Determination of total dissolved nitrogen by persulfate oxidation

Hagedorn F. 1, Schleppi P. 1

1 Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Z├╝rcherstr. 111, CH-8903 Birmensdorf, Switzerland

J. Plant Nutr. Soil Sci. 163 (2000): 81-82

DOI: 10.1002/(SICI)1522-2624(200002)163:1<81::AID-JPLN81>3.0.CO;2-1


The alkaline persulfate oxidation, converting all N into nitrate, is an easy and rapid method for determining total dissolved nitrogen. We found indications that atmospheric N is trapped during the oxidation step, which can be impeded by: (1) using always the same type of autoclave bottle and a constant sample volume; (2) minimising the remaining headspace in the bottle; (3) closing the bottle caps tightly for autoclavation; and (4) determining blanks for each test series.

Keywords: dissolved organic nitrogen, persulfate oxidation, total dissolved nitrogen