Groundwater is currently monitored by EU laboratories to control the level of contamination by trace or major elements, in particular in support to EC Directives 80/68/CEE, 80/778/CEE and 91/676/CEE which prescribe the determination of a variety of elements and compounds, e.g. Ca, Cl, Fe, K, Mg, Mn, Na, NO3, PO4, SO4. The need to control the quality of these measurements requires the availability of certified reference materials of typical groundwater samples.
The aim of the project was to produce two artificial reference materials representative of groundwater matrices and to certify them for a range of major elements.
The feasibility study was concluded in 1995 and enabled to optimise the composition of the candidate CRMs and the stabilisation procedure. The materials were successfully analysed in 1997 and subsequently certified. Both CRMs (616 and 617) are now available at the IRMM.
The parameters selected of the samples to be tested were based on a literature research which enabled to define a mean composition for two types of materials with, respectively, low and high carbonate contents. The project consisted in a feasibility study to test the stabilisation of the materials, the preparation of two batches of ampoules containing artificial groundwater (CRMs 616 and 617), the certification analyses performed by a group of ca. 20 European laboratories, and the technical and statistical evaluation of the results.