A PROGRAM TO IMPROVE THE QUALITY OF TRACE-ELEMENT DETERMINATIONS IN ESTUARINE WATER

Analyses of estuarine water are routinely performed by a number of organizations to monitor the level of contamination by toxic compounds, e.g. trace metals. In order to improve and control the quality of such determinations, the Measurements and Testing Programme (formerly BCR) of the Commission of the European Communities has organized two interlaboratory studies which allowed the detection and removal of most of the pitfalls observed in the determination of a series of eight elements, namely Cd, Co, Cu, Fe, Pb, Mn, Ni, and Zn. Moreover, this work enabled the feasibility of preparation of candidate estuarine water certified reference materials (CRMs) to be tested. The materials used in this exercise were collected in Portugal (Tagus estuary). They were carefully prepared and their homogeneity and stability were verified. This paper presents the main results of the interlaboratory studies carried out prior to the certification campaign of a reference material.