Spectroscopic Characterization of Humic Acids Extracted From Different Type of Soils of Punjab

The humic acids isolated from soils of different places of Punjab have been characterized by ultraviolet visible (UV-VIS) and Fourier transforms infrared (FTIR) spectrophotometers. The texture and chemical analyses of the whole soils were also carried out by X-ray fluorescence (XRF) spectroscopy. The molecular weight of extracted humic acids was determined by colour ratio (E₂₆₅/E₄₆₅) from absorbance values recorded in UV-VIS region. The FTIR spectra revealed the presence of different functional groups of-COOH, -OH, C-O, C=N, C-OH, etc. The texture and the chemical characteristics of the whole soils have been correlated with their humic acids. It was observed that humic acids and soils of similar textures have almost identical characteristics and molecular weights.