Determination of trace elements including platinum in tree bark by ICP mass spectrometry

The increasing emission of Pt-group metals from automobile catalytic conver ters requires the development of highly sensitive procedures for ultratrace analysis of environmental and biological systems. Tree bark, located close to motorway or industrial areas, was utilised as a substrate for collectio n of airborne particulate matter and samples after digestion (microwave ass isted dissolution with HNO3 and HCl) were analysed by ICP mass spectrometry . The study targeted Pt and other metallic contaminants and involved analys is of some 57 tree bark samples using both quadrupole and double-focusing s ector field ICP mass spectrometers. Detection limits for platinum determina tion in tree bark were 0.03 ng/g (DF-ICP-MS) and 0.2 ng/g (ICP-QMS). The pl atinum content of the bark samples ranged from 0.07-5.4 ng/g.