Determination of the microplastic content in Mediterranean benthic macrofauna by pyrolysis-gas chromatography-tandem mass spectrometry

Mission Tara Microplastics: a holistic set of protocols and data resources for the field investigation of plastic pollution along the land-sea continuum in Europe

The Tara Microplastics mission was conducted for 7 months to investigate plastic pollution along nine major rivers in Europe-Thames, Elbe, Rhine, Seine, Loire, Garonne, Ebro, Rhone, and Tiber. An extensive suite of sampling protocols was applied at four to five sites on each river along a salinity gradient from the sea and the outer estuary to downstream and upstream of the first heavily populated city. Biophysicochemical parameters including salinity, temperature, irradiance, particulate matter, large and small microplastics (MPs) concentration and composition, prokaryote and microeukaryote richness, and diversity on MPs and in the surrounding waters were routinely measured onboard the French research vessel Tara or from a semi-rigid boat in shallow waters. In addition, macroplastic and microplastic concentrations and composition were determined on river banks and beaches. Finally, cages containing either pristine pieces of plastics in the form of films or granules, and others containing mussels were immersed at each sampling site, 1 month prior to sampling in order to study the metabolic activity of the plastisphere by meta-OMICS and to run toxicity tests and pollutants analyses. Here, we fully described the holistic set of protocols designed for the Mission Tara Microplastics and promoted standard procedures to achieve its ambitious goals: (1) compare traits of plastic pollution among European rivers, (2) provide a baseline of the state of plastic pollution in the Anthropocene, (3) predict their evolution in the frame of the current European initiatives, (4) shed light on the toxicological effects of plastic on aquatic life, (5) model the transport of microplastics from land towards the sea, and (6) investigate the potential impact of pathogen or invasive species rafting on drifting plastics from the land to the sea through riverine systems.

Previous successes and untapped potential of pyrolysis-GC/MS for the analysis of plastic pollution

There is growing concern from scientists, policy makers, and the public about the contamination of natural and indoor environments with plastics, particularly micro/nanoplastics. Typically, characterizing microplastics in environmental samples requires extensive sample processing to isolate particles, followed by spectroscopic methodologies to identify particle polymer composition. Spectroscopic techniques are limited in their ability to provide polymer mass or advanced chemical composition (e.g., chemical additive content), which are important for toxicological assessments. To achieve mass fraction quantification and chemical characterization of plastics in environmental samples, many researchers have turned to thermoanalytical spectrometric approaches, particularly pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Sample preparation for Py-GC/MS may be approached similarly to techniques needed for spectroscopic approaches (e.g., isolate particles on a filter), employ pressurized solvent extraction, or use ultrafiltration techniques to concentrate nanoplastics. Great strides have been made in using calibration curves to quantify plastics in complex matrices. However, the approaches to the pyrolysis thermal program, as well as calibrant and sample preparation, are inconsistent, requiring refinement and harmonization. This review provides a critical synthesis of previous Py-GC/MS work and highlights opportunities for novel and improved Py-GC/MS analysis of plastics in the future.

A Novel Strategy to Directly Quantify Polyethylene Microplastics in PM2.5 Based on Pyrolysis-Gas Chromatography-Tandem Mass Spectrometry

The broad application of plastic products has resulted in a considerable release of microplastics (MPs) into the ecosystem. While MPs in other environmental matrices (e.g., soil and water) have been studied for a long time, the atmospheric fine particulate matter (PM_2.5)-bound MPs are rarely investigated due to the lack of an appropriate analytical approach. The prevalently used visual and spectroscopic means (e.g., optical microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy) suffer from obvious drawbacks that cannot precisely detect MPs of tiny sizes and provide quantitative information. In the present study, a novel strategy that does not require sample pretreatment was developed to first effectuate accurate quantification of polyethylene MP (PE-MP) in PM_2.5 based on pyrolysis-gas chromatography-tandem mass spectrometry (Pyr-GC-MS/MS). It featured acceptable recoveries (97%-110%), high sensitivity (LOD = 1 pg), and qualified precisions (RSD of 3%-13%). Employing this approach, for the first time, exact atmospheric concentrations of PE-MPs in PM_2.5 from megacities in North (Zhengzhou and Taiyuan) and South (Guangzhou) China were obtained, and relatively serious pollution was found in Taiyuan. The 100% sample detection rates also suggested the widespread occurrence and possible human exposure risks of PM_2.5-bound PE-MPs. In brief, the new strategy could conduct direct, sensitive, and accurate quantification of PE-MP in PM_2.5, favoring further studies of environmental fates, distributions, and toxicities of atmospheric MPs.

Advances and prospects of carbon dots for microplastic analysis

Microplastics have become the world's most emerging pollutants today due to the ubiquitous use of plastics in everyday life and their ability to migrate from micro to nanoscale to every corner of the natural world, leading to ecological imbalances and global catastrophes. However, a standardized method for separating and analyzing microplastics from actual food or environmental samples has not been established. Therefore, it is necessary to develop a simple, fast, cost-effective, and accurate method that can accurately measure the degree of contamination of microplastics. As one of these methods, fluorometry has been proposed as a cost-effective method to detect, quantify and differentiate individual plastic particles. Therefore, this review discussed the technique for analyzing microplastics using fluorescent carbon dots (CDs). This review provided an overview of the impact of microplastics and the feasibility of using CDs to detect and analyze microplastics. In particular, this review will discuss novel microplastic analysis methods using CD and future application studies. The method using CDs will overcome the limitations of current microplastic analysis technology and may become a new method for detecting and analyzing microplastics.