阅读说明：本技术 一种检测巯基含量的方法 (Method for detecting content of sulfydryl ) 是由 郭诚 王垚 李华 孟宪荣 于 2018-06-13 设计创作，主要内容包括：本发明提供了一种检测巯基含量的方法。该方法包括：预先配制用于将巯基氧化成磺酸基的氧化试剂；在第一、二容器中分别加入预设第一质量的待测含巯基的化合物和纯净水；在第一容器和第二容器中分别加入预设第一体积的氧化试剂,摇匀后静置预设的第一时长；在第一容器和第二容器中分别加入滴酚酞指示液；在第一容器和第二容器中分别用氢氧化钠标准溶液滴定至粉红色,且30秒内不褪色,分别记录第一容器和第二容器所消耗的氢氧化钠标准溶液的体积；根据第一质量、氢氧化钠标准溶液的浓度以及第一容器和第二容器所消耗的氢氧化钠标准溶液的体积,计算得到待测含巯基的化合物中的巯基含量。应用本发明可以简单、廉价、安全地检测待测物中的巯基含量。(The invention provides a method for detecting the content of sulfydryl. The method comprises the following steps: preparing an oxidizing agent for oxidizing mercapto groups into sulfonic acid groups in advance; respectively adding a preset first mass of a to-be-detected sulfhydryl-containing compound and purified water into a first container and a second container; respectively adding an oxidizing reagent with a preset first volume into the first container and the second container, shaking uniformly, and standing for a preset first time; respectively adding dropwise phenolphthalein indicator liquid into the first container and the second container; titrating the solution to pink color in a first container and a second container respectively by using a sodium hydroxide standard solution, and recording the volume of the sodium hydroxide standard solution consumed in the first container and the second container respectively, wherein the solution does not fade within 30 seconds; and calculating to obtain the content of the sulfhydryl in the sulfhydryl-containing compound to be detected according to the first mass, the concentration of the sodium hydroxide standard solution and the volumes of the sodium hydroxide standard solutions consumed by the first container and the second container. The method can be used for simply, cheaply and safely detecting the content of the sulfhydryl in the object to be detected.)

1. A method for detecting the content of sulfydryl is characterized by comprising the following steps:

preparing an oxidizing agent for oxidizing mercapto groups into sulfonic acid groups in advance;

adding a preset first mass of a to-be-detected sulfhydryl-containing compound into a first container, and simultaneously adding a preset first mass of purified water into a second container;

respectively adding an oxidizing reagent with a preset first volume into the first container and the second container, shaking uniformly, and standing for a preset first time;

respectively adding dropwise phenolphthalein indicator liquid into the first container and the second container;

titrating the solution to pink color in a first container and a second container respectively by using a sodium hydroxide standard solution, and recording the volume of the sodium hydroxide standard solution consumed in the first container and the second container respectively, wherein the solution does not fade within 30 seconds;

and calculating to obtain the content of the sulfhydryl in the sulfhydryl-containing compound to be detected according to the first mass, the concentration of the sodium hydroxide standard solution and the volumes of the sodium hydroxide standard solutions consumed by the first container and the second container.

2. The method of claim 1, wherein:

slowly dissolving concentrated sulfuric acid in hydrogen peroxide to prepare an oxidizing reagent;

wherein the mass ratio of concentrated sulfuric acid to hydrogen peroxide is 1: 80.

3. the method of claim 2, wherein:

0.5 g of concentrated sulfuric acid was slowly dissolved in 40g of 35% hydrogen peroxide to prepare an oxidizing agent.

4. The method of claim 3, wherein:

the predetermined first volume is 15 ml.

5. The method of claim 4, wherein:

the first time period is 1.5 hours.

6. The method according to claim 1, wherein the thiol content of the thiol-containing compound to be detected is calculated by using the following formula:

X＝(V₁-V₀)×C÷m÷1000，

wherein X is the mercapto content in the mercapto-containing compound to be detected, and V₁Volume of sodium hydroxide standard solution consumed by the first vessel, V₀Is the volume of the sodium hydroxide standard solution consumed by the second container, C is the concentration of the sodium hydroxide standard solution, and m is the first mass.

7. The method of claim 1, wherein:

the first container and the second container are erlenmeyer flasks.

Technical Field

The application relates to the technical field of chemical detection, in particular to a method for detecting the content of sulfydryl.

Background

The mercapto compound has properties of reduction, crosslinking, chain transfer, initiation, vulcanization, complexation and the like, so that the mercapto compound is widely applied to the fields of chemical industry, petroleum, mining and metallurgy, biology, medicine, petrochemical industry, daily chemicals, paper making, textile and the like.

In the application process of the sulfhydryl compound, the content of the sulfhydryl in the sulfhydryl compound is analyzed, which not only relates to the determination of the content of the related compound, but also relates to the detection and control of the reaction process and other aspects.

In the prior art, the thiol content can be detected by two methods, namely instrumental measurement or chemical measurement. At present, the method for measuring the content of sulfydryl by an instrument comprises the following steps: RP-HPLC method, molecular fluorescence spectrometry, high performance liquid chromatography-ultraviolet detection method, electrochemical desorption and fluorescence technology combined method, etc. However, these methods generally require expensive instruments and the measurement process is complicated.

Disclosure of Invention

In view of this, the present invention provides a method for detecting a thiol content, so that the thiol content in an analyte can be simply, cheaply and safely detected.

The technical scheme of the invention is realized as follows:

a method for detecting the content of sulfhydryl groups, which comprises the following steps:

preparing an oxidizing agent for oxidizing mercapto groups into sulfonic acid groups in advance;

adding a preset first mass of a to-be-detected sulfhydryl-containing compound into a first container, and simultaneously adding a preset first mass of purified water into a second container;

respectively adding an oxidizing reagent with a preset first volume into the first container and the second container, shaking uniformly, and standing for a preset first time;

respectively adding dropwise phenolphthalein indicator liquid into the first container and the second container;

titrating the solution to pink color in a first container and a second container respectively by using a sodium hydroxide standard solution, and recording the volume of the sodium hydroxide standard solution consumed in the first container and the second container respectively, wherein the solution does not fade within 30 seconds;

and calculating to obtain the content of the sulfhydryl in the sulfhydryl-containing compound to be detected according to the first mass, the concentration of the sodium hydroxide standard solution and the volumes of the sodium hydroxide standard solutions consumed by the first container and the second container.

Wherein, concentrated sulfuric acid is slowly dissolved in hydrogen peroxide to prepare an oxidation reagent;

wherein the mass ratio of concentrated sulfuric acid to hydrogen peroxide is 1: 80.

wherein, 0.5 g of concentrated sulfuric acid is slowly dissolved in 40g of hydrogen peroxide with the concentration of 35% to prepare an oxidizing reagent.

Wherein the predetermined first volume is 15 ml.

Wherein the first time period is 1.5 hours.

The content of the sulfydryl in the to-be-detected sulfydryl-containing compound is calculated by using the following formula:

X＝(V₁-V₀)×C÷m÷1000，

wherein X is the mercapto content in the mercapto-containing compound to be detected, and V₁Volume of sodium hydroxide standard solution consumed by the first vessel, V₀The volume of the standard solution of sodium hydroxide consumed by the second container, C being hydrogen and oxygenThe concentration of the sodium standard solution, m is the first mass.

Wherein the first and second containers are erlenmeyer flasks.

As can be seen from the above, in the method for detecting the content of thiol in the present invention, since hydrogen peroxide-sulfuric acid is used as an oxidizing reagent, the thiol in the analyte can be oxidized into a sulfonic acid group, and then the content of the sulfonic acid group can be detected by acid-base neutralization titration, the content of thiol in the analyte (one thiol can be fixedly converted into one sulfonic acid group) can be determined, so that the content of thiol in the analyte can be simply, inexpensively and safely detected. In addition, in the technical scheme of the invention, the consumption of other groups is not detected directly or by using the reaction of the sulfydryl and other groups, so that the whole detection process is simple, cheap and safe, and is suitable for a plurality of application scenes, such as small and medium-sized enterprises using or producing sulfydryl compounds.

Drawings

FIG. 1 is a flow chart of a method for detecting the content of thiol groups in an embodiment of the present invention.

Detailed Description

In order to make the technical scheme and advantages of the invention more apparent, the invention is further described in detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a flow chart of a method for detecting the content of thiol groups in an embodiment of the present invention. As shown in fig. 1, the method for detecting the content of thiol in the embodiment of the present invention includes the following steps:

step 11, an oxidizing agent for oxidizing a mercapto group into a sulfonic acid group is prepared in advance.

In the technical solution of the present invention, the above-mentioned oxidizing agent for oxidizing a mercapto group into a sulfonic acid group may be prepared in advance in various ways. The technical solution of the present invention will be described in detail below by taking one or more specific implementations thereof as examples.

For example, in one embodiment of the present invention, concentrated sulfuric acid may be slowly dissolved in hydrogen peroxide to prepare an oxidizing agent. Wherein the mass ratio of concentrated sulfuric acid to hydrogen peroxide is 1: 80.

for example, 0.5 grams (g) of concentrated sulfuric acid can be slowly dissolved in 40g of 35% strength hydrogen peroxide to formulate an oxidizing agent.

In addition, in this particular example described above, sulfuric acid was used. However, in other embodiments, the above sulfuric acid may be replaced by an acid having no redox property, such as phosphoric acid, acetic acid, or benzenesulfonic acid, and then mixed with hydrogen peroxide to prepare an oxidizing agent.

In the embodiment of the present invention, other oxidizing agents for oxidizing mercapto groups to sulfonic acid groups may be used instead of the above-described oxidizing agent using acid catalysis.

And 12, adding a preset first mass of the to-be-detected sulfhydryl-containing compound into the first container, and simultaneously adding a preset first mass of purified water into the second container.

In the technical scheme of the invention, two containers are used, wherein the first container is used for placing the to-be-tested sulfhydryl-containing compound, and the second container is used for placing purified water as blank comparison.

Further, preferably, in the embodiment of the present invention, both the first container and the second container may be a erlenmeyer flask or other container.

In addition, in the technical scheme of the invention, the first mass of the to-be-detected sulfhydryl-containing compound added into the first container can be predetermined according to the requirement of the practical application situation, so that the dosage of the subsequently used standard solution is more appropriate.

In addition, in the technical scheme of the invention, in order to detect the content of the sulfhydryl group more accurately, the used mass value can reserve at least 4 significant figures.

And step 13, adding an oxidizing reagent with a preset first volume into the first container and the second container respectively, shaking uniformly, and standing for a preset first time.

In step 11, the oxidizing reagent has been prepared in advance, so in this step, a predetermined first volume of oxidizing reagent may be added to the first container and the second container, respectively, after the stoppers are closed, the mixture may be shaken up and left to stand for a predetermined first period of time. After the oxidizing agent is added to the first container, the oxidizing agent can oxidize the mercapto group of the mercapto group-containing compound to be measured into a sulfonic acid group.

In the technical solution of the present invention, the specific value of the first volume of the oxidizing reagent added to the first and second containers can be predetermined according to the needs of the actual application and the mass of the thiol-group-containing compound to be tested that has been added to the first container before.

For example, preferably, in the embodiment of the present invention, the preset first volume may be 15 milliliters (mL).

In addition, preferably, in the embodiment of the present invention, the first time period may be 1.5 hours, or other suitable time periods.

And 14, respectively adding dropwise phenolphthalein indicator liquid into the first container and the second container.

In the step, 1-2 drops of phenolphthalein indicator liquid can be added into the first container and the second container respectively and shaken up.

And 15, titrating the solution to pink color in the first container and the second container respectively by using the sodium hydroxide standard solution, and recording the consumed volume of the sodium hydroxide standard solution in the first container and the second container respectively within 30 seconds.

In the technical scheme of the invention, when the titration operation is carried out on the first container, the sodium hydroxide standard solution can be injected into the burette firstly, and the initial scale value of the burette at the moment is recorded; then, slowly adding the sodium hydroxide standard solution into the first container while shaking the first container; after a certain drop of sodium hydroxide standard solution is dripped into the first container, the liquid in the first container turns red and does not fade for 30 seconds, stopping dripping the sodium hydroxide standard solution, and recording the current scale value of the burette at the moment; and subtracting the current scale value from the initial scale value to obtain the volume of the sodium hydroxide standard solution consumed by the first container. Likewise, the volume of the sodium hydroxide standard solution consumed by the second container can be obtained.

And step 16, calculating to obtain the content of the sulfhydryl in the sulfhydryl-containing compound to be detected according to the first mass, the concentration of the sodium hydroxide standard solution and the volumes of the sodium hydroxide standard solution consumed by the first container and the second container.

And calculating to obtain the content of the sulfhydryl in the sulfhydryl-containing compound to be detected after the first mass, the concentration of the sodium hydroxide standard solution and the volumes of the sodium hydroxide standard solution consumed by the first container and the second container are known.

For example, in an embodiment of the present invention, the following formula can be used to calculate the thiol content in the thiol-containing compound to be detected:

X＝(V₁-V₀)×C÷m÷1000，

wherein X is the content of sulfhydryl in the sulfhydryl-containing compound to be detected, and the unit is mol per gram (mol/g), V₁Volume of sodium hydroxide standard solution consumed by the first container in milliliters (mL), V₀The volume of the sodium hydroxide standard solution consumed by the second container is milliliter (mL), C is the concentration of the sodium hydroxide standard solution and is mole per liter (mol/L), and m is a first mass, namely the mass of the to-be-tested sulfhydryl-containing compound added into the first container and is gram (g).

From the above, the mercapto content in the to-be-detected mercapto-containing compound can be calculated through the above steps 11 to 16.

In summary, in the technical scheme of the present invention, since hydrogen peroxide-sulfuric acid is used as an oxidizing reagent, the mercapto group in the analyte can be oxidized into the sulfonic group, and then the sulfonic group content is detected by acid-base neutralization titration, the mercapto group content in the analyte can be determined (one mercapto group is fixedly converted into one sulfonic group); the method for detecting the content of the sulfhydryl group is easy to operate, simple, cheap, safe and quick, and does not need special instruments, so that the content of the sulfhydryl group in the object to be detected can be detected simply, cheaply and safely.

In addition, in the technical scheme of the invention, the consumption of other groups is not detected directly or by using the reaction of the sulfydryl and other groups, so that the whole detection process is simple, cheap and safe, and is suitable for a plurality of application scenes, such as small and medium-sized enterprises using or producing sulfydryl compounds.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.