Collaborative study to improve the quality control of trace element determinations in polymers. Part 2. Certification of polyethylene reference materials (CRMs 680 and 681) for As, Br, Cd, Cl, Cr, Hg, Pb, and S content.

Two polymer (polyethylene) reference materials have been produced in support of EC Directive 94/62/EC on plastic packaging and packaging material. The paper describes the preparation of the materials, the analytical work performed to characterize their homogeneity and stability, and the certification of the materials for a range of elements. The technical and statistical evaluation of the results are also summarized.