Improvement of the BCR three step sequential extraction procedure prior to the certification of new sediment and soil reference materials

TLDR

The European Commission’s BCR three‑step sequential extraction procedure for sediment analysis has been developed through expert consultation and interlaboratory studies and was recently applied to certify the extractable trace element contents of CRM 601. The project aims to identify causes of poor reproducibility in the BCR scheme and ultimately certify new sediment and soil reference materials for Cd, Cr, Cu, Ni, Pb, and Zn. A small‑scale interlaboratory study compared the original and revised extraction protocols using CRM 601 to test the improved scheme. The study demonstrates that the revised BCR procedure yields more reproducible results, enabling the production of CRMs that validate analytical data and enhance comparability across the EU.

Abstract

The Standards, Measurements and Testing Programme (formerly BCR) of the European Commission proposed a three-step sequential extraction procedure for sediment analysis, following extensive expert consultations and two interlaboratory studies. This scheme was recently used to certify the extractable trace element contents of a sediment reference material (CRM 601). Although this procedure offers a means to ensure the comparability of data in this field, some difficulties concerning the interlaboratory reproducibility still remain, and a new project is currently being conducted to determine the causes of poor reproducibility in the extraction scheme. The final objective of the project is the certification of new sediment and soil reference materials for their extractable contents of Cd, Cr, Cu, Ni, Pb and Zn. This paper presents the results of a small-scale interlaboratory study, which aimed to test a revised version of the extraction schemes by comparing the original and the modified protocols using the CRM 601 sample. This work offers an improvement to the BCR sequential extraction procedure through intercomparison exercises. This improved procedure will allow the obtaining of CRMs to validate analytical data in the analysis of soils and sediments, and it will also facilitate comparability of data in the European Union.