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Progress in Laser Desorption Mass Spectrometry: Sample Analysis in the Lab and in Space

Progress in Laser Desorption Mass Spectrometry: Sample Analysis in the Lab and in Space. Theme IV: Analytical Approaches. Outline. Theme IV Objectives Methods and Instrumentation Example Analyses What’s Next. Theme IV Objectives.

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Progress in Laser Desorption Mass Spectrometry: Sample Analysis in the Lab and in Space

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  1. Progress in Laser Desorption Mass Spectrometry: Sample Analysis in the Lab and in Space Theme IV: Analytical Approaches W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  2. Outline • Theme IV Objectives • Methods and Instrumentation • Example Analyses • What’s Next W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  3. Theme IV Objectives • Develop new techniques to study the composition of complex planetary materials and analogs in situ • APL: Optimize LDMS-based methods for organic analysis that are complementary to GC/LC-MS, for both lab and spacecraft use • Relate the composition of comets and carbonaceous asteroids, via sample analysis, to the organics found in the ISM and those thought to be “pre-biotic.” • APL: Utilize capability of laser desorption to examine nonvolatile organics and other species with little or no sample preparation • How can we best study primitive organic-bearing bodies over variable spatial scales and chemical properties? • APL: Understand in particular the importance of analyses of complex (high m.w.), non-volatile phases, at fine spatial scales, to astrobiology W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  4. Impact Plasma Chemistry: Exobiology Organic Analysis and Method Development: NAI Methods and Instrumentation (APL) Higher TRL Lower TRL LD/LA TOF-MS LD/LA EPI-TOF-MS AP-MALDI Ion Trap MS REMPI, RIMS Laser Mass Spectrometry Instrument Development: PIDDP etc. In Situ Experiments ? W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  5. Methods and Instrumentation (APL) • In situ applications: • Strong mass, power, and complexity drivers  LDI • Use the simplest version of an experiment that addresses specific, high-priority measurement objectives • Laboratory applications: • Essentially the same “simple” TOF-MS with enhanced laser, imaging, ion optical, sample manipulation, and electronics systems, is a state-of-the-art instrument • High precision (few mm) XYZ manipulation of intact meteorite chips • LD of neutrals (from 10-100 mm spots) with selectable l • Selectable direct LD ions or fully resonant L2PI, into TOF-MS • Or, LD neutral gas into LC- or GC-MS (Themes 3 and 4) • Potential to obtain spatially-correlated elemental, isotopic, and organic composition from unprepared samples W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  6. Miniature LD-TOF-MS • Laser TOF-MS can be miniaturized without major performance degradation compared with laboratory instruments. • Gridless ion optics, low-noise detectors, and nonlinear “ideal” reflectrons permit high mass resolution and low detection limits. • Caveat: measures mass only (not structure)! The reflectron corrects TOF dispersion: ions with same m/z but different energies arrive at the detector simultaneously. A nonlinear reflectron focuses LA and LD ions (wide KE band) as well as organic product ions. W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  7. LAMS • LAMS = laser ablation mass spectrometer • Elemental/ isotopic analysis from stand-off position (airless body: ~ 1 cm – 1 m range) • Nd:YAG laser (l = 1064 nm, e > 1 GW cm-2) • Sample at electrical ground • No sample preparation or contact needed • Elemental LODs as low as ppmw bulk • Probe on fine scales (spot size 30-100 mm) can probe inclusions and detect grains • Complementary to Pyr-GC/MS W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  8. DS-TOF • 355 or 337 nm pulses < 108 W cm-2 (1 - 20 Hz) • Unprepared chips or powders, mounted on insertion probe and held at +5 kV • Monolithic nonlinear reflectron • Double-sided detector system • Organic and elemental analysis capabilities • Refractory organic LODs in low ppbw range • Probe on fine scales (spot size <100 mm) Bold = detected m/z; Non-bold = inferred m/z W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  9. laser focus point ion extraction lens detector assembly ion reflectron ~ 7.5 cm “Tower” TOF • Normal incidence desorption at 266 nm (or 355, 1064, or 337 nm) • Lateral postionization at 235 – 390 nm with doubled visible OPO • Unprepared samples mounted on XYZ bellows stage with 13 mm lateral and 25 mm vertical travel • Instrument and samples are vertical • Samples at electrical ground; flight tube biased to negative voltage • No pre- or post-acceleration grids • Sensor about 50% size of DS-TOF • Elemental and organic chemical imaging at resolutions ~ 50 mm • Under development! W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  10. Green River Shale 2 mm ALH 83100 50 mm laser diam. JSC Mars-1 1 mm Sample Handling and Preparation 1st order attitude: “We don’t need no stinking sample preparation!” Fine Powders Rocks Powder samples pressed into probe tip wells. Samples must be inspected for homogeneity given small laser spot size! Intact chips: analysis of heterogeneity and association of detected organics with their formation environment. Strongly limited by low concentrations and matrix effects! W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  11. Sample Handling and Preparation 2nd order attitude: “Uh, we’d better measure sample-specific effects.” • Crushing and sieving: distinguish any real compositional biases from instrument biases (absorptivity dependence) • Thin, flat samples (e.g. H2O slurry droplet) generally give best resolution and reproducibilty (E-field uniformity?) Ground and pipetted samples for “bulk” analysis. Surface types (bare metal, tapes, Si slides, and MCP chips) have various advantages for LDMS. Palisades Basalt bulk <150 mm W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  12. A compact sample acquisition system for fines uses grooves laser-etched in Si to entrap particles in a pre-defined series of size bins below ~500 mm. Sample Handling and Preparation “How do we get the fine-grained stuff where we want it?” laser diam. 50 mm W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  13. SRM 81a Sand RLE 200 K Na Fe Cr SRM 81a Sand RLE 385 Li Na Cr K Rb Fe Cs “Simple” Samples - Sand W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  14. “Simple” Samples – Lithium • Light (6, 7 amu) alkali metal – RIMS ~ 15% • High mobility, diffusivity • Elevated d7Li of CI chondrites may indicate aqueous parent body processing1 • Li gradients and high d7Li could be tracers of major crustal water movement in the source regions of basaltic shergottites2 • Lithium is highly heterogenous in martian meteorites and zoned in pyroxene grains (degassing indicator?)3,4 • McDonough et al. LPS 2006 • Reynolds et al. LPS 2006 • Lentz et al. GCA 2001 • Herd et al. GCA 2005 W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  15. 6Li/7Li in a Li2CO3 Standard RM 8545 LSVEC • Preliminary UV LDMS data indicate “large” signatures might be recovered from unprepared samples (without matrix) • We are characterizing the small instrument bias as a function of sample mounting scheme (probe and material details) • Average of 3 spots and 3 laser pulse energies: • 6Li/7Li = 0.085 compared with LSVEC standard value of 0.0832 • Insufficient statistics to determine precision, as yet • A work in progress … may need improved LDI characteristics W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  16. “Simple” Samples – Sand + Phenanthrene m/z 178 C14H10 Na X Rb Al W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  17. TiO SRM 81a Sand + Benzoic Acid RLE 180 Cr K Na Fe Ti C10H8 Al Ti2O2 Ni Ti3 C6 FeO TiO2 Li O Rb O C6H5C C6H5C Na ONa m/z “Simple” Samples – Sand + Benzoic Acid SRM 81a Sand + Benzoic Acid RLE 180 Trace hydrocarbon impurities in C6H5COOH as provided (99.5%) m/z W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  18. “Real” Samples – Green River Shale • Less evidence of extensive high mass aromatics, compared to C-chondrites, consistent with n-alkane dominated IOM from algal source (Greenwood et al. 2004) • Chemical noise is currently limiting resolution of high-mass parent compounds in powder sample; extensive fragmentation at higher laser power  lower P and e Green River Shale RLE 200 W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  19. HWMK979 1 mm “Real” Samples – Mars Analogs W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  20. What’s Next? • DS-TOF: Systematic analyses of standards, catalyzed smoke analogs, meteorites, and Mars analogs in collaboration with Theme 3 and 4 team. • Identify overlapping or related detections w/LDMS and GCMS • Feed LDMS detections back to analog definition/analysis • Complete “Tower TOF” instrument and begin calibration and demonstration runs with blanks and standards • Addition of negative ion detection mode (3 instruments) • Set up LD-EPI-MS on DS-TOF • Set up postionization mode on Tower TOF • Fine scale chemical imaging LDMS campaigns W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  21. Electron ionization TOF-MS • miniature EI source developed at Goddard for APL TOF-MS, permits EI and LD-EPI • Analyze more volatile high mass organics W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  22. (a) (b) • Post-ionization system for REMPI/RIMS (in development) • Two-laser (Nd:YAG/OPO) LD-LPI-TOF-MS system (235 – 700 nm) • Online switch between lateral LPI (a) and coaxial LPI or resonant LD (b) W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  23. Backup Slides W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  24. Current exobiology grant at APL: Organic Synthesis in Hypervelocity Impacts (OSHI) Developed specialized instrumentation using planetary major equipment (PME) grant Using laser mass spectrometry to probe formation of organics in post-impact plasma plumes (v > 25 km s-1) TOF-MS able to distinguish plume-formed from surface desorbed molecules via kinetic energy distributions and other factors. Extensive hydrocarbon formation occurs. Addresses entire spectrum from survival through complete molecular dissociation and recondensation in impacts. An exobiology digression W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  25. HISM Electronics Mass Spectrometer Laser Head Laser Power Supply Target Probe Main Laser Objective Example HISM spectrum from simulated impact involving high-purity carbon and NH4NO3 target materials in a physical mixture. e > 1.5 GW cm-2 The Hypervelocity Impact Simulation Microprobe (HISM) is used to generate laser mass spectra that simulate dust and micrometeorite impacts over a range of velocities, impactor diameters, and compositions. Qualitative correlations between impact velocity and molecular survivability (top), and laser irradiance and processes (bottom). An exobiology digression W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  26. BHVO-2 Basalt Standard W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  27. JSC Mars-1 Simulant W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  28. W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

  29. Sample Handling and Vacuum Stuff • High-resolution in situ chemical imaging • xyz sample manipulation system developed in collaboration with Honeybee Robotics • examine location of organics in meteorites • Other Honeybee Robotics Collaborations • MSL Sample Acquisition/Sample Handling and Processing (SA/SPaH) system • Precision subsampling systems • Vacuum Issues (Mars) • Method 1: (“brute force”) Acquire samples; use vacuum seals/valves; pump out. • Method 2: (“relax requirements”) Sample and/or ionize at ambient pressure; draw into dynamically-pumped MS; consider designs that tolerate higher operating pressure. • Evaluating current generation of Creare mini TMD pumps (to be flown in SAM on MSL) W. B. Brinckerhoff, C. M. Corrigan, A. L. Ganesan, T. J. Cornish, P. R. Mahaffy Goddard Center for Astrobiology Team Meeting, March 23-24, 2006

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