Automated determination of ammonium and nitrate in soil extracts by distillation

Abstract

Automated procedures for the determination of ammonium and nitrate in soil extracts are described. Distillation of the extract with magnesium oxide, with subsequent determination of ammonia by the automated indophenol method, is used for ammonium. For ammonium plus nitrate, the nitrate is reduced with titanium(III) sulphate during distillation with magnesium oxide, and ammonia determined as before. The method has wider application, for example, to the analysis of fertilisers and water samples.