Infrared (IR) spectrometry is based on the principle that molecules absorb specific frequencies of infrared radiation, causing changes in their vibrational energy levels. Each type of chemical bond in a molecule has a characteristic vibrational frequency, which allows for the identification of functional groups within the molecule. The underlying principle of IR spectrometry relies on the interaction of infrared radiation with molecular vibrations, including stretching and bending motions of bonds. When IR radiation passes through a sample, certain wavelengths are absorbed by the molecule, resulting in a spectrum that represents the molecular fingerprint of the sample. This fingerprint can be used to identify and characterize organic and inorganic compounds, as well as to study molecular structure and bonding. The instrumentation of IR spectrometry typically involves a source of infrared radiation, a sample holder or cell, a monochromator or interferometer, and a detector. The source, such as a Globar or Nernst filament, emits infrared radiation, which passes through the sample. In Fourier-transform infrared (FTIR) spectroscopy, an interferometer modulates the radiation before it reaches the detector, producing an interferogram that is mathematically converted into a spectrum via Fourier transformation. Detectors, such as deuterated triglycine sulfate (DTGS) or mercury cadmium telluride (MCT), measure the intensity of transmitted or absorbed IR radiation. Modern IR spectrometers are highly sensitive and capable of rapid data acquisition, allowing for the analysis of gases, liquids, and solid samples in various forms, including thin films, pellets, and solutions. Environmental applications of IR spectrometry are wide-ranging. It is used to monitor air pollution by detecting and quantifying greenhouse gases like carbon dioxide, methane, and nitrous oxide. IR spectrometry can also analyze volatile organic compounds (VOCs) emitted from industrial