Certification of the Mass Concentrations of Arsenic, Cadmium, Iron, Lead, Manganese, Mercury and Nickel in Groundwater - Certified Reference Material ERM®-CA615

Abstract

This report presents the preparation and certification of groundwater reference material ERM-CA615. All steps required for the production of this water-matrix reference material are described in detail, from the sampling of natural groundwater to the characterisation exercise that lead to the final assignment of the certified values, following ISO Guide 34:2009 [1] and ISO Guide 35:2006 [2]. Homogeneity and stability of the water material were investigated with dedicated studies and the certification campaign for the material characterisation was based on an inter-comparison involving several experienced laboratories. IRMM organised and coordinated all phases of this project and carried out the evaluation of data. The certified values were calculated as the unweighted mean of the laboratory means of the accepted sets of results for each parameter, as seen below. Uncertainties were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM, ISO/IEC Guide 98-3:2008) [3]. The stated expanded uncertainties include contributions from characterisation, homogeneity and long-term stability.JRC.DG.D.2-Reference material