SU1617330A1 - Method of quantitative determination of n-benzoquinone - Google Patents

Abstract

This invention relates to analytical chemistry, in particular to the quantitative determination of p-benzoquinone. The goal is to increase the sensitivity of the determination of p-benzoquinone. The determinations are carried out by treating the sample to be analyzed with hydrogen peroxide in an alkaline medium and further processing with 4-diethylaminophthalhydrazide in the presence of ethylenediaminetetraacetate and vanadium sulfate. The process is conducted with the subsequent measurement of the luminescence intensity of the solution. The method makes it possible to increase the detection sensitivity by 18,000 times. 1 tab.

Description

The invention relates to analytical chemistry, relates to the determination of l-benzoquinone when it is contained in a solution (1 - 90) -10 µg / ml and can be used in the analysis of environmental objects, natural and waste waters of the paint and varnish, textile and leather industry, and also biochemical research x.

The purpose of the invention is to increase the detection sensitivity of g-benzoquinone. Optimal conditions for determining l-benzoquinone: SidF1 2-nd, o, M - GoM 10-2M; Go 8 - 0 - OM; G; m. The calibration graph is linear in the range of concentrations of benzoquinone (2- 90) -10 µg / ml. The detection limit of benzoquinone is I-IO µg / ml.

Chemiluminescent determination is usually carried out using a 20 ml cuvette. Solutions of DEAFG, KOH, bidistillate, starting from a total volume of 5 ml, EDTA, hydrogen peroxide and the analyzed solution are introduced into the cuvette. A solution of vanadyl sulfate is introduced last, mixed, and the maximum intensity of luminescence is measured after 10 s using a PMT-19 photomultiplier. The calibration curve is plotted in terms of the intensity of luminescence (relative units) - pC of benzoquinone.

Example 1. 0.1 ml of a M solution of 4-d11Et; 1-amino-phthalhydrazide was introduced into the cuvette;

0.5 ml of a 0.1 M solution of KOH, bidistillate, starting from a total volume of 5 ml, 0.5 ml of a 10 M solution of ethylene methyl acetate, 0.1 ml of a M solution, l-benzoquinone in an amount of from 6 to 90-10 µg / ml and 0.1 ml of 4-10 M vanadyl sulfate. The solution is stirred and the maximum intensity of the light is measured after 10 s using a PMT-19. The content of g7-benzoquinone is determined according to a calibration curve. The detection sensitivity is 1 µg / ml. The calibration curve in coordinates the intensity of luminescence (rel. Units) - pC of p-benzoquinone is linear in the range (2-90) - μg ml.

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Example 2. All components are introduced into the cuvette in the amounts indicated in Example 1, with the exception of p-benzoquinone, which is introduced in an amount of 4.3 to 10 µg / ml. Found (4.4 ± 0, µg / ml (,, 95).

Example 3. All components were introduced into the cuvette in the amounts indicated in Example 1, with the exception of p-benzoquinone, which were introduced in the amount of 17 µg / ml. Found (18.1 ± 0.9) -10 µg / ml (,, 95).

Example 4. All components were introduced into the cuvette in the amounts indicated in Example 1, with the exception of β-benzoquinone, which is administered in an amount of 35-10 µg / ml. Found (37 ± 3) -10 µg / ml (,, 95).

Example 5. All components were introduced into the cuvette in the amounts indicated in Example 2, with the exception of l-benzoquinone, which is administered in an amount of 68-10 µg / ml.

0

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Found (68 ± 6) -10 μg / ml. (,, 95).

The table shows the statistical processing of the results of the determination of l-benzoquinone in solution (examples 2-5). As can be seen from the table, the proposed method is characterized by sufficient accuracy and reproducibility. In addition, the sensitivity of the determination of p-benzoquinone is increased in comparison with the prototype by 18,000 times.

Claims (1)

Invention Formula The method of quantitative determination of p-benzoquinone by treating the sample being analyzed with hydrogen peroxide in an alkaline medium, followed by measuring the intensity of the chemiluminescence of the solution, characterized in that, in order to increase the detection sensitivity, the sample is supplemented. It is conveniently treated with 4-diethylaminophthalgide in the presence of ethylenediaminetetraacetate and vanadium sulfate. 4.3 17.3 35 68 0.13 0.06 0.07 0.09