## Inleiding

A simple and fast procedure for the analysis of total nitrogen in meat is explained. The destruction Unit K-435 in combination with the Auto Kjeldahl Unit B-323 are used to carry out the analysis.

Kjeldahl Principle

The Kjeldahl method is the mostly used official method to determine nitrogen and protein content of food and food products. It can be summarized with the following steps:

- sample homogenization
- destruction of the sample in sulfuric acid with hydrogen peroxide to convert the nitrogen from the protein to ammonium sulfate
- conversion of the ammonium salt to ammonia
- distillation of the ammonia into a boric acid solution
- direct titration of the ammonium hydroxyborate with hydrochloric acid