RESUMEN
An interlaboratory study describing the assignment of reference values to the extractable concentrations of metals in industrial sludge using NJDEP and USEPA methods is presented. Industrial waste containing high concentrations of alkali, alkaline earth, ferrous and transition metals was dried, size-reduced and homogenized. Multiple aliquots of this material were analyzed in two different government laboratories by several different combinations of extraction and analysis methodologies. Reference values for the acid-extractable concentrations of more than 15 metals were determined and will be included in the NIST Certificate of Analysis for SRM 2782, Industrial Sludge.
RESUMEN
The development of reference materials to verify the determination of metals in sludge is described. Effluents from domestic and industrial treatment facilities were dried, size-reduced and homogenized. Multiple aliquots of each material were analyzed in two different government laboratories to determine reference values for the acid-extractable concentrations of more than 15 metals. These acid-extractable concentrations are distinct from total metal values. Different sample preparation and instrumental methods, along with internal quality assurance protocols, were used to confirm the results. The data show good agreement for most metals in the domestic material. Reference values for the leachable concentrations of several toxic metals and major constituents will become part of the Certificate of Analysis for Standard Reference Material (SRM) 2781 issued by the National Institute of Standards and Technology (NIST). Data for the candidate industrial sludge reference material are also presented and discussed.