Device and method for preparing sulfide standard solution

Abstract

The invention discloses a device and a method for preparing a sulfide standard solution, and solves the problems that in the prior art, the preparation process of the standard solution is relatively complicated, and the content of the sulfide standard solution prepared from sodium sulfide is unstable due to the fact that sulfur is easily oxidized. The device comprises a hydrogen sulfide gas standard sample source in nitrogen, a zinc acetate solution reaction tank, a sodium hydroxide absorption tank and a high-purity nitrogen gas source, wherein an outlet of the hydrogen sulfide gas standard sample source in nitrogen is communicated with an inlet of the first pressure reduction and flow control device, an outlet of the first pressure reduction and flow control device is communicated with an inlet of the zinc acetate solution reaction tank, and an outlet of the zinc acetate solution reaction tank is communicated with an inlet of the sodium hydroxide absorption tank; an outlet of the high-purity nitrogen source is communicated with an inlet of the second pressure-reducing flow-controlling device, and an outlet of the second pressure-reducing flow-controlling device is communicated with the whole device. According to the method, the hydrogen sulfide gas standard sample in nitrogen is directly adopted to replace a complex process of generating hydrogen sulfide by acidifying sodium sulfide, so that the preparation process is simplified, and the preparation efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of analytical chemistry, and in particular to a device and a method for preparing a sulfide standard solution. Background Art

[0002] Reference materials are measurement standards with accurate values. They play a huge role in verifying and calibrating measuring instruments, evaluating the accuracy of measurement results, verifying the reliability of new methods, and assessing the technical level of operators. They ultimately ensure that the analysis and measurement results are accurate, consistent, and reliable, and achieve value traceability. Reference materials have been widely used in the fields of chemical measurement, biological measurement, engineering measurement, and physical measurement. Sulfide standard solution, as a "ruler" for sulfide detection in water, is widely used in the detection of sulfide in the environment. Standard solutions should have accurate values, good uniformity, and stability.

[0003] The sulfide standard solution specified in the current standards GB / T 16489-1996 and HJ 1226-2021 is a sulfur standard solution prepared with sodium sulfide, which is easily oxidized by oxygen in air and water to produce sodium sulfite, sodium sulfate, sodium thiosulfate and other sulfides. The sulfur content is unstable, so the standard stipulates that it should be prepared and used immediately and recalibrated before use. For experimenters, it is cumbersome to re-prepare or re-calibrate and re-value each time, which increases the workload of the experiment.

[0004] Patent CN1096102 A developed a zinc sulfide colloidal standard solution and its preparation method: sodium sulfide is acidified to produce hydrogen sulfide gas, which is absorbed by dilute zinc acetate using high-purity nitrogen as carrier gas to generate a slightly turbid zinc sulfide colloidal solution. The colloidal solution after filtration is fixed to the zinc sulfide standard solution. The applicant found that the prior art has the following defects:

[0005] 1) The intermediate product hydrogen sulfide also contains impurity sulfur dioxide, which may affect subsequent reactions and needs to be washed and separated to remove impurities;

[0006] 2) Nitrogen is needed as a carrier gas to introduce the generated hydrogen sulfide into the absorption liquid;

[0007] 3) It is impossible to accurately control the reaction amount and reaction rate;

[0008] 4) If hydrogen sulfide is not absorbed and treated, it may pollute the environment and easily exist in the colloidal solution, affecting the final set value.

[0009] Therefore, it is necessary to develop a device and method for preparing a sulfide standard solution to overcome the defects in the prior art. Summary of the invention

[0010] The object of the present invention is to provide a device and method for preparing a sulfide standard solution, so as to solve the technical problems that the standard solution preparation process in the prior art is relatively complicated and the sulfide standard solution prepared using sodium sulfide has unstable content due to sulfur being easily oxidized.

[0011] To achieve the above object, the present invention provides the following technical solutions:

[0012] In a first aspect, the present invention provides a device for preparing a sulfide standard solution, comprising a standard sample source of hydrogen sulfide gas in nitrogen, a first pressure reduction flow control device, a zinc acetate solution reaction tank, a sodium hydroxide absorption tank, a second pressure reduction flow control device, and a high-purity nitrogen source; wherein the outlet of the standard sample source of hydrogen sulfide gas in nitrogen is connected to the inlet of the first pressure reduction flow control device, the outlet of the first pressure reduction flow control device is connected to the inlet of the zinc acetate solution reaction tank, and the outlet of the zinc acetate solution reaction tank is connected to the inlet of the sodium hydroxide absorption tank; the outlet of the high-purity nitrogen source is connected to the inlet of the second pressure reduction flow control device, and the outlet of the second pressure reduction flow control device is connected to the entire device, so as to remove oxygen in the device and remove dissolved hydrogen sulfide in the device.

[0013] Furthermore, it also includes a first stop valve and a second stop valve, and the first stop valve and the second stop valve are respectively arranged on the outlet pipes of the first pressure reducing flow control device and the second pressure reducing flow control device.

[0014] Furthermore, the standard sample source of hydrogen sulfide gas in nitrogen is formed by dynamically diluting a high-purity hydrogen sulfide gas source and a nitrogen source through a gas diluter, and the outlets of the high-purity hydrogen sulfide gas source and the nitrogen source are both connected to the inlet of the gas diluter.

[0015] In a second aspect, the present invention provides a method for preparing a sulfide standard solution, comprising the following steps:

[0016] A1. After reducing the pressure and controlling the flow of high-purity nitrogen, the oxygen in the entire preparation device is discharged;

[0017] A2, introducing the hydrogen sulfide gas standard sample in nitrogen into the zinc acetate solution reaction tank through a pressure reducing flow control device, and reacting with the zinc acetate solution to generate a sulfide standard solution;

[0018] A3. Use high-purity nitrogen to purge the residual hydrogen sulfide in the device, and introduce the purged hydrogen sulfide gas into the sodium hydroxide absorption tank for absorption;

[0019] A4. Filter the generated sulfide standard solution;

[0020] A5. Use two calibration methods to calibrate the filtered sulfide standard solution.

[0021] Furthermore, in A2, the standard sample of hydrogen sulfide gas in nitrogen is formed by dynamically diluting high-purity hydrogen sulfide gas and nitrogen through a gas diluter.

[0022] Furthermore, in A5, the sulfide standard solution is quantified using methylene blue spectrophotometry and titration.

[0023] Based on the above technical solution, the embodiments of the present invention can at least produce the following technical effects:

[0024] (1) Simplify the operation and improve the efficiency: By directly using the standard sample of hydrogen sulfide gas in nitrogen, the complicated process of producing hydrogen sulfide by acidification of sodium sulfide is avoided, and the steps such as water washing and separation are reduced, thereby simplifying the preparation process and improving the preparation efficiency.

[0025] (2) Improve solution stability: Using hydrogen sulfide gas standard samples reduces the impact of impurities, and the resulting sulfide standard solution is purer and more stable, which is conducive to long-term storage and use.

[0026] (3) Quantitative control: By controlling the flow rate of the hydrogen sulfide gas sample in nitrogen, the concentration of zinc acetate, and the reaction time, the concentration of the generated sulfide standard solution can be precisely controlled to meet different experimental requirements.

[0027] (4) Green and environmentally friendly: During the reaction, excess hydrogen sulfide is completely absorbed by the sodium hydroxide absorption tank, avoiding environmental pollution.

[0028] (5) Broad application prospects: This preparation method is simple to operate, fast, can quantitatively control the concentration of sulfide, and has little pollution. It has great application prospects and can be widely used in environmental testing, chemical analysis and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention;

[0031] Figure 2 It is a structural diagram of embodiment 2 of the present invention.

[0032] In the figure: 1. Standard sample source of hydrogen sulfide gas in nitrogen; 2. First pressure reducing and flow controlling device; 3. First stop valve; 4. Zinc acetate solution reaction pool; 5. Sodium hydroxide absorption pool; 6. Second stop valve; 7. Second pressure reducing and flow controlling device; 8. High-purity nitrogen source; 9. High-purity hydrogen sulfide gas source; 10. Nitrogen source; 11. Gas diluter. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0034] Embodiment 1

[0035] like Figure 1 As shown, a device for preparing a standard sulfide solution includes a standard sample source 1 of hydrogen sulfide gas in nitrogen, a first pressure-reducing flow-controlling device 2, a zinc acetate solution reaction tank 4, a sodium hydroxide absorption tank 5, a second pressure-reducing flow-controlling device 7 and a high-purity nitrogen source 8.

[0036] The outlet of the nitrogen-hydrogen sulfide gas standard sample source 1 is connected to the inlet of the first decompression flow control device 2, which is used to introduce the nitrogen-hydrogen sulfide gas standard sample into the device after the flow is controlled by decompression. The outlet of the first decompression flow control device 2 is connected to the inlet of the zinc acetate solution reaction tank 4 through the first stop valve 3, so that the nitrogen-hydrogen sulfide gas standard sample after decompression flow control can enter the zinc acetate solution reaction tank 4 to react with the zinc acetate solution to generate a sulfide standard solution.

[0037] The outlet of the zinc acetate solution reaction tank 4 is connected to the inlet of the sodium hydroxide absorption tank 5, which is used to introduce the hydrogen sulfide gas remaining after the reaction into the sodium hydroxide absorption tank 5 for absorption treatment to avoid environmental pollution. The inlet of the second pressure reduction and flow control device 7 is connected to the outlet of the high-purity nitrogen source 8, and its outlet is connected to the entire device through the second stop valve 6, which is used to remove oxygen in the device before the device is operated and to purge the dissolved hydrogen sulfide in the device after the reaction is completed.

[0038] Finally, the generated sulfide product standard solution is filtered to remove any suspended impurities that may exist therein, and the filtered standard solution is calibrated to determine the sulfur content.

[0039] Embodiment 2

[0040] like Figure 2 As shown, a device for preparing a standard sulfide solution includes a high-purity hydrogen sulfide gas source 9, a nitrogen source 10, a gas diluter 11, a first decompression flow control device 2, a zinc acetate solution reaction tank 4, a sodium hydroxide absorption tank 5, a second decompression flow control device 7 and a high-purity nitrogen source 8.

[0041] The outlets of the high-purity hydrogen sulfide gas source 9 and the nitrogen source 10 are both connected to the inlet of the gas diluter 11, and the outlet of the gas diluter 11 is connected to the inlet of the first decompression flow control device 2, which is used to introduce the standard sample generated by the dynamic dilution method into the device through decompression control flow. The outlet of the first decompression flow control device 2 is connected to the inlet of the zinc acetate solution reaction tank 4 through the first stop valve 3, so that the standard sample of hydrogen sulfide gas in nitrogen after decompression flow control can enter the zinc acetate solution reaction tank 4 and react with the zinc acetate solution to generate a sulfide standard solution.

[0042] The outlet of the zinc acetate solution reaction tank 4 is connected to the inlet of the sodium hydroxide absorption tank 5, which is used to introduce the hydrogen sulfide gas remaining after the reaction into the sodium hydroxide absorption tank 5 for absorption treatment to avoid environmental pollution. The inlet of the second pressure reduction and flow control device 7 is connected to the outlet of the high-purity nitrogen source 8, and its outlet is connected to the entire device through the second stop valve 6, which is used to remove oxygen in the device before the device is operated and to purge the dissolved hydrogen sulfide in the device after the reaction is completed.

[0043] Finally, the generated sulfide product standard solution is filtered to remove suspended impurities therein, and the filtered standard solution is calibrated to determine its concentration.

[0044] Embodiment 3

[0045] A method for preparing a sulfide standard solution comprises the following steps:

[0046] A1. After reducing the pressure and controlling the flow of high-purity nitrogen, the oxygen in the entire preparation device is discharged;

[0047] A2, introducing the hydrogen sulfide gas standard sample in nitrogen into the zinc acetate solution reaction tank through a pressure reducing flow control device, and reacting with the zinc acetate solution to generate a sulfide standard solution;

[0048] A3. Use high-purity nitrogen to purge the residual hydrogen sulfide in the device, and introduce the purged hydrogen sulfide gas into the sodium hydroxide absorption tank for absorption;

[0049] A4. Filter the generated sulfide standard solution;

[0050] A5. Use methylene blue spectrophotometry and titration to determine the value of sulfide standard solution.

[0051] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of the present invention to be protected is defined by the attached claims and their equivalents.

Claims

1. A device for preparing a sulfide standard solution, characterized in that: The invention comprises a standard sample source of hydrogen sulfide in nitrogen gas (1), a first pressure-reducing flow control device (2), a zinc acetate solution reaction pool (4), a sodium hydroxide absorption pool (5), a second pressure-reducing flow control device (7) and a high-purity nitrogen source (8); wherein the outlet of the standard sample source of hydrogen sulfide in nitrogen gas (1) is connected to the inlet of the first pressure-reducing flow control device (2), the outlet of the first pressure-reducing flow control device (2) is connected to the inlet of the zinc acetate solution reaction pool (4), and the outlet of the zinc acetate solution reaction pool (4) is connected to the inlet of the sodium hydroxide absorption pool (5); the outlet of the high-purity nitrogen source (8) is connected to the inlet of the second pressure-reducing flow control device (7), and the outlet of the second pressure-reducing flow control device (7) is connected to the entire device, so as to remove oxygen in the device and hydrogen sulfide dissolved in the device.

2. The device for preparing a sulfide standard solution according to claim 1, characterized in that: It also comprises a first stop valve (3) and a second stop valve (6), wherein the first stop valve (3) and the second stop valve (6) are respectively arranged on the outlet pipes of the first pressure reducing flow control device (2) and the second pressure reducing flow control device (7).

3. The device for preparing a sulfide standard solution according to claim 1, characterized in that: The standard sample source of hydrogen sulfide gas in nitrogen (1) is formed by dynamically diluting a high-purity hydrogen sulfide gas source (9) and a nitrogen source (10) through a gas diluter (11), and the outlets of the high-purity hydrogen sulfide gas source (9) and the nitrogen source (10) are both connected to the inlet of the gas diluter (11).

4. A method for preparing a sulfide standard solution, characterized in that: The following steps are involved: A1. After reducing the pressure and controlling the flow of high-purity nitrogen, the oxygen in the entire preparation device is discharged; A2, introducing the hydrogen sulfide gas standard sample in nitrogen into the zinc acetate solution reaction tank through a pressure reducing flow control device, and reacting with the zinc acetate solution to generate a sulfide standard solution; A3. Use high-purity nitrogen to purge the residual hydrogen sulfide in the device, and introduce the purged hydrogen sulfide gas into the sodium hydroxide absorption tank for absorption; A4. Filter the generated sulfide standard solution; A5. Use two calibration methods to perform calibration on the filtered sulfide standard solution.

5. The method for preparing a sulfide standard solution according to claim 4, characterized in that: In A2, the standard sample of hydrogen sulfide gas in nitrogen is formed by dynamically diluting high-purity hydrogen sulfide gas and nitrogen through a gas diluter.

6. The method for preparing a sulfide standard solution according to claim 4, characterized in that: In A5, the sulfide standard solution is quantified using methylene blue spectrophotometry and titration.

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