Fish Reference Materials

MeHg in two fish reference materials was carried out in 1991-94, whereas a recent certification on MeHg in sediment was performed in the period 1994-96. 

The preparation of the fish extracts and the verification of their homogeneity and stability were carried out by the Danish Isotope Centre and the National Food Agency (Soborg, Denmark). The aqueous solutions were prepared at the Kemforschungsanlage (Jiilich, Germany), whereas the mussel and tuna samples were prepared at the Environment Institute of the EC Joint Research Centre of Ispra (Italy). 

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I. R. Pereiro, A. Wasik, R. Lobinski, Determination of mercury species in fish reference materials by isothermal multicapillary gas chromatography with atomic emission detection after microwave-assisted solubilization and solvent extraction, J. Anal. Atom. Spectrom., 13 (1998), 743-747. 

Tuna fish (reference material) Chromium speciesd Store at 20 and 40° C in the dark 12 months 20... 

An arsenobetaine analogue, trimethylarsoniopropionate, was reported in a coral reef fish Abudefduf vaigiensis, and in the fish reference material DORM-2... 

Bushee has determined methylmercury at 870 fig 1 in a different fish reference material and thimerosol in contact lens solutions with good agreement with values reported previously [41]. Detection limits... 

Quevauviller Ph, and Maier EA (1999) Interlaboratory studies and certified reference materials for environmental analysis - the BCR approach. Elsevier, Amsterdam Quevauviller Ph, Drabaek I, Muntau H, Biahchi M, Bortoli A, and Griepink B (1996a) Certified reference materials (CRMs 463 and 464) for the quafity control of total and methyl mercury determination in tuna fish. Trends Anal Chem 15 160-167. 

Frozen reference materials have been produced by NIST (Wise et al. 1993). These materials do not have the disadvantages of the oils or freeze-dried materials, but are more difficult to transport. Obviously they have to be kept deep-frozen during transport, which makes their use rather expensive. Since the early 1990 s a new approach in this field has been introduced. This concerned the use of wet, sterilized fish and shellfish samples. These samples, packed in glass jars or in tins, were firstly used in the QUASIMEME program as reference materials for inter-laboratory studies (de Boer 1997). Later, when it appeared that the stability was maintained for longer periods, tests for organic contaminants based on this principle were also prepared. 

A wide variety of reference materials is now available, covering several different kinds of natural matrix such as food (e.g. milk powder), human tissues (e.g. liver), marine biological materials (e.g. tuna fish) and soils and sediments. The radionuclides of interest cover naturally occurring ones (e.g. Ra), fission products... 

No standard reference materials have been certified for analysis of chlorobomanes, although several may be suitable — including fish oils and whale blubber. Analytical standards for several chlorobomanes are now available, but there is a need to identify other remaining environmentally significant congeners (Muir and de Boer 1993). More research is now recommended in the following areas ... 

The certification procedure for seven trace metals (Ba, Ca, Li, Mg, Mn, Na and Sr) in the certified reference material FEBS-1 (National Research Council Canada, Institute for National Measurement Standards, Ottawa, Canada) based on fish otolith matrix by isotope dilution - ICP-MS in comparison to ICP optical emission spectrometry and X-ray fluorescence analysis, is described by Sturgeon et al4X The isotope dilution technique is also employed for species analysis in biological systems,46 e.g., for the determination of mercury species in tuna material,54 or in aquatic systems using cold vapour ICP-MS.55... 

Clough and co-workers reported on the uncertainty contribution using single and double isotopi-cally enriched spikes in the isotope dilution approach employing a multiple ion collector ICP-MS combined with an HPLC and with cold vapour generation (CV) to form HPLC-CV-MC-ICP-MS for the determination of MeHg in fish tissue.8 Two fish tissue reference materials DORM-2 (NRC, Canada) and BCR 464 were employed in these studies. The amount of each certified reference... 

Accuracy and Analytical Quality Control Aspects The analysis of certified reference materials (CRMs) following the same analytical procedures was performed for assessment of the accuracy of the procedure and for quality control (QC). Yet, the available CRMs are mostly freeze-dried, not fresh or deep-frozen. In Table 22.3 an overview of CRMs in a seafood matrix with respect to organic Hg is given. It is certainly beneficial that more and more CRMs are becoming commercially available. Recently, a new CRM for trace elements in a matrix of lyophilized tuna fish (IMEP-20) has been produced [44]. Apart from total Hg (4.32 mg kg-1 dry mass) and Me-Hg (4.24 mg kg-1 dry mass), this material is also certified for other elements such as As, Pb, and Se. 

Wrobel, K., Wrobel, K., Parker, B., Kannamkumarath, S.S., Caruso, J.A. Determination of As(III), As(V), monomethylarsonic acid, dimethylarsinic acid and arsenobetaine by HPLC-ICP-MS analysis of reference materials, fish tissues and urine. Talanta 58, 899-907 (2002)... 

The overall coordination of the interlaboratory studies and certification campaign was managed jointly by the Laboratoire de Chimie Analytique et Minerale of the Universite Louis Pasteur in Strasbourg (France) and the CNRS, Service Central d Analyse in Vernaison (France). The Environment Institute of the Joint Research Centre of Ispra (Italy) prepared the candidate reference material of tuna fish. Arsenobetaine calibrant for the certification was synthetised and characterized in the Laboratoire de Chimie Analytique et Minerale in Strasbourg (France). 

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