Laser Desorption Mass Spectrometry

Mass Spectrometry Imaging

Machine Learning and Data Analysis

General Background

I am currently working as a NASA Postdoctoral Program (NPP) fellow at the Goddard Space Flight Center in Greenbelt, MD. I am using laser desorption - mass spectrometry (LDMS), similar to the LDMS system that is scheduled to fly onboard the Dragonfly mission to Titan, in order to build machine learning models to characterize organic compounds and organic compound classes.

I earned a PhD from the Department of Earth and Environmental Sciences at the University of Illinois Chicago in 2022. My PhD research focused on Organic Geochemistry and Mass Spectrometry Imaging of geologic samples, with a specific interest in using multiple analytical measurement techniques and statistical analysis to map the location of organic molecular biosignatures (aka biomarkers) in geologic samples.

NASA Postdoctoral Program Fellowship

I am a science associate for the Dragonfly mission. Dragonfly is a mission going to Titan, the moon of Saturn. On Titan, the Dragonfly rotorcraft will sample organic material, analyze that material using the Dragonfly Mass Spectrometer (DraMS), then fly to a new location for more sampling and analysis. Again, Dragonfly is actually going to fly around Titan.

Wow.

For data analysis, DraMS will have two modes of operation:

1) Laser Desorption Mass Spectrometry (LDMS)

2) Gas Chromatography Mass Spectrometry (GCMS)

My work is to help understand what types of organic compounds can be analyzed using the LDMS mode of DraMS. To help with this data analysis, I am building machine learning models capable of characterizing organic compounds that might be present on Titan. The work is extremely exciting, and as you can tell from my cheesy grin in the photo, very exciting.

Please check out the Dragonfly team website for more information: https://dragonfly.jhuapl.edu/

MS Imaging

For my PhD, I prepared uncovered thick sections for Mass Spectrometry imaging. MS imaging was performed using femtosecond – laser desorption postionization – mass spectrometry (fs-LDPI-MS, a prototype instrument in the laboratory of Prof. Luke Hanley at UIC) as well as Time of Flight – Secondary Ion Mass Spectrometry (ToF-SIMS) at the Center for Nanophase Material Sciences within the Oak Ridge National Laboratory.

Using MS imaging datasets, we were able to determine the spatial distribution of organic molecular biosignatures (signs of life held within the rock). Similar techniques could (Should? Yes.) be performed on samples returned from Mars in order to determine if any observed organics originate from Mars, or if they may have been introduced later in the rocks history (e.g. meteoritic or contamination).

We were able to collect so much MS imaging data (over 2 TB!) that we were able to build machine learning (ML) models capable of recognizing biomarkers in these geologic samples (publication coming soon).

Learn More

Other Relevant Experience

I am skilled at petrography, statistical data analysis, using imaging software (the Adobe suite), programming (R and Python), and using these tools to combine and interpret data sets collected on multiple instruments. I am skilled at traditional organic geochemistry including sample preparation, fraction separation, analysis via gas chromatography – mass spectrometry (GC-MS), and data interpretation. I am trained at Raman spectroscopy and scanning electron microscopy (SEM).

This selected image is from my first research project of analyzing the composition of sand collected from Lake Vida, Antarctica. While I now primarily use mass spectrometry techniques, petrographic microscopes will always have a place in my heart. Please pay attention in geology courses.

Teaching Experience

I have taught a diverse set of geoscience classes. I have been a teaching assistant for introductory Environmental Science, Earth Systems and Sedimentary Geology courses, and for advanced courses in Hydrology and Data Analysis for Environmental Scientists in R. I led and helped developed content for a field course for Environmental Science majors. I also helped to create a field trip to the dunes of Southern Lake Michigan that explores the connection between dune formation, coastal ecology, geomorphology and current and paleo lake levels.

Community Involvement and Outreach

I believe community involvement, science communication, and public outreach can benefit scientific and non-scientific communities. I helped lead and complete diverse astrobiology community initiatives as co-lead of the Network for Life Detection (NfoLD) early career council (ECC). I initiated, led, and helped develop content a series of graduate-student developed classroom visits to schools in the Chicago region to teach geology and astrobiology lessons.

Scientific Ethos

I work to discover truth, not to be correct.

(The picture of my dog is for fun and is not related to the statement above.)

Publications

Jason M. Gross, Seyedeh Reyhaneh Shavandi, Teodora Zagorac, M. J. Pasterski, Luke Hanley; Picosecond versus femtosecond-laser ablation of silicon in atmosphere, J. Laser Appl. 1 November 2023 35 (4): 042053. DOI: 10.2351/7.0001206

Pasterski, M. J., Lorenz, M., Ievlev, A. V., Wickramasinghe, R. C., Hanley, L., Kenig, F. The Determination of the Spatial Distribution of Indigenous Lipid Biomarkers in an Immature Jurassic Sediment using Time-of-Flight Secondary Ion Mass Spectrometry, Astrobiology, 2023 23 (9)., 936-950. DOI: 10.1089/ast.2022.0145

Wickramasinghe, R. C. (co-lead author), Pasterski, M. J. (co-lead author), Kenig, F., Ievlev, A. V., Lorenz, M., Gross, J. M., Hanley, L. Femtosecond Laser Desorption Postionization MS vs ToF-SIMS Imaging for Uncovering Biomarkers Buried in Geological Samples, Analytical Chemistry 2021 93 (48), 15949-15957 DOI: 10.1021/acs.analchem.1c03275

Pasterski, M.J.; Bellagamba, A.; Chancellor, S.; Cunje, A.; Dodd, E.; Gefeke, K.; Hsieh, S.; Schassburger, A.; Smith, A.; Tucker, W.; et al. Aquatic landscape change, expirations, and introductions in the Chicago Region, Urban Ecosystems 2020 (23), 1277–1288

Pasterski, M. J., Lorenz, M., Ievlev, A. V., Wickramasinghe, R. C., Hanley, L., Kenig, F. The Application of Supervised and Unsupervised Machine Learning (ML) Towards the Interpretation of Spectra Produced via ToF-SIMS Imaging. in

Related Press:

https://eos.org/articles/chicago-wetlands-shrank-by-40-during-the-20th-century

https://greatlakesecho.org/2020/11/17/study-shows-aquatic-landscape-changes-human-impact-on-chicago-area-plants-animal-life/

Select Conference Presentations

Pasterski, M.J., Lorenz, M., Ievlev, A. V., Wickramasinghe, R. C., Hanley, L., and Kenig, F. (2022). Using Machine Learning to Aid in the Interpretation of MS Imaging Datasets: Multimodal Analysis of a Geologic Sample Containing Organic Molecular Biosignatures. In American Geophysical Union, p. P25A-73.

Pasterski, M.J., Lorenz, M., Ievlev, A. V., Wickramasinghe, R. C., Hanley, L., and Kenig, F. (2022). Indigenous Organic Molecular Biosignatures are Detectable via ToF-SIMS of a Kerogen-rich Jurassic Clay. In Astrobiology Science Conference, p. 125–01.

Pasterski, M.J., Lau, G., The Network for Life Detection (NfoLD) Early Career Council (ECC). (2022). In Astrobiology Science Conference, p. 116–01.

Pasterski, M.J., Lorenz, M., Ievlev, A. V., Wickramasinghe, R. C., Hanley, L., and Kenig, F. (2021) The Detection of Indigenous Sterane Biomarkers in an Immature Jurassic Sediment using ToF-SIMS Mass Spectrometry Imaging, in American Geophysical Union, p. P15D-2134.

Pasterski, M.J., Wickramasinghe, R., Hanley, L., Lorenz, M., Ievlev, A. V., and Kenig, F. (2020). Multimodal Mass Spectrometry Imaging (MSI) of Archean and Jurassic Geologic Samples, in American Geophysical Union, p. P030-06.

Pasterski, M.J., Wickramasinghe, R., Hanley, L., and Kenig, F. (2019). Mass Spectral Imaging of a Carbon and Sulfur-rich Mudstone: Femtosecond – Laser Desorption Laser Postionization Mass Spectrometry of the Oxford Clay, in Astrobiology Science Conference, v. 89, p. 4781–4785.

Pasterski, M.J., Barry, G.E., Hanley, L., and Kenig, F. (2017). Micron Scale Mapping and Depth Profiling of Organic Compounds in Geologic Material: Femtosecond - Laser Desorption Laser Postionization - Mass Spectrometry (fs-LDPI-MS), in American Geophysical Union, p. P43G-08.

Contact

Feel free to contact me for comments, questions, or future collaborations.

Email
joseph.pasterski@nasa.gov

josephpasterski@gmail.com

Phone
(618) 698-4627