Charakterizace částic mikroplastů připravených z plastových výrobků

Abstract

Plastics are widely used due to their advantageous properties, but this has led to a growing problem of plastic waste and microplastics, small particles formed by the degradation of plastics. These particles, present in the environment and detected in the human body, pose a potential health risk. Current research on the impact of microplastics on health and ecosystems often suffers from a lack of methodological rigour and does not reflect the true nature of environmental microplastics. The aim of this bachelor thesis was to develop and validate a method for quantitative analysis of microplastic particle size, with an emphasis on their accurate characterization using light microscopy and image analysis. The theoretical part of the thesis deals with the classification and degradation of plastics, the origin and properties of microplastics and methods for measuring their size. The practical part focuses on a detailed description of sample preparation and the development of a suitable analytical method for the quantitative size analysis of microplastics that is repeatable, robust and applicable in practice. Microplastics were prepared from plolystyrene crucibles by grinding in a laboratory knife mill and then separated into four size fractions by a wet sieving process. The 63-80 µm fraction was then used to develop and validate the method. As part of the development of the analytical method itself, the optimal setting of the method parameters was tested and a suitable measurement methodology was determined. The validation results confirmed that the selected method is suitable for quantitative particle size analysis of polystyrene microplastics in the fraction (63–80 µm) prepared by the grinding process on a laboratory knife mill.