Certification of marine sediment reference materials for PAHs

The Marine Analytical Chemistry Standards Program (MACSP) of the National Research Council of Canada produces certified reference materials for several analytes, including PAHs, in marine matrices. Four harbour sediment CRMs are available, HS-3,4,5, and 6. Stocks of HS-3 and 4 are depleted and require replacement. New sediment has been collected and processed. Design goals for the project included provision of certified values for an expanded range of PAHs, and reduction of the uncertainties in the certified values. Stocks of HS-5 and 6 have been re-examined with the same goals. The methods chosen for the certification analyses were CC-MS, HPLC-MS and HPLC-fluorescence. A MACSP certified solution of perdeutero-PAHs was used as surrogate internal standard, and a separate perdeutero-PAH was used as a volumetric internal standard for the chromatographic analyses. NIST standard solutions of perproteo-PAHs were used as external standards. Problems and successes of this strategy are discussed.