Nowadays "microplastics" (MPs) is an already well-known term and results of micro-sized particles found in consumer products or environments are regularly reported. However, studies of native MPs smaller than 1 μm, often referred to as nanoplastics (NPs), in analytically challenging environments are rare. In this study, a correlative approach between scanning electron microscopy and Raman microscopy is tested to meet the challenges of finding and identifying NPs in the 100 nm range in various environments, ranging from ideal (distilled water) to challenging (sea salt, human amniotic fluid). To test the viability of this approach in principle, standardized polystyrene beads (Ø 200 nm) are mixed into the various environments in different concentrations. Promising detection limits of 2 10-3 μg/L (distilled water), 20 μg/L (sea salt) and 200 μg/L (human amniotic fluid) are found. To test the approach in practices both sea salt and amniotic fluid are analysed for native NPs as well. Interestingly a nylon-NP was found in the amniotic fluid, maybe originating from the sampling device. However, the practical test reveals limitations, especially with regard to the reliable identification of unknown NPs by Raman microscopy, due to strong background signals from the environments. We conclude from this in combination with the excellent performance in distilled water that a combination of this approach with an advanced sample preparation technique would yield a powerful tool for the analysis of NPs in various environments.

Information derived from microscopic images of Li-ion cells is the base for research on the function, the safety, and the degradation of Li-ion batteries. This research was carried out to acquire information required to understand the mechanical properties of Li-ion cells. Parameters such as layer thicknesses, material compositions, and surface properties play important roles in the analysis and the further development of Li-ion batteries. In this work, relevant parameters were derived using microscopic imaging and analysis techniques. The quality and the usability of the measured data, however, are tightly connected to the sample generation, the preparation methods used, and the measurement device selected. Differences in specimen post-processing methods and measurement setups contribute to variability in the measured results. In this paper, the complete sample preparation procedure and analytical methodology are described, variations in the measured dataset are highlighted, and the study findings are discussed in detail. The presented results were obtained from an analysis conducted on a state-of-the-art Li-ion pouch cell applied in an electric vehicle that is currently commercially available.