ABSTRACT
Spectrophotometric methods of analysis are based on the interaction of light with matter. Compounds respond differently to the incident radiation depending on the wavelength range and hence the energy of the radiation, in addition to the electronic structure and types of bonding. The UV/Vis radiation (200-750 nm) is considered an energetic radiation that can interact with valence electrons of molecules and ions to excite them to a higher energy level. Thus, the absorption in this region gives important information about the electronic nature of the compounds. In the meantime, the infrared radiation in the region (1-1000 μm) is less energetic than UV/Vis and best interact with vibration of atoms and can reflect the nature of bonding and functional groups of a compound.
