Fourier Transform Infrared Spectroscopy Lab

FTIR microscope in EPS
FTIR microscope in EPS
Frank Schrama

The Fourier Transform Infrared Spectroscopy (FTIR) Laboratory at AMNH is the focal point for vibrational spectroscopy studies of geologic materials in the New York metropolitan area. The centerpiece of the lab is a Thermo Scientific, Nicolet iN10 Infrared Microscope. The infrared microscope is equipped for mid-infrared analysis (spectral range of 750 to 4000 wavenumbers) with a liquid nitrogen cooled MCT detector. Analyses include reflectance and/or transmission spectroscopy. The infrared microscope can run individual spots with an adjustable aperture that ranges from 25 to 200 microns. Spectral resolution is adjustable between 4 and 12 wavenumber sampling. The micro-FTIR imaging system features a fully automated mechanical stage and an LRU array detector.

Besides absorption and reflectance FTIR, the instrument is equipped with micro-Attenuated Total Reflectance (ATR) and micro-Grazing Angle FTIR attachments which allow measurements of sample surfaces down to a few mono-layers.

For over 30 years FTIR spectroscopy has gained wide acceptance as an important analytical tool in geochemical and mineral studies. Infrared spectroscopy has long been used as a tool for structural determination of minerals and glasses. The emergence of FTIR spectroscopy as the tool of choice for the determination of dissolved H2O and CO2 in silicate glasses, however, has made it an indispensable technique for the analysis of volatile elements. Consequently, FTIR spectroscopy is used by geochemists and mineralogists to tackle problems ranging from the volatile contents of lavas in volcanic magma chambers to the structural state of H2O in minerals and melts. Mid-infrared spectroscopy is also commonly used on remote sensing spacecraft and our instrument has applications for building spectral libraries relevant to planetary studies.

The FTIR laboratory and scheduling are managed by Dr. Celine Martin ([email protected])