The certification of the mass fractions of polybrominated diphenyl ethers (PBDEs) and α-, β- and γ-hexabromocyclododecane (HBCD) in freshwater sediment : ERM®-CC537a

This report describes the production of ERM®-CC537a, a sediment certified for the mass fraction of polybrominated diphenyl ethers PBDE 28, 47, 99, 100, 153, 154, 183 and 209 (further referred as BDEs) and of α-, β- and γ-hexabromocyclododecane (HBCD) on a dry mass basis. This material was produced following ISO Guide 34:2009 [ ] and is certified in accordance with ISO Guide 35:2006. The starting material is a freshwater sediment originating from a small Belgian river. It was air-dried, sieved, jet-milled and finally homogenised. The obtained powdered sediment was bottled under argon atmosphere and sterilised by γ-irradiation. Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. Within-unit homogeneity was quantified to determine the minimum sample intake. The material was characterised by an interlaboratory comparison of laboratories of demonstrated competence and adhering to ISO/IEC 17025:2005. Technically invalid results were removed but no outlier was eliminated on statistical grounds only. Uncertainties of the certified values were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity, instability and characterisation. The material is intended for the quality control and assessment of method performance. As any reference material, it can also be used for control charts or validation studies. The Certified Reference Material (CRM) is available in amber glass bottles containing 40 g of sediment. The minimum amount of sample to be used is 750 mg.