Plastics in the environment are recognized as a major pollutant having a negative impact on nature and life in general. In nature, plastics are broken down into smaller particles but do not disappear. These smaller plastics, called micro-and nanoplastics can impose a major risk for animal and human health and impose a serious threat to the environment. Microplastics are found in vegetables, fruits, sea fruits like mussels, shrimps, and oysters, but also in surface waters, tap water, bottled water, beer, air, personal care products, etc.
Detection methods for microplastics often rely on manually viewing and counting microplastics in a sample under a microscope. More advanced techniques for characterization and identification use Fourier-transform infrared spectroscopy (FT-IR), Raman spectrometry, and chromatography/mass spectrometry (GC/MS, ICP-MS). Reliable, objective quantification and determination of the size of microplastics in a larger sample volume is not possible or very cumbersome with the current methods. In addition, many methods require large financial investments, a high degree of expertise and are not easy to perform on-site. Therefore there is an urgent need for more accessible, cost-effective and more rapid methods that automatically quantifies and determines the size of all micro-plastics in a wide range of different samples.
The MuScan(TM) technology, using dedicated silicon-nitride Sieve-ID(TM) membranes, allows for such rapid analysis of microplastics in a sample. Particles down to 1µm can be accurately detected and quantified. The sample, prepared similarly as required for Raman or FT-IR, is filtered using our Sieve-ID(TM) membrane, retaining all microplastic particles. Next, the microplastic particles are fluorescently stained, followed by automated scanning of the entire membrane surface using a dedicated MuScan device. The integrated image analysis software automatically reports the number of particles found and their size. Currently the possibility for direct identification using image analysis is under development.
The Sieve-ID(TM) method with MuScan(TM) analysis will be validated in 2023 within the EU-project 'PLASTICSFATE' at Innosieve Diagnostics and other laboratories. The results will be compared in a larger Inter-Laboratory Comparison with (µ)Raman and FTIR. Results will be provided as soon as available.
Microplastics are very diverse. They can be made of different materials, differ in charge, density, hydrophobicity, smoothness or shape etc. Generic staining of such diverse materials can be very difficult. Particles can for example float or sediment making in-solution staining of microplastics prone to variations. However, staining of microplastics on a membrane allows a more controlled staining.
The MuScan(TM) protocol for microplastic detection provides an optimized procedure for staining different microplastics, either rough or smooth, high or low density, charged or non-charged, hydrophobic or not. The microplastics are distributed homogeneously over the membrane, allowing an efficient automated scanning and image analysis of the full membrane, in only 3 minutes.
Quantification of microplastic particles in a sample is of high importance for health risk assessments and to determine environmental pollution levels. The level of microplastics vary between samples and sample types. Some samples may contain up to a few hundred particles, whereas other type of samples may only hold a few, to none. A high sensitivity, or Limit of Detection, is thus of utmost importance, next to the ability to allow accurate quantification of microplastic particles in different size ranges, ranging from 1µm in size up to at least 200µm in size.
The MuScan(TM) technology has shown to be highly accurate in quantification of microplastics in a range down to even 1-10 particles per sample, at which the particle size was either 40µm or 5µm. Further validation will include a larger set of different types of microplastics and a range of microplastics varying in size from 100µm down to 1µm.
Identifying the microplastics can be important to trace back to the origin of pollution or to define the diversity of microplastics in a sample.
The MuScan(TM) protocol for microplastic analysis provides the possibility to identify microplastics. Its principle is based on the differences in emission spectra upon excitation at different wavelengths between the different types of microplastics. Further image analysis software developments will provide a first-level identification of microplastics. If for any reason, a more in-depth identification is required, the membrane can be used for subsequent Raman analysis. Herewith the full spectrum of requirements for microplastic analysis is offered.
The MuScan method provides all of the mentioned needs. No concessions are made in view of sensitivity, quantification, speed or ease of use. And all down to particle sizes of 1µm.
Are you interested in our Rapid Method for detecting, quantifying and identifying microplastics in your products?Let's discuss!