Method development for Microplastic analysis in Marine Sediment

As a follow-up of a pilot study, an additional method development project was performed, aimed at improving the cleaning of sediment samples regarding natural organic and calcium-containing materials. Because the budget and time for this project was limited, this study was focussed on the most organic-rich sample Dutch sediment location, Voorland 1 (in the Westerschelde estuary). We tested several methods for digestion of organic matter, and finally selected a two-stage digestion using KOH and NaOCl, respectively. The resulting digestion method appeared to be promising, and will be tested in a NIVA-RWS method development project in 2025.