ABSTRACT
Characterization of airborne particulate matter consists not only of the determination of average elemental composition but also includes identification and quantitative determination of the compounds present and a characterization of the particles in terms of size, shape, and morphology. The only method of breaking down a complex mixture is by spatial separation of the conglomerate and analysis of the individual particles. In electron microscopy, the particles can be viewed directly, or the contrast can be enhanced by shadowing with metal oxides or metals. Electron microscopy performed with a transmission electron microscopy or scanning transmission electron microscopy is the most important technique for the characterization of airborne particles in the submicron range. For investigation of an airborne particle with ion probe microanalysis, the particle must lie on a substrate that has a low secondary ion yield in the region of interest and a low trace element level.
