Requirements for Thermal Analysis by Variable-Temperature Diffuse Reflectance Infrared Spectroscopy

Abstract

The effect of temperature on diffuse reflectance infrared spectroscopy measurements is discussed. Instrumental parameters that determine the accuracy of variable-temperature diffuse reflectance Fourier transform infrared spectroscopy (VT-DRIFTS) measurements are identified, and methods for removing baseline artifacts resulting from fluctuations in these parameters are given. Procedures for extracting structure-specific quantitative information from DRIFTS spectra acquired at different temperatures are outlined. The use of VT-DRIFTS to generate vibration-specific absorbance band intensity and center frequency temperature profiles for calcium oxalate monohydrate is described, and correlations between these profiles and the known thermal behavior of calcium oxalate monohydrate are given.