ERM-CA713: Trace elements in waste water

The material was  produced following ISO Guide 34:2009.The starting material was 200 L of a wastewater effluent collected at a wastewater treatment facility in Belgium. The sample was filtered,  acidified and spiked before filling into 100 mL borosilicate ampoules which were flame-sealed  after filling. The material was sterilised by  ?  -irradiation.  Between unit-homogeneity and stability during di  spatch and storage have been assessed in  accordance with ISO Guide 35:2006. Due to the inherent homogeneity of filtered water  samples, determination of minimum sample intake (within-unit heterogeneity) was not  required. The certified values were obtained by using a range of different analytical techniques. 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 for statistical reasons 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 heterogeneity, instability and characterisation.  The material is intended for quality control and assessment of method performance. As any reference material, it can also be used for control charts or validation studies.

keywords: environmental material , wastewater , trace elements , heavy metals