Tech Briefs

Mass Spectrometry of Spacecraft Contamination Using the Direct Analysis in Real-Time Ion Source

NASA’s Jet Propulsion Laboratory, Pasadena, California

Mass spectrometry is presented as a powerful tool for the analysis of spacecraft contamination when coupled to the Direct Analysis in Real Time (DART) ionization source. DART technology is based on soft ionization and desorption using metastable helium (MSHe). This provides efficient sample introduction for the rapid analysis of polymers and bio-organic compounds. It is particularly useful to the evaluation of polymers that may outgas in the space environment. In addition, this approach provides sensitive analysis of bio-marker and organic compounds that may interfere with organic and life detection instruments on future spacecraft missions.

The approach demonstrated here allows the rapid screening of polymers for excessive levels of vacuum labile compounds. For contamination modeling, the information is complementary to the standard methods by providing the molecular weight and the identity of components. Residual monomers, oligomers, and additives in polymeric materials are readily assessed. The DART ion source uses MSHe as a reagent gas that mediates atmospheric sample introduction and provides soft ionization suitable for mass spectroscopy. When combined with a high-mass-accuracy, time-of-flight mass spectrometer, the “DARTAccuTOF” system provides highly sensitive (picogram level), rapid, non-contact analysis of materials at ambient pressure.

This work was done by Mark S. Anderson of Caltech for NASA’s Jet Propulsion Laboratory. NPO-48163