nai

Project Progress

This year Dworkin finalized construction of the laboratory infrastructure in Goddard Space Flight Center (GSFC) building 2, room W109. Significant electrical upgrades were installed along with state-of-the-art analytical equipment for determining the organic composition of the material generated in the Cosmic Ice and Cosmic Dust Laboratories, amino acid contamination in Stardust aerogels, and meteoritic organics. Figure 1 (right) shows the major pieces of equipment installed in the laboratory:

• LC ToF-MS (Waters 2695XE HPLC attached to Waters LCT Premier): Material injected in the high precision liquid chromatograph (HPLC) flows through an ultraviolet (UV)-Visible diode array and UV fluorescence detectors to the time of flight mass spectrometer (ToF-MS) with an electrospray ion source. The MS has a mass accuracy of >3 ppm, a resolution of 10,000, and a range of 20 to 30,000 m/z.
• nLC ToF-MS (Waters nanoAcquity UPLC attached to Waters LCT Premier): The nanoflow ultraprecision liquid chromatograph (UPLC) runs at pressures double that of HPLC and flows from 50µL/min to 10nL/min through capillary columns to a miniaturized electrospray nozzle. We anticipate purchasing a laser-induced fluorescence detector to sit between the nanoAcquity and the LCT Premier.
• GCMS (Thermo Finnigan Trace DSQ): This gas chromatograph-mass spectrometer (GCMS) has as a mass range from 1-1050 amu, with a scan rate up to 10,000 amu/sec.

{{ 1 }}

Lab Personnel and Responsibilities

Name Institution Effort Specific Responsibility
Dr. Jason Dworkin GSFC 70% GCMS & LC ToF-MS & nLC ToF-MS
Dr. Daniel Glavin GSFC 10% meteorites & LC ToF-MS
Dr. Gözen Ertem Catholic U. America 50% nucleotides & quinoline LC ToF-MS
Ms. Mildred Martin Catholic U. America 50% GCMS
Mr. James Doty DeMatha High School 100-10% LC ToF-MS of bases and amino acids
Mr. Matthew Pasek U. Arizona occasional LC ToF-MS of phosphates

Research Projects

Amino Acid and Nucleobase Detection:
We have been working on the simultaneous analysis of nucleobases and amino acids via LC ToF-MS (Figure 2). The refinement of our separation techniques was lead by our high school intern, J. Doty. He worked over the summer (100% commitment) on amino acid and nucleobase separations by LC ToF-MS. He will be assisting our analyses of these compounds in carbonaceous meteorites in afternoons after school (10% commitment). We anticipate that he will be able to present his results as a poster at the next AbSciCon and Origin of Life Gordon Conference. His future in this laboratory depends on in what region of the country he attends college next year.

{{ 2 }}

Attomolar Sensitivities:
We have demonstrated the detection of the most abundant amino acids in an extract of 15 grains with a diameter of ~20µm of the carbonaceous Murchison meteorite. We are beginning to transfer our methodology to nLC ToF-MS. This will allow us to detect these compounds at ~10^-17 mole (~10 amol) sensitivities (Figure 2, lower right).

Stardust:
We are now (unfunded) members of the Stardust preliminary assessment team. We have been analyzing the amines in flight aerogels from 36 different cells on the collection grid as well as mud and water samples from the future landing site. We hope to use our ability to detect amino acids via nLC ToF-MS on particles from comet P/Wild 2 and aerogel returned by Stardust in January 2006.

Prebiotic Phosphates:
We are working with D. Lauratta’s graduate student, M. Pasek on the analysis and mechanism of the corrosion of the mineral schreibersite, Fe₃P, found in iron-nickel meteorites to form activated phosphates and organophosphates. Currently, we have been able to confirm via MS, the presence of pyrophosphate and related species. We are working towards understanding the inventory of organo-phosphates generated when schreibersite corrodes in the presence of small organic acids (e.g. acetic and glycolic).

NAI Research Synergy

Carbonaceous Meteorite Analysis:
We are in the process of extracting nucleobases from the Murchison meteorite for stable isotopic analysis in collaboration with M. Fogel of the CIW NAI team. This work is leveraged against our ROSES Exobiology effort (PI: D. Glavin). We will be extending this work to analyze amino acids in hot water extracts of the CM2 meteorites: Murchison, LEW90500, and ALH83100 and comparing these to the soils or ices representative of their recovery environment. This work will be in collaboration with Dr. O. Botta and Dr. P. Ehrenfreund and her student, Ms. Z. Martins.

Cosmic Ice Irradiation:
We have been working on the analysis of the products of the 0.8 MeV proton irradiation of acetonitrile (CH₃CN) 10 K ices via GCMS. Experiments were carried out with unlabeled, C1, C2, and double ¹³C labeled CH₃CN ice. The products are rich and numerous, so far we have confirmed the presence of HCN, succinonitrile, 3-aminocrotononitrile, and glutaronitrile. There are still numerous tentative detections, including several heterocycles and the nitriles of glycine, β-alanine, aspartic acid. Furthermore, we have hydrolyzed the unlabeled and fully labeled material and detected an abundance of the following amino acids by LC ToF-MS: glycine, β-alanine, alanine, α, β, and y-aminobutyric acids, aspartic acid, glutamic acid, ammonia, methylamine, ethylamine, isopropylamine, and n-propylamine. Current work is on water-rich ices with low concentrations of acetonitrile.

Interstellar Ice Photolysis:
We have analyzed amino acid samples and are working do develop conditions for the analysis of oxidized quinolines from ice photolysis experiments conducted by M. Bernstein of the NASA Ames NAI team.

Mars Science Laboratory (MSL) Mission:
We have contributed to the Sample Analysis at Mars (SAM) instrument suite by using our vacuum apparatus to characterize the freezing point and volatility under simulated martian conditions of the derivatization cocktail for the MSL GCMS.

Nucleotide Polymerization:

Dr. Gözen Ertem has been leading a research program on the analysis of the trimer and tetramers of nucleotides abiotically synthesized over montmorillonite clays in collaboration with R. Hazen of the CIW NAI team. The sequences of these oligonucleotides are non-random (as has been demonstrated with the dimers) and current work is in elucidating the sequences via MS.

Protosolar Nebular Dust:
Gaseous products from the Fisher-Tropsch-type syntheses of organic compounds over simulated proto-solar grains were analyzed by freezing products onto a 1,4 dioxane or acetonitrile for GCMS analysis. Tentative identifications of xylenes, propylbenzene, indane, and naphthalene have been made. Furthermore, the decrease in production of volatile organics in the FFT simulations over time has been monitored. The next step will be to characterize the non-volatile organic production.