The N-N[H4.sup.+] and N-N[O2.sup.-] levels were measured weekly with indophenol blue and sulphanilamide
In this method, the spectrophotometric measurement of azo-dye obtained from the reaction of N-(1-naphtyl)-ethylenediamine with diazonium salt, formed by the reaction of the nitrite and sulphanilamide
in the acidic environment, is carried out (Fig.
The nitrate present in the filtrate was then reduced to nitrite, which was measured by diazotization of sulphanilamide
and coupled with naphthylethylene diamine, as in Najawa and Cortas's method.
Keliher, "Spectrophotometric determination of nitrite with composite reagents containing sulphanilamide
, sulphanilic acid or 4-nitroaniline as the diazotisable aromatic amine and N-(1-Naphthyl)ethylenediamine as the coupling agent," Analyst, vol.
This was followed by addition of 100 [micro]l of Griess reagent (0.1% N-ethylenediamine dihydrochloride and 1% sulphanilamide
in 5% [H.sub.3]P[O.sub.4]) and incubated for 15 min at RT in dark.
In this reaction, nitrite reacts with a mixture of N-(1-Naphthyl)ethylenediamine and sulphanilamide
and forms a chromophore that has strong absorbance at 545 nm.
a.)--Zorka Pharma (Serbia), DPPH radical, Sacetylthiocholine iodide, sulphanilamide
(SA), N-(1-naphthyl)-ethylenediamine dihydrochloride (NEDA) --Alpha Aesar (Germany); Folin-Ciocalteu (FC) reagent --Merck (Germany); sodium bicarbonate, iron(II)-sulphate, acetic acid and methanol (pro aanalysis)--POCH (Poland); gallic acid, aluminium chloride, 2-deoxy-D-ribose, 2-thiobarbituric acid --Sigma Aldrich (USA); hydrogen peroxide--Lach-Ner (Czech Republic); quercetin--Extrasynthese (France); 5,5'-dithiobis-(2-nitrobenzoic acid)--J.
Then, 20ul of Griess reagent 1: 1 mixture of 1% sulphanilamide
dihydrochloride and 0.1% Naphthyl ethylenediamine dihydrochloride in 2.5% H3PO4.
14 Nitrite-nitrogen (N[O.sub.2]-N) Sulphanilamide
, NED method.
In brief, nitrous acid was formed in an acid medium and, in the presence of nitrite, the formed acid diazotizes sulphanilamide
, which was coupled with N- (1-naphthyl) ethylenediamine, and the resulting azo dye could then be measured at 540 nm.