TWI766341B - Method of detecting sulfide content by metal ion solution - Google Patents

Abstract

A method of detecting sulfide content by metal ion solution is provided, which includes providing a metal ion solution, a sulfur-containing analyte, and a chemically reducing agent. Mixing the metal ion solution and the sulfur-containing analyte to result in a mixture solution. The chemically reducing agent is added into the mixture solution to obtain a detection result. The detection result is observed to determine whether the sulfide content of the sulfur-containing analyte is over a threshold value. When the sulfide content of the sulfur-containing analyte is less than the threshold value, the detection result has precipitation.

Description

Method for detecting sulfide content by metal ion solution

The present disclosure relates to a method for confirming whether the sulfide content in a sulfur-containing analyte exceeds the standard.

Petrochemical products are widely used in daily life, but limited by the existing technology, sulfides will be formed in the production process of petroleum products; or for safety, additional sulfides will be added to odorless liquefied petroleum gas and natural gas. However, when the sulfide content is too high, it will not only cause air pollution, but also easily increase the risk of cancer. Therefore, there are global control standards for the content of sulfides.

Laboratory testing or on-site quick screening of sulfide content requires a certain amount of analysis cost. Taking about 2,500 gas stations in Taiwan as an example, each gas station has on-site quick screening of 92, 95, and 98 unleaded gasoline and diesel and regular screening. It needs to detect tens of thousands of sulfur-containing analytes every year, which is expensive and time-consuming. Therefore, a new rapid screening technology is urgently needed to reduce the cost of screening and to more quickly confirm whether the sulfide content in the oil exceeds the standard.

An embodiment of the present invention provides a method for detecting sulfide content with a metal ion solution, including: providing a metal ion solution, a sulfur-containing analyte, and a reducing agent; and mixing the metal ion solution and the sulfur-containing analyte to form a mixed solution Add the reducing agent to the mixed solution to obtain the detection result; observe the detection result to confirm whether the sulfide content of the sulfur-containing test object exceeds the threshold value, wherein when the sulfide content of the sulfur-containing test object is less than the threshold value, the test result has a precipitation .

An embodiment of the present invention provides a method for detecting sulfide content with a metal ion solution, including providing a metal ion solution, a sulfur-containing analyte, and a reducing agent. For example, the concentration and volume of the metal ion solution, the volume of the sulfur-containing analyte, and the amount of the reducing agent can be confirmed according to the threshold. In one embodiment, commercially available metal salts can be prepared into metal ion solutions of different volumes. In one embodiment, the metal ions include gold ions, silver ions, copper ions, chromium ions, cadmium ions, other metal ions that can be prepared into nanoparticles, or combinations thereof, but not limited thereto. When the metal ion is a gold ion, the metal salt can be chloroauric acid, gold trichloride, or other suitable gold ions. When the metal ion is a silver ion, the metal salt can be silver chloride, silver nitrate, or other suitable silver ions. When the metal ion is copper ion, the metal salt may be copper sulfate, copper acetate, copper nitrate, or other suitable copper ions. When the metal ion is a cadmium ion, the metal salt can be cadmium selenide, cadmium acetate, or other suitable cadmium ion.

A sulfur-containing analyte is formulated at a specific concentration (the so-called threshold) of sulfur compounds, and the volume of the sulfur-containing analyte is determined. For different volumes of metal ion solutions, a reducing agent that can completely reduce the metal ions in the metal ion solution to metal atoms is prepared. For example, the amount of the reducing agent is 10-1000 times that of the metal ion solution. In one embodiment, the reducing agent may be sodium borohydride, sodium citrate, ferric sulfate, ferric chloride, ascorbic acid, oleylamine (oleylamine), amino acid (amino acid), aqueous solution of other suitable reducing agents, or a combination of the above, but not limited thereto. Then, a fixed volume of the sulfur-containing analyte is taken and mixed with different volumes of metal ion solutions to form a mixed solution. Next, a reducing agent was added to the mixed solution, and it was confirmed whether or not precipitation occurred.

Confirm from a smaller volume of metal ion solution to a larger volume of metal ion solution, once the mixed solution of the minimum specific volume of metal ion solution and a fixed volume of sulfur-containing analyte is found, it will be clarified without precipitation after adding a reducing agent , the specific volume of the metal ion solution with this concentration can be used to detect whether the sulfide content of the sulfur-containing analyte exceeds the threshold. It can be understood that the concentration and volume of the above-mentioned metal ion solution, the fixed volume of the sulfur-containing analyte, and the dosage of the reducing agent are not limited to any specific values, and the design can be adjusted according to user needs. On the other hand, the above steps of confirming the volume and concentration of the metal ion solution, the sampling volume of the sulfur-containing analyte, and the amount of the reducing agent are only examples, and those with ordinary knowledge in the art can adopt other logical steps to achieve the above purpose.

The metal ion solution can then be mixed with the sulfur-containing analyte to form a mixed solution. The reducing agent is added to the mixed solution to obtain the detection result. Observe the test results to confirm whether the sulfide content of the sulfur-containing analyte exceeds the threshold. When the sulfide content of the sulfur-containing analyte is less than the threshold value, the detection result has precipitation. In one embodiment, the sulfur-containing analytes include petrochemicals, such as oils or solvents. For example, the oil may be unleaded gasoline, automotive diesel, liquefied petroleum gas, or other oils. On the other hand, the solvent can also be ethanol, isopropanol, propylene glycol methyl ether, propylene glycol methyl ether acetate, n-butyl acetate, cyclopentanone, acetone, N-methylpyrrolidone, or other suitable solvents.

In one embodiment, the threshold is between 0.1 ppmw and 30000 ppmw, eg, about 0.1-1 ppmw, 1-10 ppmw, 10-100 ppmw, 100-1000 ppmw, 1000-4000 ppmw, 4000-10000 ppmw, or 10000-30000 ppmw. If the threshold value is too low, even if the sulfide content of the sulfur-containing analyte does not exceed the threshold value, the concentration of gold atoms generated by the reduction of gold ions may be too low to see precipitation. If the threshold is too high, the amount of metal ions may be too high and the cost will be increased. For sulfur-containing analytes with high sulfide content, it may be considered to dilute the sulfur-containing analytes before testing to lower the threshold.

In one embodiment, the volume of the metal ion solution can be between 1 mL and 30 mL, such as about 1-5 mL, 5-10 mL, 10-15 mL, 15-20 mL, 20-25 mL, or 25-30 mL, The concentration of the metal ion solution can be between ^1M and ^10-10M , for example, about ^1-10-1M , ^{10-1-10-2M , 10-2-10-4M , 10-4-10- 6} M, 10 ^-6 -10 ^-8 M, or 10 ^-8 -10 ^-10 M. If the volume of the metal ion solution is too small, it is difficult to observe the precipitation reaction. If the volume of the metal ion solution is too large, the volume of the detection kit will be increased and the shipping cost will be increased. If the concentration of the metal ion solution is too low, even if the sulfide content of the sulfur-containing analyte does not exceed the threshold value, the concentration of gold atoms produced by the reduction of gold ions may be too low to see the precipitation phenomenon. If the concentration of the metal ion solution is too high, precipitation reactions will occur in all samples, resulting in misjudgment.

In one embodiment, the sampling volume of the sulfur-containing analyte is between 1 mL and 30 mL, such as about 1-5 mL, 5-10 mL, 10-15 mL, 15-20 mL, 20-25 mL, or 25-mL 30mL. If the sampling volume of the sulfur-containing analyte is too small, it is easy to cause sampling errors. If the sampling volume of the sulfur-containing analyte is too large, the amount of metal ions will be increased and the cost will be increased.

In one embodiment, the above-mentioned detection method of sulfide content lasts less than 10 minutes, such as 3 minutes or 5 minutes. Compared with the currently commonly used detection methods for sulfide content, the detection method of the present disclosure can greatly shorten the detection time. In one embodiment, the sulfides include hydrogen sulfide, mercaptans, sulfides, thiophenes, persulfides, polycyclic thiophenes, combinations thereof, etc., but are not limited thereto. In addition, in one embodiment, the functional group of the sulfide includes sulfonyl group, sulfonic acid group, sulfinyl group, mercapto group, thiocyanate, disulfide bond, a combination of the above, etc., but is not limited thereto.

The key to the present disclosure is the sequence of steps in the detection. The metal ion solution must be mixed with the sulfur-containing analyte before adding the reducing agent to confirm the test result for precipitation. If the metal ion solution and the reducing agent are mixed first, the precipitation end depends on the concentration of the metal ion solution, and has nothing to do with the sulfide content of the sulfur-containing analyte. For example, if the metal ion solution is mixed with the reducing agent to form a precipitate, even if the sulfide content of the sulfur-containing analyte added later exceeds the threshold, the precipitate will not disappear. In some embodiments, the detection technology can also be combined with an instrument (eg, ultraviolet-visible light spectrometer, infrared spectrometer, or other suitable instrument) to analyze the sulfur content concentration value of the detection result, so that the application is more extensive.

In order to make the above-mentioned content and other objects, features, and advantages of the present disclosure more obvious and easy to understand, preferred embodiments are given below, which are described in detail as follows: [ Embodiment ]

Example 1 Take commercially available chloroauric acid to prepare gold ion solutions of different volumes. An oil with a sulfur compound concentration of 9.6 ppmw was formulated. For different volumes of gold ion solutions, a reducing agent (such as an aqueous solution of sodium borohydride) that can completely reduce the gold ions of the gold ion solution to gold atoms is prepared. Take a fixed volume of oil and add different volumes of gold ion solution to mix to form a mixed solution, and then add a reducing agent to confirm whether precipitation occurs. Confirm from the smaller volume of gold ion solution to the larger volume of gold ion solution. Once the mixed solution of a specific volume of gold ion solution and a fixed volume of oil is found, it is clarified without precipitation after adding a reducing agent. The volume of solution available for quick screening of oils with a threshold of 9.6 ppmw. It can be understood that the concentration, volume of the gold ion solution, the fixed volume of the oil, and the amount of the reducing agent are not limited to any specific values, and the design can be adjusted according to user needs.

The vehicle diesel and biodiesel were taken as the sulfur-containing analytes, and the content of sulfur compounds in the sulfur-containing analytes was measured by a portable X-ray machine and the standard measurement method ASTM D5453. On the other hand, after adding a fixed volume of the sulfur-containing analyte into the above-mentioned gold ion solution and mixing, add a reducing agent to observe whether the detection result produces precipitation. The regulatory specification for the sulfide content of diesel fuel is 10 ppmw, while the threshold set by the above detection method is 9.6 ppmw. The measurement results are shown in Table 1:

Table 1 Portable X-ray machine ASTM D5453 Gold ion solution measurement cost 1000NTD 8000NTD <100NTD Time required for measurement 5 minutes 12 minutes 3 minutes Vehicle Diesel-1 3.9ppmw 6.4ppmw Precipitation (<threshold) Vehicle Diesel-2 5.3ppmw 4.4ppmw Precipitation (<threshold) Biodiesel-1 8.8ppmw 7.9ppmw Precipitation (<threshold) Biodiesel-2 8.0ppmw 7.1ppmw Precipitation (<threshold) Check Vehicle Diesel-1 9.2ppmw 9.0ppmw Precipitation (<threshold) Check Vehicle Diesel-2 11.0ppmw 10.5ppmw Clarification (>threshold)

It can be seen from Table 1 that the gold ion solution is first mixed with the oil, and then the reducing agent is added to confirm whether the precipitation occurs to confirm whether the sulfide content in the oil exceeds the threshold, which is obviously fast, reliable, and the cost is greatly reduced.

Example 2 Take commercially available chloroauric acid to prepare gold ion solutions of different volumes. An oil with a sulfur compound concentration of 9.6 ppmw was formulated. For different volumes of gold ion solutions, a reducing agent (such as an aqueous solution of sodium borohydride) that can completely reduce the gold ions of the gold ion solution to gold atoms is prepared. Take a fixed volume of oil and add different volumes of gold ion solution to mix to form a mixed solution, and then add a reducing agent to confirm whether precipitation occurs. Confirm from the smaller volume of gold ion solution to the larger volume of gold ion solution. Once the mixed solution of a specific volume of gold ion solution and a fixed volume of oil is found, it is clarified without precipitation after adding a reducing agent. The volume of the solution can be used to detect oils with a threshold of 9.6 ppmw. It can be understood that the concentration, volume of the gold ion solution, the fixed volume of the oil, and the amount of the reducing agent are not limited to any specific values, and the design can be adjusted according to user needs.

Take unleaded gasoline as the sulfur-containing analyte, and measure the sulfur compound content of the sulfur-containing analyte by the standard measurement method ASTM D5453. On the other hand, after adding a fixed volume of the sulfur-containing analyte into the above-mentioned gold ion solution and mixing, add a reducing agent to observe whether the detection result produces precipitation. The regulatory norm for the sulfide content of unleaded gasoline is 10 ppmw, while the threshold set by the above detection method is 9.6 ppmw. The measurement results are shown in Table 2:

Table 2 ASTM D5453 Gold ion solution measurement cost 8000NTD <100NTD Time required for measurement 12 minutes 3 minutes 92 unleaded gasoline-1 2.2ppmw Precipitation (<threshold) 92 unleaded gasoline-2 7.6ppmw Precipitation (<threshold) 95 unleaded gasoline-1 3.3ppmw Precipitation (<threshold) 95 unleaded gasoline-2 7.6ppmw Precipitation (<threshold) 98 unleaded gasoline-1 3.0ppnw Precipitation (<threshold) 98 unleaded gasoline-4 5.1ppmw Precipitation (<threshold) Check Unleaded Gasoline-1 9.0ppmw Precipitation (<threshold) Check Unleaded Gasoline-2 11.1ppmw Clarification (>threshold)

It can be seen from Table 2 that the gold ion solution is first mixed with the oil, and then the reducing agent is added to confirm whether the precipitation occurs to confirm whether the sulfide content in the oil exceeds the threshold, which is obviously fast, reliable, and the cost is greatly reduced.

Example 3 Take commercially available chloroauric acid to prepare gold ion solutions of different volumes. The oil was formulated with a sulfur compound concentration of 45 ppmw. For different volumes of gold ion solutions, a reducing agent (such as an aqueous solution of sodium borohydride) that can completely reduce the gold ions of the gold ion solution to gold atoms is prepared. Take a fixed volume of oil and add different volumes of gold ion solution to mix to form a mixed solution, and then add a reducing agent to confirm whether precipitation occurs. Confirm from the smaller volume of gold ion solution to the larger volume of gold ion solution. Once the mixed solution of a specific volume of gold ion solution and a fixed volume of oil is found, it is clarified without precipitation after adding a reducing agent. The volume of the solution can be used to detect oils with a threshold of 45ppmw. It can be understood that the concentration, volume of the gold ion solution, the fixed volume of the oil, and the amount of the reducing agent are not limited to any specific values, and the design can be adjusted according to user needs.

The liquefied petroleum gas was taken as the sulfur-containing analyte, and the sulfur compound content of the sulfur-containing analyte was measured by a portable gas chromatograph (GC) and the standard measurement method ASTM D6667. On the other hand, after adding a fixed volume of the sulfur-containing analyte into the above-mentioned gold ion solution and mixing, add a reducing agent to observe whether the detection result produces precipitation. The regulatory specification for the sulfide content of LPG is 50 ppmw, while the threshold set by the above detection method is 45 ppmw. The measurement results are shown in Table 3:

table 3 Portable GC ASTM D6667 Gold ion solution measurement cost 8000NTD 8000NTD <100NTD Time required for measurement 15 minutes 12 minutes 3 minutes Vehicle LPG-1 20ppmw 23ppmw Precipitation (<threshold) Vehicle LPG-2 17ppmw 23ppmw Precipitation (<threshold) Vehicle LPG-3 18ppmw 24ppmw Precipitation (<threshold) Vehicle LPG-4 19ppmw 21ppmw Precipitation (<threshold) Check LPG-1 Untested 25ppmw Precipitation (<threshold) Check LPG-2 Untested 50ppmw Clarification (>threshold)

It can be seen from Table 3 that the gold ion solution is first mixed with LPG, and then a reducing agent is added to confirm whether precipitation occurs to confirm whether the sulfide content in LPG exceeds the threshold, which is obviously fast, reliable, and the cost is greatly reduced. .

Example 4 Natural gas with known sulfide concentration was passed into a fixed volume of solvent for a fixed period of time, and then the sulfide concentration in the solvent was confirmed by the standard measurement method ASTM D5504. In this way, the sulfide concentration in the solvent, the sulfide concentration in the natural gas, the time for the natural gas to pass into the solvent, and the volume of the solvent can be calculated. The regulation specification for the sulfide content of natural gas is 45 mg/m ³ . The appropriate time and volume of the natural gas to be passed into the solvent were selected with the above functions to achieve a threshold value of 40 mg/m ³ of sulfide content.

Take commercially available chloroauric acid to prepare gold ion solutions of different volumes. A solvent with a sulfur compound concentration of 40 mg/m ³ was formulated. For different volumes of gold ion solutions, a reducing agent (such as an aqueous solution of sodium borohydride) that can completely reduce the gold ions of the gold ion solution to gold atoms is prepared. Take a fixed volume of solvent and add different volumes of gold ion solution to form a mixed solution, and then add a reducing agent to confirm whether precipitation occurs. Confirm from the smaller volume of gold ion solution to the larger volume of gold ion solution. Once the mixed solution of a specific volume of gold ion solution and a fixed volume of solvent is found, it will be clarified without precipitation after adding a reducing agent. A volume of 40 mg/m ^of solvent is available for detection threshold. It can be understood that the concentration, volume, fixed volume of the solvent, and the amount of the reducing agent mentioned above are not limited to any specific values, and the design can be adjusted according to user needs.

The sulfide content of natural gas was directly measured with a commercially available detector tube (brand: Gastec). On the other hand, take natural gas and pass it into a fixed volume of solvent for a fixed period of time to be used as the sulfur-containing analyte. The sulfur compound content of the sulfur-containing analyte was measured by the standard measurement method ASTM D5504. On the other hand, after adding a fixed volume of the sulfur-containing analyte into the above-mentioned gold ion solution and mixing, add a reducing agent to observe whether the detection result produces precipitation. The measurement results are shown in Table 3:

Table 4 detection tube ASTM D5504 Gold ion solution measurement cost 200NTD 8000NTD <100NTD Time required for measurement 1 minute 15 minutes 3 minutes natural gas-1 11.1mg/ ^m3 5.6mg/ ^m3 Precipitation (<threshold) Gas-2 11.1mg/ ^m3 10.0mg/ ^m3 Precipitation (<threshold) Gas-3 3.6mg/ ^m3 2.4mg/ ^m3 Precipitation (<threshold) Gas-4 9.1mg/ ^m3 3.9mg/ ^m3 Precipitation (<threshold) Check Gas-1 Untested 38.9mg/ ^m3 Precipitation (<threshold) Check Gas-2 Untested 45.8mg/m ³ Clarification (>threshold)

It can be seen from Table 4 that the gold ion solution is first mixed with the solvent that absorbs sulfides in natural gas, and then a reducing agent is added to confirm whether precipitation occurs, so as to confirm whether the sulfide content in natural gas exceeds the threshold, which is obviously fast, reliable, and cost-effective. advantages such as reduction.

Example 5 Take commercially available chloroauric acid to prepare gold ion solutions of different volumes. Solvents were formulated with a sulfur compound concentration of 0.45 ppmw. For different volumes of gold ion solutions, a reducing agent (such as an aqueous solution of sodium borohydride) that can completely reduce the gold ions of the gold ion solution to gold atoms is prepared. Take a fixed volume of solvent and add different volumes of gold ion solution to form a mixed solution, and then add a reducing agent to confirm whether precipitation occurs. Confirm from the smaller volume of gold ion solution to the larger volume of gold ion solution. Once the mixed solution of a specific volume of gold ion solution and a fixed volume of solvent is found, it will be clarified without precipitation after adding a reducing agent. The volume of solvent available for detection with a threshold of 0.45 ppmw. It can be understood that the concentration, volume, fixed volume of the solvent and the amount of reducing agent mentioned above are not limited to any specific values, and the design can be adjusted according to user needs.

Ethanol and isopropanol with different sulfur content concentrations were prepared as sulfur-containing analytes. After adding a fixed volume of sulfur-containing analyte into the above gold ion solution and mixing, add a reducing agent to observe whether the detection result produces precipitation. The threshold value set by the above detection method is 0.45ppmw. The measurement results are shown in Table 5:

table 5 Sulfide content Gold ion solution Ethanol 0.1ppmw Precipitation (<threshold) 0.5ppmw Clarification (>threshold) 1.0ppmw Clarification (>threshold) isopropyl alcohol 0.1ppmw Precipitation (<threshold) 0.5ppmw Clarification (>threshold) 1.0ppmw Clarification (>threshold)

It can be seen from Table 5 that the gold ion solution can confirm whether the sulfide content of the sulfur-containing analyte exceeds a very low threshold (eg 0.1 ppmw).

Example 6 Take commercially available silver nitrate to prepare silver ion solutions of different volumes. Solvents were formulated with a sulfur compound concentration of 0.45 ppmw. For different volumes of silver ion solutions, a reducing agent (such as an aqueous solution of sodium borohydride) that can completely reduce the silver ions of the silver ion solution to silver atoms is prepared. Take a fixed volume of solvent and add different volumes of silver ion solution to form a mixed solution, and then add a reducing agent to confirm whether precipitation occurs. Confirm from the smaller volume of silver ion solution to the larger volume of silver ion solution. Once the mixed solution of a specific volume of silver ion solution and a fixed volume of solvent is found, after adding a reducing agent, it is clarified without precipitation. The volume of solvent available for detection with a threshold of 0.45 ppmw. It can be understood that the concentration, volume of the silver ion solution, the fixed volume of the solvent, and the dosage of the reducing agent are not limited to any specific values, and the design can be adjusted according to user needs.

Ethanol and isopropanol with different sulfur content concentrations were prepared as sulfur-containing analytes. After adding a fixed volume of the sulfur-containing analyte into the above silver ion solution and mixing, add a reducing agent to observe whether the detection result produces precipitation. The threshold value set by the above detection method is 0.45ppmw. The measurement results are shown in Table 6:

Table 6 Sulfide content silver ion solution Ethanol 0.1ppmw Precipitation (<threshold) 0.5ppmw Clarification (>threshold) 1.0ppmw Clarification (>threshold) isopropyl alcohol 0.1ppmw Precipitation (<threshold) 0.5ppmw Clarification (>threshold) 1.0ppmw Clarification (>threshold)

It can be seen from Table 6 that the silver ion solution can confirm whether the sulfide content of the sulfur-containing analyte exceeds a very low threshold (eg 0.45ppmw).

Example 7 Take commercially available copper nitrate to prepare copper ion solutions of different volumes. Solvents were formulated with a sulfur compound concentration of 0.45 ppmw. For different volumes of copper ion solutions, a reducing agent (such as an aqueous solution of sodium borohydride) that can completely reduce the copper ions of the copper ion solution to copper atoms is prepared. Take a fixed volume of solvent and add different volumes of copper ion solution to mix to form a mixed solution, and then add a reducing agent to confirm whether precipitation occurs. Confirm from a smaller volume of copper ion solution to a larger volume of copper ion solution. Once a mixed solution of a specific volume of copper ion solution and a fixed volume of solvent is found, after adding a reducing agent, it is clarified without precipitation. The volume of solvent available for detection with a threshold of 0.45 ppmw. It can be understood that the concentration, volume, fixed volume of the solvent, and the dosage of the reducing agent are not limited to any specific values, and the design can be adjusted according to user needs.

Ethanol and isopropanol with different sulfur content concentrations were prepared as sulfur-containing analytes. After adding a fixed volume of the sulfur-containing analyte into the above copper ion solution and mixing, add a reducing agent to observe whether the test result produces precipitation. The threshold value set by the above detection method is 0.45ppmw. The measurement results are shown in Table 7:

Table 7 Sulfide content Copper ion solution Ethanol 0.1ppmw Precipitation (<threshold) 0.5ppmw Clarification (>threshold) 1.0ppmw Clarification (>threshold) isopropyl alcohol 0.1ppmw Precipitation (<threshold) 0.5ppmw Clarification (>threshold) 1.0ppmw Clarification (>threshold)

It can be seen from Table 7 that the copper ion solution can confirm whether the sulfide content of the sulfur-containing analyte exceeds a very low threshold (eg 0.45ppmw).

Example 8 Take commercially available cadmium nitrate to prepare cadmium ion solutions of different volumes. Solvents were formulated with a sulfur compound concentration of 0.45 ppmw. For different volumes of cadmium ion solutions, a reducing agent (such as an aqueous solution of sodium borohydride) that can completely reduce cadmium ions in the cadmium ion solution to cadmium atoms is prepared. Take a fixed volume of solvent and add different volumes of cadmium ion solution to form a mixed solution, and then add a reducing agent to confirm whether precipitation occurs. Confirm from a smaller volume of cadmium ion solution to a larger volume of cadmium ion solution. Once a mixed solution of a specific volume of cadmium ion solution and a fixed volume of solvent is found, after adding a reducing agent, it is clarified without causing precipitation, then this cadmium ion solution The volume of solvent available for detection with a threshold of 0.45 ppmw. It can be understood that the concentration, volume, fixed volume of the solvent, and the amount of reducing agent mentioned above are not limited to any specific values, and the design can be adjusted according to user needs.

Ethanol and isopropanol with different sulfur content concentrations were prepared as sulfur-containing analytes. After adding a fixed volume of the sulfur-containing analyte into the above-mentioned cadmium ion solution and mixing, add a reducing agent to observe whether the detection result produces precipitation. The threshold value set by the above detection method is 0.45ppmw. The measurement results are shown in Table 8:

Table 8 Sulfide content Cadmium ion solution Ethanol 0.1ppmw Precipitation (<threshold) 0.5ppmw Clarification (>threshold) 1.0ppmw Clarification (>threshold) isopropyl alcohol 0.1ppmw Precipitation (<threshold) 0.5ppmw Clarification (>threshold) 1.0ppmw Clarification (>threshold)

It can be seen from Table 8 that the cadmium ion solution can confirm whether the sulfide content of the sulfur-containing analyte exceeds a very low threshold (eg 0.45ppmw).

Example 9 Take commercially available chloroauric acid to prepare gold ion solutions of different volumes. An oil with a sulfur compound concentration of 9.6 ppmw was formulated. For different volumes of gold ion solutions, a reducing agent (such as an aqueous solution of sodium citrate, ferric chloride, or vitamin C) that can reduce gold ions in the solution to gold atoms is prepared. Take a fixed volume of oil and add different volumes of gold ion solution to mix to form a mixed solution, and then add a reducing agent to confirm whether precipitation occurs. Confirm from the smaller volume of gold ion solution to the larger volume of gold ion solution. Once the mixed solution of a specific volume of gold ion solution and a fixed volume of oil is found, it is clarified without precipitation after adding a reducing agent. The volume of the solution can be used to detect oils with a threshold of 9.6 ppmw. It can be understood that the concentration, volume of the gold ion solution, the fixed volume of the oil, and the amount of the reducing agent are not limited to any specific values, and the design can be adjusted according to user needs.

Take diesel fuel for vehicles as the sulfur-containing analyte, and measure the sulfur compound content of the sulfur-containing analyte by the standard measurement method ASTM D5453. On the other hand, after adding a fixed volume of the sulfur-containing analyte into the above-mentioned gold ion solution and mixing, add a reducing agent to observe whether the detection result produces precipitation. The regulatory specification for the sulfide content of diesel fuel is 10 ppmw, while the threshold set by the above detection method is 9.6 ppmw. The measurement results are shown in Table 1:

Table 9 ASTM D5453 Gold ion solution (using the reducing agent sodium citrate) Gold ion solution (using reducing agent ferric chloride) Gold ion solution (using reducing agent vitamin C) Vehicle Diesel-1 6.4ppmw Precipitation (<threshold) Precipitation (<threshold) Precipitation (<threshold) Vehicle Diesel-2 4.4ppmw Precipitation (<threshold) Precipitation (<threshold) Precipitation (<threshold) Check Vehicle Diesel-1 9.0ppmw Precipitation (<threshold) Precipitation (<threshold) Precipitation (<threshold) Check Vehicle Diesel-2 10.5ppmw Clarification (>threshold) Clarification (>threshold) Clarification (>threshold)

It can be seen from Table 9 that the gold ion solution is mixed with the oil first and then different kinds of reducing agents are added. It can also be used to confirm whether the sulfide content in the oil exceeds the threshold.

Example 10 Select the concentration of the gold ion solution of embodiment 9, volume, the fixed volume of oil product, reducing agent, and reducing agent consumption, respectively to sulfur content concentration is that the vehicle diesel oil of 7ppmw and 10.6ppmw carries out sulfur content detection, and with ultraviolet-ray- The visible light spectrometer analyzes the UV absorption spectrum of the detection results. When the sulfur content is 7ppmw, because the sulfur content is less than the threshold (9.6ppmw), there will be precipitation visible to the naked eye, the color appearance is wine red, and the absorption intensity of its UV spectrum decreases with the particle precipitation (Figure 1). When the sulfur content is 10.5ppmw, the sulfur content is greater than the threshold value, so no visible precipitation is produced. Even with the increase of the reaction time, the absorption intensity of the UV spectrum is relatively unchanged because the particles have no precipitation (Figure 2). It can be seen from the above that the detection technology can also be combined with an instrument (such as an ultraviolet-visible light spectrometer) to analyze the sulfur content concentration value of the detection result, so that the application is wider.

Although the present disclosure has been disclosed above with several preferred embodiments, it is not intended to limit the present disclosure. Anyone with ordinary knowledge in the technical field can make any changes without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the appended patent application.

none.

FIG. 1 shows the ultraviolet spectrum of the detection result when the sulfur content is less than a threshold in an embodiment of the present disclosure. FIG. 2 shows the ultraviolet spectrum of the detection result when the sulfur content is greater than the threshold in an embodiment of the present disclosure.

Claims (12)

A method for detecting sulfide content with a metal ion solution, comprising: providing a metal ion solution, a sulfur-containing analyte, and a reducing agent; mixing the metal ion solution and the sulfur-containing analyte to form a mixed solution Add this reducing agent to this mixed solution to obtain a test result; observe this test result to confirm whether the sulfide content of this sulfur-containing test substance exceeds a threshold, wherein when the sulfide content of this sulfur-containing test substance is less than the When the threshold value is reached, the detection result has precipitation, wherein the metal ions of the metal ion solution include gold ions, silver ions, copper ions, cadmium ions or a combination thereof. The method for detecting sulfide content in a metal ion solution according to claim 1, wherein the reducing agent comprises sodium borohydride, sodium citrate, ferric sulfate, ferric chloride, vitamin C, oleylamine, amino acid, or a combination thereof . The method for detecting sulfide content in a metal ion solution according to claim 1, wherein the threshold value is between 0.1 ppm and 30000 ppm. The method for detecting sulfide content with a metal ion solution according to claim 1, wherein the reducing agent completely reduces the metal ions in the metal ion solution that have not interacted with the sulfide into metal atoms, wherein the amount of the reducing agent is 30% of the metal ion solution. 10-1000 times. The method for detecting sulfide content in a metal ion solution according to claim 1, wherein the sulfur-containing analyte includes petrochemical products. The method for detecting sulfide content with a metal ion solution according to claim 1, wherein the volume of the metal ion solution is between 1 mL and 30 mL. The method for detecting sulfide content with a metal ion solution according to claim 1, wherein the concentration of the metal ion solution is between 1M and ^10-10M . The method for detecting sulfide content with a metal ion solution according to claim 1, wherein the volume of the sulfur-containing analyte is between 1 mL and 30 mL. The method for detecting sulfide content with a metal ion solution according to claim 1, wherein the metal ion solution and the sulfur-containing analyte are mixed to form the mixed solution; the reducing agent is added to the mixed solution to obtain the detection result; The step of observing the detection result to confirm whether the sulfide content of the sulfur-containing analyte exceeds the threshold value is less than 10 minutes in total. The method for detecting sulfide content in a metal ion solution according to claim 1, wherein the sulfide includes hydrogen sulfide, mercaptan, sulfide, thiophene, persulfide, polycyclic thiophene, or a combination thereof. The method for detecting sulfide content in a metal ion solution as claimed in claim 1, wherein the functional groups of the sulfide include sulfonyl group, sulfonic acid group, sulfinyl group, mercapto group, thiocyanate, disulfide bond or any of the above combination. As claimed in claim 1, the method for detecting sulfide content with a metal ion solution further includes analyzing the sulfur content concentration value of the detection result with an instrument.

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