Comparative ATR FTIR spectroscopic analysis of urban soils from different regions of Punjab India for forensic application

Soil is an important material in both environmental and forensic studies, as it can reveal information about its place of origin and the factors that have affected it. Urban soil, in particular, contains traces from pollution, construction, industries, and daily human traces, which make it unique for each locality. This study focuses on comparing urban soil samples collected from five major locations across Punjab, India, starting with Pathankot (north), Fazilka (west), Mansa (south), Mohali (east), and Ludhiana (central). These locations were selected to represent the four corners and the central region of the state. All collected soil samples were shadow dried to remove moisture, sieved to remove stones and other particles, dried further, and ground into a fine powder. The samples were then analyzed directly using Fourier Transform Infrared (FTIR) spectroscopy. This method helps to identify the different chemical bonds and functional groups present in the soil. The initial FTIR spectra showed that the five soil samples had mostly similar absorption peaks, with only small changes in the intensity and position of certain peaks. These small variations could be related to local environmental factors such as pollution, road dust, or nearby industrial activity. Although the results are quite similar, this study provides valuable baseline data for understanding the composition of urban soils in Punjab. In forensic science, such information can be useful in matching soil samples found at crime scenes to their possible locations. The work also supports the idea of building a reference FTIR database for future forensic and environmental research in Punjab.