METHOD FOR DETERMINING MASS CONCENTRATION OF 1,1-DIMETHYLHYDRAZINE DEGRADATION PRODUCTS IN PLANT SAMPLES Russian patent published in 2021 - IPC G01N21/59 G01N1/00 

FIELD: analytical chemistry.

SUBSTANCE: invention relates to analytical chemistry; it can be used to control the mass concentration of 1,1-dimethylhydrazine and its degradation products in plant samples. A method for determining the mass concentration of 1,1-dimethylhydrazine and its degradation products in plant samples includes isolation of 1,1-dimethylhydrazine and its degradation products from a plant sample and determination of their concentrations in plant samples, while isolation of 1,1-dimethylhydrazine and its degradation products is carried out by flushing from the surface of plant leaves with an area of 0.5 m² using 50-200 cm³ of distilled water, the resulting aqueous solution is clarified by adding 1 cm³ of 1% KOH solution and 1% Zn₂SO₄ solution, the solution is filtered through a paper filter with a pore diameter of 1.0-2.5 nm, after purification, reactions of the formation of colored complexes are carried out: to determine the concentration of 1,1-dimethylhydrazine, an alcoholic solution of p-nitrobenzaldehyde is added, a yellow complex is formed in an alkaline medium, a solution of 1,2-naphthoquinone-4-sulfonic acid is added to determine the mass concentration of dimethylamine, sodium salt forms an orange-brown complex, a Griss reagent is used to determine the content of nitrite ions, a mixed reagent of ferrotic salt and caustic sodium is used to determine the content of nitrate ions; acetylacetone is used in the determination of formaldehyde; an alcohol solution of bindon is used in the determination of tetramethyltetrazene, the optical density is measured using a spectrophotometer relatively to a comparison solution that does not contain the ingredient being determined, the concentration of the substance is set according to a pre-built calibration graph.

EFFECT: reducing the sample preparation time and reducing errors of determinations.

1 cl, 1 dwg, 1 tbl