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Chemistry & Undesirables Laboratory


Foto: Eivind Senneset

The Chemistry and Undesirables Laboratory performs analysis of undesirable substances in seafood and the environment. We analyse samples of fish, fish feed, other seafood like crab and shellfish, as well as sediments. The results help to monitor and map the contents of illegal drugs, residues of legally used drugs, pesticide residues, microplastics and various environmental toxins found in seafood and the environment. This information gives IMR the scientific background to determine the state of seafood and the environment in Norwegian marine and coastal areas, as well as the state of products originating from fish farming. The laboratory has a modern instrument park where the main principle is chromatography, coupled to mass spectrometry.

Most of the methods at the laboratory are accredited according to NS-EN ISO / IEC 17025 (2017), and for several of the methods we hold the status of National Reference Laboratory (NRL).

Organic pollutants

Environmental organic pollutants are very resistant to environmental degradation (persistent). We have analytical methods to determine organic pollutants in both sediment and biological samples; dioxins, furans, polychlorinated biphenyls (PCBs), dichloro- diphenyl- trichloroethane (DDT), brominated flame retardants (BFRs), polyaromatic hydrocarbons (PAHs), total hydrocarbon content (THC) and perfluorinated alkylated substances (PFAS). The results help to build basic knowledge about seafood, fish feed and the environment.


Residues of pesticides are analyzed in both seafood, fish feed and sediments. The analyses provide basic knowledge about how much of previously used (now banned) pesticides are still present in the environment and in the seafood. The analyses also answer whether pesticides that are still in use are up-concentrated in the food chain and thus in the seafood. In addition, the analytical results provide answers to what pesticide residues can be found in fish feed, and whether these are also found in farmed fish.

As the composition of feed for farmed fish is changing to become increasingly plant-based, the laboratory has established screening methodology to detect new pesticides in fish feed.

Veterinary drug residues

In order to ensure that farmed fish for human consumption do not contain residues of legally used veterinary drugs in harmful concentrations, Norway has a control system that complies with international guidelines in this area. Veterinary drugs often have a Maximum Residue Limit (MRL). We analyse farmed fish from all over the country, both as pooled and individual samples. The veterinary drug residue analytical program is carried out in accordance with EU Directive 96/23, and uses methods for the detection of relevant antibiotics, anti-sea lice agents and other veterinary drug residues. The limit of detection (LOD) for these methods are well below the current MRL values.


We have established a new and modern laboratory for analysis of microplastics in seafood and the environment, and we are in the process of establishing methodology for sample preparation for analysis of microplastics and additives. The laboratory is equipped with the most modern analytical instruments for this purpose. Information on the type of polymer, amount, particle shape and size are important concepts. A focal-plane array µ-Fourier transform infrared (FPA µ-FTIR) microscope provides visual identification of microplastic particles down to 2.5–10 µm, while pyrolysis in combination with gas chromatography mass spectrometry (py-GC-MS) provides quantitative determination of different polymer types regardless of particle size. The analysis results will be included in basic surveys of Norwegian seafood. The new laboratory places strict requirements on cleanliness since it is known that microplastic particles are found everywhere in the environment, and it is equipped with overpressure and LAF benches.