Angular Dependence of Diffuse Reflectance Infrared Spectra. Part III: Linearity of Kubelka-Munk Plots

Abstract

The linearity of plots of the Kubelka-Munk function against concentration is investigated for weak and strong absorption bands in the spectrum of a typical organic analyte, caffeine. The linear region is extended when measurements are made with an off-axis optical geometry, in comparison to an in-line configuration. For the latter configuration, the linearity is improved when crossed polarizers are placed before and after the sample.