The extensive applications of plastic have brought great convenience to modern life, but have also led to serious plastic pollution in different environments. More than 3 million tons of plastic are produced every year, an important part of which end up as microplastic (MPs) waste. MP pollution is drawing increasing concern worldwide since it has occurred in the ocean, wastewaters, surface waters, soils, sediments, food, and air.

A growing number of separation and characterization methods and technologies have been developed in the last few years for either the removal of MPs from environmental matrices or for the study of the fate and toxicity of MPs. Passive atmospheric deposition and active pumped sampling have been adopted as sample collection methods for the atmosphere or water. Classical technologies, including coagulation, floatation, and filtration, are confirmed to be effective for the separation of MPs from aquatic environments. The enriched MP samples can then be analyzed via a combination of visual inspection and techniques to identify their chemical composition (i.e. Raman and FT-IR). In terms of MP quantification, GC-MS has preceded pyrolysis or TDS.

However, gaps still exist in both the determination of environmental (sub)micro/nanoplastics and the lack of standard protocols to validate MP and (sub)micro/nanoplastic separation and characterization methods. The ecotoxicology study of MPs should be performed based on a reliable protocol of separation and characterization methodology. The accumulation of MPs and additives in tissues of organisms may cause a series of adverse effects, including: oxidative stress, pathological stress, inflammation, reduced growth rate, and reproductive toxicity.

This Collection should be of great help in promoting methods for separating and characterizing MPs, as well as ecotoxicological analyses. It will provide insights into this emerging field of public interest.