Fourier Transform InfraRed Spectroscopy (FTIR) is most useful for identifying chemicals that are either organic or inorganic in nature. It relies on the identification of the types of chemical bonds (functional groups). The wavelength of light absorbed is characteristic of the chemical bond. FTIR spectra of pure compounds are generally so unique that they are like a molecular “fingerprint”. It can be utilized to quantitate some components of an unknown mixture. It can be applied to identify chemicals (e.g., fluxes, cleaners, coatings and contaminants). The spectrum of an unknown can be identified by comparison to STI’s library of known materials used within the industry.