Platinum, palladium and rhodium content in road dust, tunnel dust and common grass in Bia ystok area (Poland): a pilot study

Automobile traffic is the main source of Pt, Pd and Rh, i.e. platinum-group elements (PGEs), contamination in urban areas and there is growing concern about the effects of these emerging contaminants for people living in these areas. PGE contents were determined in samples of road dust, tunnel dust and common grass as well as pine needles collected from the residential areas of Bia ystok, northeast Poland. High resolution (HR) and quadrupole inductively coupled plasma mass spectrometry (ICP-MS) were compared for their adequacy in the environmental analysis of Pt and Rh. Palladium was determined by total X-ray fluorescence (TXRF) and HR-ICP-MS after matrix separation by reductive co-precipitation with Hg. The highest PGEs concentration was found in road dust samples. Platinum content in road dust varied from 34.2 to 110.9 ng g−1, while that of Rh from 6.0 to 19.7 ng g−1. The mean concentration of Pd in this matrix was 32.8 ng g−1 as determined by TXRF analysis and 42.2 ng g−1 by HR-ICP-MS. The highest Pt concentration in tunnel dust was found in the size fraction below 75 μm (22.3–23.3 ng g−1). The mean concentrations of PGEs in grass were 8.63 ng g−1 for Pt, 0.65 ng g−1 for Rh and 3.2 ng g−1 for Pd. The concentration of PGEs in pine needles was below the limits of detection of the methods used.