Fourier transform infrared spectroscopy (FTIR) is one of the most powerful spectroscopy methods in analytical chemistry. Infrared spectroscopy reveals information about the vibrational states of a molecule. The intensity and spectral position of IR absorption bands allow the identification of the structural elements of molecule. In an FTIR spectrometer the infrared spectrum is obtained by first collecting an interferogram of a sample signal using an interferometer and then performing a Fourier transform on the interferogram. The advantage is that data is collected at many wavelengths simultaneously (rather then consecutively) resulting in faster and more sensitive measurements. Our instrument is Nicolet 6700 FTIR spectrometer from Thermo Scientific equipped with CsI beamsplitter and several accessories to measure in transmission, grazing-angle reflection and attenuated total reflection modes.