A novel method for magnetic labelling and extraction of small-sized microplastics (4 μm) from soil

Ubiquitous microplastics (MP) have emerged as a global environmental concern. However, limited attention is given to the behaviour of small-sized MP (¡ 10 μm) due to the challenges associated with separating and quantifying MP from an exceedingly complex matrix. We hypothesised that magnetic labelling of MP would greatly facilitate MP extraction efficiency. Magnetic labelling was achieved by heating MP (4 µm polystyrene spheres) to induce surface melting in a suspension containing Fe3O4 magnetic nanoparticles (MNS) in water, followed by shaking at room temperature, thus fixating MNS in the MP surface layer during cooling, and extraction using a magnet. Herein, 4 μm MP (1581 items) were spiked in 5 ml water, the conditions were optimized for maximizing MP recovery. Incubating MP and MNS at 90°C for 2.5 h gave the highest MP recovery rate of 91.67 ± 7.09 Also see: https://micro2024.sciencesconf.org/558479/document