The certification of trace elements mass fraction in electrolytic copper: ERM-EB074A, B and C : certification report

This report describes the production of ERM®-EB074A, B and C, a pure copper material with low level of added impurities certified for the mass fractions of Ag, As, Au, Be, Bi, Cd, Co, Cr, Fe, In, Mg, Mn, Ni, P, Pb Sb, Se, Te, Ti and Zn. The material was produced following ISO Guide 34:2009 . A melt is consisting of pure copper and alloy to obtain a copper material with added impurities. After casting, the material was processed by hot extrusion and cold machining to produce discs of 39 mm diameter (ERM-EB074A), cylinders of 8 mm diameter (ERM-EB074B) and chips of 250 mg (ERM-EB074C). Between unit-homogeneity was quantified and stability during dispatch and storage were assessed following ISO Guide 35:2006. Within-unit homogeneity was quantified to determine the minimum sample intake. The material was characterised by an intercomparison among 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 compliance with the Guide to the Expression of Uncertainty in Measurement (GUM); the estimated total uncertainty includes uncertainties related to possible inhomogeneity, instability and characterisation. The material is intended for use in 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 three different formats: - ERM-EB074A: disc of 39 mm diameter; 30 mm thick; packed in a a box - ERM-EB074B: cylinder of 8 mm diameter; 100 mm length; sealed in a plastic sachets under vacuum - ERM-EB074C: bottle of 50 g of chips; chip weight of approximately 250 mg For ERM-EB074A, B and C, the minimum amount of sample to be used is 10 mg for Ag, As, Be, Bi, Cd, Co, Cr, Fe, Mg, Mn, Ni, P, Pb, Sb, Se, Ti and Zn; 20 mg for Au, In and Te. The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials Consortium.