METHOD OF DETERMINING NITRITE IONS Russian patent published in 2020 - IPC G01N21/78 

FIELD: chemistry.

SUBSTANCE: invention relates to analytical chemistry and specifically to a method of determining nitrite ions. Method involves treatment of an analyzed sample with organic reagent solutions, one of which is based on p-nitroaniline, and the other is diphenylamine, separating the micellar phase from the obtained reaction mixture in the presence of a surfactant and estimating the content of nitrite ions. Surfactant used is sodium dodecyl sulphate, and the organic reagents used are aqueous solutions of 4-nitroaniline and diphenylamine, obtained by their dispersion in sodium dodecyl sulphate solution. Dispersed solution of 4-nitroaniline is additionally acidified with hydrochloric acid till pH 1–3. Obtained mixture of 4-nitroaniline and sodium dodecyl sulphate is added to the analyzed sample in amount of 1·10^-4–2·10^-3 M and 2·10^-3–1·10^-2 M respectively, and mixture of diphenylamine and sodium dodecyl sulphate in amount of 8·10^-4–2·10^-3 M and 2·10^-2–4·10^-2 M. Extraction of the micellar phase is carried out by adding to the reaction mixture hydrochloric acid in amount of 2.7–4.1 M. Evaluation of content of nitrite ions is carried out on a calibration curve or a visual test method by comparing coloring micellar phases with color scale coloring.

EFFECT: disclosed is a method of determining nitrite ions.

1 cl, 3 ex, 6 dwg