SU1354077A1 - Method of determining orthonitrophenols and derivatives thereof - Google Patents

Abstract

This invention relates to analytical chemistry, in particular to the determination of orthonitrophenols (ONF) and their derivatives. In order to increase the selectivity and sensitivity of the determination, the ONF determination is carried out by dissolving the sample being analyzed in dimethylformamide (DMF), followed by treating the resulting solution successively with zinc dust, hydrochloric acid and color reagent. As the latter, a 0.25% solution of copper (II) sulfate in DMF is used. Water in an amount of up to 30% by volume is added to the colored solution; it is photometric. The sensitivity of the method is 10 times higher. 6 tab. (L 00 J O-h

Description

The invention relates to analytical chemistry, namely, to the analysis of orthonitrophenols and their derivatives, and can be applied in the practice of production and control and analytical laboratories, central factory laboratories of chemical plants, sanitary epidemiological stations, plant protection stations .

The purpose of the invention is to increase the selectivity and sensitivity of the determination.

The method is carried out as follows.

The sample to be analyzed is dissolved in dimethylformamide (DMF), treated with a zinc broach and hydrochloric acid solution, and then with copper (II) sulfate solution in DMF, after which the amount of water in the reaction mixture is adjusted to 30 vol.%, And the resulting colored solution is photometrized .

Example 1, Determination of 2-methyl-4 5 6-dinitrophenol,

Qualitative definition. About 2 mg of the analyte is diluted in 2 ml of DMF, 50 mg of zinc dust and 0.5 ml of a 24% hydrochloric acid solution are added to the resulting solution. Then, 1.5 ml of a 0.25% solution of copper sulfate (II in DMF and 1 ml of distilled water) are introduced into the reaction mixture. A cherry-colored staining appears.

Quantitative determination of ' - 2-Methyl-4,6-dinitrophenol interacts with copper sulfate (II) in a ratio of 1: 1. The optical density of the colored solution remains stable for one hour,

Construction of the calibration graph In six volumetric flasks with a capacity of 25 ml. make 0.25; 0.50; 0.75; , 00; 1.25-1.50 ml of a 0502% standard solution of 2 methyl-456-dinitrophenol in DMF; add 1E75, -1.50, respectively; 1.25; 1,00; 0.75; U, 50 ml DMF. Then 50 mg of zinc dust, 0.5 ml of a 24% hydrochloric acid solution and 2.5 ml of a 0.25% copper (II) sulfate solution in DMF are added to each flask. ; 13 ml of DMF are added to the flask and the total volume is made up to 25 ml with water. The optical density of the colored solutions formed is measured on

KFO-1 with light filter No. 2 (wavelength 50 ni) in a cuvette with a layer thickness of 50 mm. According to the results of measurements, a graph of the dependence of optical density on the solution concentration is obtained. The light absorption of the colored solutions follows the Bouguer-Lambert-Beer law in a concentration range of 2 to 12 μg / ml. The least squares method calculates the equation for the calibration graph, which in this case is D 0.06229C +0.009 where D is the optical density; C is the concentration of the colored solution in µg / ml.

Quantitative determination method. About 0.1 g (exact weight) of 2-methyl-4,6-d, initrophenol is dissolved in a 100 ml volumetric flask, DMF (solution no. 1), 5 ml of no. 1 solution are transferred into a 25 ml volumetric flask and brought up to the DMF label (solution No. 2), 1 ml of solution No. 2 was added to a 25 ml measuring solution, 1 ml of DMF was added and further operations were performed according to the scheme indicated for the construction of the calibration graph. Determination of the amount of 2-methyl-4,6-dinitrophenol is carried out according to the equation of the calibration graph. The results of the quantitative determination and metrological characteristics are presented in Table 1, Reaction sensitivity 0.5 µg / ml

PRI me R 2 Definition of 2,4,6-trinitrofecol,

Qualitative definition. About 2% of the analyte is dissolved in 2 M of L DMF, 50 mg of zinc dust and 0.5 ml of a 24% hydrochloric acid solution are added to the resulting solution. Then, 1.5 ml of a 0525% solution of copper (II) sulfate in DMF and 1 ml of distilled water are introduced into the reaction mixture. A blue color appears.

Quantitation. 2e4,6-Trinitrophenol interacts with copper (II) sulphate in a 1: 1 ratio. The optical density of the colored solution remains stable for an hour,

The construction of the calibration graph In six volumetric flasks with a capacity of 25 ml PASSAGE 0.25; 0.50; 0.75; 1.00 1.25; 1.50 ml of 0.02% standard solution of 2.4,6-trinitrophenol in DMF

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1.75, 1.50-, 1.25, respectively; 1,00; 0.75; 0.50 ml DMF. Then, 50 mg of zinc dust, 0.5 ml of a 2A% hydrochloric acid solution and 2.5 ml of a 0.25% copper (II) sulfate solution in DMF are added to each flask. After 2-3 minutes, 13 ml of DMF was added to each flask and the total volume was made up with distilled water to 25 ml. The optical density of the stained colored solutions was measured on a KFO-1 instrument at a No. 3 optical filter (wavelength of 530 nm) in a cell with a 50 mm working layer thickness. According to the measurement results, a graph of the dependence of the optical density on the solution concentration was plotted. The light absorption of the colored solutions follows the Bouguer-Lambert-Beer law in a concentration range of 2 to 12 μg / ml. The least squares method calculates the equation of the calibration graph, which in this case has the form D 0.025860 + 0.014, where D is the optical density; C is the concentration of the colored solution in µg / ml.

Quantitative determination method. About 0.05 g (exact weight) of 2,4,6-trinitrophenol is dissolved in DMF in a 50 ml volumetric flask and the content of DMF flask is added to the mark (solution 1: 1). 5 ml of solution No. 1 is transferred to a 25 ml capacity volumetric flask and adjusted to the mark with DMF (solution no. 2). 1 ml of solution No. 2 is transferred to a 25 ml volumetric flask, 1 ml of DMF is added and further operations are carried out according to the scheme specified for the construction of a calibration graph. The results of the determination and metrological characteristics are presented in Table. 2. The sensitivity of the reaction is 1.5 µg / ml.

PRI me R 3. Determination of the ammonium salt of 6-sec-butyl-2,4-dinitrophenol.

Qualitative definition. About 2 mg of the analyte are dissolved in 2 ml of DMF, 50 mg of zinc dust and 0.5 ml of a 24% hydrochloric acid solution are added to the resulting solution. Then, 1.5 ml of a solution of copper (II) sulfate in DMF and 1 ml of distilled water is added to the reaction mixture. In this case, a magenta color is produced.

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Number of {noe definition. The ammonium salt of 6-sec-butyl-2,4-dinitrophenol interacts with copper (II) sulfate in a 1: 1 ratio. The optical density of the colored solution remains stable for one hour.

Calibration plotting

Six six volumetric flasks with a capacity of 25 ml bring 0.25, 0.50, 0.75, 1.00, 1.25, 1.50 ml of the standard 0.04% ammonium salt 6-sec-butyl-2 4- solution. dinitrophenol in DMF, 1.75 respectively; 1.50; 1.25; 1,00; 0.75; 0.50 ml DMF. Then, 50 mg of zinc dust, 0.50 ml of a 24% hydrochloric acid solution I, are added to each flask.

2.5 ml of a 0.25% solution of copper (II) sulfate in DMF. After 2-3 minutes, 13 ml of DMF was added to each flask and the total volume was made up with distilled water to 25 ml; The optical density of the resulting colored solutions was measured on a KFO-1 instrument with a No. 2 light filter (500 nm wavelength) in a cell with a working layer thickness of 50 mm. According to the measurement results, a graph of the dependence of optical density on the concentration of solutions is plotted. Submission to the Bouguer-Lambert-Beer law is observed in the concentration range of 4-24 µg / ml. The least squares method calculates the equation of the calibration graph, which in this case has the form D 0.0285С + 0.016, where D is the optical density; C is the concentration of the colored solution in µg / ml.

Quantitative determination method. About 0.1 g (precise weight) of 6-sec-butyl-2,4-dinitrophenol ammonium salt is dissolved in a 50 ml volumetric flask and brought to the DMF mark (solution no. 1). 3 ml of solution - 1 is transferred to a 25 ml volumetric flask and brought to the DMF label (solution No. 2). 1 ml of solution No. 2 is introduced into a 25 ml measuring flask, 1 ml of DMF is added, and further operations. carried out according to the scheme indicated for the construction of a calibration graph. The results of the quantitative determination and metrological characteristics are presented in Table 3. The sensitivity of the reaction is 1 µg / ml.

PRI me R 4. Determination of 6-sec butyl-2,4-dinitrophenyl isopropyl carbonate.

Qualitative definition. About 2 ml of the analyte are dissolved in 2 ml of DMF, 50 mg of zinc potty and 0.5 ml of a 24% hydrochloric acid solution are added to the resulting solution. Then, 1.5 ml of a 0.25% copper sulphate solution (I in DMF and 1 ml of distilled water) are added to the reaction mixture. A cherry color appears.

Quantitative determination. 6-Second-butyl-2,4-dinitropens1 Isopropylcarbonate interacts with copper (II) sulfate in a ratio of 7: 3. The optical density of the colored solution remains stable for one hour.

Construction of the calibration graph. 0.25; six measuring flasks with a capacity of 25 ml; 0.50; 0.75; 1,00; 1.25; 1.50 ml of a standard 0.05% solution of 6-sec-butyl-2,4-dinitrophenylisopropyl carbonate in DMF, 1.75 respectively; 1.50; 1.25 1.00; 0.75; 0.50 ml DMF. Then 50 mg of zinc dust, 0.5 ml of a 24% hydrochloric acid solution and 2.5 ml of a 0.25% copper (II) sulfate solution in DMF were added to each flask. After 2-3 minutes, 13 ml of DMF was added to each flask and the total volume was made up to the mark with distilled water. The optical density of the resulting colored solutions was measured on a KFO-1 instrument with a No. 2 light filter (500 nm wavelength) with a working cell thickness of 50 mm. According to the measurement results, a graph of the dependence of optical density on the concentration of solutions is plotted. Submission to the Bouguer-Lambert-Beer law is observed in the concentration range 5-30 µg / ml. The least squares method calculates the equation of the calibration graph, which in this case has the form D 0,016С + 0,014, where D is the optical density, and c is the concentration of the colored solution in µg / ml.

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Quantitative determination method. About 0.125 g (precise weight) of 6 sec-butyl-2,4-dinitrophenyl isopropyl carbonate is dissolved in a 50 ml volumetric flask in DMF (solution no. 1). 5 ml of solution No. 1 is transferred to a 25 ml measuring flask and adjusted to the DMF label (patTBop No. 2). 1 ml of solution No. 2 is introduced into a 25 ml volumetric flask, 1 ml of DMF is added and further operations are carried out according to the scheme indicated for the construction of the calibration graph. Determination of the amount of 6-Satbutyl-2,4-dinitrophenyl isopropyl carbonate is carried out according to the equation of the calibration graph. The results of quantitative determination and metrological characteristics are presented in table. 4. The sensitivity of the reaction is 2 μg / ml.

In tab. Table 5 shows the dependence of the optical density of the solutions on the water content (measured on a KFO-1 instrument with a No. 2 optical filter, 1.5 mm), in Table. 6 - comparative data on the selectivity and sensitivity of the proposed and known methods.

The proposed method is more selective, its efficiency is 10 times higher.

I, what is known, feel it

Claims (1)

Invention Formula The method of determining ortho-nitrophenols and their derivatives by dissolving the sample being analyzed, treating the resulting solution successively with zinc dust, hydrochloric acid and a color reagent followed by photometric measurement of the resulting colored solution, characterized in that, in order to increase the selectivity and sensitivity of determination, dissolution is carried out in dimethylformamide, A 0.25% solution of copper (II) sulfate in dimethylformamide is used as a color reagent and added to the analysis before photometry. Water in an amount up to 30 vol.%. Table 1 Table A Found Metrological j. specifications : LJ: 1 -...... „.. 0.115797, 06X 98.39 0.1430100.700 1.89 0.174698,, 74 0.125495 ,,, b98 0.1233899.60 A 2.01 0.127599.22 a 98, 01 Table.5 Water content Optical density% D 20 .0,580 300,630 400,625 500,610 600,580 700,560 800,460 Indicators t The proposed method Method. Allows selective determination of orotonitrophenols and their derivatives. The definition is not hampered by the presence of meta- and paranitrophenols, as well as the presence of substances related to Table 6 Known method The method does not allow the selective determination of orthonothrophenols and their derivatives. The presence of various classes of nitro compounds interferes with the determination: 2,4-dinitrochlorobenzene 2,4-dinitrophenylhydrazine; nitrobenzene, 1- (2-hydroxyethyl) - -2-methyl-5-nitroimidazole; 1 ,, 2-dihydro-7-nitro-5-phenyl-3H-1,4-benzodiazepin-2-one; semicarbazone Z-nitrofurfural; 1- (4- -nitrophenyl) -2-dichloro-acetamido-1,3-propanediol; 5-NITRO-8-OXYHINOLIN {nitrocoumarin, H- (5-nitro-2-furfurylidene) -1-amino-hydantoin; K- (5-nitro-2- -furfurylidene) -3-amino-oxazolin-2-oHi 1-methyl-4-nitro-5-chlorimidazole {6- (1-methyl-4-nitroimazole-5) - mercaptopurine Sensitivity 0.5-2 µg / ml Compiled by L.Rusanova Editor I.Gorna Tehred I.Popovich Order 5686/38 Circulation 776 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5 Production and printing company, Uzhgorod, st. Project, 4 Troy compounds of different structure. The sum of the nitro compounds of various structures is determined. 5-50 mcg / ml Proofreader N.Korol