System and method for measuring concentration of trimethyl borate in alcoholic solution

Abstract

The invention discloses a system and a method for measuring the concentration of trimethyl borate in an alcoholic solution. The alcoholic solution is arranged in the measuring cell, and the alcoholic solution contains trimethyl borate with the concentration to be measured; one end of the indicator electrode is soaked in the alcoholic solution, and the other end of the indicator electrode extends out of the alcoholic solution; the reference electrode and the indicator electrode are arranged at an interval, one end of the reference electrode is soaked in the alcoholic solution, and the other end of the reference electrode extends out of the alcoholic solution; the measuring instrument is connected with one ends, far away from the alcoholic solution, of the indicator electrode and the reference electrode; and a titration pump for outputting a titrant into the alcoholic solution. According to the measurement system and the measurement method provided by the invention, the concentration of trimethyl borate can be simply, quickly, automatically and accurately measured.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power plants, and in particular to a system and method for measuring the concentration of trimethyl borate in an alcohol solution. Background Art

[0002] High abundance 10 BF 3 After being converted into enriched boric acid products, they can be used as neutron absorbers in nuclear devices to control nuclear fuel fission reactions, inhibit the production of core corrosion products, and ensure core safety and pressure boundary integrity. 10 BF 3 To convert to boric acid enriched products, the esterification-hydrolysis method is generally used for conversion. However, due to the low overall recovery rate of the esterification-hydrolysis method, the concentration of trimethyl borate, a key intermediate product of the esterification reaction, needs to be monitored to ensure high abundance. 10 BF 3 Convert it into trimethyl borate as much as possible, thereby improving production efficiency and process yield.

[0003] There are currently no national or industry standards to follow for online monitoring of trimethyl borate in boric acid enrichment production systems, nor are there any corresponding online measurement practice cases. If conventional methods such as gas chromatography, gas chromatography-mass spectrometry or hydrolysis titration are used for detection, there are problems such as inaccurate test results and high detection costs. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a system and method for measuring the concentration of trimethyl borate in an alcohol solution, which can simply, quickly, automatically and accurately measure the concentration of trimethyl borate.

[0005] To solve the above technical problems, the present invention is implemented through the following technical solutions.

[0006] The present invention provides a system for measuring the concentration of trimethyl borate in an alcohol solution, comprising at least:

[0007] Measuring cell;

[0008] An alcohol solution is disposed in the measuring cell, and the alcohol solution contains trimethyl borate at a concentration to be measured;

[0009] an indicator electrode, one end of which is immersed in the alcohol solution and the other end of which extends outside the alcohol solution;

[0010] A reference electrode is arranged at a distance from the indicator electrode, and one end of the reference electrode is immersed in the alcohol solution, and the other end extends out of the alcohol solution;

[0011] a measuring instrument connected to the indicator electrode and the reference electrode at one end away from the alcohol solution; and

[0012] The titration pump outputs the titrant into the alcohol solution.

[0013] In one embodiment of the present invention, the alcohol solution includes an alcohol solvent and the trimethyl borate, the methyl borate is uniformly dispersed in the alcohol solvent, and the alcohol solvent includes at least one of methanol or ethanol.

[0014] In one embodiment of the present invention, the measuring system further comprises a stirrer, and the measuring cell is arranged on the stirrer.

[0015] The present invention also provides a method for measuring the concentration of trimethyl borate in an alcohol solution, using the above-mentioned measuring system, and at least comprising the following steps:

[0016] Loading a preset mass of an alcohol solution into a measuring cell, wherein the alcohol solution contains trimethyl borate at a concentration to be measured;

[0017] An indicator electrode and a reference electrode are arranged in the alcohol solution at intervals, wherein one end of the indicator electrode and the reference electrode are respectively immersed in the alcohol solution, and the other end thereof is respectively extended out of the alcohol solution;

[0018] A measuring instrument is arranged outside the measuring cell, and one end of the indicator electrode and the reference electrode away from the alcohol solution are respectively connected to the measuring instrument;

[0019] Starting the titration pump to deliver a titrant of a preset concentration into the alcohol solution, and stirring continuously;

[0020] According to the detection result of the measuring instrument, the operation of the titration pump is stopped, and the titration amount of the titrant added to the alcohol solution is obtained; and

[0021] The concentration to be measured is obtained according to the titration amount, the preset concentration and the preset mass.

[0022] In one embodiment of the present invention, stopping the operation of the titration pump according to the detection result of the measuring instrument at least includes the following steps:

[0023] When the measuring instrument measures that the pH value of the alcohol solution suddenly changes to a preset value, the operation of the titration pump is stopped.

[0024] In an embodiment of the present invention, the preset value is at least 9.

[0025] In one embodiment of the present invention, the concentration to be measured is obtained according to the following formula:

[0026]

[0027] Wherein, W is the concentration to be measured, C is the preset concentration of the titrant, V is the titration amount of the titrant, M is the relative molecular mass of trimethyl borate, and m is the preset mass of the alcohol solution.

[0028] In one embodiment of the present invention, the titrant includes at least one of sodium hydroxide or potassium hydroxide.

[0029] In one embodiment of the present invention, after obtaining the concentration of trimethyl borate to be measured, the measuring cell, the indicator electrode and the reference electrode are continuously cleaned with a cleaning agent, and the cleaning agent after cleaning is collected until the conductivity of the cleaning agent after cleaning reaches a preset value, then the cleaning is stopped and the measuring cell, the indicator electrode and the reference electrode are stored for standby use.

[0030] In an embodiment of the present invention, the preset value is 0.05 μS / cm-0.15 μS / cm.

[0031] In summary, the present invention provides a system and method for measuring the concentration of trimethyl borate in an alcohol solution, which can simply, quickly, automatically and accurately measure the concentration of trimethyl borate, and based on the measured concentration of trimethyl borate, optimize the reaction conditions in the esterification-hydrolysis method to improve the yield of enriched boric acid. Moreover, the system and method for measuring the concentration of trimethyl borate in an alcohol solution provided by the present invention do not require expensive instruments and equipment, can reduce measurement costs, and are suitable for large-scale promotion and application.

[0032] Of course, any method of implementing the present invention does not necessarily need to achieve all of the advantages mentioned above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0034] Figure 1 Schematic diagram of a system for measuring the concentration of trimethyl borate in an alcohol solution in one embodiment of the present invention.

[0035] Figure 2 The figure is a flow chart of a method for measuring the concentration of trimethyl borate in an alcohol solution in one embodiment of the present invention.

[0036] Description of labels:

[0037] 11. Measuring cell; 12. Indicator electrode; 13. Reference electrode; 14. Measuring instrument; 15. Titration pump; 16. Stirrer. DETAILED DESCRIPTION

[0038] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0039] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0040] The technical solution of the present invention is further described in detail below in conjunction with the embodiments and drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0041] The high abundance 10 BF 3 During the conversion into a boric acid-enriched product, 10 BF 3 First, an esterification reaction is carried out with a low-grade alcohol to generate low-boiling-point trimethyl borate, and the generated trimethyl borate is distilled to initially separate impurities, and then the trimethyl borate reacts with water to hydrolyze to generate alcohol and an enriched boric acid solution, and the enriched boric acid solution only needs to be recrystallized to obtain a commercial-grade enriched boric acid product. Since the total recovery rate of the esterification-hydrolysis conversion method is low, it is necessary to monitor the concentration of trimethyl borate, a key intermediate product of the esterification reaction, online, and based on this, optimize the reaction conditions and improve the yield of the enriched boric acid product.

[0042] See also Figure 1As shown, the present invention provides a system for measuring the concentration of trimethyl borate in an alcohol solution, which at least includes a measuring cell 11, an indicator electrode 12, a reference electrode 13, a measuring instrument 14 and a titration pump 15, etc., wherein an alcohol solution is arranged in the measuring cell 11, and the alcohol solution contains trimethyl borate of a concentration to be measured, the indicator electrode 12 and the reference electrode 13 are arranged in the alcohol solution in the measuring cell 11 at intervals, and one end of the indicator electrode 12 and the reference electrode 13 are respectively immersed in the alcohol solution, and the other end is respectively extended to the outside of the alcohol solution and is respectively connected to the measuring instrument 14, and the titration pump 15 outputs a titrant into the alcohol solution in the measuring cell 11. In the measurement system provided by the present invention, the initial pH of the alcohol solution is neutral, but with the addition of the titrant, trimethyl borate begins to hydrolyze to generate boric acid, and the boric acid reacts with the titrant to generate borate, and the alcohol solution changes from neutral to acidic. With the continuous addition of the titrant, after the trimethyl borate is completely converted into borate, the alcohol solution changes from acidic to alkaline, the addition of the titrant is stopped, and the concentration of trimethyl borate in the alcohol solution is obtained according to the amount of the titrant, so that the concentration of trimethyl borate can be measured simply, quickly, automatically and accurately.

[0043] See also Figure 1 As shown, in one embodiment of the present invention, the measuring pool 11 provides a place for measuring the concentration of trimethyl borate. The measuring pool 11 is, for example, a container such as a beaker, a volumetric flask or a conical flask, and the volume of the measuring pool 11 can be selected according to actual conditions.

[0044] See also Figure 1 As shown, in one embodiment of the present invention, an alcohol solution is provided in the measuring cell 11, the alcohol solution contains trimethyl borate and an alcohol solvent, the trimethyl borate is uniformly dispersed in the alcohol solvent, and the concentration of the trimethyl borate in the alcohol solution is the concentration to be measured. The alcohol solvent includes, for example, at least one of alcohols such as methanol and ethanol, and the pH of the alcohol solution is, for example, neutral. Since trimethyl borate is very easy to hydrolyze, trimethyl borate cannot stably exist under acidic and alkaline conditions, and trimethyl borate can only stably exist in a neutral environment such as an alcohol solution.

[0045] See also Figure 1 As shown, in one embodiment of the present invention, the titration pump 15 outputs the titrant to the alcohol solution in the measuring cell 11. The titrant includes, for example, at least one of strong alkaline solutions such as sodium hydroxide or potassium hydroxide. In this embodiment, the titrant is sodium hydroxide solution as an example to illustrate the acid-base titration process. Since the initial pH of the alcohol solution is neutral, trimethyl borate does not ionize in the alcohol solution, but with the addition of sodium hydroxide solution, trimethyl borate is rapidly hydrolyzed to generate boric acid and methanol, and sodium hydroxide reacts with boric acid to generate NaH 2 BO 3At this time, the system changes from neutral to acidic. With the continuous addition of sodium hydroxide solution, all the trimethyl borate in the alcohol solution is converted into NaH 2 BO 3 After that, the system changes from acidic to alkaline. Therefore, the pH of the system changes to alkaline, which means that trimethyl borate is completely converted to NaH 2 BO 3 The concentration of trimethyl borate in the alcohol solution can be obtained by the amount of sodium hydroxide solution, the concentration of sodium hydroxide solution and stoichiometry.

[0046] See also Figure 1 As shown, in one embodiment of the present invention, one end of the indicator electrode 12 is immersed in the alcohol solution in the measuring cell 11, and the other end extends out of the alcohol solution. The indicator electrode 12 is, for example, a glass electrode or a platinum electrode.

[0047] See also Figure 1 As shown, in one embodiment of the present invention, the reference electrode 13 and the indicator electrode 12 are arranged at intervals. Specifically, one end of the reference electrode 13 is immersed in the alcohol solution in the measuring cell 11, and the other end extends outside the alcohol solution. The reference electrode 13 is, for example, a saturated calomel electrode or a silver chloride electrode.

[0048] See also Figure 1 As shown, in one embodiment of the present invention, the end of the indicator electrode 12 away from the alcohol solution and the end of the reference electrode 13 away from the alcohol solution are respectively connected to a measuring instrument 14. The measuring instrument 14 is, for example, a potentiometric titrator, etc., which detects the potential in the working battery composed of the indicator electrode 12, the alcohol solution and the reference electrode 13 in real time, and determines the pH of the alcohol solution according to the potential, and uses the sudden change of the pH of the alcohol solution to alkalinity as a basis to judge the end point of the acid-base titration. In the acid-base titration process, the acid-base change of the system generally needs to be subjectively judged based on the change of the indicator color, which leads to inaccurate judgment of the titration end point, thereby affecting the accuracy of the concentration measurement of trimethyl borate. In the present application, by setting the indicator electrode 12 and the reference electrode 13, the indicator electrode 12, the alcohol solution and the reference electrode 13 form a working battery, and the potential of the working battery is measured during the acid-base titration process, and the pH of the alcohol solution is determined based on the potential, so as to judge the end point of the acid-base titration, which can accurately determine the end point of the acid-base titration and improve the accuracy of the concentration measurement result.

[0049] See also Figure 1 As shown, in one embodiment of the present invention, the measuring system further includes a stirrer 16, which is disposed below the measuring cell 11 to mix the alcohol solution in the measuring cell 11 and the titrant outputted to the measuring cell 11 by the titration pump 15, so as to prevent the residual trimethyl borate in the alcohol solution from not participating in the conversion into NaH 2 BO 3process, thereby improving the accuracy of the concentration measurement of trimethyl borate.

[0050] See also Figure 1 to Figure 2 As shown, based on the above-mentioned measurement system, the present invention also provides a method for measuring the concentration of trimethyl borate in an alcohol solution, which at least includes steps S11-S16.

[0051] Step S11, loading an alcohol solution of a preset mass into a measuring cell, wherein the alcohol solution contains trimethyl borate of a concentration to be measured.

[0052] Step S12, an indicator electrode and a reference electrode are arranged in the alcohol solution at intervals, one end of the indicator electrode and the reference electrode are respectively immersed in the alcohol solution, and the other end thereof are respectively extended out of the alcohol solution.

[0053] Step S13: a measuring instrument is arranged outside the measuring cell, and the ends of the indicator electrode and the reference electrode away from the alcohol solution are respectively connected to the measuring instrument.

[0054] Step S14, starting the titration pump to deliver the titrant of the preset concentration into the alcohol solution, and stirring continuously.

[0055] Step S15: according to the detection result of the measuring instrument, stop the operation of the titration pump, and obtain the titration amount of the titrant added to the alcohol solution.

[0056] Step S16, obtaining the concentration of trimethyl borate to be measured according to the titration amount, the preset concentration and the preset mass.

[0057] See also Figure 1 to Figure 2 As shown, in one embodiment of the present invention, in step S11, the mass of the alcohol solution is, for example, m, in g, and the concentration of trimethyl borate to be measured in the alcohol solution is, for example, W, in wt%.

[0058] See also Figure 1 to Figure 2 As shown, in one embodiment of the present invention, in steps S12 and S13, the indicator electrode 12, the alcohol solution and the reference electrode 13 constitute a working battery, and the measuring instrument 14 measures the potential of the working battery in real time and obtains the pH of the alcohol solution according to the potential.

[0059] See also Figure 1 to Figure 2As shown, in one embodiment of the present invention, after the working battery is set, in step S14, the titration pump 15 is started to transport the titrant to the alcohol solution in the measuring cell 11, and at the same time, the stirrer 16 stirs the alcohol solution and the titrant in the measuring cell 11, and the titrant performs acid-base titration on the trimethyl borate in the alcohol solution. Among them, the preset concentration of the titrant is, for example, C, in mol / L, and the acid-base titration process is described by taking the titrant as sodium hydroxide solution as an example. Specifically, the initial pH of the alcohol solution is neutral, and trimethyl borate does not ionize in the alcohol solution, but with the addition of sodium hydroxide, trimethyl borate is rapidly hydrolyzed to generate boric acid and methanol, and sodium hydroxide reacts with boric acid to generate NaH 2 BO 3 At this time, the system changes from neutral to acidic. With the continuous addition of sodium hydroxide solution, all the trimethyl borate in the alcohol solution is converted into NaH 2 BO 3 After that, the system changes from acidic to alkaline. Therefore, the pH of the system changes suddenly and changes to alkaline, which means that trimethyl borate is completely converted to NaH 2 BO 3 The sign of , and then the concentration of trimethyl borate in the alcohol solution can be calculated by the amount of sodium hydroxide solution, the concentration of sodium hydroxide solution and stoichiometry.

[0060] See also Figure 1 to Figure 2 As shown, in one embodiment of the present invention, during the acid-base titration, the pH of the alcohol solution and the potential of the indicator electrode 12 are one-to-one corresponding, so in step S15, the potential in the working battery composed of the indicator electrode 12, the alcohol solution and the reference electrode 13 is measured by the measuring instrument 14, and the pH of the alcohol solution is obtained according to the potential. When the measuring instrument 14 detects that the pH value of the alcohol solution suddenly changes to a preset value, the titration end point appears, the titration pump 15 is stopped, the titration is completed, and the titration amount V of the titrant during the titration process is recorded in mL. The preset value is, for example, at least 9.

[0061] See also Figure 1 to Figure 2 As shown, in one embodiment of the present invention, after the titration is completed, in step S16, the concentration of trimethyl borate in the alcohol solution to be measured is calculated according to the following formula:

[0062]

[0063] Wherein, W is the concentration of trimethyl borate to be measured in the alcohol solution, C is the preset concentration of the titrant, V is the titration amount of the titrant, M is the relative molecular mass of trimethyl borate, and m is the mass of the alcohol solution.

[0064] See also Figure 1 to Figure 2As shown, in one embodiment of the present invention, after the titration is completed, the measuring instrument 14 in the working battery is removed, the indicator electrode 12 and the reference electrode 13 are taken out from the alcohol solution, and the alcohol solution in the measuring cell 11 is removed, and then the measuring cell 11, the indicator electrode 12 and the reference electrode 13 are continuously cleaned with a cleaning agent, and the cleaning agent after cleaning is collected until the conductivity of the cleaning agent after cleaning reaches a preset value, and then the cleaning is stopped, and the measuring cell 11, the indicator electrode 12 and the reference electrode 13 are stored for standby use so as to perform the next measurement. Among them, the cleaning agent is, for example, ultrapure water, and the preset value is, for example, 0.05μS / cm-0.15μS / cm. By cleaning, the trimethyl borate remaining on the measuring cell 11, the indicator electrode 12 and the reference electrode 13 can be removed, so as to avoid the trimethyl borate remaining on the measuring cell 11, the indicator electrode 12 and the reference electrode 13 affecting the next measurement.

[0065] See also Figure 1 to Figure 2 As shown, for the concentration of trimethyl borate in the alcohol solution, it is difficult to measure the qualitative analysis of gas chromatography and gas chromatography-mass spectrometry in the mixture, especially boric acid will affect the retention time of trimethyl borate, resulting in inaccurate measurement results, and the instruments used by gas chromatography and gas chromatography-mass spectrometry are all expensive, which will increase the production cost of enriched boric acid production enterprises. The hydrolysis titration analysis method has complicated steps, and trimethyl borate needs to be hydrolyzed first, and then the pH of the solution to be tested is adjusted to neutral, and then a variety of indicators are used to continuously select the best titration end point. In the present invention, by acid-base potentiometric titration, the concentration of trimethyl borate can be simply, quickly, automatically and accurately measured, and the cost of the measurement process can also be reduced, which is suitable for large-scale promotion and application.

[0066] See also Figure 1 to Figure 2 As shown, based on the above-mentioned measuring system and measuring method, the present invention also provides three embodiments, firstly, a trimethyl borate-methanol mixed solution with a trimethyl borate concentration of 45wt% is prepared, and then in each embodiment, an electronic balance is used to weigh 1 portion of the trimethyl borate-methanol mixed solution with a mass of about 0.5g, and then the concentration of the trimethyl borate-methanol mixed solution in each embodiment is measured by the above-mentioned measuring system and measuring method, and the concentration of trimethyl borate is calculated, and the analysis results of each embodiment are shown in Table 1. Wherein, the titrant is a sodium hydroxide solution, and the preset concentration C of the sodium hydroxide solution is 0.1mol / L.

[0067] Table 1 Analysis results of Examples 1-3

[0068]

[0069] As shown in Table 1, in the three embodiments, the concentration W of trimethyl borate measured is close to 45wt%, indicating that the measurement system and measurement method provided by the present invention can accurately measure the concentration of trimethyl borate. Moreover, the relative deviation between each embodiment is very small, indicating that the measurement system and measurement method provided by the present invention can improve the consistency and accuracy of the measurement results when measuring the concentration of trimethyl borate.

[0070] In summary, the present invention provides a system and method for measuring the concentration of trimethyl borate in an alcohol solution. Through a measuring cell, an indicator electrode, a reference electrode and a measuring instrument, the concentration of trimethyl borate can be measured simply, quickly, automatically and accurately, and based on the measured concentration of trimethyl borate, the reaction conditions in the esterification-hydrolysis method are optimized to improve the yield of enriched boric acid. Moreover, the system and method for measuring the concentration of trimethyl borate in an alcohol solution provided by the present invention do not require expensive instruments and equipment, can reduce measurement costs, improve the consistency and accuracy of measurement results, and are suitable for large-scale promotion and application.

[0071] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A system for measuring the concentration of trimethyl borate in an alcohol solution, characterized in that: At least: Measuring cell; An alcohol solution is disposed in the measuring cell, and the alcohol solution contains trimethyl borate at a concentration to be measured; an indicator electrode, one end of which is immersed in the alcohol solution and the other end of which extends outside the alcohol solution; A reference electrode is arranged at a distance from the indicator electrode, and one end of the reference electrode is immersed in the alcohol solution, and the other end extends out of the alcohol solution; a measuring instrument connected to the indicator electrode and the reference electrode at one end away from the alcohol solution; and The titration pump outputs the titrant into the alcohol solution.

2. The measuring system according to claim 1, characterized in that The alcohol solution includes an alcohol solvent and the trimethyl borate, the methyl borate is uniformly dispersed in the alcohol solvent, and the alcohol solvent includes at least one of methanol or ethanol.

3. The measuring system according to claim 1, characterized in that The measuring system further comprises a stirrer, and the measuring cell is arranged on the stirrer.

4. A method for measuring the concentration of trimethyl borate in an alcohol solution, characterized in that: The measuring system according to any one of claims 1 to 3 comprises at least the following steps: Loading a preset mass of an alcohol solution into a measuring cell, wherein the alcohol solution contains trimethyl borate at a concentration to be measured; An indicator electrode and a reference electrode are arranged in the alcohol solution at intervals, wherein one end of the indicator electrode and the reference electrode are respectively immersed in the alcohol solution, and the other end thereof is respectively extended out of the alcohol solution; A measuring instrument is arranged outside the measuring cell, and one end of the indicator electrode and the reference electrode away from the alcohol solution are respectively connected to the measuring instrument; Starting the titration pump to deliver a titrant of a preset concentration into the alcohol solution, and stirring continuously; According to the detection result of the measuring instrument, the operation of the titration pump is stopped, and the titration amount of the titrant added to the alcohol solution is obtained; and The concentration to be measured is obtained according to the titration amount, the preset concentration and the preset mass.

5. The measuring method according to claim 4, characterized in that: According to the detection result of the measuring instrument, stopping the operation of the titration pump at least comprises the following steps: When the measuring instrument measures that the pH value of the alcohol solution suddenly changes to a preset value, the operation of the titration pump is stopped.

6. The measuring method according to claim 5, characterized in that: The preset value is at least 9.

7. The measuring method according to claim 4, characterized in that: The concentration to be measured is obtained according to the following formula: Wherein, W is the concentration to be measured, C is the preset concentration of the titrant, V is the titration amount of the titrant, M is the relative molecular mass of trimethyl borate, and m is the preset mass of the alcohol solution.

8. The measuring method according to claim 4, characterized in that: The titrant includes at least one of sodium hydroxide or potassium hydroxide.

9. The measuring method according to claim 4, characterized in that: After obtaining the concentration of trimethyl borate to be measured, the measuring cell, the indicator electrode and the reference electrode are continuously cleaned with a cleaning agent, and the cleaning agent after cleaning is collected until the conductivity of the cleaning agent after cleaning reaches a preset value, then the cleaning is stopped and the measuring cell, the indicator electrode and the reference electrode are stored for standby use.

10. The measuring method according to claim 9, characterized in that: The preset value is 0.05 μS / cm-0.15 μS / cm.

Images