Analysis of traces of precious metals in soils

铂族金属（PGMs）被用作汽车催化转化器中的活性元素。主要是高度分散的铂（Pt）、钯（Pd）和铑（Rh）纳米颗粒（NP）在陶瓷载体材料上被应用，并且由于热和机械磨损而部分地随废气排放。每公里最多可排放约100纳克铂族化合物，主要是作为特殊物质。这些颗粒的重量的多达三分之一的尺寸小于5 nm。排放的颗粒物沉降在道路旁边，并以迄今未知的方式渗入路边土壤。拟议项目的目的是评估PGM在土壤中的迁移和积累。因此，将调查铂族元素在表土中的迁移深度，它们在哪种土壤类型和土层中积累，以及是否估计渗入地下水。从沿着不同交通密度的道路的渗透盆地中采集几个样品，测定不同土壤深度的Pd、Pt和Rh浓度。为此，将进一步开发用于预富集Pd痕量的流动注射分析系统，以分析痕量Pt和Rh。这种新方法将被优化和验证。该项目的结果将有助于PGM-NPs在一般环境中的风险评估。

Platinum group metals (PGMs) are used as active elements in car catalytic converters. Mainly highly dispersed platinum (Pt), palladium (Pd), and rhodium (Rh) nanoparticles (NPs) on ceramic support materials are applied and are partly emitted with the exhaust due to thermal and mechanic abrasion. Up to some 100 ng PGMs per kilometre can be emitted mainly as particular matter. Up to a third of the weight of these particles are smaller than 5 nm in size. The emitted particles settle beside roads and are infiltrated in so far unknown manner in roadside soils. The aim of the proposed project is to evaluate the transport and accumulation of PGM in soils. Thereby, it will be investigated in what depths the PGMs are transported in topsoil, in which soil types and layers they are accumulated and whether infiltration into ground water is to be estimated. Several samples from infiltration basins along roads with different traffic densities will be taken and Pd, Pt, and Rh concentrations will be determined in different soil depth. For this purpose a flow injection analysis system for pre-concentration of Pd traces will be further developed in order to analysis traces of Pt and Rh. This new method will be optimized and validated. The results of this projects will contribute to the risk assessment of PGM-NPs in the environment in general.