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Modified method of nitrite determination in soils by sulphanilic acid/N‐(1‐naphthyl)ethylenediamine
Author(s) -
Puttanna K.,
Rao E. V. S. Prakasa
Publication year - 1986
Publication title -
zeitschrift für pflanzenernährung und bodenkunde
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 0044-3263
DOI - 10.1002/jpln.19861490502
Subject(s) - ethylenediamine , nitrite , sodium nitrite , chemistry , absorbance , soil water , inorganic chemistry , nuclear chemistry , chromatography , organic chemistry , nitrate , environmental science , soil science
When high nitrite concentrations are encountered in soils, the conventional method using sulphanilic acid and N‐(1‐naphthyl)ethylenediamine poses some working problems. In order to increase the working range, pH of the solution of the azo‐dye formed by the reaction of nitrite with sulphanilic acid and N‐(1‐naphthyl)ethylenediamine was raised to 6.0 by adding sodium acetate solution and the absorbance was measured at 480 nm. In combination with the conventional method, the modified method allows analysis of soils containing 1 to 75 ppm nitrite‐N conveniently without the necessity of changing the size of the aliquot. The modified method was tested in soils varying in pH from 4.8 to 8.0 and organic carbon from 0.4% to 9.8% and was shown to give better results than the conventional method at high nitrite concentrations.