0045-6535(95)00226-X Chemosphere. Vol. 32, No. 1, pp. 25-30, 1996 Elsevier Science Ltd Printed in Great Britain NIST SRM 1945, WHALE BLUBBER, NIST SRM 1974a. ORGANICS IN MUSSEL TISSUE, AND NIST SRM 194la, ORGANICS IN MARINE SEDIMENT AS CERTIFIED REFERENCE MATERIALS FOR POLYCHLORINATED DIOXINS AND FURANS IN MARINE ECOSYSTEMS Laura&, Piero Gardinali, Hank Chambers, Terry L. Wade, Thomas Jackson, and James M. Brooks Geochemical and Environmental Research Group Texas A&M University 833 Graham Road, College Station, TX 77845 Abstract Few natural matrix Standard Reference Materials are available for the validation of analytical methods measuring polychlorinated dioxins and furans (PCDDs and PCDFs) in marine ecosystems. The concentrations of PCDDs and PCDFs in NIST SRM 1945, SRM 1974a. and SRM 194la are of interest because the analysis of marine mammal, mussel tissues and sediments have become important tools in the determination of organochlorine contamination of the environment. Because these SRMs have been demonstrated to be homogenous for other organic contaminants, they would be expected to be reliable standards for validation of polychlorinated dioxins and furans in marine mammals, mussels and sediments as well. Introduction Ideally, standard reference materials (SRMs) should be used by laboratories to validate their analytical methods and assess accuracy. Even after validation, these methods must be monitored to verify that they continue to produce acceptable data and are in a state of statistical control’. The SRM matrix and analyte concentrations used should be a reasonable match to that of the samples to be analyzed’. It is virtually impossible to find an SRM that meets all of the matrix and concentration requirements and, therefore, some compromises are inevitable. Even though the availability of SRMs has increased in the past few years, and their use is the best available approach to determination of the accuracy of measured data, few natural matrix SRMs are available for the validation of analytical methods measuring polychlorinated dioxins and furans (PCDDs and PCDFs) in marine ecosystems. The National Institute of Standards and Technology (NIST) has developed several SRMs to assist in the validation of analytical measurements of environmental contaminants in natural matrices. NIST SRM 1945, Whale Blubber, is a frozen blubber homogenate that has been certified for 26 polychlorinated biphenyl (PCB) congeners and for 15 chlorinated pesticides3. NIST SRM 1974a. Organics is Mussel Tissue, is a frozen mussel tissue homogenate with cunently non-certified, concensus values for PAHs, PCBs, chlorinated pesticides, and inorganic 25