Attenuated total refection spectroscopy under conditions weak absorption: New method for determination of integrated intensities

The basic principles of attenuated total reflection (ATR) spectroscopy are briefly described and its main areas of application are listed. It is shown using symbolic calculations that in the case of ATR spectra measured under conditions of weak absorbance, the area under the curve of absorbance of an isolated Lorentz absorption band is directly proportional to the integral band intensity. It is shown that the proportionality factor between these quantities contains a single a priori unknown parameter, i.e., the real part of dielectric constant of the studied medium in the maximum of the studied band. This fact offers a new scope for determining the integrated intensities of isotropic condensed media directly based on experimental ATR data.