What is the basic principle of FTIR?
In FTIR spectroscopy, an interference wave is synthesized from two beams separated by a beam splitter, the detected interference waveform (interferogram) is Fourier-transformed, and a spectrum is obtained by separating each wavenumber..
What does FTIR mean?
Fourier transform infraredFTIR stands for Fourier transform infrared, the preferred method of infrared spectroscopy. When IR radiation is passed through a sample, some radiation is absorbed by the sample and some passes through (is transmitted).
What is the range of FTIR?
Fourier Transform Infrared spectrophotometers (FTIR) are mainly used to measure light absorption of so-called mid-infrared light, light in the wavenumber range of 4,000 to 400 cm-1 (wavelengths 2.5 to 25 µm), in order to identify and quantify various materials.
What is FTIR and how does it work?
Fourier-transform infrared spectroscopy (FTIR) is a technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid or gas. An FTIR spectrometer simultaneously collects high-spectral-resolution data over a wide spectral range.
Why interferometer is used in FTIR?
The wavelengths that are absorbed by the sample are characteristic of its molecular structure. The FTIR spectrometer uses an interferometer to modulate the wavelength from a broadband infrared source. A detector measures the intensity of transmitted or reflected light as a function of its wavelength.
How do you interpret FTIR results?
Once the initial testing and spectrum collection is complete, interpretation of FTIR spectra comes next. Typically, interpreting FTIR spectra starts at the high frequency end to identify the functional groups present. The fingerprint regions are then studied to positively identify the compound.
Why KBr is used in FTIR?
This method exploits the property that alkali halides become plastic when subjected to pressure and form a sheet that is transparent in the infrared region. Potassium bromide (KBr) is the commonest alkali halide used in the pellets. … Degassing is performed to eliminate air and moisture from the KBr powder.
What are the selection rules for FTIR absorption?
The selection rule says, that vibrations are only IR active (or allowed), if the molecular dipole moment changes during the vibration. A diatomic molecule with the same atoms cannot be excited to vibrate because no dipole moment is present.
Can FTIR detect metals?
Based on our observation, FTIR technique proves to be an efficient tool for detecting structural changes and probable binding sites induced by the presence of a metal pollutant, cadmium, in the marine environment.