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Updated: May 7, 2026

Protocol for Microplastics Sampling on the Sea Surface and Sample Analysis
Published on: December 16, 2016
A new analytical approach for monitoring microplastics in marine sediments
Marie-Theres Nuelle1, Jens H Dekiff, Dominique Remy
1Institute of Environmental Systems Research, University of Osnabrueck, Barbarastraße 12, D-49076 Osnabrueck, Germany; Department of Biology/Chemistry, Division of Ecology, University of Osnabrueck, Barbarastraße 13, D-49076 Osnabrueck, Germany.
Abstract:
A two-step method was developed to extract microplastics from sediments. First, 1 kg sediments was pre-extracted using the air-induced overflow (AIO) method, based on fluidisation in a sodium chloride (NaCl) solution. The original sediment mass was reduced by up to 80%. As a consequence, it was possible to reduce the volume of sodium iodide (NaI) solution used for the subsequent flotation step. Recoveries of the whole procedure for polyethylene, polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polystyrene and polyurethane with sizes of approximately 1 mm were between 91 and 99%. After being stored for one week in a 35% H2O2 solution, 92% of selected biogenic material had dissolved completely or had lost its colour, whereas the tested polymers were resistant. Microplastics were extracted from three sediment samples collected from the North Sea island Norderney. Using pyrolysis gas chromatography/mass spectrometry, these microplastics were identified as PP, PVC and PET.
