Optimizing Density-Based Separation Techniques for Saltmarsh Sediments: Method Development and Refinement

Microplastics (MPs) are increasingly recognized as pervasive environmental pollutants, posing significant risks to ecosystems through both direct and indirect pathways. Sediments are recognised as an important sink for MPs and density separation is the most reported in the literature to study such pollutants. These frequently use sodium chloride (NaCl) solutions to isolate MPs from environmental samples, due to accessibility and its ecofriendly nature. However, there is no standardized method for the extraction of MPs from sediments meaning a lack of consistency in studies. Furthermore, a significant knowledge gap exists regarding the role of saltmarshes in MP trapping. In this study, we evaluated five published density separation methods to determine their efficacy in recovering both low- and high-density MPs from saltmarsh sediments. Our findings identify the method proposed by Zhu et al. (2021) as the most effective, achieving an average recovery efficiency of 70.1