Abstract

Platinum, gold and calcium concentrations of 20 samples of airborne dust collected at two sampling sites between 1995 and 1997 in the city of Copenhagen, which suffers from heavy traffic, were determined by instrumental neutron activation analysis (INAA). INAA of platinum using the ¹⁹⁹Au daughter of ¹⁹⁹Pt was performed. Two interferences on the INAA of platinum were removed by calculations. The spectral interference on ¹⁹⁹Au from the ⁴⁷Sc daughter of ⁴⁷Ca was removed by separating the 157–161 keV doublet peak into its components by calculating the counts due to ⁴⁷Sc from the counts of the parent ⁴⁷Ca. The contribution of ¹⁹⁷Au to ¹⁹⁹Au by two neutron absorption was corrected for using the ratio ¹⁹⁸Au/¹⁹⁹Au in a pure Au standard. From the INAA results, high platinum concentrations are present in air in the range 0.25–2.74 ng m⁻³ and gold concentrations in the range 0.10–1.96 ng m⁻³.