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W. Nischkauer, M.-A. Néouze, C. Puls, A. Limbeck:
"Platinum Group Elements in Urban Roadside Dust: Analyte Enrichment and Matrix Removal via Dispersed Particle Extraction";
Vortrag: 10. Symposium Massenspektrometrische Verfahren Elementspurenanalyse, Tulln, Austria; 10.09.2012 - 12.09.2012; in: "ABSTRACTBAND", (2012), S. 29.

Catalytic converters are widely applied in modern vehicles in order to reduce the emission of harmful combustion by-products. Due to thermal and mechanical wear, the surface of the catalytic converter is constantly subjected to abrasion causing the emission of Platinum Group Elements (PGEs). Under environmental conditions (e.g., in the presence of humic acids), the water-solubility of these traffic-induced PGEs is enhanced which in turn increases their bio-availability. Therefore, the determination of the water-soluble fraction of PGEs is of major interest in order to evaluate the mobility of these elements in the environment. However, due to the low concentration level of PGEs in roadside dust (50 - 100 ng g-1), their still very low solubility in water and the presence of high amounts of potentially interfering matrix constituents (e.g., Cu, Zn, Sr... in the higher µg g-1 range), the quantification of PGEs in aqueous extracts via ICP-MS is a challenging task. In this contribution, the novel concept of Dispersed Particle Extraction is applied to improve the determination of PGEs in aqueous extracts of roadside dust: a nano-particulate anion-exchanging material is dispersed directly in the liquid sample. The analytes (in the form of anionic PGE-chlorocomplexes) are retained on the surface of the nano-particles whereas cationic or neutral species do not interact with the particles. By physically separating the nano-particles from the supernatant solution, the concentration of the analytes can be increased while potentially interfering matrix constituents are strongly diluted. On account of these two effects, the ratio analyte : interferences is improved by roughly three orders of magnitude which allows a practically interference-free determination of PGEs in aqueous extracts of roadside dust.

Dispersed particle extraction, functionalized nanoparticles, platinum group elements