We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Cryogrinding and sieving techniques as challenges towards producing controlled size range microplastics for relevant ecotoxicological tests
AI summary Read the abstract
Researchers tested cryogenic grinding and liquid sieving methods to produce controlled-size microplastics (20-60 μm) from real pearl farming equipment for ecotoxicological testing, finding the protocol effective but noting challenges with overproduction of smaller particles.
The impact of microplastics (MP) has attracted much attention from the scientific community and many laboratory assessments have been made of their effects on aquatic organisms. To produce MP from real environmental plastic waste, which would enable more realistic experiments, we used plastic pearl farming equipment from French Polynesian lagoons. Here, the pearl oyster Pinctada margaritifera could encounter MP coming from their breakdown in its surrounding environment. We tested an established method based on mechanical cryogenic grinding and liquid sieving. Our desired size range was 20-60 μm, corresponding to the optimal particle size ingested by P. margaritifera. The protocol was effective, generating MP particles of 20-60 μm (∼17,000-28,000 MP μg), but also produced too many smaller particles. The peak in the desired size range was thus flattened by the many small particles <3 μm (∼82,000-333,000 MP μg; 53-70% of total analysed particles), visible at the limit of Coulter counter analysis (cut-off point: 2 μm). Laser diffraction analysis (cut-off point: 0.4 μm) provided greater detail, showing that ∼80-90% of the total analysed particles were <1 μm. Diverging particle size distributions between those expected based on sieving range and those really observed, highlight the need to perform fine-scaled particle size distribution analyses to avoid underestimating the number of small micro- and nanoplastics (MNP) and to obtain an exact estimation of the fractions produced. Size and microstructure characterization by scanning electron microscopy suggested spontaneous particle self-assembly into crystal superstructures, which is the supposed cause of the divergence we observed. Overall, our results emphasize that particle self-assembly is a technical hurdle requiring further work and highlight the specific need to finely characterize the size distribution of MNP used in ecotoxicological experiments to avoid overestimating effects.
More Papers Like This
An assessment of methods used for the generation and characterization of cryomilled polystyrene micro- and nanoplastic particles
AI summary Read the abstract
Researchers evaluated cryomilling as a method for generating environmentally realistic microplastic and nanoplastic particles from polystyrene for use in laboratory studies. They found that increasing the number of milling cycles consistently produced smaller particles without altering the polymer's chemical composition. The study provides optimized protocols for creating heterogeneous test particles that more closely resemble the microplastics found in real environmental samples.
Optimisation of cryomilling parameters to produce microplastic particles
AI summary Read the abstract
Researchers optimized cryomilling — a technique that uses freezing to make materials brittle before grinding — to produce well-defined microplastic particles for laboratory experiments. Controlling variables like temperature, grinding time, and mill settings allowed production of particles with more consistent size and shape distributions than other methods. Reliable production of laboratory microplastics is important for toxicity studies where particle characteristics need to match what is found in the environment.
Exploring fragmentation techniques for the preparation of test microplastics
AI summary Read the abstract
To advance microplastic research, scientists need standardized test particles that mimic real-world plastic fragments, but producing these reliably is challenging. This study compared three cryogenic grinding techniques — mixer mill, immersion blender, and ultracentrifugal mill — for preparing laboratory microplastics, providing practical guidance for harmonizing methods across the research community.
Methods for the Generation and Characterization of Cryomilled Micro- and Nanoplastics
AI summary Read the abstract
Researchers developed a cryomilling method to produce environmentally realistic microplastics and nanoplastics for laboratory studies, creating particles that better mimic real-world plastic fragments in size, shape, and surface properties. Having more realistic test particles improves the accuracy of research into how microplastics affect living organisms.
Cryogenic Milling of Consumer Plastics for High‐Throughput Characterization of Polydisperse, Amorphous Microplastics
AI summary Read the abstract
Researchers developed a cryogenic milling method to produce realistic microplastic samples from common consumer plastics for use in laboratory studies. The technique generates particles with the irregular shapes and surface properties of real-world microplastics, unlike the smooth spherical beads typically used in experiments. The study provides a standardized way to create more environmentally representative test materials, which could improve the accuracy of microplastic toxicity research.
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.