Chemical Analysis of Individual Alkali-Containing Aerosol Particles: Design and Performance of a Surface Ionization Particle Beam Mass Spectrometer

摘要: A mobile particle beam mass spectrometer has been developed to measure the alkali metal content in individual submicron aerosol particles. The instrument employs an aerodynamic inlet system for efficient sampling of particles into vacuum, and detection is based on decomposition surface ionization a hot platinum surface. boxlike design ionizing shown limit problems associated with bounce effects incomplete ionization, decomposition/ionization process not sensitive detailed properties. High transmission efficiencies quantitative determination diameters down 14 nm are demonstrated. Experiments doped salt show that size range may be extended few nanometers after further improvements system. resolution can achieved sizes tens nanometers, as illustrated by multiply charged passing through DMA. robustness makes it suitable field measurement applications, technique demonstrated at 12 MW biomass combustion facility. performance refinements discussed, potential applications laboratory studies outlined.