PYROLYSIS-GAS CHROMATOGRAPHY MASS-SPECTROMETRY ANALYSES OF BIOLOGICALPARTICULATES COLLECTED DURING RECENT SPACE-SHUTTLE MISSIONS

Biological particulates collected on air filters during shuttle missio ns (STS-40 and STS-42) were identified using pyrolysis-gas chromatogra phy/mass spectrometry (Py-GC/MS). A method was developed for identifyi ng the atmospheric particles and their sources through the analysis of standard materials and the selection of ''marker'' compounds specific to the particle type. Pyrolysis spectra of biological standards were compared with those of airborne particles collected during two space s huttle missions; marker compounds present in the shuttle particle spec tra were matched with those of the standards to identify the source of particles. Particles of 0.5-1-mm diameter and weighing as little as 4 0 mu g could be identified using this technique. The Py-GC/MS method i dentified rat food and soilless plant-growth media as two sources of p articles collected from the shuttle atmosphere during flight.