Infrared internal reflection spectra of methanol-water mixtures

Infrared spectra of 0-100 vol% methanol-water mixtures were recorded over the 3900-900 cm^-1 range at 8 cm^-1 resolution using internal reflection techniques and a Fourier transform spectrometer. There were interactions of the water and methanol which made themselves evident as changes of the water OH stretching and deformation band frequencies. The methanol band frequencies were unaffected by changes in concentration and consequently those bands can be used for quantitative purposes, but water bands should not be used for precise determinations.