The KBr Pellet: A Useful Technique for Obtaining Infrared Spectra of Inorganic Species

Abstract

The reproducibility of the KBr pelleting technique for inorganic sulfates was assessed using a Fourier transform infrared spectrometer. Day-to-day variation in peak frequencies of selected bands had standard deviations ranging from 0. to 1.5 cm⁻¹. This 1 cm⁻¹ standard deviation was shown to be due to changes in bandshape, probably due to variations in sample preparation from operator to operator. It was concluded that the reproducibility of sulfates in KBr is sufficient to allow the design of computerized spectral matching programs to identify specific sulfate species based on band frequencies and intensities.