FT-IR Spectroscopy has made significant contributions in identification and characterization of materials. The origins of infrared spectroscopy as an analytical tool can be traced back to the pioneering work of Sir William Herschel in 1800. Since this time FT-IR spectroscopy has evolved in three notable phases
- First-generation instruments introduced in late 1950s were based on NaCl prism as light dispersing element. Due to major constraints the first generation was short lived
- Second generation was introduced in 1960s when the prism was replaced by the grating. Notable improvements were achieved but drawbacks such as slow speed, poor sensitivity and poor wavelength reproducibility limited lifespan of second generation instruments
- The third generation evolved around the same time when the first generation instruments were in vogue. The Michelson interferometer which had been invented in 1881 replaced the need for isolation of single wavelength bands as all wavelengths could be scanned simultaneously. The first FT-IR spectrum was recorded in 1949 by Peter Fellgett. For several years thereafter it required hours to transform the interferometer to the useful spectrum using large and expensive computer systems. In 1966 Cooley- Tukey algorithm was applied for quick Fourier transformations. With this application FT -IR spectroscopy acquired the required muscle and it quickly overthrew dispersive IR instruments.
Early day FT-IR instruments were expensive and large in size. The technological advances in coming years made FT-IR spectrometers affordable and improved their performance features several fold. Today FT-IR spectroscopy finds numerous applications in pharmaceuticals and foods R&D, polymer characterization, forensic investigations, lubricants and fuel additives, surface coating characterization and biochemical studies.
The increased demand for FT-IR spectrometers has given rise to emergence of several reputed instrument manufacturers whose products can be seen in laboratories across the world.
Some of the popular names are: