Single-Particle Elemental Analysis of Vacuum Bag Dust Samples Collected From the International Space Station by SEM/EDX and sp-ICP-ToF-MS
Air quality on board the International Space Station (ISS) is a significant health concern for astronauts living on the station. Due to the absence of gravitational settling, airborne particles can remain suspended for a long time. Aerosol particles are generated from a variety of sources, including on-board equipment, electronics, and the astronauts themselves.
In this study, Jahn and co-workers examined the particulate matter collected with a handheld vacuum cleaner on board the ISS. The returned vacuum bag dust samples were analyzed with scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX) and single-particle multi-element inductively coupled plasma time-of-flight mass spectrometry (sp-ICP-TOFMS) using TOFWERK’s icpTOF.
SEM/EDX and sp-ICP-TOFMS provided different but complementary information regarding the composition of the dust particles. SEM/EDX analysis revealed many large particles that are most commonly clothing fibers or of biological origin, along with smaller numbers of carbonaceous particles possibly from polymer materials. sp-ICP-TOFMS analysis quantitatively determined the metal concentrations in particles approximately <10 µm in diameter and identified several distinct particle compositions. Some of these, such as stainless steel (Fe-Cr-Ni-Mn), antiperspirant (Al-Zr), silver (Ag), and titanium oxide (Ti) particles, are consistent with particle types identified through past aerosol and vacuum bag sampling and analyses. Other types, including Fe-Al and other types of Al and Zr particles, do not have a clear origin consistent with past work.
The icpTOF’s capability of multi-element acquisition at high time resolution was crucial for the characterization of different particles in this study.