Standardisierung eines europaeischen Referenzmess-verfahrens zur Bestimmung von Pb, As, Cd und Ni in der Aussenluft Validierung und Bestimmung der Messunsicherheit

摘要

In the EU Framework Directive in total 13 air pollutants, among others the four elements Pb, As, Cd and Ni as well as their compounds are listed, which are of high priority for the European air quality. WG 14 of CEN/TC 264 "Air Quality" is presently drafting a European Standard which specifies a reference measurement method for the determination of the four metals in ambient air. For the validation of the measurement method (PM_(10) sampling, microwave digestion, analysis with graphite tube AAS and ICP-MS) WG 14 performs an extensive four step validation program. A first draft of the new European Standard was distributed for discussion in CEN/TC 264 by end of 2002. Besides limit values respectively target values also requirements for the maximum uncertainty at the limit value will be fixed in the daughter directives of the EU Framework Directive. For the determination of the measurement uncertainty the working group prepared a practical method which allows to calculate respectively to estimate the non random and random uncertainty parts by using the results of the laboratory and field validation tests. By extrapolation respectively interpolation on to the limit value the maximum expanded uncertainty at the limit value was calculated. The analysis of the validation program showed that for all four elements the required respectively discussed measurement uncertainties are met.