A Novel Technique for Recording Infrared Spectra of Powders: Attenuated Total Reflection Immersion Medium Spectroscopy

Abstract

A new recording technique for the measurement of infrared spectra of powders using ATR spectroscopy is presented in this paper. The method, called ATRIMS (attenuated total reflection immersion medium spectroscopy), circumvents some ofthe problems of conventional methods. With ATRIMS, an ATR reflection element is covered with a thin film of liquid paraffin (Nujol) as an immersion medium for the powder. Compared to ATR spectroscopy of dry powders on the surface of a reflection element, ATRIMS shows higher band intensities, lower detection limits, reduced necessary sample amount, easier handling, and shorter analysis time. The resulting spectra have the typical band intensity-wavelength relationship of ATR spectra. The method is well suited for the investigation of strong absorbing substances (e.g. magnetite) and strong scattering substances (e.g. hydrargillite).