ABSTRACT
The most generally accepted theory concerning diffuse reflectance and the transparency of light-scattering and light-absorbing layers has been developed by Kubelka and Munk. Since chromatography is becoming an increasingly interesting field for the application of diffuse reflectance spectroscopic techniques it seems appropriate to examine the validity of the Kubelka-Munk theory in relation to systems of nature of adsorbent. The Kubelka-Munk theory can, however, hardly be expected to be valid with such an experimental setup, and approximations would have to be used with the original function. The phenomenon of radiative transfer for diffuse incident radiation and isotropic scatter can be treated more rigorously than the Kubelka-Munk equations, particularly in cases where the refractive index of scattering particles is unity. Certain rules have to be observed if the Kubelka-Munk equation is to be used under meaningful conditions, no matter whether the spots are investigated in the transmission or reflectance mode.
