The detection and quantification of microplastics in the marine environment is essential for understanding the overall impact of plastic pollution on ecosystems and human health. Here we investigate the ability to detect very low concentrations of colloidal particles with diameter d=0.1 μm-0.8 μm in seawater using Static Light Scattering (SLS) and Dynamic Light Scattering (DLS) techniques. The detection limit of the instrument was determined using monodisperse spherical polystyrene latex model particles of 0.2 μm and 0.5 μm diameter. Colloid concentrations and sizes have been shown to be measurable down to about 10 g/L-6 g/L. Light scattering measurements of seawater from various locations in Western Europe showed that DLS detected colloidal particles in filtered seawater with a pore size of 0.8 μm. These particles had concentrations below 1 μg/L and average diameters of approximately 0.6 μm. We emphasize that these particles are not necessarily made of plastic. No particles were detected after filtration.
Published Date: 2023-09-15; Received Date: 2023-06-14
