Comparison of a short method for Kjeldahl digestion using a trace of selenium as catalyst, with other methods

A short digestion method for Kjeldahl nitrogen determination, using a trace of selenium as catalyst and described in this paper, gives results comparable to the American Association of Cereal Chemists (1976) method using mercuric oxide catalyst, for all compounds tested except for nicotinic acid. However, nicotinic acid is a minor component of food materials and it is not normally assayed by the Kjeldahl method. Selenium, like mercury, is known to be toxic7 but mercury ranks more highly than selenium as an environmental problem.