Trace Platinum In Environmental Samples, Rhodium, Palladium Method For Determination Of The Research And Application

The research for the distributions of platinum group elements (PGEs) has revealed that the abrasion of catalytic converters causes an increase in emission of microscopic particles containing low solubility PGE. Pt, Pd and Rh existed in environments in trace concentrations (in the μg/kg rang in road dust) are distributed ubiquitously in the civilized areas. Therefore traffic seems to be the main source of PGEs contamination in urban area. In this thesis:Chapter one: the main physiological action and the regular analysis method of PGEs were introduced; research progress of PGEs in the environment sample was summaried. The history and development of inductively Coupled Plasma Mass Spectrometry (ICP-MS), the overview of ICP-MS major components and the interferences of ICP-MS were introduced.Chapter two: dust samples collected from the Beijing metropolitan area (China) were evaluated for the distribution of platinum group elements (PGEs) concentrations. Concentrations of Pt, Rh and Pd were found between 3.96-356.3 ng/g, 2.76-97.11 ng/g and 0.1-124.9 ng/g, respectively, while for the samples collected from suburban as the background were very low in the ranges of 0.1-0.9 ng/g for Pt, 0.5-1.4 ng/g for Pd and 0.8-2.2 ng/g for Rh, respectively. The distributions of PGEs from road dust reflect the pollution most adequately matching the local traffic conditions.Chapter three: inductively coupled plasma-mass spectrometry (ICP-MS) has been employed to determine palladium in plants. The spectroscopic interferences of Pd in ICP-MS determination were studied in detail. Spectral interferences towards Pd were corrected using mathematical correction equation based on abundance ratio. The potential of the method was evaluated by the determination of Standard Reference Materials (GBW07293).Chapter four: Platinum and lead have been determined by inductive coupled plasma-mass spectrometry (ICP-MS) in roadside dust and plants including Japanese pagoda, Annual grass, Holly and Pine tree samples collected from main roads in Beijing, during 2005. The higher Pt and Pb concentrations were found in samples along road with higher traffic volume. Among the plants examined, Pb contents in all selected plants well match with the result in dust. The level of Pt in Annual grass reflects most adequately the pollution of Pt in soil samples.Chapter five: with modified sequential extraction and separation analysis method, platinum group elements (PGEs) in roadside dust were divided into five fractions: water soluble, weak acid soluble, exchangeable, acid soluble and residual. All the five forms of PGEs and total PGEs were determined with ICP-MS, showing that this method has good precision, accurate, reliable and easy to operate. Concentrations of Pt, Rh and Pd were found between 3.96-356.3 ng/g, 2.76-97.11 ng/g and 0.1-124.9 ng/g, respectively It's shown that the sum of exchangeable and carbonate fractions presented the amounts of bio-available fraction in urban roadside dust in the order: Rh (29.14%)>Pd (23.87%)>Pt (7.92%).