85 % of the world’s nitrogen demand for fertilizer is primarily derived from ammonia in the form of urea, ammonium nitrate, phosphate and sulfate. Ammoniacal components can also be found in soil, sludge and bio waste. In those sample matrices, a mixture of several nitrogen containing compounds as urea, nitrogen from other organic origin such as amino acids, proteins, nitrate, nitrite and ammonium can be found.
Using the Kjeldahl equipment, selective nitrogen determination of the Total Kjeldahl Nitrogen (TKN and TKN+), the ammonium (ammonium distillation) and the nitrate concentration (Devarda distillation) of a sample is possible. In addition, to these parameters, the organic nitrogen content can be calculated.