Essay On Ir Spectroscopy

oduction

Spectroscopy is the interaction between the electromagnetic radiation and the matter, which results in different spectra. These spectra are useful to detect functional information about the chemical compounds. Several sources o regions are involved in spectroscopy in which one involves the use of infrared region that ranges from 400- 800nm. The infrared spectroscopy interest in the fundamental vibrations of the molecules caused with the interaction of IR radiation. IR spectra is used to identify the functional groups in the compounds as each bond has a different tendency to vibrate. IR spectra are used as a fingerprint for the chemical structures.

IR spectra are usually recorded as the absorption spectra; the absorption pattern of

The interferogram is subjected to Fourier transform, which yield the spectrum of background. Then the single beam is fed to sample to obtain the spectrum from Fourier transform of interferogram. Computer software is programmed to automatically subtract the spectrum of background from sample spectrum. In this way, we obtain the spectrum of any compound. The spectrum is almost same as the spectrum is obtained by dispersive IR spectrometer. FTIR spectrum is a plot of intensity versus time ( time domain spectrum.

Detectors: output of detectors is in digital form. All the computers can easily perform this operation. Even slow speed computers can also do this. The commonly used detectors in FTIR spectrometer are:

(1) pyro electric detectors (2) photo electric detectors.

Advantages of FTIR over dispersive IR spectrometers

(1) Time saving; Interferogram is obtained in less than a second.

(2) It gives better signal -to-noise ratio. (3) Better sensitivity

(4) It is computer based, give out put in digital form and allow multiple scans of same sample and store them in the memory of computer.

Drawback of