FTIR Microscopy

Fourier transform infrared spectroscopy (FTIR) is used to identify the functional groups (e.g., amide, phosphate, carbonate and hydroxyl) present in organic and inorganic compounds by measuring their absorption of infrared radiation over a range of wavelengths (e.g., 50 to 5000 cm-1 wavenumber). A modern FTIR spectrometer collects and digitizes the interferogram, performs the Fourier transform and displays the FTIR spectrum. The coupling of a FTIR spectrophotometer to an optical microscope produces a system capable of doing FTIR microspectroscopy. The success in application of IR microspectrophotometers and FTIR microscopes to many areas of research (semiconductors, polymers, and pharmaceuticals), as well as forensic investigation, has established this technique as a powerful tool in the analysis of small samples. The application of FTIR analysis to archaeological investigation ranges widely from dating, to use of space, ancient pyrotechnologies, diagenesis and transformation of the archaeological record; all major aspects of site formation processes.