The Dumas principle is an analytical chemistry method to determine the carbon and nitrogen content in samples. The method is based on the combusting of a sample at 1000°C in the presence of oxygen, whereby the carbon and nitrogen are converted to CO2 and NOx respectively. Both gasses are separated by chromatography and measured in a thermal conductivity cell. To calculate the crude protein content of samples (multiplying N with 6.25 ) the Dumas method can be used as an alternative for the Kjeldahl method.
The total analysis time after preparation and calibration of the equipment is approximately 10 minutes per sample. The Dumas method is relatively easy to perform. The sample preparation is limited to the weighing of the material in a cup.
In contrast to the Kjeldahl method, the Dumas method is faster and does not require hazard chemicals.
The Dumas method has a high accuracy and precision and is calibrated regularly.
ISO 16634-1 (2008) Determination of total nitrogen content by combustion according to the Dumas principle and calculation of crude protein content. Part 1: oilseeds and animal feeding stuffs. Geneva, Switzerland.
ISO 16634-2 (2009) Determination of total nitrogen content by combustion according to the Dumas principle and calculation of crude protein content. Part 2: cereals, pluses and milled cereals. Geneva, Switzerland.
ISO 14891(2008) Milk and milk products - Determination of total nitrogen content. Routine method using combustion according to the Dumas principle. Geneva, Switzerland.