Spectral Characterization of Airborne Particulate Matter in the Gyeongbuk region Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy

In this study, attenuated total reflectance fourier transform infrared (ATR-FTIR) spectroscopy was applied to investigate the chemical characteristics of atmospheric particulate matter collected in Gyeongsangbuk-do, Korea. In the PM2.5 samples, functional groups associated with alkanes, carbonyls, ammonium, sulfate, and nitrate were identified. In contrast, the PM10 samples exhibited, in addition to these components, strong absorption peaks attributable to Si–O bonding, indicating a relatively greater contribution of mineral components. Samples collected from Gyeongsan, Uiseong, Sangju, Gumi, and Cheongdo showed generally similar spectral patterns, while minor differences were attributed to the presence of mineral species such as CaCO3, CaSO4·2H2O, and hydroxyl-bearing compounds (OH functional groups). Notably, the PM10 samples from Pohang displayed pronounced absorption bands associated with hydroxyl- bearing minerals, reflecting the influence of local industrial emission sources, particularly those related to the steel industry. Naturally derived yellow dust samples also exhibited spectral features similar to those of the Pohang PM10 samples, characterized by a dominance of mineral components. These results demonstrate that FTIR analysis is effective in characterizing bonding features between organic and inorganic constituents and functional groups in particulate matter, thereby contributing to a fundamental understanding of component interactions and chemical behavior in airborne particulate matters.