Elemental association and fingerprinting of traffic related metals in road sediments

Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) can be used for the study of elemental associations in solid environmental matrices through direct ablation. The elemental associations of Ph and platinum group metals (PGMs) in road sediments were investigated by ablating the sediment surface followed by multielemental analysis by ICP-MS, When the UV laser was tuned into a small spot size together with a low energy, the true geochemical associations of the elements in road sediments could be obtained. Pb showed a high degree of association for the Fe/Mn and Ca/Mg/Sr phases, while PGMs were not associated with a particular geochemically defined fraction. Automobile catalysts are the main source of PGMs in road sediments, and association with Ce demonstrated that PGMs remain bound to autocatalyst particles in road sediments.