THE CASE OF N/PROTEIN DETERMINATION IN FISHMEAL: DUMAS AND KJELDAHL METHOD COMPARISON

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.

Kjeldahl determination 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.

Read the dedicated Application Note about protein determination in fishmeal to learn how to perform the analysis with the Dumas and Kjeldahl methods and discover all the results obtained with VELP analytical instruments on BIPEA proficiency testing sample.

Proficiency Testing Programs organized by institutions like BIPEA allow the comparison of several laboratories’ results, in order to evaluate their analytical performance on the same homogeneous sample. By taking part in such programs on a regular basis, the performance of VELP instruments is constantly evaluated. Samples provided by BIPEA are analyzed in accordance with predetermined conditions and the obtained results are successfully compared with the given tolerance range.