Open AccessSpeciation Study of Nitrite/Nitrate through Diazo-Coupling Reaction Using Silica-Perchloric Acid as a Novel Catalyst at Trace Level: Application to Environmental Samples
Author(s) -
Narayanamma Chinna Adeppagari,
Nayana Kudluru Omkarappa,
Pandurangappa Malingappa
Publication year - 2021
Publication title -
asian journal of chemistry/asian journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.145
H-Index - 34
eISSN - 0975-427X
pISSN - 0970-7077
DOI - 10.14233/ajchem.2021.23107
Subject(s) - chemistry , nitrite , nitrate , diazo , perchloric acid , inorganic chemistry , catalysis , sulfanilic acid , nuclear chemistry , organic chemistry
A simple, sensitive and rapid spectrophotometric method has been developed based on the diazocoupling reaction in the quantification of nitrite/nitrate at trace level using silica perchloric acid (SPCA)as an acid catalyst. 5-Amino-2-mercapto benzimidazole has been used as a novel amine and coupledwith N-(1-naphthyl)ethylenediamine dihydrochloride (NEDA) to produce an intense coloured azodye. The proposed method showed wide linearity in the concentration range 0.1-1000 ppm of nitrite.The molar absorptivity and Sandell′s sensitivity were found to be 1.6 × 106 L mol–1 cm–1 and 0.0012 μgcm–2 respectively. Nitrate was measured after its reduction to nitrite using optimized copper-cadmiumreductor column. The proposed method has been successfully applied to measure trace levelnitrite/nitrate from a variety of sample matrices like water, soil, milk and radiator coolant.