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Fourier transform infrared spectroscopy (FTIR) [1] 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-resolution spectral data over a wide spectral range.
Reflection-absorption FTIR: Sample is usually prepared as a thick block and is polished into a smooth surface. [4] As the IR beam strikes the sample surface, some of the energy is absorbed by the top layer (<10 μm) of the bulk sample. The altered incident beam is then reflected and carry the composition information of the targeted surface area.
The peak at the center is the ZPD position ("zero path difference"): Here, all the light passes through the interferometer because its two arms have equal length. The method of Fourier-transform spectroscopy can also be used for absorption spectroscopy. The primary example is "FTIR Spectroscopy", a common technique in chemistry.
A common spectroscopic method for analysis is Fourier transform infrared spectroscopy (FTIR), where chemical bonds can be detected through their characteristic infrared absorption frequencies or wavelengths. These absorption characteristics make infrared analyzers an invaluable tool in geoscience, environmental science, and atmospheric science.
It is also used in forensic analysis in both criminal and civil cases, for example in identifying polymer degradation. It can be used in determining the blood alcohol content of a suspected drunk driver. IR spectroscopy has been used in identification of pigments in paintings [2] and other art objects [3] such as illuminated manuscripts. [4]
An infrared spectroscopy correlation table (or table of infrared absorption frequencies) is a list of absorption peaks and frequencies, typically reported in wavenumber, for common types of molecular bonds and functional groups.
The linear absorption (FTIR) spectrum is indicated above the 2D IR spectrum. The two peaks in the 1D spectrum reveal no information on coupling between the two states. After the waiting time in the experiment, it is possible to reach double excited states. This results in the appearance of an overtone peak.
The accessibility, rapid sample turnaround and ease of use of ATR with Fourier transform infrared spectroscopy (FTIR) has led to substantial use by the scientific community. This evanescent effect only works if the crystal is made of an optical material with a higher refractive index than the sample being studied. Otherwise light is lost to the ...