Kjeldahl Practice Guide

At the time when Johan Kjeldahl published his method for the determination of nitrogen in 1883 the electric lamp was just patented and the technical age in its childhood. Seldom in human history has an invention remained basically unchanged for such a long time as Kjeldahl’s method for nitrogen determination. As in 1883 a Kjeldahl nitrogen determination starts with sample preparation, proceeds to the digestion followed by separation using steam distillation and subsequent volumetric determination of the amount of ammonia formed in the process. Kjeldahl’s visionary idea of providing a simple method for nitrogen and protein determinations, which can also be carried out by non-academic lab personnel, has been put into practice by BUCHI’s Kjeldahl systems since 1961.