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The Microplastics Problem

Tiny plastic bits are everywhere!

Our use of plastics has skyrocketed, and now we’re finding these microplastics in everything from food chains to oceans. These little pieces don’t break down easily and might harm the environment, even ending up in us! To understand their impact, we need to identify them.

Raman spectroscopy: A powerful tool to see the small stuff

This technique lets us examine individual particles automatically and painlessly. Unlike other methods, Raman can analyze a wide range of particle sizes, from 1 micrometer to hundreds of micrometers. It can also tell similar materials apart very well. We can use Raman to study microplastics in anything from rivers to animal guts, even drinking water and the air!

Automating the analysis: Finding microplastics in bottled water

We filtered bottled water through a special filter and used a powerful microscope with Raman to analyze a tiny area. This area contained a lot of particles!

The image was analyzed using the Renishaw’s Particle Analysis module to produce a list of 5,663 particles for potential analysis. 3. In this case, the particles to target for analysis were chosen based on their size relative to the filter holes. The minimum particle area was limited to 4 µm2 (2.3 µm in diameter) producing 1,026 particles. The largest particle, fiber-like in aspect ratio, had a length of 147 µm. Each particle was analyzed sequentially and automatically using 532 nm laser excitation and a 50× objective. The microscope then automatically analyzed each particle, one by one.

What did we find?

We identified 18 different materials, including things like minerals, pigments, dyes, and of course, microplastics! We found that most of the particles were either polypropylene (a type of plastic) or calcium carbonate (a mineral). Smaller particles were mostly calcium carbonate, while larger ones were more likely to be polypropylene.

 

Raman can even identify dyes and pigments!

This information can help bottled water companies improve their filtration processes. Raman can even analyze particles with mixed components, like a particle containing both plastic and a pigment.

This powerful technique allows us to see and identify tiny plastic particles with incredible detail, helping us understand the microplastics problem.