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Updated: Sep 24, 2025
Sampling, Sorting, and Characterizing Microplastics in Aquatic Environments with High Suspended Sediment Loads and Large Floating Debris
Published on: July 28, 2018
An assessment workflow to recover microplastics from complex biological matrices
Marina F M Santana1, Frederieke J Kroon2, Lynne van Herwerden3
1College of Science and Engineering, James Cook University (JCU), Townsville, Queensland 4811, Australia; Australian Institute of Marine Science (AIMS), Townsville, Queensland 4810, Australia; AIMS@JCU, Division of Research and Innovation, James Cook University, Townsville, Queensland 4811, Australia.
This study evaluated microplastic separation methods, finding that chemical digestions and density flotations have specific limitations with marine biological samples. Method suitability is crucial for accurate microplastic contamination assessments.
Area of Science:
- Environmental Science
- Marine Biology
- Analytical Chemistry
Background:
- Microplastic contamination is a growing global concern, particularly in marine ecosystems.
- Accurate quantification of microplastics requires effective separation from complex biological matrices.
- Existing separation methods may have limitations when applied to diverse marine organisms.
Purpose of the Study:
- To assess the effectiveness of four microplastic separation methods (nitric acid, potassium hydroxide digestions; sodium chloride, potassium iodide flotations) on four marine taxa.
- To evaluate the impact of these methods on five common microplastic types.
- To identify limitations and provide guidance for microplastic analysis in marine samples.
Main Methods:
- A criteria-guided workflow was employed for method evaluation.
- Four separation techniques were tested on hard coral, sponge, sea squirt, and sea cucumber.
- Five polymers (polyethylene, polystyrene, PET, PVC, rayon) were analyzed for recovery and integrity.
Main Results:
- Potassium hydroxide digestion showed unacceptably low matrix clarification.
- Polyethylene terephthalate (PET) discolored with all reagents; rayon unraveled and discolored with nitric acid.
- High recovery rates were generally observed, with exceptions for dense plastics using NaCl; potassium iodide was effective for rayon recovery.
Conclusions:
- Specific separation methods exhibit limitations with different biological matrices and microplastic types.
- The integrity of certain microplastics (rayon) can be compromised by separation treatments.
- Careful assessment of method suitability is essential for reliable microplastic contamination data in marine environments.
