ABSTRACT
Dispersive spectroscopy is one important method of collecting infrared (IR) data. Traditionally, the IR spectrum is generated by passing a beam of dispersed IR light through a sample and onto a detector. The dispersed radiation is generated by passing IR radiation through a prism or grating to separate the light into each of its frequencies. These frequencies pass into the sample and are selectively absorbed if they match an excitation frequency of a functional group or other molecular vibrations in the material. The analytical power of chromatograph-interfaced IR spectrometer is available for many analyses requiring gas chromatograph and liquid chromatograph separation techniques. The normal IR frequency range used for routine purposes is 4000 to 200 cm-1: this covers most vibrational modes of interest in an organic material. The far IR is defined in the region of 650 to 10 cm-1 and used for studying metallic compounds and in analyzing the lattice motions of crystals for morphological studies.
