Microplastics testing

Different types of water are the most common sample matrix in microplastics testing. Plastic particles can be screened from natural waters to identify polluted river, lake, or sea areas. Analysis may also focus on bottled water to optimize the production process and packaging so that as few particles as possible end up in the product. 

Microplastic analysis of wastewater is typically focused on optimizing filtration systems to minimize the release of plastics into the environment. Testable systems can range from small filters intended for washing machines to filters used on large ships.

Microplastics can be analyzed using several methods, the most common of which are Raman, FTIR, and py-GC/MS. Raman and FTIR can identify and quantify microplastic particles by size range and plastic type. Identification is based on reference libraries, so even rarer plastics can be detected. Very small particles (< 1 µm) are generally not detected, however, which makes these methods unsuitable for nanoplastic analysis.

Pyrolysis-GC/MS, on the other hand, can detect nanoplastics but does not provide information on particle size distribution. Instead, the overall quantity of microplastics within a set size range is reported as a mass fraction (in µg/l). If detailed information about the shape and size of plastic particles is needed, SEM imaging can also be used.

You can read more about the differences between analysis methods in our article on ISO 16094 standards, which outline the procedures for detecting microplastics in clean water samples with vibrational spectroscopy and thermoanalytical methods.