Optimization, performance, and application of a pyrolysis-GC/MS method for the identification of microplastics

Plastics 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 °C, a split ratio of 5 and 300 °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 μg. 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 μ-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.

Ludovic Hermabessiere, Charlotte Himber, Béatrice Boricaud, Maria Kazour, Rachid Amara, Anne-Laure Cassone, Michel Laurentie, Ika Paul-Pont, Philippe Soudant, Alexandre Dehaut, Guillaume Duflos, Analytical and Bioanalytical Chemistry, , Volume 410, Issue 25, pp 6663–6676

The article

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The Impact of Microplastics on Marine Copepods

Marine atmospheres are exposed to a widespread of anthropogenic pollutants, including radionuclides, nanoparticles, sewage, endocrine disruptors, hydrophobic contaminants and plastic debris. Plastic debris is a wide range contaminant of both freshwater and marine ecosystems, where it can accumulate over time and pose a risk to the health of aquatic organisms (Barnes et al. 2009; Derraik 2002). In the last 60 years, there has been a rapid growing in plastic manufacture, and in 2012 over 288 million tonnes of plastic was produced globally (Plastics Europe 2013) which demonstrates 2.8% development upon the previous year (Plastics Europe 2013). It is held on that 10% of plastics mass produced are likely to end up in the marine environment (Thompson 2006).

P. Raju, S. Gunabal, P. Santhanam, Basic and Applied Zooplankton Biology, pp 429-442, , chapter

The chapter

LIFE and the marine environment – Tackling the blight of marine litter

LIFE (“The Financial Instrument for the Environment and Climate Action”) is a programme launched by the European Commission and coordinated by the Environment and Climate Action Directorates-General. The Commission has delegated the implementation of many components of the LIFE programme to the Executive Agency for Small and Medium-sized Enterprises (EASME).

LIFE projects are practical tools in the fight against marine litter or invasive alien species, among others. They help balance or reduce any negative impacts of fishing and aquaculture, underwater noise, marine contaminants and eutrophication.

European Union, 2018, 76 pages, The report

Tackling the blight of marine litter, Stopping microplastics from clothes washing into the sea (p. 39)

Plastic pollution: Scientists identify two more potential ‘garbage patch’ zones in world’s oceans

Study attempts to locate remaining 99% of plastic unaccounted for by conventional surveys.

An attempt to locate millions of tons of “missing” plastic in the world’s oceans has thrown up two locations that may contain enormous, previously unreported patches of debris.

Plastic has risen to the top of the environmental agenda after scientists sounded the alarm about the potential impact it as having on marine life.

Best estimates suggest 10 million tons of plastic are dumped in the sea every year. (…) (Theindependent, 13/09/2018)

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Effect of Microplastic Amendment to Food on Diet Assimilation Efficiencies of PCBs by Fish

Diet assimilation efficiencies (AEs) of polychlorinated biphenyls (PCBs) absorbed to microplastics and food were determined in goldfish (Carassius auratus). Microplastics were spiked with 14 environmentally rare PCBs and incorporated into fish pellets previously spiked with a technical PCB mixture (Aroclor 1254). Five diet treatments were created having microplastic contents of 0, 5, 10, 15, 20, and 25% and fed to fish within 24 h of the diet creation. Fish from each treatment were fed a microplastic amended food pellet and PCB AEs were determined by mass balance. Microplastic-associated PCBs had lower AEs (geomean 13.36%) compared to food matrix-associated PCBs (geomean 51.64%). There were interactions between PCB AEs and the microplastic content of the diet. PCBs affiliated with microplastics became more bioavailable with increasing microplastic content of food while food matrix-associated PCB bioavailability declined when microplastic contents exceeded 5%. Despite controlling for microplastic-food contact time, there was some evidence for redistribution of lower KOW food matrix-associated PCBs onto microplastics causing a decrease in their AE relative to nonplastic and low plastic containing diets. The low bioavailability of microplastic-associated PCBs observed in the present study provides further support to indicate that microplastics are unlikely to increase POPs bioaccumulation by fish in aquatic systems.

Stefan Grigorakis and Ken G. Drouillard, Environ. Sci. Technol., Article ASAP, August 16, 2018

The article

Marine litter disrupts ecological processes in reef systems

Marine litter (ML) contaminates essentially all global coastal and marine environments and drives multiple ecosystem-level effects. Although deleterious effects of ML on several organisms have been investigated in the last years, this information tends to be dispersed or underreported, even in marine biodiversity hotspots such as reef ecosystems. Two are the main goals of this paper: (i) to integrate and synthesize current knowledge on the interactions of ML and reef organisms, and (ii) to evaluate the multiple disruptions on the ecological processes in reef systems. We report here ML-driven ecological disruptions on 418 species across eight reef taxa, including interactions that were previously not addressed in detail, and evaluate their major conservation implications. These results can help raise awareness of global impacts on the world’s reefs by highlighting ML associations in different reef systems around the world, and can aid in ML input reduction and marine management.

Gustavo F. de Carvalho-Souza, Marcos Llope, Moacir S. Tinôco, Diego V. Medeiros, Rodrigo Maia-Nogueira, Cláudio L.S. Sampaio, Marine Pollution Bulletin, Volume 133, August 2018, Pages 464–471

The article

Styrene impairs normal embryo development in the Mediterranean mussel (Mytilus galloprovincialis)

This study analysed the effects of styrene, a main monomer in plastic manufacturing and acknowledged to be amongst the most common plastic leachates, on early embryo development of the Mediterranean mussel. Embryotoxicity tests showed that styrene impaired normal embryo development at concentrations (0.01 μg/L–1 mg/L) encompassing the environmental range. Occurrence of normal D-veligers was significantly reduced up to 40% of the total, and larval size was reduced of about 20%. D-veligers grown in the presence of styrene (0.1 and 10 μg/L) showed significant reduction of total Multixenobiotic resistance (MXR) efflux activity that was not apparently related to transcriptional expression of genes encoding P-glycoprotein (ABCB) and Mrp (ABCC), the two main ABC transporters of embryonal MXR system. Indeed, ABCB transcription was not affected by styrene, while ABCC was up-regulated. At these same concentrations, transcriptional profiles of 15 genes underlying key biological functions in embryo development and potential targets of adverse effects of styrene were analysed. Main transcriptional effects were observed for genes involved in shell biogenesis and lysosomal responses (down-regulation), and in neuroendocrine signaling and immune responses (up-regulation). On the whole, results indicate that styrene may affect mussel early development through dysregulation of gene transcription and suggest the possible conservation of styrene mode of action across bivalve life cycle and between bivalves and humans, as well as through unpredicted impacts on protective systems and on shell biogenesis.

Rajapaksha Haddokara Gedara Rasika Wathsala, Silvia Franzellitti, Morena Scaglione,
Elena Fabbri, Aquatic Toxicology, Volume 201, August 2018, Pages 58-65

The article