Environ Monit Assess 2025 May 29;1976:694. doi: 10.1007/s10661-025-14188-y.

Use of concentrated detergent to optimize the analysis of microplastics in water samples with chitinous zooplankton fragments.

???displayArticle.abstract???
Microplastics (MPs) are pollutants of increasing concern, requiring labor-intensive investigation with rigorous quality control to enhance the reliability, comparability, and reproducibility of research. Some organic materials present in environmental samples are hard to eliminate and need additional steps in preparation methods. Zooplankton appendages are an example of these material and can resemble tiny MPs, complicating the visualization and separation of real MPs from the sample matrix. To address this, we developed a method to reduce chitinous zooplankton fragments in marine water samples that can be extended to freshwater. Samples were collected along the São Paulo (Brazil) coast by trawling a 300 μm plankton net, then oven-dried, and treated with H2O2 (30%, 24 h) and HNO3 (65%, 24 h). Despite these treatments, chitinous fragments remained, often resembling tiny MP fibers. We dissolved the fragments using Extran® detergent (20 mL), stirred and heated in a sand bath at 50°C for 1 and 2 h. This approach effectively eliminated chitinous material (80.5 ± 5.6%, after 2 h), accelerating visual MP identification and improving analytical accuracy. The method is recommended for samples with high chitinous zooplankton content, as it streamlines MP analysis and enhances result reliability.

???displayArticle.pubmedLink??? 40439796
???displayArticle.link??? Environ Monit Assess