For the determination of the protein content of fish meal, both the Kjeldahl wet chemical method
and the Dumas high-temperature combustion analysis
are officially approved.
is considered the classical method of protein determination in feed, based on traditional wet chemistry. As stringent standards started being applied in the 1990s with regards to the use of harmful chemicals, many laboratories evaluated the Dumas method
as an alternative.
The Dumas combustion technique
, innovative dry chemistry, is easy to use and highly accurate. The analysis is completed in few minutes, the sample is burned in a combustion furnace and elemental compounds are obtained.
The Kjeldahl and Dumas techniques are primary methods for nitrogen and protein determination, working in accordance with international standards such as AOAC, AACC, ASBC, ISO, IFFO, OIV. However, they differ in many aspects, including sample preparation, analytical procedures, and obtained values.