Microplastics and Nanoplastics Analysis

Imaging Solutions from ZEISS

Our environment is heavily polluted with microplastics. The term microplastics usually refers to particles with a size of 5 millimeters or smaller; in the environment they are fragmented into smaller units of 1 µm or smaller, then called nanoplastics. Pollution with plastic occurs in oceans, soils, consumer products and food, it endangers the health of these systems and of humans.

  • SEM for imaging and filter particle segmentation
  • AI guided software for classification and quantification
  • Raman spectroscopy for chemical identification
  • A multi-modal combination of all three techniques

Healthy oceans, seas, coastal and inland waters are vital for our societies and the future of our planet.

Funding Program 'Horizon Europe'

by the European Union

The classification model is capable of distinguishing the different particle types based on their properties. Color code: PE=green, PVC=red, PA=dark blue, PS=light blue.

Particle Analysis with ZEN Intellesis

Reveal Microplastics with Machine Learning

When using machine learning for particle analysis you may start with imaging the MNPs on a filter via SEM. The software ZEISS ZEN Intellesis automatically identifies particles with a deep learning model on a SEM image.

The user trains the classification model by mouse clicks on a few images, indicating different objects and assigning particle types manually. The resulting model distinguishes particle properties like diameter, orientation or chemical properties after correlation with Raman spectroscopy results, e.g. different polymers like PVC, PA, PS, and PE.

Time-consuming segmentation steps on hundreds of images are done by machine learning algorithms (including Deep Learning). ZEN Intellesis Object Classification, a Python-powered tool offers pixel classification with real multichannel feature extraction and segmentation. By pre-trained networks even complex multidimensional, multi-modal data can be analyzed, regardless of their origin.

The image is a combination of SEM images (grey), Raman map of polyvinylchloride (red) and LM darkfield image (blue). A good example of multi-modal microscopy, supported by ZEISS ZEN Connect software and nanoGPS navYX (Horiba).

Raman-SEM-Correlation with ZEN Connect

Identify Nanoplastics in a Multi-Modal Approach

SEM is able to find nanometer sized particles being well within the range of both micro- and nanoplastics. But SEM alone cannot distinguish between types of particles, especially organic ones. The correlation with Raman enables the detection of the latter. Laboratories already equipped with a standalone Raman, are enabled to use it in combination with a standalone ZEISS SEM.

A so-called NanoGPS chip from Horiba is used as a marker on your specimen to aid relocation of the point of interest in both SEM and Raman. The software module ZEISS ZEN Connect offers a correlative workspace tailored for multi-modal experiments. It supports the import of Horiba Raman maps and enables image-based navigation in the SEM. Additionally, connection of multi-modal data, overlay, and alignment of images and analytical results are possible with ZEN Connect.

RISE Microscopy

An Integrated Nanoplastics Analysis Solution

An alternative to using two separate systems is to perform Raman-SEM correlations with a fully integrated solution. RISE (Raman Imaging and Scanning Electron Microscopy) is the combination of WITec Confocal Raman Imaging with a ZEISS FE-SEM all in one instrument.

Combining the chemical sensitivity of Raman with the SEM allows you to analyze nanoplastic particles more efficiently, accurately and reliably than before. The sample with its regions of interest stays in the vacuum chamber, is transferred from one objective, SEM or Raman, to the other. The workflow is streamlined and convenient to use, from SEM imaging to Raman spectroscopy, delivering complementary information of the specimen - a chemical fingerprint.

Download the White Papers

Two white papers about microplastics analysis

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