title: Gas analysis of the atmosphere within sealed glass ampoules using a quadrupole mass spectrometer.
mesh_terms: D001688:Biological Products; D005612:Freeze Drying; D005740:Gases / Q000032:analysis*; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D009584:Nitrogen / Q000032:analysis; D011309:Preservation, Biological; D012015:Reference Standards
chemical_list: D001688:Biological Products; D005740:Gases; D009584:Nitrogen