The microanalysis of individual aerosol particles using the nuclear microscope

Abstract

More than 150 cascade impactor samples were collected at two locations in Singapore during a two-week period. The samples were collected on a specially developed ultra-thin backing foil which allows the full range of nuclear analytical techniques to be carried out. Off-axis STIM maps were used to determine particle size distributions and to identify areas of interest, while the concentrations of both matrix elements (C, O, Si, Al, etc.) and trace elements of individual particles were determined using RBS and PIXE spectra. In such a way more than 300 individual airborne particles were analysed for 29 elements. Principal component analysis and cluster analysis were utilised to identify nine different groups of particles. The results are statistically evaluated and discussed. © 1995.