Improvement in the traceability of environmental analysis by the relevant use of certified pure solutions and a matrix certified reference material

摘要

The METREAU project aimed to demonstrate and quantify in a real-life situation the benefits of implementing the principles of metrology in field laboratories. It involved building up an operational traceability chain in a practical case of the determination of two heavy metals (cadmium and lead) in groundwater. Pure solutions for calibration were certified and used by 46 laboratories in a proficiency-testing (PT) scheme. During this intercomparison, laboratories had to analyse a spiked pure water and a certified reference material (CRM) of groundwater. Results showed a measurable bias in lead analysis in the groundwater for all the methods used by laboratories routinely performing water analysis. This project demonstrated the interest, for the improvement of quality of water analysis, in a metrological approach to method calibration, method validation and estimation of measurement uncertainty. It underlined the role of a matrix CRM in estimating bias in method validation.