Platinum concentrations in Danish air samples determined by instrumental neutron activation analysis

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