3 research outputs found
Etudes des microplastiques appliquĂ©es Ă la sĂ©curitĂ© sanitaire des produits de la pĂȘche
International audienceLes plastiques ainsi que leurs produits de dĂ©gradation comme les microplastiques (MPs) sont prĂ©sents en quantitĂ©s importantes dans les OcĂ©ans. Si les consĂ©quences des MPs sur lâenvironnement et le biote sont de plus en plus documentĂ©es, en revanche peu dâĂ©tudes concernent les organismes aquatiques en tant quâaliment. Nos recherches portent sur lâimpact des MPs sur la sĂ©curitĂ© sanitaire des produits de la pĂȘche.Afin de pouvoir rĂ©aliser des Ă©tudes comparables, des modes opĂ©ratoires uniformisĂ©s sont nĂ©cessaires. Ainsi lors dâune premiĂšre Ă©tude, nous avons cherchĂ© Ă sĂ©lectionner parmi un ensemble de protocoles issus de la littĂ©rature, celui permettant dâextraire puis dâidentifier un maximum de polymĂšres plastiques. La mĂ©thode retenue utilise une solution dâhydroxyde de potassium 10% pendant 24H Ă 60°C. Elle a permis de digĂ©rer des Ă©chantillons de produits de la mer tout en sâassurant que 14 des 15 types de polymĂšres testĂ©s ne sont pas dĂ©gradĂ©s par la mĂ©thode.ParallĂšlement Ă cette partie rĂ©cupĂ©ration des MPs, des travaux ont Ă©tĂ© menĂ©s en terme dâidentification des polymĂšres plastiques par une approche de pyrolyse couplĂ©e Ă un chromatographe en phase gaz et un spectromĂštre de masse (Py-GC/MS). Cette mĂ©thode a fait lâobjet dâune validation : estimation de la limite de dĂ©tection, tests de rĂ©pĂ©tabilitĂ© et de reproductibilitĂ©. Cette technique pourrait ĂȘtre appliquĂ©e en complĂ©ment dâautres techniques dâidentification comme la microspectromĂ©trie Raman ou le FT-IR pour identifier des particules de petite taille comme les fibres ou encore les âpigmentsâ.Par ailleurs, la Py-GC/MS sous rĂ©serve dâappliquer des tempĂ©ratures de pyrolyse faibles (<100°C) serait Ă©galement capable de dĂ©tecter la prĂ©sence dâadditifs dans les polymĂšres. Dans le cadre de cette thĂ©matique, un modĂšle digestif in vitro a Ă©tĂ© dĂ©veloppĂ© pour le poisson et lâHomme. Lâapplication de cet outil Ă des polymĂšres contenant diffĂ©rents additifs permettra dâĂ©valuer la possibilitĂ© dâun relargage de produits chimiques dans le chyme
Development of a Py-GC/MS method and its application to identify marine microplastics
International audiencePlastics are found to be major debris composing marine litter; microplastics (MP, < 5 mm) are found in all marine compartments. The amount of MPs tends to increase with decreasing size leading to a potential misidentification when only visual identification is performed. These last years, pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS) has been used to get information on the composition of polymers with some applications on MP identification. The purpose of this work was to optimize and then validate a Py-GC/MS method, determine limit of detection (LOD) for eight common polymers, and apply this method on environmental MP. Optimization on multiple GC parameters was carried out using polyethylene (PE) and polystyrene (PS) microspheres. The optimized Py-GC/MS method require a pyrolysis temperature of 700 degrees C, a split ratio of 5 and 300 degrees C as injector temperature. Performance assessment was accomplished by performing repeatability and intermediate precision tests and calculating limit of detection (LOD) for common polymers. LODs were all below 1 mug. For performance assessment, identification remains accurate despite a decrease in signal over time. A comparison between identifications performed with Raman micro spectroscopy and with Py-GC/MS was assessed. Finally, the optimized method was applied to environmental samples, including plastics isolated from sea water surface, beach sediments, and organisms collected in the marine environment. The present method is complementary to mu-Raman spectroscopy as Py-GC/MS identified pigment containing particles as plastic. Moreover, some fibers and all particles from sediment and sea surface were identified as plastic
Py-GC/MS method development and application for the identification of microplastics from seafood
International audiencePlastics are found to be major debris composing marine litter; microplastics (MP, < 5 mm) are found in all marine compartments. The amount of MPs tends to increase with decreasing size leading to a potential misidentification when only visual identification is performed. These last years, pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS) has been used to get information on the composition of polymers with some applications on MP identification. The purpose of this work was to optimize and then validate a Py-GC/MS method, determine limit of detection (LOD) for eight common polymers, and apply this method on environmental MP. Optimization on multiple GC parameters was carried out using polyethylene (PE) and polystyrene (PS) microspheres. The optimized Py-GC/MS method require a pyrolysis temperature of 700 degrees C, a split ratio of 5 and 300 degrees C as injector temperature. Performance assessment was accomplished by performing repeatability and intermediate precision tests and calculating limit of detection (LOD) for common polymers. LODs were all below 1 mug. For performance assessment, identification remains accurate despite a decrease in signal over time. A comparison between identifications performed with Raman micro spectroscopy and with Py-GC/MS was assessed. Finally, the optimized method was applied to environmental samples, including plastics isolated from sea water surface, beach sediments, and organisms collected in the marine environment. The present method is complementary to mu-Raman spectroscopy as Py-GC/MS identified pigment containing particles as plastic. Moreover, some fibers and all particles from sediment and sea surface were identified as plastic. Graphical abstract