ISSN:
1435-0661
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
3 analysis, however, require expensive equipment or complicated procedures. The objective of this study was to develop a simple, rapid accurate procedure for NO3 analysis that can be conducted in laboratories worldwide, without the need for specialized equipment. We based our studies on a colorimetric method that involves electrophilic aromatic substitution (nitration) between nitronium and salicylate. The simplified procedure was tested for NO3 analysis of water, soil, and resin extracts. Only 1 mL of sample containing 0 to 4 mg NO3−N L−1 is required, and a single solution (TRI solution made as a mixture of sodium salicylate [2-hydroxybenzoic acid monosodium salt], NaCl, and ammonium sulfamate [sulfamic acid monoammonium salt]) is used for color development. The detection limit is 0.1 μg NO3−N, with linearity up to 4μg NO3−N in a final volume of 11 mL. Evaporation of the sample may be done in several ways to remove water from reactants, as long as the temperature for activation of nitration is attained. Resin extracts from 2 M HCl required neutralization with 2 M NaOH prior to analysis, and soil extracts from 1 M KCl provided more uniform results than from 2 M KCl. Results from all types of solution samples were highly significantly correlated with those by the automated Cd-reduction method. This simplified sodium salicylate procedure (SSP) for NO3 analysis is simple, reproducible, and it requires only inexpensive equipment.
Type of Medium:
Electronic Resource
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