Determination of ammonium in KCl extracts of soils by the salicylate method1
作者:
DarreilW. Nelson,
期刊:
Communications in Soil Science and Plant Analysis
(Taylor Available online 1983)
卷期:
Volume 14,
issue 11
页码: 1051-1062
ISSN:0010-3624
年代: 1983
DOI:10.1080/00103628309367431
出版商: Taylor & Francis Group
关键词: Colorimetric method;Inorganic N;EDTA complexation
数据来源: Taylor
摘要:
A method is described for the direct estimation of NH+4‐N in 2MKCl extracts of soils based on the emerald green color formed when NH3and salicylate react in the presence of NaOCl at high pH.‐The reagent concentration, solution pH, and time and temperature of color development specified are those giving maximum molar asorptivity. Precipitate formation observed when KCl extracts containing divalent cations were treated with color developing reagents was eliminated by addition of 1 mL of 6% EDTA to complex Ca2+and Mg2+. Free EDTA or complexed Ca2+or Mg2+did not markedly affect color development or molar absorptivity. The proposed method efficiently recovered NH+4‐N added to 2MKCl extracts of soils and studies showed that the proposed method and two other procedures differing in principle gave similar values for NH+4‐N in extracts of 5 soils. The proposed method is a simple, rapid, accurate, and precise technique for the colorimetric determination of NH+4‐N in KCl extracts of soils.
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