ERM-BD151: Skimmed milk powder

The starting material was 1000 L of fresh raw milk. The milk was skimmed and pasteurised, and divided in two batches of about 500 L. Spike solutions of Cd, Cu, Fe, Hg and Pb were added to each batch. The batches were again pasteurised, concentrated by evaporation, and  spray dried to produce fine powders.  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 inter-comparison 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) and include uncertainties related to  possible inhomogeneity, instability and characterisation.  The materials are intended for quality control and assessment of method performance. As  any reference material, they can be used for control charts or validation studies. The minimum amount of  sample to be used is 500 mg for Fe and 200 mg for all other elements. 

keywords: biological material , foodstuff , Milk/Dairy products, trace elements, nutrients