ATR-FTIR Spectroscopic Studies On Rural Area Soil Samples From Prayagraj For Forensic Considerations

Abstract

The ATR-FTIR spectroscopy is a versatile tool which is used to characterize the organic/inorganic part of soil samples including plant materials along with their various decomposition stages, flora/fauna, humic substances, suspended organic minerals. FTIR is also useful tool for analysis of soil minerals that includes primary i.e. quartz, feldspars; secondary i.e. silicates, clays, aluminosilicates soil minerals. Infrared spectroscopy with the transformation of (FTIR) gives detailed characteristics of the soil from the smallest samples (1 mg), making it a very important aid for forensics science. FTIR spectra of 69 samples (from the surface layer, at 15 cm depth) are qualitatively analysed. The absorption frequencies of the peaks in the spectra of each site in wave number units (cm-1) are reported along with the with the identified minerals. The minerals in the study were identified as quartz, Feldspar (albite, microcline, orthoclase) clay minerals (kaolinite, montmorillonite, illite,) and metal oxide (Hematite), in the soil samples. From the study of number of i.r. absorption peaks it can be concluded that quartz and feldspars are the primary minerals in the study area while clay mineral and metal oxide is a minor constituent.