PLATINUM ANALYSIS AND SPECIATION IN URBAN GULLYPOTS

Concentrations of platinum in the <63-mu m fraction of some Swedish ro ad sediments have been shown to increase from 3.0 ng g(-1) in 1984 to 8.9 ng g(-1) in 1991. Road sediments contained 39-88% more Pt than gul lypot sediments and sequential extraction showed a distinct shift from predominantly inorganic Pt on the road surface to wholly organic Pt i n the gullypot. Dissolved Pt concentrations in disturbed gullypot liqu or were within the range 1.7 ng l(-1) to 3.8 ng l(-1) and are explaine d by bacterial action in the gullypot sediment mobilizing organically bound dissolved Pt forms.