The certification of the mass fractions of hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD) in fish tissue : ERM®-CE100 : certification report

This report describes the production of ERM®-CE100, a fish (biota) material certified for the mass fractions of hexachlorobenzene and hexachlorobutadiene. This material was produced following ISO Guide 34:2009 and is certified in accordance to ISO Guide 35:2006. The starting material was wild Wels catfish (Silurus glanis) caught in the area of the Flix reservoir at the Ebro River, Spain. The filleted fish was cut and cryogenically milled before mixing. Pre-cooking followed and after further mixing, the material was filled in jars, sterilised in an autoclave and finally labelled as ERM-CE100. 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. Technically invalid results were removed but no outlier was eliminated on statistical grounds only. Uncertainties of the certified values were calculated in accordance 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 with any reference material, it can be used for establishing quality control charts or validation studies. The CRM is available in glass jars closed with twist-off lids containing at least 40 g of sterilised fish paste. The minimum amount of sample to be used is 1 g (wet mass). The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium