Potassium dichromate, in an acidic solution, will oxidize organic material. The reduction to the chromium ion is associated with a color change, which can be measured as a change in absorbance using a spectrophotometer. The degree of change is linearly related to the total energy contained in a sample and this information can be used to predict the energy content of unknown samples. However, the slopes of these relationships are significantly different for carbohydrates and proteins. It is hypothesized that these variations are due to differences in the reaction kinetics and that these differences can be used to predict the biochemical composition of mixtures of proteins and carbohydrates. Data collected to date indicate changes to the procedure are necessary for accurate estimation of biochemical content.
Schneider '00, William J., "An Assay for the Estimation of Organic Content in Unknown Biological Samples" (2000). Honors Projects. Paper 22.