Determination of the Noble Metals Gold, Palladium, Platinum and Rhodium by ETAAS, ICP-AES and ICP-MS - Evaluation of the Reliability and the Measurement Uncertainty

The concentrations of noble metals in the environment are still very low (low ng/g and sub ng/g range), although they are emitted to an increasing extent as components of catalytic exhaust emission converters into the environment. The determination of these elements can be error prone even when the determinations are carried out by use of highly sensitive methods in combination with high performance sample preparation techniques. Accurate data with smallest possible measurement uncertainties are a prerequisite for the interpretation of the distribution of noble metals in the environment and their possible toxicological effects. Difficulties related to the determination of the noble metals could be the incomplete recovery after sample preparation, sample digestion and interferences arising in subsequent instrumental determination methods. For this reason different sample decomposition methods in combination with powerful instrumental techniques are checked for suitability for the determination of the noble metals in environment-relevant samples.