The total protein amount is important information for quality control and protein values for the food and feed industry along with research facilities. Alpha Resources offers a variety of certified reference materials suitable for use with the Dumas Method.
The most efficient way to find the Nitrogen/Food Protein values is the Dumas Method which combusts samples using a high-temperature furnace in an oxygen-rich environment. The Dumas method is much easier to use, faster and fully automated compared to the Kjeldahl method. Also, as with Kjeldahl, it does not give a measure of true protein which requires different correction factors to obtain a correct value.
Dumas nitrogen determination requires well-homogenized samples, heated in a high-temperature furnace where the combustion takes place rapidly at over 1000 °C in the presence of pure oxygen. This produces mostly water, carbon dioxide and nitrogen as well as several oxides (NyOx). This gas mixture (most water is removed) is passed through a reduction chamber containing copper heated to around 650 °C. This converts nitrogen oxides into elemental nitrogen and collects the oxygen in excess. Different traps remove the residual water and carbon dioxide. Total nitrogen content is measured by a thermal conductivity detector.