Proton microprobe single particle analysis
The analytical technique PIXE (Particle Induced X-ray Emission) has been extensively applied over the past two decades in the study of elemental composition of bulk aerosol samples. Since the absolute amount required for elemental analysis is in the sub-picogram range, even single aerosol particles can be characterised, provided the proton beam is focused to micrometer dimensions and scanned over the sample. A scanning proton microprobe (SPM) set-up offers this possibility. Since the projectile bremsstrahlung is much lower for 2-3 MeV protons than for 10-30 keV electrons, the continuous background X-ray radiation poses a less severe problem for the scanning proton microprobe than for the electron probe microanalysis (EPMA). As a consequence, the resulting limits of detection are orders of magnitude lower when using protons instead of electrons as projectiles. Furthermore, multi-elemental quantification of single aerosol particles in the micrometer range requires no previous knowledge or estimation of the matrix composition, since the energy loss of protons in micrometer size particles is small.
Bibliographic Reference: Paper presented: 2nd European Aerosol Conference, Zürich (CH), Oct. 1-5, 1990
Availability: Available from (1) as Paper EN 35701 ORA
Record Number: 199011621 / Last updated on: 1994-12-02
Original language: en
Available languages: en