SU1177296A1 - Method of producing reagent for colorimetric determination of hydrogen sulfide or thiols - Google Patents

Abstract

Od afford reagents for the colorimetric determination of hydrogen sulfide or thiol, characterized in that, in order povy .sheni desired product quality, 1-hydroxy-8-chloro (bromo) naphthalene-3, 6-e is reacted disulfokislrtu 4.4 -ditiobic (phenydiazine) dibrophoteride in the presence of sodium carbonate.

Description

1C

with

The invention relates to methods for the preparation of reagents for the colorimetric determination of hydrogen sulfide or thiols, which can be used for various anapisations in industry, in medicine, in scientific studies for environmental control. The new reagent has the following structural formula: R OH HOjS - SOjH where R is chlorine or bromine, in the form of disodium salts with a gross formula: Cj2n gCl2N4Na20, .jO (1) C Il jBr N NazO StSHzO (11 Purpose of the invention — improving the quality of the target product by increasing the extinction of the colored product of the analytical reaction. Example 1. Synthesis of 4.4 bis (-hydroxy-8 chloro-3,6-disulfo-2-naphthylazo (diphenyl disulfide) of the formula (In a glass from heat-resistant glass with a capacity of 0.5 l, equipped with a thermometer stirrer, load 0.15 l of water, 1.0 g of sodium carbonate and 10.1 g (0.03 mol) of 1-hydroxy-8-chlornaft ling-3, 6-disulfonic acids. With vigorous stirring and a temperature of 20-25 €, for 5 minutes, 5.3 g (0.01 mol) of 4,4-dithio-bis- (phenyldiazonium) dibrofluoride is charged. The reaction solution is stirred at After 1 hour, it is cooled to 8 - and mixed with 0.15 l of ethanol. The resulting suspension is stirred for 5 minutes and the precipitate is filtered off and washed on the filter with ethyl alcohol (0.05 L) and ether (0.05). lo Yield 9.0 g (76%). For purification, they are transferred to a 0.2 liter beaker, C is poured in, 1 liter of ethanol and the suspension is stirred for 5 minutes. The precipitate is filtered off on a filter. 0.05 l of ether is dried with no moisture access for 4 hours. 4,4-bis- (1-hydroxy-8-chloro-3, 6-disulfo-2-naphthylazo) diphenyl disulfide disodium salt is obtained. . Found,%: C 36.0; N 5.3; B 2,3; C1 6.6%. Cj2H CljN4NajOHS64H20. Calculated,%: C 36.2; H 2.3; C1 6.6; N 5.3%. Example 2. Synthesis of 4,4-bis- (1-hydroxy-8-bromo-3, 6-disulfo-2-naphthylazo) diphenylsulfide of the formula (1J). In a glass of heat-resistant glass with a capacity of 0.5 liters, equipped with a stirrer and thermometer I, load 0.1 l of concentrated hydrobromic acid and 2.0 g of copper bromide. At 80 ° C and vigorous stirring, a suspension of 30.0 g of 1-hydroxy-8-diazonionaphthalene-3, 6-disulfonic acid bromide in 15% hydrobromic hydrochloric acid is loaded into a beaker for 10-12 minutes. Then the reaction mixture is stirred at 70-80 ° С for 0.5 h. Then it is cooled and filtered. 5 grams of sodium bromide is added to the mother liquor before precipitation occurs. The precipitate is filtered off, dissolved in 0.04 L, the solution is heated to 50 mL of sodium sulphide is added and the precipitated black precipitate is filtered off. The hot liquor is cooled in an ice bath and the precipitate is filtered off. If the precipitate does not dissolve the precipitate, 5 g of sodium bromide is preliminarily added. The precipitate is washed on the filter with 100 ml of acetone and dried at 2 hours. The yield of 1-hydroxy-8-bromonaphthalene-3H, 6-disulfonic acid is 16.3 g (59%). In a glass of heat-resistant glass with a capacity of 0.5 l, equipped with a stirrer and a thermometer, load 0.15 l of water, 1.0 g of sodium carbonate and 10 g of 1-hydroxy-8-bromonaphthalene-3, 6-disulfonic acids. Then, with vigorous stirring and a temperature of 20, 5.3 g (0.01 mol) of 4,4-dithiobis (fensh diazonium) dibromofluoride are charged in 5 minutes. After that, the reaction mixture was stirred at the same temperature for 1 h, cooled to 8 -, 0.15 L of ethyl alcohol was added. Stir the resulting suspension for 5 minutes and filter the precipitate. The precipitate is successively washed on the filter with 50 ml of ethyl alcohol and 50 ml of diethyl

3

the ether. Dry at 40-50 ° C for 3 hours. Yield 7.8 g (58%).

To purify, transfer the precipitate to a 0.2 liter beaker, add 0.1 l of ethanol and transfer the suspension for 5 minutes. The precipitate is filtered, washed on the filter with 0.05 l of ether, dried with no access of moisture for 4 hours. 4 (1-hydroxy-8-bromo-3, 6-disulfo-2-naphthylazo) -diphenyl disulfide disodium salt 3-water is obtained.

Found,%: C 33.7; H 2.0; Br 4.1; N 5.0; S 16.7%.

C32H jBr2N4Na20i4S ".- 3H20

Calculated,%: C 39.9; H 2.1; N 4.9; Br 14.0; S 16.9%.

Substances of formulas (1) and (11) form aqueous solutions of an intense red color. When thiols (dithiotreitol, cysteine, thiophenol, etc.) or hydrogen sulfide are added, the color of the solutions changes to intense 1st violet-blue. Spectral data are given in Table. 1, but for comparison, similar information is given about Ellman's reagent.

As can be seen from the table. 1, new substances form products of interaction with thiols (hydrogen sulfide), exceeding in extinction a similar product from Ellman's reagent by more than 2.5 times.

Example. Determination of thiols (hydrogen sulfide).

64

To 0.5 ml 41 () of an aqueous solution of a disulfide of formula (1) with a pH of solution of 8.5, 4.5 ml of an aqueous test solution are poured and after 0.5 min the optical density of the resulting solution is measured relative to the blank sample. Measurements are carried out under normal conditions. The optical density of the analytical solutions in the closed cell of the spectrophotometer chamber is stable for at least 10 hours. Table. 2 shows the results of the determination of hydrogen sulfide and dithiothreitol using a disulfide of the formula (1)

here, for comparison, similar results are obtained using Ellman's reagent. 4 From the table. 2 data shows that the disulfide of formula (1)

surpasses the Elman reagent in sensitivity of the determination of dithiothreitol and hydrogen sulfide by 4 times. For disulfide of formula (IT), results are obtained that almost coincide

with data for the disulfide of formula (1). New compounds are available and have analytical properties that can be used as water-soluble reagents.

For the colorimetric determination of hydrogen sulfide and thiols. In addition, they are superior to the Ellman reagent by the extinction of the colored reaction product by more than 2.5 times, and by the sensitivity of the determination of hydrogen sulfide and thiols by 4 times.

Table 1

4, 4-Dinitro-3,3-dicarboxydiphenyl disulfide (Ellman's reagent).

 The extinction is calculated by assuming that the concentration of the reaction product is twice as large as the concentration of the starting disulfide.

Absorbance is measured relative to water. Absorbance is measured relative to a blank.

412 (13800)

table 2

Claims (1)

METHOD FOR PRODUCING REAGENT FOR COLORIMETRIC DETERMINATION OF HYDROGEN SULPHIDE OR THIOLS, characterized in that, in order to improve the quality of the target product, 1-hydroxy-8-chloro (bromo) -naphthalene-3,6-disulfonic acid is reacted with 4,4'-dithiobis ( phenyldiazonium) diborfluoride in the presence of sodium carbonate.