title: Detection of trace organics in Mars analog samples containing perchlorate by laser desorption/ionization mass spectrometry.
abstract: Evidence from recent Mars missions indicates the presence of perchlorate salts up to 1 wt % level in the near-surface materials. Mixed perchlorates and other oxychlorine species may complicate the detection of organic molecules in bulk martian samples when using pyrolysis techniques. To address this analytical challenge, we report here results of laboratory measurements with laser desorption mass spectrometry, including analyses performed on both commercial and Mars Organic Molecule Analyzer (MOMA) breadboard instruments. We demonstrate that the detection of nonvolatile organics in selected spiked mineral-matrix materials by laser desorption/ionization (LDI) mass spectrometry is not inhibited by the presence of up to 1 wt % perchlorate salt. The organics in the sample are not significantly degraded or combusted in the LDI process, and the parent molecular ion is retained in the mass spectrum. The LDI technique provides distinct potential benefits for the detection of organics in situ on the martian surface and has the potential to aid in the search for signs of life on Mars.
authors.affiliation: 1 Center for Space Science and Technology, University of Maryland , Baltimore County, Baltimore, Maryland, USA.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Danell
authors.forename: William B
authors.initials: WB
authors.lastname: Brinckerhoff
authors.forename: Veronica T
authors.initials: VT
authors.lastname: Pinnick
authors.forename: Friso
authors.initials: F
authors.lastname: van Amerom
authors.forename: Ricardo D
authors.initials: RD
authors.lastname: Arevalo
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Getty
authors.forename: Paul R
authors.initials: PR
authors.lastname: Mahaffy
authors.forename: Harald
authors.initials: H
authors.lastname: Steininger
authors.forename: Fred
authors.initials: F
authors.lastname: Goesmann
mesh_terms: D002118:Calcium / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry; D018559:Exobiology; D007834:Lasers; D008274:Magnesium / Q000737:chemistry; D018535:Mars; D013058:Mass Spectrometry; D009930:Organic Chemicals / Q000737:chemistry; D010472:Perchlorates / Q000032:analysis* / Q000737:chemistry; D011083:Polycyclic Compounds / Q000737:chemistry; D012235:Rhodamines / Q000737:chemistry; D017640:Silicates; D013026:Space Flight / Q000295:instrumentation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002254:Carbonates; D009930:Organic Chemicals; D010472:Perchlorates; D011083:Polycyclic Compounds; D012235:Rhodamines; D017640:Silicates; C060346:basalt; C026188:rhodamine 6G; C005479:magnesium carbonate; C012256:coronene; D008274:Magnesium; D002118:Calcium; C494474:perchlorate