ATR-FTIR spektroscopy with the Bruker Alpha

IR spectra can provide important information for process and product control of organic synthesis. By assigning functional groups of organic compounds on specific absorption or transmission bands in a spectrum identification and quantification are possible.

Modern Fourier transform infrared spectroscopes have a significant time advantage over dispersive spectrometers. By using Fourier transformation an interferogram (interference pattern) is calculated by a mathematical operation to a spectrum.

The installed ATR-FT-IR spectroscope (Bruker Alpha-FT-IR spectroscope with an ECO-ATR module) is very compact and uses a attenuated total reflection (ATR).

The sample gets applied on the surface of a ZnSe ATR crystal, which is functioning as fiber optics. Upon entry of the light waves in the sample, a total reflection occurs. This attenuated totally reflected beam gets measured and the resulting signal gets converted into an infrared spectrum by means of a Fourier transformation.

ATR-FT-IR spectroscopy has the advantage over transmission measurements that in most cases the measurement of liquid, pasty and solid sample can be executed without extensive sample preparation, simply by applying the sample directly onto the crystal.