Certified reference materials for the quality control of trace element determinations in groundwater

Groundwater is currently monitored by EU laboratories to control the level of contamination by major or trace elements in line with EC directives. Compliance with these directives implies that data should be accurate, which requires the availability of representative CRMs as a tool for quality control. This paper describes the preparation of groundwater reference materials, CRMs 609 and 610 (low and high trace element content) and CRMs 611 and 612 (low and high bromide content), the homogeneity and stability studies and the analytical work performed for the certification of Al, As, Cd, Cu and Pb using a range of different techniques, and bromide based on ion-chromatographic measurements.