Intercomparison of trace element determinations in simulated and real air particulate samples

Results are presented of an intercomparison study involving twenty‐two investigators who collectively used six different analytical techniques. Synthetic dried solution and particulate deposits were prepared and, together with natural aerosol samples, were used for the study. Analytical techniques utilized by the participants were wavelength dispersive X‐ray spectometry, two different energy dispersive X‐ray techniques, atomic absorption spectrometry, emmision spectroscopy and neutron activation analysis. Results showed that energy dispersive X‐ray spectrometry, is a reliabnle technique for the multi‐element analysis of particulate matter collected on filter media. It reported the most elemental determinations per man‐hour invested and provided satisfactory accuracy for the quantitative determination of elements pottassium (Z = 19) and above, with somewhat larger errors for elements down to aluminium (Z = 13). The study demonstrated the need for a better understanding and practical application of particle size corrections for lighter elements. The non X‐ray techniques were neither well represented nor strongly supported by the study.