Airborne microplastics (AMPs), known to be persistent pollutants, have recently been detected in the atmosphere and even in human lung tissue, raising concerns about potential human respiratory exposure. In light of these concerns, this study aimed to investigate the distribution and composition of AMPs in Seoul. μ-Raman spectroscopy was employed to identify fine particles (≥5 μm) and to contribute to the development of standardized monitoring protocols. Monthly air sampling was conducted from September 2023 to March 2024 at an urban rooftop site using a PM10 air sampler. Samples were pretreated with hydrogen peroxide to remove organic matter, then filtered through a silicon filter. μ-Raman spectroscopy was applied for qualitative and quantitative analysis of microplastics. The mean concentration of AMPs was 74.0 ± 29.9 particles/m3, with polyethylene (46.7%) and polystyrene (21.8%) being the most prevalent polymer types. Most particles (64.5%) were in the size range of 5–10 μm, and fragment type particles accounted for 98.9% of the total. These results indicate that respirable microplastics are commonly present in urban air and that polymer composition may reflect both material properties and usage patterns. This research provides baseline data for future exposure and risk assessments and supports the need for international standardization of airborne microplastic analysis protocols.

Raman Spectroscopy is a non-destructive analysis method without complex pre-processing and it can reduce the costs and time. A surface-enhanced Raman scattering (SERS) technique was tried to the detection of Benzo[a]pyrene which is one of the hazardous minor components of foods. To demonstrate the Raman signal enhancement effect by graphene as substrate, thymine was used as the standard material. As a result, the Raman signal of thymine has 102 enhancement. Herein, new SERS trials established to pursue improve the speed, simplicity and suitability of detecting minor components in foods.

An enantioselective recognition of D- and L-tryptophan (Trp)-b-cyclodextrin (CD) inclusion complex was performed using electrochemical and FT-Raman spectroscopic analysis. From the electrochemical analysis, the selectivity coefficient (KDL) of b-CD inclusion complexes was found higher than that of the D- and L-Trp in phosphate buffered saline (PBS, pH=7.0) solution. The percentage of enantioselectivity (I%ee) for peak current of D-Trp-b-CD inclusion complexes was observed higher than that of L-Trp-b-CD inclusion complexes in PBS solution. From Raman spectroscopy, chemical shift difference (D, cm-1) for the C=C stretch, ring vibration, and ring breathing of D-Try-b-CD inclusion complex were observed higher than that of L-Trp-b-CD inclusion complex. The electrochemical and Raman spectroscopic analyses were found very useful for chiral detection of racemic amino acid in the presence of b-CD.

Raman characteristics of various minerals constituting natural rocks collected from uranium deposits in Okcheon metamorphic zone in Korea are presented. Micro-Raman spectra were measured using a confocal Raman microscope (Renishaw in Via Basis). The focal length of the spectrometer was 250 mm, and a 1800 lines/mm grating was installed. The outlet of the spectrometer was equipped with a CCD (1,024256 pixel) operating at -70°C. Three objective lenses were installed, and each magnification was 10, 50, and 100 times. The diameter of the laser beam passing through the objective lens and incident on the sample surface was approximately 2 m. The laser beam power at 532 nm was 1.6 mW on the sample surface. Raman signal scattered backward from the sample surface was transmitted to the spectrometer through the same objective lens. To accurately determine the Raman peak position of the sample, a Raman peak at 520.5 cm-1 measured on a silicon wafer was used as a reference position. Since quartz, calcite, and muscovite minerals are widely distributed throughout the rock, it is easy to observe with an optical microscope, so there is no difficulty in measuring the Raman spectrum. However, it is difficult to identify the uraninite scattered in micrometer sizes only with a Raman microscope. In this case, the location of uraninite was first confirmed using SEM-EDS, and then the sample was transferred to the Raman microscope to measure the Raman spectrum. In particular, a qualitative analysis of the oxidation and lattice conditions of natural uraninite was attempted by comparing the Raman properties of a micrometer-sized natural uraninite and a laboratory-synthesized UO2 pellet. Significantly different T2g/2LO Raman intensity ratio was observed in the two samples, which indicates that there are defects in the lattice structure of natural uraninite. In addition, no uranyl mineral phases were observed due to the deterioration of natural uraninite. This result suggests that the uranium deposit is maintained in a reduced state. Rutile is also scattered in micrometer-sizes, similar to uraninite. The Raman spectrum of rutile is similar in shape to that of uraninite, making them confused. The Raman spectral differences between these two minerals were compared in detail.