We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Microplastic extraction from sediments established? – A critical evaluation from a trace recovery experiment with a custom-made density separator
AI summary Read the abstract
Scientists evaluated the accuracy of a custom density separator for extracting small microplastic particles from sediment, finding variable recovery rates across different polymer types. Standardized and validated extraction methods are essential for accurate measurements of microplastic contamination in sediment environments.
By now, microplastics are present in every environmental compartment of which sediments are considered one major sink. As a result, several approaches for their enrichment from sediments have been established in microplastic analysis. At the same time, the smaller microplastics gained increasing attention regarding their ecotoxicological relevance. A customized sediment separator was evaluated with trace amounts of small microplastic particles (150-300 μm) of the nine most common polymers. Separation was performed with sodium bromide (ρ = 1.5 g cm-3). The experimental recovery comprises pristine as well as incubated polymers to include early biofouling effects. Polymer quantification was achieved exclusively using pyrolysis-gas chromatography-mass spectrometry. The results reflected an overall mean recovery of 65%. Interestingly, the observed behaviour seems to be density related. While polymers of higher densities revealed higher average extraction efficiencies (74-97%), those of less dense polymers are reduced and span between 34 and 65%. These observations hypothesize possible polarity related surface interactions as a relevant factor for microplastic particle extraction. In contrast, the density of the separation fluid seemed to be of subordinate relevance, if small microplastic particles were extracted in trace amounts. Early biofouling enhanced recoveries of some polar polymers, whereas the effect on apolar polymers was even negative in some cases. In a comparative synopsis with other published density separation approaches, a limited number of comparable experimental setups concerning particle size, polymer density range and polymer concentration were revealed. Nonetheless, some related experiments point to similar density/polarity driven extraction behaviour. In conclusion, the presented study suggests a re-evaluation of current separation approaches for extraction of low number/mass concentrations of small microplastics from sediments to enable a more comprehensive insight into factors that influence surface properties for microplastics extraction. Concurrently, it raises the question of how an ideal environment relevant recovery experiment can be designed.
More Papers Like This
An optimized density-based approach for extracting microplastics from soil and sediment samples
AI summary Read the abstract
Researchers optimized a density-based extraction method for isolating microplastics from soil and sediment samples, testing different density solutions and separation steps to maximize recovery efficiency. The improved protocol reduces contamination risks and particle loss, enabling more accurate quantification of microplastics in terrestrial and freshwater sediment matrices.
Not all microplastics are created equal. Quantifying efficacy bias and validation of density separation methods
AI summary Read the abstract
Researchers systematically evaluated density separation methods used to extract microplastics from environmental matrices (water, soil, sediment), investigating whether efficacy varies by polymer density and identifying potential sources of bias in current approaches. The study highlighted risks from lack of methodological standardisation and called for detailed reporting to improve reproducibility across microplastics research.
Extraction of microplastics from sediment matrices: Experimental comparative analysis
AI summary Read the abstract
Extraction efficiencies of four methods for separating microplastics from sediment matrices were experimentally compared using spiked samples, finding that density separation with saturated NaCl was adequate for most polymer types but underperformed for high-density polymers, and that no single method achieved complete recovery across all particle sizes and shapes.
Separation of microplastics from deep-sea sediment using an affordable, simple to use, and easily accessible density separation device
AI summary Read the abstract
Researchers developed an affordable, simple, and accessible density separation device for extracting microplastics from deep-sea sediment, addressing the lack of accuracy and reproducibility in existing extraction methods. The study included spike-recovery experiments as positive controls to validate extraction performance across different sediment matrices.
Not all microplastics are created equal. Quantifying efficacy bias and validation of density separation methods
AI summary Read the abstract
Researchers evaluated and validated density separation methods for extracting microplastics from environmental matrices, quantifying efficacy bias across different polymer types with varying densities. They found that recovery rates differ substantially depending on polymer density relative to the separation solution, introducing systematic bias in microplastic concentration estimates across studies.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.