RU2724591C1 - Method of photometric identification and determination of concentration of components of tank mixture - Google Patents

Abstract

FIELD: chemistry.SUBSTANCE: invention relates to analytical chemistry and a method of photometric identification and determination of concentration of components of tank mixture. Method consists in sampling an aliquot of the mixture, diluting it, introducing a reagent-indicator of the determined ion, photometric determination of ion concentration. At that, in each component of the tank mixture at the production stage, an ion-label is introduced in an amount which is an order greater than the background level of the content of the given ion in the component of the tank mixture, aliquot is successively diluted with an organic polar solvent with dielectric permeability equal to 12–50 F/m, and water in volume ratio of aliquot : solvent : water equal to 1:0.5–11.05:0–7.55, and concentration of ion content of the component in the tank mixture is determined.EFFECT: technical result is higher accuracy of preparing solutions and enabling determination of counterfeit products.4 cl, 1 tbl

Description

The invention relates to analytical chemistry, and in particular to a method for rapid field analysis of components of tank mixtures used as complex solutions of a chemical plant protection system (CWP).

The closest is a method for determining the concentration of ions by photometric measurement of an aliquot solution after it is diluted with an indicator solution. The result obtained is compared with the calibration data and the ion concentration is determined [patent DE 201610208967, IPC G01N 21/31, G01N 21/64, G01N 21/77, G01N 33/18; 2017].

The disadvantage of this method is the impossibility of its application to identify the components of tank mixtures.

The objective is to develop a method for identifying and determining the concentration of components of tank mixtures, which allows for monitoring the preparation of solutions of the chemical plant protection system, monitoring the correct dosage of components, and also for determining the qualitative and quantitative composition of ready-made mixtures and identifying counterfeit drugs.

The technical result is to increase the accuracy of the preparation of solutions of the chemical plant protection system, the possibility of determining counterfeit products, which allows to increase the efficiency of the chemical plant protection system.

The technical result is achieved in the method of photometric identification and determination of the concentration of the components of the tank mixture, which consists in the selection of an aliquot of the mixture, its dilution, the introduction of a reagent-indicator of the detected ion, photometric determination of the concentration of the ion, while an ion tag is introduced into each component of the tank mixture at the production stage, in an amount an order of magnitude higher than the background level of the given ion in the component of the tank mixture, an aliquot is successively diluted with an organic polar solvent with a dielectric constant of 12-50 F / m and water in an aliquot volumetric ratio: solvent: water of 1: 0.5-11 , 05: 0-7.55, and the concentration of the component in the tank mixture is determined by the concentration of the ion-tag.

The method of photometric identification and determination of the concentration of the components of the tank mixture, characterized in that pesticides are used as components of the tank mixture.

The method of photometric identification and determination of the concentration of the components of the tank mixture, characterized in that herbicides are used as components of the tank mixture.

A method for photometric identification and determination of the concentration of components of a tank mixture, characterized in that pesticides and herbicides are used as components of the tank mixture.

Currently in agriculture in Russia and abroad, tank-mixes are intensively used - solutions consisting of several functionally bi-directional bioactive components of various chemical nature, unstable in water and possibly antagonized to each other in particular, mixtures of pesticides and herbicides. The preparation of tank mixtures, as a rule, is carried out in the field, and the composition of a particular mixture can vary significantly depending on the cultivated crop and geographic region of use. It is not possible to analyze the working solution for the content of each component directly in the field in view of the complexity of such an analysis, which requires expensive equipment and the conditions of a specialized chemical laboratory. Accordingly, the problem arises of the express cost-effective method of input control, control of the correct dosage, as well as the detection of counterfeit drugs.

The essence of the proposed method for identifying and determining the concentration of components of tank mixtures consists in introducing individual inorganic ion-tags into each pesticide and / or herbicide at the production facilities of the supplier-manufacturer of plant protection products. The introduced ion-tags allow the photometric method to determine the compliance of the prepared solution with the required qualitative and quantitative composition of the components of the tank mixture (chemical plant protection system), determine the composition of the finished mixture and verify the authenticity of the starting preparations. Thus, the quality of tank mixtures is ensured, which increases the effectiveness of the chemical plant protection system (CWP).

The main requirements for the introduced ion: the label should not be “masked” by the components of the mixture, it should not harm the environment, it should be detected photometrically without complications against the background of the pesticidal and / or herbicidal composition, and it should not interfere with the photometric determination of other ion-tags introduced to other components of the tank mixture. Since the exact content of the labels in the initial components of the tank mixtures is known, the determination of their ratio in the tank mixture in the field allows you to set and control the quantitative ratio of the components of the mixture - pesticides and / or herbicides.

At the production stage, special salts of transition metal ions (labels) are introduced into the components of tank mixtures in strictly specified quantities, an order of magnitude higher than the background level. Each component (pesticide, herbicide) has its own ion tag.

To identify the component of tank mixtures (CWS), the mixture is homogenized and a standard reagent indicator is added. At the same time, organic solvents are used to achieve the optical transparency of the working solution of SHP.

The use of organic solvents is justified by the behavior of the dispersed system of the working solution of CWP with dilution. A simple dilution with water (even 20-50 times) does not lead to a true solution from the original colloidal system, since due to micelle formation the solution acquires intense Rayleigh scattering and opalescent, which makes it optically opaque. The introduction of an organic solvent into the working solution of SChzr allows one to reduce the dielectric constant of the medium and, as a result, to destroy micelles formed by the active components of hhzr and adjuvants. As a result of dilution, the solution becomes optically transparent, which allows it to be analyzed.

As organic solvents, organic solvents in structure belonging to different classes of compounds can be used. Most preferred are slightly polar solvents with a dielectric constant ε = 12 ÷ 50 F / m, for example, alcohols (methanol, ethanol, n-propanol, isopropanol, ethylene glycol), ketones (acetone, butanone-2), heterocyclic compounds (tetrahydrofuran, dioxane , pyridine, morpholine, methylpyrrolidone), dimethyl sulfoxide (DMSO), N, N-dimethylformamide (DMF), acetonitrile.

The obtained optically transparent solution is examined using a photocolorimeter or spectrophotometer. The result obtained is compared with the data of the calibration graph (purchased complete with each pesticide and herbicide). The ion concentration is determined by which the content of the component in the mixture is calculated.

The method allows the analysis of both individual components of tank mixtures, and the tank mixtures themselves.

The table shows examples of tank mixtures (CWS).

The invention is illustrated by the following examples.

Example 1. Identification and determination of the concentration of the components of the solution of CWS.

and). Rapid determination of the mass fraction of the component Dexter KS in the solution of CPS by the content of the cobalt label Co ²⁺ .

In a volumetric flask with a capacity of 100 ml, 20 ml of the analyzed solution of CXPR are pipetted, 2 ml of hydrochloric acid solution (5 wt.% Aqueous solution), 2 ml of potassium rhodanide (or ammonium) solution (50 wt.% Aqueous solution) are added, several drops of a solution of ascorbic acid (10 wt.% aqueous solution) until the red color disappears and 1 ml is excess.

Then add 20 ml of isopropyl alcohol, measured by a cylinder, and thoroughly mix the contents of the flask. Assess the transparency of the mixture: if the solution is transparent - make up the mark with isopropyl alcohol; if turbidity is observed - bring to the mark with distilled water.

Determine the optical density of the solution at a wavelength of λ 570-650 nm (λ _max = 620 nm) with respect to the reference solution not containing cobalt Co ²⁺ , using cuvettes with a light absorbing layer thickness of 50 mm.

According to the calibration graph, the content of cobalt Co ²⁺ (A) in the analyzed solution (μg) is found. The mass concentration of cobalt Co ²⁺ in the analyzed solution is found by the formula

Where

20 - the volume of an aliquot of the solution of CWS, ml;

A is the mass content of the label ion (for example 1a, cobalt Co ²⁺ ) in the sample, μg.

The mass fraction of the component Dexter KS (X) in 1 l of a solution of SCS is determined by the formula

Where

K is the coefficient of the SCHR solution in terms of the content of the label ion (ml / μg) - for cobalt Co ²⁺ in Dexter KS is 0.1 ml / μg;

A - mass content of cobalt Co ²⁺ in the sample, mcg.

b) Rapid determination of the mass fraction of the Agron BP component in the SCHS solution by the content of the phosphate ion label.

In the field, 20 ml of the tank mixture (CWS) are taken and pipetted into a 100 ml volumetric flask, 2 drops of the reagent solution are added to phosphates (GOST 10671.6). After 3 minutes, add 1 drop of a solution of tin dichloride in glycerol (GOST 10671.6).

Then add 10 ml of acetone, measured by a cylinder, and thoroughly mix the contents of the flask. Estimate the transparency of the mixture: if the solution is transparent - bring acetone to the mark; if turbidity is observed - bring to the mark with distilled water.

, используя кюветы с толщиной поглощающего свет слоя 50 мм.The optical density of the solution is determined at a wavelength of λ 670-730 nm (λ _max = 712 nm) with respect to the comparison solution not containing phosphate ions

using cuvettes with a light absorbing layer thickness of 50 mm.

(А) в анализируемом растворе (мкг).According to the calibration graph find the mass content of phosphate ion

(A) in the analyzed solution (μg).

в анализируемом растворе находят по формуле (1).Mass concentration of phosphate ions

in the analyzed solution is found by the formula (1).

The mass fraction of the component Agron BP (X) in 1 l of a solution of CHSR is determined by the formula (2)

составляет 0,075 мл/мкг;where the coefficient of the solution of CWSR (K) in terms of phosphate ions

is 0.075 ml / μg;

в пробе, мкг.A - mass content of phosphate ions

in the sample, mcg.

in). Rapid determination of the mass fraction of the Kari Max Fluid component in the SCSS solution by the nickel content of Ni ²⁺ .

In the field, 20 ml of the tank mixture are taken and pipetted into a 250 ml volumetric flask, 2 ml of dimethylglyoxime solution (1 wt.% Aqueous solution), 2 ml of ammonium sulfate solution (4 wt.% Aqueous solution) are added, 5 ml ammonia.

Then add 140 ml of ethylene glycol measured by a cylinder, and the contents of the flask are thoroughly mixed. Assess the transparency of the mixture: if the solution is transparent - bring to the mark with ethylene glycol; if turbidity is observed - bring to the mark with distilled water.

After 10 minutes, the optical density of the solution was determined at a wavelength of λ 420-470 nm (λ _max = 445 nm) with respect to the reference solution not containing Ni ²⁺ nickel, using cuvettes with a light absorbing layer thickness of 50 mm.

According to the calibration graph find the content of Nickel Ni ²⁺ (A) in the analyzed solution (μg). The mass concentration of nickel Ni ²⁺ in the analyzed solution is found by the formula (1).

The mass fraction of the component Kari Max Fluid (X) in 1 l of a solution of CHSR is determined by the formula (2)

where the coefficient of the solution of CWSR (K) in terms of nickel Ni ²⁺ is 0.1 ml / μg;

A - mass content of nickel Ni ²⁺ in the sample, μg.

d). Rapid determination of the mass fraction of the component Bifor 22 K7 in the SCSR solution by the content of Fe ³⁺ iron labels.

In the field, 20 ml of the tank mixture are collected and placed in a 250 ml volumetric flask, 2 ml of hydrochloric acid solution (5 wt.% Aqueous solution), 2 ml of potassium thiocyanate (or ammonium) solution (50 wt.% Aqueous solution) are added.

Then add 100 ml of tetrahydrofuran, measured by a cylinder, and thoroughly mix the contents of the flask. Assess the transparency of the mixture: if the solution is clear, make up with tetrahydrofuran to the mark; if turbidity is observed - bring to the mark with distilled water.

The optical density of the solution is determined at a wavelength of λ 470-540 nm (λ _max = 495 nm) with respect to the reference solution not containing Fe ³⁺ iron, using cuvettes with a light absorbing layer thickness of 50 mm.

According to the calibration graph, find the mass content of iron Fe ³⁺ (A) in the analyzed solution (μg). The mass concentration of iron Fe ³⁺ in the analyzed solution is found by the formula (1).

The mass fraction of the component Bifor 22 K7 (X) in 1 l of a solution of SCP is determined by the formula (2)

where the coefficient of the solution of CWS (K) in terms of iron Fe ³⁺ is 0.65 ml / μg;

A - mass content of iron Fe ³⁺ in the sample, mcg.

e). Rapid determination of the mass fraction of the Legion Combi component in the SCSR solution by the content of Cu ²⁺ copper label.

In the field, 20 ml of the tank mixture are taken and pipetted into a 100 ml volumetric flask, 5 ml of ammonium citrate solution (10 wt.% Aqueous solution), 2 ml of ammonia solution (20 wt.% Aqueous solution) are added, 5 ml cuprizone (0.1 wt.% alcohol solution).

Then add 60 ml of acetonitrile, measured by a cylinder, and thoroughly mix the contents of the flask. Assess the transparency of the mixture: if the solution is clear, make up with acetonitrile; if turbidity is observed - bring to the mark with distilled water.

The optical density of the solution is determined at a wavelength of λ 590-610 nm (λ _max = 600 nm) with respect to the reference solution not containing Cu ²⁺ copper, using cuvettes with a light absorbing layer thickness of 50 mm.

According to the calibration graph, the mass content of copper Cu ²⁺ (A) in the analyzed solution (μg) is found. The mass concentration of copper Cu ²⁺ in the analyzed solution is found by the formula (1).

The mass fraction of the component Legion Combi (X) in 1 l of a solution of SCP is determined by the formula (2)

where the coefficient of the solution of CWS (K) in terms of copper Cu ²⁺ is 0.2 ml / μg;

A - mass content of copper Cu ²⁺ in the sample, μg.

Example 2

and). Rapid determination of the mass fraction of the Agron BP component in the SCSR solution by the content of Fe ³⁺ iron label.

In the field, 20 ml of the tank mixture are taken and placed in a 100 ml volumetric flask, 2 ml of hydrochloric acid solution (5 wt.% Aqueous solution), 2 ml of potassium rhodanide (or ammonium) solution (50 wt.% Aqueous solution) are added.

Then add 10 ml of dimethyl sulfoxide, measured by a cylinder, and thoroughly mix the contents of the flask. Assess the transparency of the mixture: if the solution is transparent - make up with dimethyl sulfoxide to the mark; if turbidity is observed - bring to the mark with distilled water.

The optical density of the solution is determined at a wavelength of λ 470-540 nm (λ _max = 495 nm) with respect to the reference solution not containing Fe ³⁺ iron, using cuvettes with a light absorbing layer thickness of 50 mm.

According to the calibration graph, find the mass content of iron Fe ³⁺ (A) in the analyzed solution (μg). The mass concentration of iron Fe ³⁺ in the analyzed solution is found by the formula (1).

The mass fraction of the component Agron BP (X) in 1 l of a solution of CHSR is determined by the formula (2)

where the coefficient of the solution of CWS (K) in terms of iron Fe ³⁺ is 0.65 ml / μg;

A - mass content of iron Fe ³⁺ in the sample, mcg.

b) Rapid determination of the mass fraction of the Legion Combi component in the SCSR solution by the content of the cobalt label Co ²⁺ .

In a volumetric flask with a capacity of 100 ml, 20 ml of the analyzed solution of CXPR are pipetted, 2 ml of hydrochloric acid solution (5 wt.% Aqueous solution), 2 ml of potassium rhodanide (or ammonium) solution (50 wt.% Aqueous solution) are added, several drops of a solution of ascorbic acid (10 wt.% aqueous solution) until the red color disappears and 1 ml is excess.

Then add 30 ml of dimethylfomamide, measured by a cylinder, and thoroughly mix the contents of the flask. Assess the transparency of the mixture: if the solution is transparent - make up with dimethylfomamide; if turbidity is observed - bring to the mark with distilled water.

Determine the optical density of the solution at a wavelength of λ 570-650 nm (λ _max = 620 nm) with respect to the reference solution not containing cobalt Co ²⁺ , using cuvettes with a light absorbing layer thickness of 50 mm.

According to the calibration graph, the content of cobalt Co ²⁺ (A) in the analyzed solution (μg) is found. The mass concentration of cobalt Co ²⁺ in the analyzed solution is found by the formula (1).

The mass fraction of the component Legion Combi (X) in 1 l of a solution of SCP is determined by the formula (2)

where the coefficient of the solution of CWSR (K) in terms of the cobalt content of Co ²⁺ is 0.1 ml / μg;

A - mass content of cobalt Co ²⁺ in the sample, mcg.

in). Rapid determination of the mass fraction of the Dexter KS component in the SCS solution by the nickel content of Ni ²⁺ .

In the field, 20 ml of the tank mixture are taken and pipetted into a 250 ml volumetric flask, 2 ml of dimethylglyoxime solution (1 wt.% Aqueous solution), 2 ml of ammonium sulfate solution (4 wt.% Aqueous solution) are added, 5 ml ammonia.

Then add 70 ml of ethanol, measured by a cylinder, and thoroughly mix the contents of the flask. Estimate the transparency of the mixture: if the solution is transparent - make up the mark with ethanol; if turbidity is observed - bring to the mark with distilled water.

After 10 minutes, the optical density of the solution was determined at a wavelength of λ 420-470 nm (λ _max = 445 nm) with respect to the reference solution not containing Ni ²⁺ nickel, using cuvettes with a light absorbing layer thickness of 50 mm.

According to the calibration graph find the content of Nickel Ni ²⁺ (A) in the analyzed solution (μg). The mass concentration of nickel Ni ²⁺ in the analyzed solution is found by the formula (1).

The mass fraction of the component Dexter KS (X) in 1 l of a solution of CXP is determined by the formula (2)

where the coefficient of the solution of CWSR (K) in terms of nickel Ni ²⁺ is 0.1 ml / μg;

A - mass content of nickel Ni ²⁺ in the sample, μg.

d). Rapid determination of the mass fraction of the component Bifor 22 K7 in the SCSR solution by the content of the Cu ²⁺ copper label.

In the field, 20 ml of the tank mixture are taken and pipetted into a 250 ml volumetric flask, 5 ml of ammonium citrate solution (10 wt.% Aqueous solution), 2 ml of ammonia solution (20 wt.% Aqueous solution) are added, 5 ml cuprizone (0.1 wt.% alcohol solution).

Then add 90 ml of N-methylpyrrolidone, measured by a cylinder, and thoroughly mix the contents of the flask. Assess the transparency of the mixture: if the solution is clear - make up to the mark with N-methylpyrrolidone; if turbidity is observed - bring to the mark with distilled water.

The optical density of the solution is determined at a wavelength of λ 590-610 nm (λ _max = 600 nm) with respect to the reference solution not containing Cu ²⁺ copper, using cuvettes with a light absorbing layer thickness of 50 mm.

According to the calibration graph, the mass content of copper Cu ²⁺ (A) in the analyzed solution (μg) is found. The mass concentration of copper Cu ²⁺ in the analyzed solution is found by the formula (1).

The mass fraction of the component Bifor 22 K7 (X) in 1 l of a solution of SCP is determined by the formula (2)

where the coefficient of the solution of CWS (K) in terms of copper Cu ²⁺ is 0.2 ml / μg;

A - mass content of copper Cu ²⁺ in the sample, μg.

e). Rapid determination of the mass fraction of the Kari Max Fluid component in the SCHS solution by the content of the phosphate ion label.

In the field, 20 ml of the tank mixture (CWS) are taken and pipetted into a 100 ml volumetric flask, 2 drops of the reagent solution are added to phosphates (GOST 10671.6). After 3 minutes, add 1 drop of a solution of tin dichloride in glycerol (GOST 10671.6).

Then add 20 ml of butanone-2, measured by a cylinder, and thoroughly mix the contents of the flask. Assess the transparency of the mixture: if the solution is transparent - bring to the mark with butanone-2; if turbidity is observed - bring to the mark with distilled water.

, используя кюветы с толщиной поглощающего свет слоя 50 мм.The optical density of the solution is determined at a wavelength of λ 670-730 nm (λ _max = 712 nm) with respect to the comparison solution not containing phosphate ions

using cuvettes with a light absorbing layer thickness of 50 mm.

(А) в анализируемом растворе (мкг).According to the calibration curve find the mass content of phosphate ion

(A) in the analyzed solution (μg).

в анализируемом растворе находят по формуле (1).Mass concentration of phosphate ions

in the analyzed solution is found by the formula (1).

The mass fraction of the component Kari Max Fluid (X) in 1 l of a solution of CHSR is determined by the formula (2)

составляет 0,075 мл/мкг;where the coefficient of the solution of CWSR (K) in terms of phosphate ions

is 0.075 ml / μg;

в пробе, мкг.A - mass content of phosphate ions

in the sample, mcg.

Thus, the method of photometric identification and determination of the concentration of the components of the tank mixture, which consists in introducing at the stage of production into each component of the tank mixture - a pesticide and / or herbicide - tag ion, in an amount that exceeds the background level of this ion in the component of the tank mixture by an order of magnitude , in the selection of an aliquot of the mixture, the introduction of a reagent-indicator of the ion being determined, the photometric determination of the ion concentration, the successive dilution of an aliquot with an organic polar solvent with a dielectric constant of 12-50 F / m and water in an aliquot volume ratio: solvent: water equal to 1: 0.5 -11.05: 0-7.55, and determining the content of the component in the tank mixture by the concentration of the tag ion, can be used for input express control in the field of pesticides / herbicides in the agricultural storage complex in the agrochemical complex of the Russian Federation and provides increased accuracy of preparation solutions of the chemical plant protection system, the possibility of determining counterfeit products, which improves the efficiency of chemical plant protection systems.

Claims (4)

1. The method of photometric identification and determination of the concentration of the components of the tank mixture, which consists in the selection of an aliquot of the mixture, its dilution, the introduction of a reagent indicator of the detected ion, photometric determination of the concentration of the ion, characterized in that an ion tag is introduced into each component of the tank mixture at the production stage amount, an order of magnitude higher than the background level of the given ion in the component of the tank mixture, an aliquot is successively diluted with an organic polar solvent with a dielectric constant of 12-50 F / m and water in a volume ratio of aliquot: solvent: water equal to 1: 0.5 -11.05: 0-7.55, and the concentration of the component in the tank mixture is determined by the concentration of the label ion. 2. The method according to p. 1, characterized in that pesticides are used as components of the tank mixture. 3. The method according to claim 1, characterized in that herbicides are used as components of the tank mixture. 4. The method according to p. 1, characterized in that pesticides and herbicides are used as components of the tank mixture.