CN114894960A - Method for detecting KOH moisture content - Google Patents
Method for detecting KOH moisture content Download PDFInfo
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- CN114894960A CN114894960A CN202210583500.7A CN202210583500A CN114894960A CN 114894960 A CN114894960 A CN 114894960A CN 202210583500 A CN202210583500 A CN 202210583500A CN 114894960 A CN114894960 A CN 114894960A
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- koh
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
- G01N31/16—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using titration
- G01N31/168—Determining water content by using Karl Fischer reagent
Abstract
The invention relates to the technical field of analysis and test, and discloses a method for detecting the water content of KOH, which comprises the following steps: step one, preheating a container; step two, adding a solvent into a container; introducing neutral gas into the container to remove air in the container; and step four, adding a KOH sample to be detected into the container, stirring, titrating by using a titrant, and repeatedly detecting. The method can effectively avoid KOH deliquescence when the KOH moisture content is detected; the detection method is simple, accurate in detection and high in repeatability.
Description
Technical Field
The invention relates to the technical field of analysis and test, in particular to a method for detecting the water content of KOH.
Background
Moisture determination is an important analysis index in industrial production, most of the existing moisture detection methods in the market are only suitable for liquid and gas substances, the moisture detection method for solid substances is less, and the common detection method for the moisture content of the solid substances is a drying method. Although the drying method is commonly used for measuring most solid samples (a large sample needs to be crushed), the operation is simple; however, the following detection conditions need to be met: moisture is a volatile substance; ② does not contain bound water; chemical changes of other components in the sample caused by heating can be ignored; the disadvantage is the low accuracy. For solid substances which are extremely easy to absorb moisture, a better detection method is not available for detecting moisture temporarily.
In order to solve the technical problems, a method for obtaining the moisture content of a special solid substance by dissolving the solid substance in a specified solution, detecting the solution by using a common liquid moisture detection method, namely a Karl Fischer method, and calculating the moisture content is developed. The karl fischer method is usually used for measuring water content due to its stable and accurate characteristics, and its principle is mainly that water reacts with iodine and sulfur dioxide in titrant to form methyl sulfate, the reaction is continuously carried out, water is continuously consumed, iodine ions are generated, and the water content is completely consumed until the end point of the reaction titration. When all the water completely reacts with iodine, the excess iodine is present in the reaction solution, and the iodine around the double platinum needles is "conducted", so that only a small voltage (about 100mV) is required to maintain the set polarization current, and when the voltage drops to the set value, the titration is finished. However, the Karl Fischer method has certain requirements on the pH value in the determination of the moisture content, the optimal pH value is 5-7, and the pH value needs to be adjusted to ensure the accuracy of the determination result when a sample with strong acidity or a sample with strong alkalinity is determined. Therefore, it is necessary to develop a method for measuring the water content in KOH, which is easy to handle and accurate in measurement result.
Disclosure of Invention
The invention aims to provide a method for detecting the water content of KOH, which aims to solve the problems of low detection accuracy and inconvenient operation of the method for detecting the water content of KOH in the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme: a method for detecting the moisture content of KOH comprises the following steps:
step one, preheating a container;
step two, adding a solvent into a container;
introducing neutral gas into the container to remove air in the container;
and step four, adding a KOH sample to be detected into the container, stirring, titrating by using a titrant, and repeatedly detecting.
The principle and the advantages of the scheme are as follows: during the development of the technology, the inventors tried to put KOH into H with a larger concentration 2 SO 4 The reaction mixture was neutralized with HCl, and the results were measured. However, the acid-base neutralization reaction in the method has large heat release, so that the method has high danger, and test data are unstable and are finally abandoned; in addition, the inventors have also tried the most common flash drying method, but the mass after KOH drying is larger than the mass before drying, and analyzed the reason reversely, it was found that it is due to KOH deliquescence. In the technical scheme, aiming at the problem that the moisture content of strong base is easy to deliquesce in the prior art, the inventor considers starting from the root and avoids the problem of low detection accuracy caused by moisture absorption by a method of isolating moisture and carbon dioxide in the air. In order to realize the isolation of water and carbon dioxide in the air, the air in the container is removed by introducing neutral gas in the technical scheme, so that KOH and H in the air can be effectively avoided 2 O and CO 2 Reaction is carried out, and the influence on the measurement result is avoided; and then, the water content is determined by titration with Karl Fischer reagent, so that the method is simple and easy to implement, and the detection result is accurate and reliable.
The beneficial effects of this technical scheme lie in:
1. according to the technical scheme, neutral gas is introduced, so that KOH deliquescence can be effectively avoided, and the accuracy of a detection result is ensured.
2. In the technical scheme, the detection method is simple and is suitable for popularization and application in the industry.
3. The detection method of the technical scheme has the advantages of simple and easily-obtained actual instruments and low cost.
Preferably, as an improvement, in the first step, the container is a glass container with good sealing performance, and the preheating temperature is 15-60 ℃.
In the technical scheme, the preheating temperature is the reaction temperature, the detection data is most stable when the temperature is 15-60 ℃, and the reaction is incomplete when the temperature is too high or too low, so that the data result is unstable.
Preferably, as an improvement, in the second step, the solvent is ethanol, acetaldehyde, acetone, formaldehyde, methanol, chlorobenzene, styrene or cyclohexane.
In the technical scheme, the solvent can ensure effective dissolution of the sample, and the accuracy of subsequent titration cannot be influenced.
Preferably, as a modification, in the second step, the volume ratio of the solvent to the container is 0.01-0.5: 1.
In the technical scheme, when the volume ratio of the solvent to the container is in the range of the proportion, the preferable proportion is adopted, and the detection operation is easy.
Preferably, as an improvement, in the third step, the neutral gas is nitrogen, and the introducing time of the neutral gas is more than or equal to 40 s.
In the technical scheme, the nitrogen is stable in property, effective air discharge is guaranteed, reaction with a reagent or a sample can be avoided, and accuracy of result determination can be guaranteed. Experiments prove that the nitrogen gas introducing time is crucial to the accuracy of detection results, and the gas introducing time can ensure that the air in the container can be completely removed within at least 40 s.
Preferably, as a modification, in the fourth step, the KOH sample is membrane KOH or ion membrane KOH.
The detection method of the technical scheme is suitable for a diaphragm method KOH and an ion membrane method KOH, and can realize accurate detection of different KOH moisture contents.
Preferably, as an improvement, in the fourth step, the mass ratio of the KOH sample to the solvent is 0.01-0.6: 1.
In the technical scheme, the mass ratio of the KOH sample to the solvent influences the detection accuracy, the too small mass ratio increases the error of a detection result, the too large mass ratio causes the KOH to be insoluble, and the mass ratio range is a better range verified by practice.
Preferably, as an improvement, in the fourth step, the stirring time is more than or equal to 10 min.
In the technical scheme, the stirring time is the reaction time, the reaction is incomplete due to too short stirring time, KOH cannot be completely dissolved, and the detection result is wrong.
Preferably, as an improvement, in step four, the titrant is karl fischer reagent.
In the technical scheme, the Karl Fischer reagent is used as a titrant, and the source of the reagent is wide and the technology is mature.
Preferably, as an improvement, in the step four, the number of times of repeated detection is more than or equal to 2 times.
In the technical scheme, the detection is repeated for many times, so that the human error can be reduced, and the accuracy of the detection result is further ensured.
Detailed Description
The following is a detailed description of the embodiments, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents and the like used are all commercially available.
The scheme is summarized as follows:
a method for detecting the moisture content of KOH comprises the following steps:
step one, a preheating device is a Karl Fischer water titrator, and the preheating temperature is controlled to be 15-60 ℃;
adding a solvent into the container, wherein the solvent is common organic solvents such as ethanol, acetaldehyde, acetone, formaldehyde, methanol, chlorobenzene, styrene or cyclohexane, and the volume ratio of the solvent to the container is 0.01-0.5: 1;
step three, introducing neutral gas into the container for at least 40s, and removing air in the container, wherein the neutral gas is nitrogen;
and step four, adding a KOH sample into the container, wherein the KOH is a KOH by a diaphragm method or an ion membrane method, the mass ratio of the KOH sample to the solvent is 0.01-0.6:1, then stirring, the stirring time is more than or equal to 10min, titrating by using a titrant, measuring the water content in the KOH sample, and repeatedly detecting.
Example 1
A method for detecting the moisture content of KOH comprises the following steps:
this example was carried out using the following instrument: the instrument model is as follows: v20; volume capacity of the container: 250 mL;
step one, preheating a device, and setting the temperature to be 30.4 ℃;
step two, adding 50.1084g of ethanol solvent into a container;
step three, introducing neutral gas into the solvent in the step two for 120s, and removing air in the container, wherein the neutral gas in the embodiment is nitrogen;
step four, adding 10.0421g of the KOH sample to be detected by the diaphragm method into the container in the step three, stirring and reacting for 60min, titrating by using a Karl Fischer reagent, determining the water content in the KOH sample, and repeatedly detecting for 3 times.
Examples 2-6 differ from example 1 only in the setting of some of the parameters, as detailed in the table below.
TABLE 1
Example 7
The present embodiment is different from embodiment 1 in that: the KOH sample to be detected is KOH by an ion membrane method.
Experimental example KOH moisture content test result
TABLE 2
As can be seen from Table 2, the data is most stable at a temperature of 20-40 ℃, and the reaction is incomplete due to over-high or over-low temperature, so that the data is unstable; as can be seen from examples 1 and 5, the reaction was completed when the reaction time of the system was 60min, the reaction time was prolonged, and the detection results were almost unchanged. To sum up: the method is efficient and reliable, and particularly within the preferred range, the data is more stable.
The foregoing is merely an example of the present invention and common general knowledge in the art of designing and/or characterizing particular aspects and/or features is not described in any greater detail herein. It should be noted that, for those skilled in the art, without departing from the technical solution of the present invention, several variations and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.
Claims (10)
1. A method for detecting the water content of KOH is characterized by comprising the following steps: the method comprises the following steps:
step one, preheating a container;
step two, adding a solvent into a container;
introducing neutral gas into the container to remove air in the container;
and step four, adding a KOH sample to be detected into the container, stirring, titrating by using a titrant, and repeatedly detecting.
2. The method for detecting the moisture content of KOH according to claim 1, wherein: in the first step, the container is a glass container with good sealing performance, and the preheating temperature is 15-60 ℃.
3. The method for detecting the moisture content of KOH according to claim 2, wherein: in the second step, the solvent is ethanol, acetaldehyde, acetone, formaldehyde, methanol, chlorobenzene, styrene or cyclohexane.
4. A method of detecting the moisture content of KOH according to claim 3 wherein: in the second step, the volume ratio of the solvent to the container is 0.01-0.5: 1.
5. The method for detecting the moisture content of KOH according to claim 4, wherein: in the third step, the neutral gas is nitrogen, and the introduction time of the neutral gas is more than or equal to 40 s.
6. The method for detecting the moisture content of KOH according to claim 5, wherein: in the fourth step, the KOH sample is membrane KOH or ion membrane KOH.
7. The method for detecting the moisture content of KOH according to claim 6, wherein: in the fourth step, the mass ratio of the KOH sample to the solvent is 0.01-0.6: 1.
8. The method of claim 7, wherein the KOH moisture content is detected by: in the fourth step, the stirring time is more than or equal to 10 min.
9. The method of claim 8, wherein the KOH moisture content is detected by: in the fourth step, the titrant is Karl Fischer's reagent.
10. The method for detecting the moisture content of KOH according to claim 9, wherein: in the fourth step, the repeated detection times are more than or equal to 2.
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| CN202210583500.7A CN114894960A (en) | 2022-05-25 | 2022-05-25 | Method for detecting KOH moisture content |
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5340541A (en) * | 1993-03-05 | 1994-08-23 | Eli Lilly And Company | Automated Karl Fischer titration apparatus and method |
| US6131442A (en) * | 1999-07-28 | 2000-10-17 | Riverwood International Corporation | Method of wood chip moisture analysis |
| CN102937618A (en) * | 2012-10-26 | 2013-02-20 | 河北省电力公司电力科学研究院 | Post-desulphurization flue gas moisture content determination method and apparatus |
| CN205003116U (en) * | 2015-10-12 | 2016-01-27 | 王志刚 | Novel gaseous karl fischer moisture appearance |
| CN107505429A (en) * | 2017-07-27 | 2017-12-22 | 广西中烟工业有限责任公司 | A kind of Karl_Fischer method measure electronic cigarette W/O divides content |
| CN109917070A (en) * | 2019-03-26 | 2019-06-21 | 东莞东阳光科研发有限公司 | The detection method of free lithium content is remained in tertiary cathode material |
| JP2019113327A (en) * | 2017-12-21 | 2019-07-11 | 株式会社三菱ケミカルアナリテック | Moisture measurement method and moisture measurement apparatus |
| CN111624300A (en) * | 2020-07-01 | 2020-09-04 | 内蒙古通威高纯晶硅有限公司 | Moisture determination method and moisture determination device |
| CN111879891A (en) * | 2020-06-30 | 2020-11-03 | 武汉钢铁有限公司 | Method for rapidly determining content of sulfite in industrial sulfuric acid |
-
2022
- 2022-05-25 CN CN202210583500.7A patent/CN114894960A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5340541A (en) * | 1993-03-05 | 1994-08-23 | Eli Lilly And Company | Automated Karl Fischer titration apparatus and method |
| US6131442A (en) * | 1999-07-28 | 2000-10-17 | Riverwood International Corporation | Method of wood chip moisture analysis |
| CN102937618A (en) * | 2012-10-26 | 2013-02-20 | 河北省电力公司电力科学研究院 | Post-desulphurization flue gas moisture content determination method and apparatus |
| CN205003116U (en) * | 2015-10-12 | 2016-01-27 | 王志刚 | Novel gaseous karl fischer moisture appearance |
| CN107505429A (en) * | 2017-07-27 | 2017-12-22 | 广西中烟工业有限责任公司 | A kind of Karl_Fischer method measure electronic cigarette W/O divides content |
| JP2019113327A (en) * | 2017-12-21 | 2019-07-11 | 株式会社三菱ケミカルアナリテック | Moisture measurement method and moisture measurement apparatus |
| CN109917070A (en) * | 2019-03-26 | 2019-06-21 | 东莞东阳光科研发有限公司 | The detection method of free lithium content is remained in tertiary cathode material |
| CN111879891A (en) * | 2020-06-30 | 2020-11-03 | 武汉钢铁有限公司 | Method for rapidly determining content of sulfite in industrial sulfuric acid |
| CN111624300A (en) * | 2020-07-01 | 2020-09-04 | 内蒙古通威高纯晶硅有限公司 | Moisture determination method and moisture determination device |
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