The chemical analysis of these VOCs at very low concentrations in animal matrices is technically demanding and may suffer from lack of robustness and reproducibility. Secondly, the ideal way of sampling and storing the (fish) samples is yet unclear. Therefore, the following objectives are to be achieved: - Improvement of the reliability of the analytical technique - Development of a reference material with known VOC contents as a tool of quality control - Improvement of sampling and sample storage conditions, on board as in the lab. Planned activities and expected results The analytical technique is based on a purge-and-trap equipment, coupled with a gas chromatograph station, in turn equipped with a mass spectrometer. At first, the analytical methodology will be improved and validated, supported by the development of a reference material and the calculation of control limits. Secondly, the integrity and stability of the reference material under different storing conditions will be studied. The integrity of the samples during sampling and sample storage on board and in the laboratory, using a fish model based on a fish oil containing semipermeable membrane device (SPMD) will be investigated. After validation of the appropriate sampling and storage methodology various international laboratories will be contacted to ask for their willingness to participate in a proficiency testing scheme, in order to further evaluate the robustness of the methodology. This can be done in collaboration with ICES (International Council for the Exploration of de Sea) or the Quasimeme project office (Quality Assurance of information for marine environmental monitoring in Europe). Presentation of the research unit The division Analytical Chemistry of the Sea Fisheries Department is specialised at the analysis of organic pollutants present in marine sediments and organisms. In the frame of the Conventions of Oslo and Paris, polychlorobiphenyls (PCBs), persistent organochloropesticides (OCPs) and polyaromatic hydrocarbons (PAHs) are analysed annually at well-described sampling places on the Belgian Continental Platform and in the estuary of the Scheldt river. These data are collected on a European scale and used to evaluate the contamination of the marine environment, in order to support the European environmental policy.