Different metallic substrates such as beryllium, aluminium, silicon and silver were rigorously tested in all aspects of energy-dispersive electron probe x-ray microanalysis of single particles, including the semi-quantitative determination of low-Z elements. The effect of the collecting substrate on the capability to locate, to analyse and to classify particles automatically was extensively studied by the analysis of particulate standards and aerosol particles collected at the Belgian coast. Beam-sensitive particles such as ammonium sulphate and ammonium nitrate were analysed using a liquid nitrogen-cooled sample stage. The dependence of the beam-damage effect on the type of collecting substrate was also studied using standard aerosol particles. The results obtained show that the use of beryllium as a collecting surface offers some advantages: (i) detailed spectral information can be obtained in a broad elemental range (6 ≤ Z ≤ 92) without overlap with x-ray lines of the substrate and (ii) complete chemical classification can be done with one set of analyses.
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