Diergeneesmiddelen in aquacultuur

De Nederlandse visteelt heeft nog niet de beschikking over toegestane diergeneesmiddelen, terwijl de noodzaak om bepaalde middelen te gebruiken in de praktijk bestaat. Deze middelen zijn met name: flumequine, mebendazole, oxolinezuur, oxytetracycline, praziquantel en trimethosulfmix. Wat op dit moment niet duidelijk is is de farmacokinetiek van deze middelen voor de vissoorten die in Nederland gekweekt worden. Deze informatie is van belang om te voorkomen dat residuen van de geneesmiddelen in voor consumptie bestemde visproducten terecht komen. Om meer inzicht te krijgen in bestaande farmacokinetische data voor de meest gebruikte middelen is een literatuuronderzoek uitgevoerd

Comparison of quantification methods for the analysis of polychlorinated alkanes using electron capture negative ionization mass spectrometry.

Four quantification methods for short-chain chlorinated paraffins (SCCPs) or polychlorinated alkanes (PCAs) using gas chromatography electron capture negative ionisation low resolution mass spectrometry (GC-ECNI-LRMS) were investigated. The method based on visual comparison of congener group patterns of external standards used for quantification and fish samples was very sensitive for the choice of the quantification standard. Two other methods used the existing relation of the response factors with the chlorine content of SCCP mixtures for quantification. Results from the three methods above deviated from nominal values less than 20%. This was ~50% when individual PCA standards were applied for quantification of SCCPs. The deviation is probably caused by the fact that only C10 carbon chain length standards with 5-9 chlorine atoms could be used. However, quantification using individual PCA standards is a promising method provided more standards will become commercially available. The clear advantage is that the standards are defined, which makes quantification comparable between different laboratories. Application of all four quantification methods to the analysis of four different fish samples gave results that agreed with the median values within ±40

Environmental Levels and Trends of 1,2-dichloroethane, vinyl chloride and chloroform in water, sediment and biota for the European and Arctic regions: literature study

Data on concentrations of chloroform, 1,2-dichloroethane and vinyl chloride in European and Arctic waters, sediments and biota were collected from scientific literature and monitoring programmes for the period 1980–2005 and are presented in this report

Chemical/biological analyses of harbour porpoise samples to indentify contaminants in the food chains

One of the main objectives of the “Koploper” project “Identificatie van mogelijke probleemstoffen in voedselketens en toppredatoren” is to identify possible causes of the increasing number of harbour porpoises that are stranded on the Dutch coast. In order to find out whether chemical contamination could cause the increased stranding, Deltares has contracted IMARES to analyse main organohalogenated contaminants in the harbour porpoises found stranded during year 2006

Het concentreren en opwerken van waterige monsters volgens de XAD procedure

In opdracht van RWS-RIZA is het project “Het concentreren en opwerken van waterige monsters volgens de XAD procedure” uitgevoerd. De XAD procedure is uitgevoerd volgens een protocol dat is gebaseerd op methoden ontwikkeld bij het RIVM, Laboratorium voor Ecotoxicologie te Bilthoven. Daarna zijn de waterige monsters naar TNO IMARES in Den Helder gegaan voor beoordeling van de toxiciteit

Preparation of three biological reference material for QUASIMEME inter-laboratory testing

Three biological materials have been prepared for IVM, Free University, Amsterdam to be used in QUASIMEME interlaboratory studies. The materials prepared are: 300 glass jars of homogenized Mediterranean mussels (QM06-1), 280 tins of homogenized blue mussels from German Bight (QM06-3) and 300 tins of homogenized Baltic herring fillets (QO06-4) The homogeneity test of the Mediterranean-mussel material (QM06-1) was performed by analysing mercury concentration and it was confirmed that the material is homogeneous

Water sampling at the Berge Helene FPSO at Chinguetti field in Mauritania using passive samplers

Three rounds of water sampling were performed at the Berge Helene FPSO at the Chinguetti field in Mauritania using passive samplers attached to the FPSO to determine the levels of contamination that could potentially accumulate in organisms. Two rounds were carried out prior to the commencement of oil production (pre-PFW) and one following the start of produced formation water discharge (post-PFW). Although water was sampled at 3-m and 10-m depths, bioaccumulation data were possible to report only for 3-m depth due to the repeatable loss of samplers deployed at 10-m depth. The reason for these losses remains un-known. Retrieved passive samplers from each round were analysed for total bioaccumulative (petroleum) hydrocarbons, 9 phenols, benzene, toluene, ethylbenzene, xylene and 16 EPA polycyclic aromatic hydrocarbons. The accumulated amounts of chemicals during the two pre-PFW samplings were very similar and both of them can be considered to be representative for the pre-PFW phase. Surprisingly, the accumulated amount of chemicals during the post-PFW sampling round (i.e. after and during regular PFW discharges) was lower than in the pre-PFW sampling round. The most probable explanation is that drilling activities have stronger impact than the regular PFW discharges, but the possibility that the results were influenced by a variation in meteorological and hydrological conditions, such as ,e.g., direction and strength of the currents, could not be fully rejected. The biomimetic nature of the Empore® disk extraction was used to estimate total body residues of chemicals in biota. These values were compared with critical body residues for three toxicological effects to evaluate baseline toxicity of the environment under the FPSO. Results showed that the total body residue levels in the aquatic environment under the FPSO are below the no-effect level for sub-lethal fish toxicity. However, in all measurements the levels exceed safe level for effects on ecosystem (HC5): in pre-PFW sampling significantly, while in post-PFW only slightly. As these levels were observed directly at the source of possible contamination, the effects on the environment are likely to be substantially lower at increased distance from the FPSO

Preparation of fish material for interlaboratory study on PFCs

The Institute for Environmental Studies, Vrije Universiteit (IVM) has requested Wageningen IMARES for the preparation of fish material for use in interDlaboratory performance study on analysis of perfluorinated compounds (PFCs). It was requested that the material should be prepared from fillet of flounder caught in Western Scheldt and packed in glass jars. This document provides report on the material preparation