ABSTRACT
Fast Fourier transform (FFT) is a mathematical-computer procedure that can process and convert information from an interferogram into a typical infrared spectrum. Infrared spectroscopy has experienced a vast improvement are resolution, sensitivity, speed, the development of innovative IR accessories, analysis software, micro sampling and new analytical techniques. These improvements may be attributed to two major factors: the merger of the Michelson Interferometer with the mathematics computer technique of FFT and advances in computer technology, allowing infrared spectrometers to be interfaced with microcomputers for data acquisition, analysis, processing and spectral searching. Infrared studies of aqueous solutions were once prohibited due to the strong infrared absorption of water and the absence of suitable water insoluble infrared cells. When infrared radiation enters certain crystalline materials with high refractive indices, the radiation is totally internally reflected. In addition, the internal reflectance creates a wave called an evanescent wave that extended slightly beyond the surface of the attenuated internal reflectance crystal.
