ABSTRACT
The diffuse reflectance spectra obtained for the oxytetracycline-magnesium silicate mixture showed a significant difference between the spectrum of the equilibrated mixture and the physically mixed sample and also from those of the individual components. In order to obtain meaningful data for the physical-chemical studies of adsorption phenomena, the preparation of samples is extremely important. A comprehensive review on the application of diffuse reflectance spectroscopy to problems in inorganic chemistry has been presented by W. L. Clark. Possible uses of diffuse reflectance spectroscopy for the investigation of organic compounds have been discussed in numerous papers. Most of the work in diffuse reflectance spectroscopy has been carried out at ambient temperatures. Even in cases where samples were heated in order to investigate certain temperature effects on kinetic processes, removal of co-adsorbed moisture, irreversible decomposition, and other chemical changes, the samples will have cooled down to ambient temperatures by the time measurements are carried out.
