), Organic amine biomarker detection in the Yungay region of the Atacama Desert with the Urey instrument, J. Geophys. Res., 112, G04S11, doi:10.1029/2006JG000329.
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