Hi Esho, the reference I shared may be helpful regarding methods, but of course, the methods will vary depending on the sampling (sea surface, sediment, wastewater plant, snow etc.) and the organism. You can modify other methods according to your sampling matrix.
MSFD Technical Group on Marine Litter, Galgani, et al., 2023. Guidance on the Monitoring of Marine Litter in European Seas An update to improve the harmonised monitoring of marine litter under the Marine Strategy Framework Directive, EUR 31539 EN, Publications Office of the European Union, Luxembourg, 2023, ISBN 978-92- 68-04093-5, doi:10.2760/59137, JRC133594.
Would you please be more specific for the sampling area or the organism?
You might need to search more on the WoS. I hope these can also help you.
Sahai, H., Aguilera del Real, A. M., Alcayde, A., Bueno, M. J. M., Wang, C., Hernando, M. D., & Fernández- Alba, A. R. (2025). Key insights into microplastic pollution in agricultural soils: A comprehensive review of worldwide trends, sources, distribution, characteristics and analytical approaches. TrAC Trends in Analytical Chemistry, 185, 118176. https://doi.org/10.1016/j.trac.2025.118176.
Chen, Z., Carter, L. J., Banwart, S. A., & Kay, P. (2025). Microplastics in Soil–Plant Systems: Current Knowledge, Research Gaps, and Future Directions for Agricultural Sustainability. Agronomy, 15(7), 1519. https://doi.org/10.3390/agronomy15071519.
Sedat Gündoğdu, Muhittin Onur Akça, Mehmet Gursoy, Murat Yılmaz, Zhang, X., Andrés Rodríguez-Seijo, Bibi, A., Luisa, M., & Milica Velimirovic. (2025). Microplastics in soil: a comprehensive review of analytical techniques. Frontiers in Soil Science, 5. https://doi.org/10.3389/fsoil.2025.1614075.