Determination of Platinum at Trace Levels in Environmental and Biological Materials

Abstract

The treatment of exhaust gases from motor vehicles equipped with autocatalytic converters has resulted in the removal of about 90% of carbon monoxide, unburned hydrocarbons, and nitrogen oxides from the exhaust. However, contamination of the environment occurs in the form of airborne particulate material (or dust) from the abrasion and deterioration of the catalysts. The dust contains precious metals, mainly platinum together with palladium and rhodium. It is deposited along the roadways, on soil and vegetation, and in bodies of water. Sensitive analytical methods are required for determinations of very low levels of platinum in environmental samples in order to ascertain the extent and the seriousness of this relatively new source of pollution. The difficulties in obtaining accurate results in analyses even for total platinum concentrations are formidable. This review is a summary of recent research on the determinations of platinum and other precious metals in dust, vegetation, soil, water, and biological materials. Some results of studies of speciation of platinum in environmental materials are presented also.

Complexation of platinum, palladium and rhodium with inorganic ligands in the environment

“…Indeed, there is accumulating evidence that PGEs are released from autocatalysts and that concentrations of these metals have increased significantly over the last two decades in various environmental compartments, including in the air as airborne particulate matter, in roadside dusts, soils, river and oceanic sediments and in vegetation. According to Barefoot (1999), the concentration of Pt in soils near German roads is now c. 70 times higher than background values. Increases in PGE concentrations have also been measured in UK towns over the period 1982Hutchinson et al 2000).…”

The Unfavorable Influence of Transport on the Environment

“…So-called three-way controlled catalytic convertors are currently used the most; they use a mixture of platinum metals -platinum (Pt), rhodium (Rh) and palladium (Pd) are contained as catalytically effective substances. Considering the fact that catalytic convertors are exposed to high temperature differences, the platinum metals are released into the environment (Farago et al, 1996, Gómez et al, 2001) which may have a negative influence on human health (Barefoot, 1997).…”

The application of inductively coupled plasma mass spectrometry in clinical pharmacological oncology research

“…Glassware should be avoided as it may contain considerable amounts of Pt. Moreover, sample pretreatment needs to be performed in a dedicated area to prevent environmental Pt or Ru originating from, for example, pollution by car exhaust catalysts (Barefoot, 1997), from interfering with the analysis. Besides the prevention of contamination it is relevant that blanks do not contain detectable levels of analyte.…”