Dumas method
In analytical chemistry, the Dumas method is a method of elemental analysis for the quantitative determination of nitrogen in chemical substances based on a method first described by Jean-Baptiste Dumas in 1826.[1]
The Dumas technique has been automated and instrumentalized, so that it is capable of rapidly measuring the crude protein concentration of food samples. This automatic Dumas technique has replaced the Kjeldahl method as the standard method of analysis for nutritional labelling of protein content of foods (except in high fat content foods where the Kjeldahl method is still preferred due to fire risks).[citation needed][2]
Method
The method consists of combusting a sample of known mass to a temperature between 800 and 900 °C in the presence of
Advantages and limitations
The Dumas method has the advantages of being easy to use and fully automatable. It has been developed into a considerably faster method than the Kjeldahl method, and can take a few minutes per measurement, as compared to the hour or more for Kjeldahl. It also does not make use of toxic chemicals or catalysts. One major disadvantage is its high initial cost, although new technology developments are reducing this drawback. Also, as with Kjeldahl, it does not give a measure of actual protein, as it registers non-protein nitrogen, and different correction factors are needed for different proteins because they have different amino acid sequences.
See also
- Combustion analysis, a similar approach to Dumas but involving carbon, hydrogen, and nitrogen as well
- Bicinchoninic acid assay, a colorimetric analysis method for protein-nitrogen
References
- ^ Dr. D. Julian McClements. "Analysis of Proteins". University of Massachusetts Amherst. Retrieved 2007-04-27.
- ISBN 9781441914774.