Nitrogen Determination in Nitrate Free Fertilizers
Nitrogen Determination in Nitrate Free Fertilizers according to AOAC 955.04-C (Kjeldahl Method) – Block Digestion
Nitrogen determination is one of the key analyses performed in quality control. The samples require digestion with sulphuric acid to convert nitrogen into ammonium sulphate. After conversion to ammonia through the alkalisation with sodium hydroxide it is distilled into a boric acid receiver via steam distillation, followed by a titration with sulphuric acid solution. The nitrogen content is calculated using the volume from the sulphuric acid and the weight from the sample.