JP7107563B2 - Sensitive substance naturally occurring anion-selective electrode - Google Patents

Description

The present invention relates to a plastic membrane type sensitive material spontaneously generated anion selective electrode using cations that are spontaneously generated in the curing reaction of an epoxy resin or its analogue as an anion selective sensitive material. .

The following are known anion-selective electrodes using an epoxy resin as a base material or a part of the base material.
* The "base material" mentioned here means an object that maintains its shape. For example, in the case of a conventional liquid film electrode, the sensitive substance that responds to the object to be measured is in liquid or powder form and cannot maintain its shape by itself. Therefore, this is dissolved in a plasticizer and diffused in the resin, and used as an electrode response film.

(1) A chloride ion sensitive electrode membrane having a polymer matrix containing at least one electroactive component (sensitive substance), the polymer matrix containing an epoxy resin together with an amine compound as a curing agent. (Patent Document 1)
* Patent Literature 1 does not describe a specific method for fabricating the film.

(2) the base polymer matrix contains an epoxy resin and an amine containing amide groups, the amine being present in stoichiometric excess and serving as both a curing agent and a chloride screener (sensitizer); A functional chloride-selective electrode membrane. (Patent document 2)

(3) Anion-selective electrodes prepared by mixing and curing an epoxy resin main agent and a curing agent, or an epoxy resin main agent, a curing agent, and a curing accelerator without adding an anion-selective sensitive substance. wherein the quaternary ammonium cation generated during the curing reaction of the epoxy resin main agent is present as an anion-selective sensitive substance in the electrode response membrane, 1. A responsive membrane for an anion selective electrode containing a potential stabilizer, wherein the potential stabilizer is blended. (Patent document 3)

In (1), since a substance that responds (sensitizes) to chloride ions is added to the electrode base material, there is no structural difference from conventional responsive electrode membranes based on vinyl chloride and plasticizer. Method (2) uses a stoichiometric excess of amine as a sensitive substance, but since excess amine can be regarded as a sensitive substance, it is not much different from (1). In contrast, in (3), no sensitive substance is added, and the quaternary ammonium salt produced during the epoxy resin curing reaction is used as it is as a sensitive substance.

Patent No. 3350728 Patent No. 4503599 Patent No. 3970032 Japanese Patent Laid-Open No. 61-178654 Japanese Patent Application Showa 55-153907 JP 2001-124735 Special table 2007-534949 Patent No. 3975086

For any of the responsive membranes (1) to (3), the responsive membrane is prepared according to the analyte to be measured, and the selectivity for interfering substances (for example, bromide ion and bicarbonate ion when chloride ion is to be measured) is improved. increasing. As an example, preparations may be made to increase selectivity for interfering substances present in the measurement system by weakening selectivity for interfering substances not present in the measurement system.

Roughly speaking, the following three points need to be considered in addition to selectivity in response membranes for ion-selective electrodes.
(a) Robustness of response membrane (b) Uniformity of response membrane (c) Non-pinhole property (non-conductivity) of response membrane

(a) is mechanical strength. If the responsive membrane introduced into the measurement system is destroyed by, for example, water flow, the measurement cannot be performed. Also, if (ii) is not achieved, the responsiveness will differ at each position on the responsive membrane, making it impossible to obtain correct measurement results. (C) is also related to (A), but if there is a so-called pinhole or crack, measurement cannot be performed in principle (it does not act as an electrode).
In addition, there are other requirements that must be achieved as a responsive membrane, but they can be considered within the scope of common sense, so they are omitted (for example, if the measurement system is an aqueous solution system, in principle, materials that dissolve in water are cannot be selected, etc.).

An object of the present invention is to improve the above-mentioned (c) mainly with respect to the above-mentioned (3) type electrode response membrane. At the same time, (a) is also improved.

One of the type (3) responsive membranes produced so far had a thin film thickness of several hundred micrometers, and therefore had a high frequency of occurrence of pinholes. In addition, double-sided tape or solvent was used to attach the response membrane to the electrode cell or electrode stick. The frequency of conduction between the outside of the electrode and the inside of the electrode (a state similar to the occurrence of a so-called pinhole) was high. Another type of (3) type responsive membrane is prepared by applying a mixture that will become the electrode responsive membrane after the epoxy reaction to the inner surface of the flow-through electrode cell, which has previously closed the sample contact surface with a fluorine resin tube. When subjected to an impact such as being dropped, the electrode responsive membrane often peeled off from the inner surface of the electrode cell. In addition, if left for a long time (two weeks or more), it may come off by itself. It is considered that this is because there was a small gap between the inner surface of the electrode cell and the hardened epoxy resin from the time of manufacture, and the gap grew over time, eventually leading to the peeling.

The present invention has been made in view of such circumstances, and epoxy resin is added at the boundary between the electrode cell passage portion or the outside of the electrode stick and the space filled with the electrode internal liquid inside the electrode cell or inside the electrode stick. A mixture obtained by mixing a resin main agent and a curing agent or an epoxy resin main agent, a curing agent, and a curing accelerator without adding an anion-selective sensitive substance is applied to the border or cured by direct contact. This was achieved by a sensitive material spontaneously occurring anion-selective electrode obtained by In addition, since the electrode cell side is subjected to a surface treatment to make it difficult for the mixture to peel off after the reaction, peeling due to impact is less likely to occur. Moreover, the divergence due to long-term neglect (two weeks or more) virtually disappeared. A certain level of film thickness (1 mm or less) is obtained, so pinholes do not occur, and double-faced tape or solvents are not used to bond the electrode (response film) to the electrode cell or electrode stick, so that wrinkles and adhesion errors do not cause conduction. In addition, since the electrode cells are processed so that the electrodes are difficult to peel off, neither shock nor spontaneous peeling will occur.
* In Patent Documents 1 to 3, the electrode part is all expressed as a "film", but in the case of the present invention, the electrode part is simply expressed as an "electrode" instead of a "film" because the manufacturing method described above is used. did. Of course, the "electrode" of the present invention may be regarded as an "electrode-applied film".

The "epoxy resin main agent" mentioned in the present invention is a compound described below.
Compound name: bisphenol A type resin main agent, bisphenol F type resin main agent, polyfunctional resin main agent, flexible type resin main agent, brominated type resin main agent, glycidyl ester type resin main agent, polymer type resin main agent, biphenyl type resin main agent, and analogues of the above.

The "epoxy resin curing agent" mentioned in the present invention is a compound described below.
Compound name: Mercaptan compounds (including aliphatic thioethers, aromatic-containing thioethers, aliphatic thioesters, etc.), aliphatic polyamine compounds, polyaminoamide (polyamide resin) compounds, aromatic diamine compounds, alicyclic diamine compounds compounds, imidazole compounds, tertiary amine compounds (including trisdimethylaminomethylphenol, etc.), phenol resin compounds, amino resin compounds, dicyandiamide compounds, Lewis acid complex compounds, silane resin compounds (aminated silane compounds), and analogues of the above.

The "epoxy resin curing accelerator" mentioned in the present invention is a compound described below.
Compound names: aliphatic polyamine compounds, polyaminoamide (polyamide resin) compounds, aromatic diamine compounds, alicyclic diamine compounds, imidazole compounds (imidazole, 2-ethyl-4(5)-methylimidazole, 1 -benzyl-2-methylimidazole, 1-isobutyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4(5)-methylimidazole, 2-heptadecylimidazole, 2-methylimidazole azine, 2-undecylimidazole etc.), tertiary amine-based compounds (including trisdimethylaminomethylphenol, etc.), phenolic resin-based compounds, amino resin-based compounds, dicyandiamide-based compounds, Lewis acid complex compounds, silane resin-based compounds, and similar to the above thing.

"Epoxy resin curing agents" and "epoxy resin curing accelerators" are compound groups that cannot be categorized unconditionally, and some compounds cover the above categories. Therefore, the above is a convenient division.

The "potential stabilizer" mentioned in the present invention is a compound described below.
Compound name: quaternary ammonium salts (methyltridodecylammonium chloride, butyltridodecylammonium chloride, tetraoctadecylammonium chloride, (8S,9R)-(-)-benzylcincodinium chloride, 1,14-distearylbicyclo[2 , 2, 2] octal, 14 ammonium dichloride, etc.), an ion association consisting of a quaternary ammonium anion and a polystyrene sulfonate anion (((8S,9R)-(-)-benzylcincodinium cation and polystyrenesulfonate anions, 1,14-distearylbicyclo[2,2,2]octa-1,14ammonium dications and polystyrenesulfonate anions), and Similar to the above.

The reason why the amount of the potential stabilizer added in the present invention is set to less than 0.8% is that the potential stabilizer itself can be a sensitive material if it exists in a certain amount, but it cannot be less than 0.8%. is. Otherwise, the present invention cannot be called a "sensitive substance spontaneously generated anion-selective electrode".

The scope of claims of JP-A-61-178654 "Ion sensitive membrane electrode" includes the following description.
``1 It consists of an unplasticized polymeric matrix and at least one electrically active component, and the content of the electrically active component contained in the polymeric matrix is 50 to 90. An ion-sensitive membrane electrode with an anion-sensitive membrane configured in % by weight. 2. The polymeric substrate is polyvinyl chloride, the electroactive component is methyltridodedylammonium chloride, and the content of the electroactive component is 60-80% by weight. The ion-sensitive membrane electrode according to claim 1. 』
Therefore, according to this patent document, unless the content of the electrically active component is 50 to 90% by weight, it does not act as a sensitive substance. Alternatively, the quaternary ammonium salt methyltridodedylammonium chloride must be present in an amount of 60 to 80% by weight to function as a sensitive substance.

The claims of Japanese Patent Application No. 55-153907 "Anion selective electrode" include the following description.
"1. An ion selective electrode comprising a container containing an internal liquid, an internal electrode in contact with the internal liquid, and a sensitive membrane containing a polymeric material as a support material, wherein the sensitive membrane has 8 to 16 carbon atoms. A shade characterized by a composition comprising 4.0 to 60 weight percent linear fatty alcohol, 20 to 30 weight percent quaternary ammonium salt of the sensitive material, and 10 to 40 weight percent support material. ion selective electrode. 』
Therefore, according to this patent document, unless the quaternary ammonium salt is 20 to 30% by weight, it does not act as a sensitive substance.

The scope of claims of JP-A-2001-124735 "Chloride ion sensitive electrode membrane" includes the following description.
"[Claim 8] The membrane is composed of about 80 wt% epoxy resin, about 10 ± 2 wt% curing agent, and about 10 ± 3 wt% methyltridodecyl ammonium chloride, including the plasticizer. The chloride ion sensitive electrode film according to any one of claims 4 to 7. 』
Therefore, according to this patent document, methyltridodecylammonium chloride, which is a quaternary ammonium salt, does not act as a sensitive substance unless it is present in an amount of 10±3% by weight.

The following description is given in Japanese National Publication of International Patent Application No. 2007-534949 "Potentiometric electrode and manufacturing method of the electrode".
"Paragraph No. 0102" (Omitted) In the electrodes or gradient polymers disclosed herein as one form of the invention, the maximum ionophore concentration in the membrane region is 0.1-20%, 0.1-10% , 0.1-9%, 0.1-8%, 0.1-7%, 0.1-6%, 0.1-5%, 0.1-4%, 0.1-3%, 0.1-2%, 0.1-1%, preferably 1%, most preferably 1-2% ionophore. For the measurement of organic acids, the ionophore is any one molecule from FIG. These surface-active receptor molecules greatly enhance the ability to detect organic acids. Addition of MTDDACl at a ratio of 0.2% gives good ionic conductivity. 』
Thus, according to this patent, the most preferred amount of ionophore is 1-2%. This is believed to be the ionophore content on the electrode surface.
However, the above quotation includes the description "0.1~". As far as the said patent document is concerned, it seems that "0.1 to 0.9% amount of ionophore" acts as a "potential stabilizer" as referred to in the present invention. Therefore, it can be judged that "0.1 to 0.9% amount of ionophore" alone is insufficient as a sensitive substance amount, and good electrode response cannot be obtained. That is, if less than 0.8 percent of the potential stabilizer of the present invention is present, it cannot be called a sensitizer. In many tests conducted by the applicant himself, the result was obtained that the measured potential was not stable unless at least 1 to 2% of the sensitive substance was contained.

In the present invention, the "surface treatment that makes it difficult for the electrode applied to the electrode cell to peel off" is as follows.
1) Machining in which the electrode cell is finely scratched vertically, horizontally, and obliquely with a cutter or an equivalent blade (within a 0.5 mm interval between each).
2) Blasting processing similar to 1.
By performing the above surface treatment, when the mixture (mainly epoxy resin) is cured, the mixture enters the electrode cell portion that has been roughened by scratching or blasting, and is caught in that portion during the curing reaction. Since it hardens, it becomes difficult for peeling to occur after curing. As a result, the electrode (in this case, the composite including the electrode cell and the internal liquid) has a long life.

The anion-selective electrode according to the present invention improves on some of the drawbacks of the conventional electrode of type (3). Therefore, the characteristics of conventional electrodes (excellent mechanical strength, various chemical environments can be set, and excellent linearity and selectivity are achieved without the need to add anion-selective sensitive substances). ), there is no pinhole (conductivity) during fabrication, so the liquid inside the electrode does not come into contact with the specimen, the electrode (response membrane) does not peel off from the electrode cell and electrode stick, and it can be used for a long time. is obtained.

Outline of the electrode cell (flow path portion) that is one embodiment of the present invention (before inner surface processing) Outline of the electrode cell (flow path) that is one embodiment of the present invention (after inner surface processing) Outline of the electrode cell (flow path section) that is one embodiment of the present invention (after electrode (response membrane) adhesion) Outline of the electrode cell (flow path portion) that is one embodiment of the present invention (before inner surface processing) from another side Outline of Electrode Cell (Flow Path Part) According to One Embodiment of the Present Invention (After Inner Surface Processing) From Another Side Outline of the electrode stick that is one embodiment of the present invention (before processing the electrode (response membrane) adhesive surface) Outline of the electrode stick that is one embodiment of the present invention (after processing the electrode (response membrane) adhesive surface) Outline of an electrode stick that is one embodiment of the present invention (after electrode (response membrane) adhesion) Overview of measurement system (flow-through type) that is one embodiment of the present invention Overview of measurement system (dip type) that is one embodiment of the present invention Chloride ion linearity test results using the anion selective electrode response membrane of the present invention Simultaneous reproducibility test results of chloride ion using the responsive membrane for anion selective electrode of the present invention Chloride ion selectivity test results using the anion selective electrode response membrane of the present invention Results of diurnal variation test of chloride ion using the responsive membrane for anion selective electrode of the present invention (1) Result of diurnal variation test of chloride ion using the responsive membrane for anion selective electrode of the present invention (2) Chloride ion long-term life test results using the anion selective electrode response membrane of the present invention Nitrate ion measurement results in liquid fertilizer using the responsive membrane for anion selective electrode of the present invention

The present invention is a new and progressive improvement of Japanese Patent No. 3970032 "Response Membrane for Anion Selective Electrode Containing Potential Stabilizer" and Japanese Patent No. 3975086 "Response Membrane for Anion Selective Electrode". Therefore, it can be applied to all raw materials used in the examples described in the above patent documents. In addition, the examples described below are merely "examples" and are not limited to them.

The procedure for processing the inner surface of the electrode cell (channel portion) (1) as a pretreatment is shown below.
1) The tip of a fluorine resin tube having a diameter slightly larger than the diameter of the flow path is extended and put into the flow path (2) of the electrode cell (flow path section) (1). This is a measure to prevent contamination of the flow path during processing.
2) Cut vertically, horizontally and diagonally with a utility knife. Each is performed at intervals of 0.5 mm or less.
When blasting, ask a contractor to make the scars as rough as the cutter knife.
3) Remove resin debris with a brush or the like, and replace the fluorine resin tube.
Next, a method for producing an electrode will be described below.
(4) Epicoat 807 (abbreviation: 807) (seller: oily shell epoxy) (110 mg) Quick 30 (agent A) (abbreviation: 30A) (seller: Konishi) (20 mg), bond E set (agent B) (abbreviation: EB) (seller: Konishi) (20 mg), Epomate QX11 (abbreviation: QX11) (seller: oleic shell epoxy) (60 mg), cup cure 3-800LC (abbreviation: 3800) (seller: oil Weigh out (16 mg) using a spatula.
5) Add EB, QX11, 3800 to an agate or ceramic mortar and knead well. Next, 807 and 30A are added and kneaded uniformly (work for about 60 seconds during this time).
6) Apply the mixture prepared in step 5 to the inner surface of the previously prepared electrode cell (channel portion) (1) (the amount of the mixture is equivalent to three electrode cells. This work will be completed in about 30 seconds).
7) Heat and leave on a hot plate (60° C.) for one hour.
8) After completion of heating, remove from the hot plate, allow to cool, and pull out the fluorine resin tube.
9) Using cyclohexanone, the electrode cell (flow path portion) (1) is adhered to the electrode cell (terminal portion) (12), left overnight, and dried.
10) The electrode internal liquid (14) is filled into the completed electrode cell (integrated flow channel and terminal) and sealed.

The performance of the completed sensitive substance spontaneously generated anion-selective electrode was used as a chloride ion-selective electrode and its performance was evaluated. As an evaluation instrument, an electrolyte analyzer EX-Z manufactured by Joko was used.

Three identical electrodes were prepared, and after calibration, the certified practical reference materials for ion electrodes (ISE CRS) were measured five times without correction. The results were used to calibrate the instrument and the calibrated values were compared to the ISE CRS certified values. The results are shown in Table 1.

For all electrodes, the difference between the corrected measured value and the ISE CRS certified value fell within ±1 mol/L. This is within the "target value ± 2 mol/L", which is an A rating in many electrode surveys.

An electrode was adhered to the electrode cell (channel portion) (1) treated in the same manner as in Example 1 by the following procedure.
1) Methyltridodecyl ammonium chloride (abbreviation: MTDDA-Cl) (seller: Sigma-Aldrich) (1.44 mg) and Epicort 815XA (abbreviation: 815) (seller: Mitsubishi Chemical) (156.0 mg) in a spoon Then, 2,4,6-tris(diaminomethyl)phenol (abbreviation: DMP-30) (distributor: Tokyo Kasei Kogyo) (26.4 mg) is weighed out with a Pasteur pipette.
2) Add MTDDA-Cl to an agate or ceramic mortar and crush, then add 815 and mix well, finally add DMP-30 and knead evenly (work for about 30 seconds during this).
Subsequent procedures are the same as 6 to 10 of the first embodiment.

The performance of the completed sensitive substance spontaneously generated anion-selective electrode was used as a chloride ion-selective electrode and its performance was evaluated. As an evaluation instrument, an electrolyte analyzer EX-G manufactured by Joko was used.

Linearity test A linearity test was performed using an aqueous solution of sodium chloride. The results are shown in FIG. The concentrations of the aqueous solutions are as follows.
Chloride ion concentration (mmol/L): 30.0, 70.0, 100.0, 120.0, 150.0, 200.0, 250.0, 300.0

Simultaneous reproducibility test Simultaneous reproducibility test was performed using QAP trol (distributor: Sysmex) 1 and 2 as serum controls. The results are shown in FIG.

Ion selectivity test An ion selectivity test was performed based on calibration solution 1 of EX-G. The results are shown in FIG. A sodium salt of a compound described later was prepared so as to have a concentration of 100 mmol/L, and was used as a test solution. However, the ion concentration of sodium sulfate was set to 50 mmol/L. Also, triethanolamine and butyric acid are not sodium salts.
Anionic species: thiocyanate, iodide, azide, nitrate, bromide, salicylate, formate, sulfate, bicarbonate, acetate, dihydrogen phosphate, triethanolamine, butyric acid

A day-to-day variation test was performed using QAP trol (distributor: Sysmex) 1 and 2 as a serum control. The results are shown in FIGS. 14 and 15. FIG.

Long-term life test A long-term life test was performed using a total of 16 electrodes. The results are shown in FIG. Each inspection item and acceptance criteria are as follows.
1) Calibration 3 times in a row → No error 2) Slope → -34.0 to -43.0
3) Reproducibility of calibration solution 2 → No error and coefficient of variation (c.v.): less than 0.4 * Passes when all the above three tests are cleared.
About three years and two months have passed since the start of the test, and 11 chloride electrodes have passed the test. A similar test was also conducted with sodium electrodes and potassium electrodes, but the numbers of those passing were 5 and 6, respectively. Therefore, as far as this test is concerned, it can be said that the chloride electrode has a relatively longer life than the sodium electrode and the potassium electrode. Also, when the electrode peeled off, the slope became zero. Therefore, it can be seen that the electrode (response film) is not separated from the electrode cell.

In addition to the above, various tests were conducted, but since the tendencies were the same, they are omitted.

The same "sensitive substance spontaneously generated anion-selective electrode" used in Example 2 was evaluated as a nitrate ion-selective electrode. Liquid fertilizer (for hydroponics) was used as an object, and an electrolyte analyzer EX-Z manufactured by Joko was used as an evaluation instrument. Since the EX-Z is an instrument for clinical examination, we developed a new calibration solution for hydroponics and changed the type of reference electrode (these are not disclosed).

Liquid fertilizer (liquid fertilizer) is used for growing fruits. There are various ways to use it, but the one tested this time was a system that stored liquid fertilizer in a storage tank and circulated it with a pump. New liquid fertilizer was added at regular intervals, and we paid attention to the change in nitrate ion concentration before and after that. We also paid attention to the difference in concentration depending on the place where the liquid fertilizer was collected. The date and place of liquid fertilizer collection are as follows.
Daily difference and confirmation before and after replacement of liquid fertilizer First day (in storage tank) (1)
Second day (in storage tank) (3)
Day 3 (in storage tank) (5)
Replacing liquid fertilizer Day 3 (in storage tank) (10)
Day 1 (where the liquid is sent from the fruit to the storage tank) (2)
Day 2 (Transportation point from fruit to storage tank) (4)
Day 3 (Transportation point from fruit to storage tank) (6)
Replacing the liquid fertilizer Fourth day (where the liquid is sent from the fruit to the storage tank) (11)
Confirmation before and after stirring On the third day (two points in the storage tank on the diagonal line) before stirring (7), (8)
On the third day (two points in the diagonal storage tank) after stirring (9)
Fourth day (two locations in the storage tank on the diagonal line) before stirring (12), (13)
Fourth day (two locations in the diagonal storage tank) after stirring (14)

The results of liquid fertilizer measurement are shown in FIG. The potassium ion concentration was also measured in the EX-Z, and the hydrogen ion exponent (pH) and the calcium ion concentration were additionally measured using a Joko electrolyte analyzer EX-Ca. As a result, we found the following.
1) A large concentration change was observed before and after replacement of the liquid fertilizer.
2) From (1), (2), (3), (4), (5), and (6), it was found that there is a difference in each ion concentration in the liquid fertilizer tank and at the point where the liquid is sent from the fruit to the liquid fertilizer tank. .
3) From (7), (8), and (12) and (13), since there is no significant change in the ion concentration at the two locations in the liquid fertilizer tank on the diagonal line, the liquid fertilizer concentration in the liquid fertilizer tank is almost constant. I found out.
4) From (7), (8) and (9), and (12), (13) and (14), there is no significant change in the concentration of each ion before and after the agitation of the liquid fertilizer tank. It could be inferred that the stirring was carried out naturally.
5) Compared with fluctuations in each ion concentration, it was found that pH fluctuations were small and maintained at slightly less than 7.

As described above, by using the "spontaneously generated anion-selective electrode of the sensitive substance" according to the present invention, at least chloride ions and nitrate ions can be stably measured for a long period of time. Other features include excellent mechanical strength, ability to set various chemical environments, and excellent linearity and selectivity without the need to add anion-selective sensitive substances. .

1 electrode cell (flow path)
2 flow path 3 flow path hole 4 electrode cell inner surface before processing 5 adhesion surface with electrode cell (terminal part) 6 electrode cell inner surface after processing 7 electrode (response membrane)
8 Electrode stick (channel)
9 Electrode (response membrane) adhesion surface (before processing)
10 Electrode (response membrane) adhesive surface (after processing)
11 Fluorine resin tape 12 Electrode cell (terminal part)
13 inner electrode 14 electrode internal liquid 15 reference electrode 16 liquid junction 17 reference electrode inner electrode 18 reference electrode internal liquid 19 potentiometer 20 sample

Claims (5)

At the boundary between the electrode cell passage or the outside of the electrode stick and the space filled with the electrode internal liquid inside the electrode cell or inside the electrode stick,
A mixture (excluding a solvent-containing mixture) obtained by mixing an epoxy resin main agent and a curing agent, or an epoxy resin main agent, a curing agent, and a curing accelerator without adding an anion-selective sensitive substance ,
In the mixture, quaternary ammonium cations generated during the curing reaction of the epoxy resin main agent are present as anion-selective sensitive substances,
The boundary portion is surface-treated to make it difficult for the mixture to peel off after the epoxy reaction,
A spontaneously occurring sensitive substance-generating anion-selective electrode, characterized in that the mixture is coated on the boundary portion or cured by direct contact with the boundary portion without using a solvent to prepare a responsive membrane. 2. The spontaneously generated anion-selective electrode according to claim 1, wherein said anion-selective sensitive substance acts as a chloride ion-selective sensitive substance. 2. The spontaneously occurring sensitive material anion selective electrode according to claim 1, wherein said anion selective sensitive material acts as a nitrate ion selective sensitive material. A method for producing a sensitive substance spontaneously occurring type anion-selective electrode, comprising:
Mixing an epoxy resin main agent and a curing agent, or an epoxy resin main agent, a curing agent and a curing accelerator without adding an anion-selective sensitive substance to prepare a mixture (excluding those containing a solvent). process and
a step of performing a surface treatment on the boundary between the electrode cell channel or the outside of the electrode stick and the space filled with the electrode internal liquid inside the electrode cell or inside the electrode stick so as to make it difficult for the mixture to peel off after the epoxy reaction; ,
A method for producing a spontaneously-generated sensitive anion-selective electrode, characterized in that the mixture is applied to the boundary portion or cured by direct contact without using a solvent to prepare a responsive membrane. The amount of the potential stabilizer added is less than 0.8% in the step of mixing the epoxy resin main agent and the curing agent or mixing the epoxy resin main agent, the curing agent and the curing accelerator to prepare the mixture. 5. The method for producing a sensitive substance spontaneously occurring type anion selective electrode according to claim 4, wherein

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