Scouting Out Microparticles in the Battle With Microplastics

There are many reasons that one might want to detect microparticles in a sample, and equally many sources from which microparticles may be generated. From dust in clean rooms to powders in cosmetics or pharmaceuticals, and contaminants in the food or environment, some microparticles are welcome whilst others most certainly are not. Whatever your reason for needing to identify microparticles, having a system available that can rapidly and easily detect and identify microparticles from diverse sources and in varied samples is key to any analytical toolbox.

Of growing interest recently is the identification of microplastics, not just in the environment but also in the food chain. Concern has been increasing not only for the damage being caused to the environment but also for the potential negative impacts on health as these tiny particles find their way into the food chain. Great effort is consequently being channeled into trying to understand the scale of the issue.

We spoke to Harald Fischer, Marketing Director at WITec, about ParticleScout, their latest Raman-based solution for rapid identification of microparticles, and the role it can play in assisting microplastic studies.

Karen Steward (KS): How did the conception of ParticleScout come about?

Harald Fischer (HF): Over the past several years we’ve received an increasing number of requests for analyses of powders and filtered samples. Microplastics, in particular, have become very important along with investigations of other forms of contamination. We created ParticleScout specifically to address this growing demand.  

KS: How does ParticleScout compare to previous methods for the identification of microparticles?

HF: Microparticle measurements can be tedious and time consuming if individual particles are located and characterized one at a time. ParticleScout automates every step in the process. We leveraged the sensitivity of our hardware and the speed of our electronics to greatly accelerate the experimental workflow. ParticleScout can find, classify and identify microparticles with unequalled speed and user-friendliness.

KS: Is ParticleScout accessible to a no-expert user?

HF: Yes. Raman microscopy is the underlying technology, but one doesn’t need to be a Raman specialist or any sort of spectroscopist to get the full benefit of the system. White light microscopy is used to survey the sample and detect particles. The researcher then specifies the particles that they’re interested in and a Raman spectrum is automatically acquired from each one. The Raman spectra identify the particles like a fingerprint. With our TrueMatch integrated Raman database management software, the process can be further refined by drawing on catalogs of established Raman spectra.  

KS: Identification of microplastics, a growing area of interest, has been highlighted as one particular application for ParticleScout. Were there any challenges presented in the identification of microplastics – for example the large diversity in plastic types, form or effects of degradation of the plastics?

HF: Excitation wavelength selection is always a consideration when looking at different materials because of fluorescence, but that’s also been automated in our alpha300 confocal Raman microscope series. When looking at microparticles of diverse size and shape, focus stacking keeps even larger particle images sharp and advanced algorithms are there to analyze particle outlines for the mask generation. Substrates that are uneven or tilted can generally be compensated for with our integrated autofocus. The degree to which some microplastics can become less Raman active as they degrade over time in saltwater and sunlight is a very interesting area of research. Even then ParticleScout is great tool for acquiring precise, comprehensive results.  

KS: What types of samples are you seeing ParticleScout being used on for the identification of microplastics?

HF: Just about any microparticle sample where the particles remain stationary will work. Particles from the sub-micron range through several hundred microns can be investigated rapidly and precisely. That includes ones with sparsely or densely distributed particles and ones with filters of cellulose, metal, silicon and many other materials. 

KS: Could you tell us about any particular microplastics studies in which ParticleScout has been a game-changer?

HF: For microplastics at least, the game is just getting started. This is a field of application with immense growth potential in industrial and regulatory development. ParticleScout is an analytical tool that arrived right on time.

Harald Fischer was speaking to Dr Karen Steward, Science Writer for Technology Networks.