Advances in analytical techniques for micro and nanoplastic characterization: Addressing the need for standardization and reference materials

The misuse of plastics and poor waste management translates into a parallel rise in environmental plastic waste that is continuously degraded into micro and nanoplastics. Due to the presence of these compounds in various media and their harmful effects on living organisms, efforts to develop techniques to identify and quantify microplastics have increased. However, the evaluation of these particles is limited by the lack of standardized analytical methods and reference materials. The aim of this study is to develop standards of micro and nanoplastics with known properties to be used in the development of analytical techniques. At AIMPLAS we are developing methods to obtain microplastics from different polymers. We also obtain nanometric PLA and micrometric spherical PP, PE, and PET. To facilitate monitoring, fluorescently labelled microplastic standards are also being developed. This is particularly useful in targeted assays like bioassays and for the evaluation of the degradation of microplastics in different media such as compost, soil or water. There are several techniques currently used to analyse plastics. Nevertheless, these techniques are limited by the small size and different morphology of the particles. In this scenario, spectroscopic techniques with microscopy and chromatographic techniques coupled to specific sampling devices are appearing. The analysis of microplastics requires a methodology adapted to the type of sample and oriented towards the most appropriate analytical technique depending on the information to be obtained. On the one hand, microscopy coupled with infrared radiation (µ-FTIR) is used to determine the size, shape or colour of the particles and the nature of the polymers. On the other hand, pyrolysis coupled to gas chromatography and mass spectrometry (Pyr-GC/MS) is used to identify and quantify polymers and additives. This study demonstrates the importance of developing micro and nanoplastic reference materials for boosting methodologies based on different analytical techniques. Also see: https://micro2024.sciencesconf.org/557349/document