New certified and candidate certified reference materials for the analysis of PCBs, PCDD/Fs, OCPs and BFRs in the environment and food

Three new matrix-type certified reference materials (CRMs) have been produced for polychlorinated biphenyls (PCBs) in sterilized and wet (shell) fish matrices – BCR-682 (PCBs in mussels), BCR-718 (PCBs in herring) and BCR-719 (non-ortho PCBs in chub). Additional feasibility studies have been carried out to evaluate the conditions under which production and certification of CRMs are feasible for brominated flame retardants (BFRs), chlorinated dibenzo-p-dioxins and furans (PCDD/Fs), PCBs and organochlorine pesticides (OCPs) in various food, animal feed and environmental matrices.The results of these feasibility studies indicate that homogeneous and stable CRMs can be produced for all materials with the protocols developed during these studies. The user of these materials may need to apply simple rehomogenization of the material prior to use (e.g., for the milk material, slight phase separation resulting from sterilization was observed). The decreased precision or accuracy of applied analytical methods close to the method detection limit was found to affect the homogeneity and the stability for some low-concentration compounds studied. For example, as a result, the homogeneity and the stability of 1,2,3,4,7,8,9-HpCDF in the fish material could not be confirmed. However, based on analogy with compounds with the same degree of chlorination, we do not expect that 1,2,3,4,7,8,9-HpCDF would not be stable or homogeneously distributed over the sample matrix.The BCR-682, −718 and −719 CRMs are strong quality-assurance tools to support laboratories analyzing (non-ortho) PCBs in fish and shellfish samples at the (low) levels determined in everyday routine samples. The materials from the feasibility studies can also support laboratories that analyze BFRs, OCPs, PCDD/Fs and dioxin-like PCBs (dl-PCBs) in the matrices investigated. However, these materials are currently not available for laboratories.