Problematic of microplastics in the context on seafood safety
Résumé
Plastics and their degradation products such as microplastics (MPs) are present in huge quantities in Oceans. Consequences of MP on environment and biota are more and more documented, contrariwise to studies concerning organisms being considered as food. Our research dealt with the impact of MP on seafood safety.
In order to carry out comparable studies, standard procedures and harmonization are needed. Thus, during a first study, we sought to select from a set of protocols from the literature, the one allowing the best extraction of MP, without disturbance of identification, for a maximum of plastic polymers. The selected method uses 10% potassium hydroxide solution for 24 hours at 60 ° C. It was able to digest seafood samples while ensuring that 14 of the 15 types of polymers tested were not degraded by the method.
Alongside this recovery part of the MP, a work was carried out in terms of identification of plastic polymers by developing a pyrolysis approach coupled to a gas chromatograph and a mass spectrometer (Py-GC / MS). Performances of this method were assessed estimating repeatability and theoretical limit of detection. This technique could be applied in addition to other identification techniques such as Raman microspectrometry or FT-IR to identify small particles such as fibres or "pigments".
Besides Py-GC / MS, under reserve of being carried out at low pyrolysis temperatures (<100 ° C), would also be able to detect the presence of additives in the polymers. As part of this theme, an in vitro digestive model has been developed for fish and human being. The application of this tool to polymers containing different additives will make it possible to evaluate the possibility of a release of chemicals into the chyme.