Feasibility study prior to the certification of trace elements in urban and industrial wastewater reference materials

Reliable results for the determination of trace elements in urban and indus trial wastewaters are of paramount importance for both checking the perform ance of sewage treatment and for detecting possible urban or industrial con tamination sources. The quality control of measurements should in principle rely on external tools such as certified reference materials (CRM), which should represent, as closely as possible, the matrix of samples currently a nalysed, e.g., in the frame of environmental monitoring. To date, however, no CRM representatives of wastewater composition are available, which limit s the possibility for control laboratories to check their QC externally. To fill this gap, the European Commission's Standards, Measurements and Testi ng Programme (formerly BCR) has started a European collaborative project of which the aim is to test the feasibility of preparation of wastewater refe rence materials and the analytical state-of-the-art to enable the certifica tion of trace elements in such matrices. This paper presents the results of the first phase of this project, namely the feasibility study and the resu lts of an interlaboratory trial.