JPS6010163A - Flow communication type ion sensor - Google Patents

Abstract

PURPOSE:To obtain a long life sensor of which the ion responsive film is not delaminated, by forming a metal electrode, a halide-containing polyvinyl chloride resin layer and a laminated ion responsive film comprising a polyvinyl chloride resin containing ion responsive substances to the inner peripheral surface of the through-hole provided to an insulating board. CONSTITUTION:A through-hole with a diameter of 2.5mm. is formed to the center of an insulating board 11 made of an epoxy resin and a Ag-layer 13 having a lead wire connected thereto is provided to a part of the inner peripheral surface of said hole while a AgCl-layer 14 is formed to the surface of the Ag-layer 13 by an electrolytic process using said layer 13 as an anode. In the next step, a polyvinyl chloride resin film layer 15 containing KCl but not containing a plasticizer is formed so as to cover the layer and the insulating board 11. Subsequently, a polyvinyl chloride resin layer 16 containing a K<+>-selective substance and a plasticizer is formed on the layer 15 to obtain a K<+>-selective electrode 31. Similarily, a Na<+>-selective electrode 32, a Cl<->-selective electrode 33 and a reference electrode 35 are formed by using a polyvinyl chloride resin and the whole is received in a case through an insulating member (silicon rubber) 35 to obtain a flow communication type sensor. Each responsive film has good close adhesiveness and a long life sensor showing stable potential is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an ion sensor body that can selectively measure the concentration of a specific ion.

More specifically, the adhesion of the ion-sensitive membrane is excellent, and therefore,
The present invention relates to a flow-through type ion sensor body that exhibits a stable potential and has a long life.

[Technical background of the invention and its problems]

Ion-selective electrodes have traditionally had the feature of being able to selectively quantify the concentration of specific ions in a liquid;
It has been used in a wide range of fields such as monitoring the concentration of specific ions and analyzing water P4.

For example, in the case of a cation-selective electrode, the difference between the active Ma+ of 1% ion as a counter SL and the potential E exhibited by the cation-selective electrode is E = F, '+ 2.303 (a 'r7 z F
) kIga - (1) As shown in 10, in the case of an anion-selective electrode, the relationship between the activity a- of the target anion and the potential shown by the anion-selective electrode is B= B'-2,303(RT/zF) keg
Since there is a relationship in which the logarithm of the activity is proportional to the potential, such as a-=121, i)t! of the potential is established. The activity of the target ion can be easily calculated from the i constant value.

In the above equations (11 and (2)), R is a gas constant, T is an absolute temperature, 2 is an ion valence, F is a Faraday constant, and Eo is a standard electric fence potential of the system.

In this way, if an ion-selective electrode is used, it is possible to quantify ion concentrations over a wide range of concentrations by simply measuring the potential. Measurement with samples will be the January performance. As such, ion-selective electrodes are convenient and have recently been used for medical purposes, especially for ions present in blood, such as Na.
Attempts to use the constant it≦ of each ion, such as ``, K+, C1-, etc., are becoming more popular.

In addition, various types of analyzers using the ion-selective electrode (b) have been proposed, and their use as analyzers for medical treatment of blood and the like is becoming widespread.

Among these ion-swampy electrodes, recently, ion-selective electrodes with a partial structure in which there is no internal 14L dislodging solution and an ion-sensitive/responsive membrane is formed on the metal have been developed, especially in the production of electrodes.
It is attracting attention because its handling and maintenance are BJ@.

In addition, each i of multiple types of ions in the liquid to be measured is
A convenient method for continuously measuring turbidity is the so-called flow cell method, in which multiple ion-selective electrodes are arranged in parallel in the flow path of the liquid to be measured, and the electricity from each electrode is analyzed in terms of μ'1. It is known that

Furthermore, recently, the ion-selective 'NI! ! ! ! A see-through ion sensor body of 8 coupled in a monolithic niflow cell manner has been developed.

This flow-type ion sensor body has a flow surface for the liquid to be measured that is formed by the electrode surfaces of the plurality of ion selection 1 main electrodes, making it compact and versatile. It has the advantage that only a small amount of constant liquid is required.

Such city-type inn 1senpu holidays include gold, silver%,
There is a known vibrator coated with an ion 1-layer film.

However, the flow-through type ion sensor body made of a precious metal pipe is expensive because it uses a multi-H shell metal abrasive, and the adhesiveness between the metal and the ion-sensitive membrane is rapid, resulting in a short lifespan. It had the following drawback.

For this reason, instead of the gold) N4 pipe, a through hole was provided on the surface of the plastic plate through which the W liquid to be measured flows, and a thin gold film was coated on the inward part of this through hole. The electrodes used are proposed.

A flow-through type ion centimeter body using a plastic plate is inexpensive because it uses less metal material, and the ion-sensitive membrane can be spread and coated not only on the metal surface but also on the plastic surface adjacent to the metal part. By this,
It can be expected that the tightness of the ion-sensitive membrane will be improved.

The plastic plates that have been used to date for this purpose have been made of acrylic resin, phenolic resin, epoxy resin, and the like.

However, the density uniformity between these plastic plates and the polyvinyl chloride resin film of the ion-sensitive membrane base material was not as good as expected, and separation occurred, causing the liquid to be measured to contact the metal plate. There was a problem in that the potential became unstable due to the short circuit, which significantly reduced the lifespan of the ion centimeter.

[Purpose of the invention]

An object of the present invention is to provide a flow-through type ion centrifugal body that has excellent adhesion of an ion-sensitive membrane, exhibits a stable potential, and has a long life.

[Summary of the invention]

In order to achieve the above object, the present inventors have conducted intensive research and have found that a flow-through type ion sensor body in which through-holes formed in a plate made of an insulating material serve as flow paths for a liquid to be measured, After applying the first layer consisting of a halogen compound and polyvinyl chloride resin containing no agent, a second layer consisting of a polyvinyl chloride resin containing at least an ion-sensitive substance was applied. The inventors have completed the present invention by discovering the fact that the accumulation of ion-sensitive LIS films is significantly improved when an ion-sensitive film made of n is formed.

That is, the flow-through type ion centimeter body of the present invention has the following characteristics:
1. A cotton conductor part arranged to form at least a part of the inner circumferential surface of the through hole; and an insulating member in contact with the surface of the conductive member forming the inner surface of the through hole and the surface of the conductive member. A plurality of ion-selective electrodes each comprising: an ion-sensitive membrane made of a polyvinyl chloride resin film covering at least a portion of the surface of the material plate; and a lead wire connected to the conductive member;
In a flow type ion centrifugal body in which through-holes are integrally connected to each other via an electrically insulating member to form a flow path for a liquid to be measured, the ion sensitive membrane is composed of a halogen compound and a polyvinyl chloride-based membrane. A layer consisting of a first layer made of resin and a second layer made of polyvinyl chloride resin containing at least an ion-sensitive substance, and the polyvinyl chloride resin layer containing the ion-sensitive substance serves as a flow path for the liquid to be measured. It is characterized by being provided to form a

As the halogen compound used in the present invention, alkali metal halides are generally preferred, and practical examples include KCtt, NaCx, KBr, and the like.

Next, referring to the drawings, the ion centimeter body of the present invention is expressed as Ji<j L
.

I will explain.

FIG. 1 is a conceptual cross-sectional view of one embodiment of a sodium ion selective electrode according to the present invention.

In the figure, a through hole 12 is bored in the center of the epoxy resin plate 11, and the silver 13 deposited along the through hole 12 forms part of the inner peripheral surface of the through hole 12. There is. This silver 1
The surface of No. 3 is covered with a silver chloride layer 14. Silver chloride layer 1
4 and an epoxy resin layer 11, the inner peripheral surface of the through hole 12 is coated with an n+ layer 15 made of polyvinyl chloride resin containing potassium chloride, and further coated with an ion-sensitive substance monensin and a plasticizer ortho. consisting of polyvinyl chloride resin containing nitrophenyl octyl ether
+2tv1e is coated with an ion-sensitive membrane provided with an ion-sensitive membrane, forming a surface for measuring the ion concentration of the liquid to be measured flowing through the h through hole 12.

FIG. 2 shows Jt4 used in a preferred embodiment of the present invention.
This is the WrifI concept of one embodiment of the single-coupling electrode.

In the figure, there is a negative through hole 2 in the center of the epoxy 4IIU fat plate 21.
2 is bored, and the silver 23 deposited along the through hole 22 forms a part of the inner peripheral surface of the through hole. The surface of this silver 23 is covered with a silver chloride layer 24. The inner circumferential surface of the through hole 22 consisting of the silver chloride layer 24 and the epoxy resin plate 21 is covered with a polyvinyl chloride resin film 25 containing potassium chloride, and this polyvinyl chloride resin film 25 protects the silicone polymer. 119-26.

Figure fA3 is a conceptual diagram showing a cross-sectional view of one embodiment of the ion centimeter of the present invention. In the figure, numerals 31, 32, 33 and 34 represent sodium, potassium and chloride ion selective electrodes and reference electrodes, respectively.

These ion-selective electrodes 31, 32, 33 and reference electrode 34 are integrally connected to each other via an electrically insulating member 35 so that their respective through holes form a flow path for the liquid to be measured.

Furthermore, this flow type ion centrifuge body has a liquid to be measured inlet 36 and a liquid to be measured outlet 37 connected to the through hole, and the lead wires 38, . 38', 38' are surrounded by an exterior 39 having an electrical signal output port for leading the signals to the outside. For example, the following method can be used to form the ion-sensitive part of each ion-selective electrode (
(Explained using FIG. 1).

First, a solution of a polyvinyl chloride resin and potassium chloride dissolved in a solvent such as tetrahydrofuran, a polyvinyl chloride resin, an ion selective substance such as monensin, palinomycin, or a quaternary ammonium salt, and dioctyl adipate or dioctyl phthalate are prepared. and a plasticizer such as orthonitrophenyl octyl ether are dissolved in a solvent such as tetrahydrofuran to obtain an ion-sensitive membrane forming solution.

Next, “1. A polyvinyl chloride thread 1'=J fat solution containing potassium A chloride is applied to the through hole 12 of the epoxy resin plate 11 and the inner peripheral surface of the chloride L/M 14, and after drying, an ion-sensitized solution is applied on top of it. When the molding solution is applied and dried, an ion-sensitive tri-film layer 16 is obtained.

In the present invention, C-C uses the polyvinyl chloride resin layer 15, which does not contain plasticizer, on the epoxy resin plate 11 as the base for the 11 ion-sensitive membranes 16, which contain a desiccant agent. The layer density is extremely good.

Since the vinyl chloride resin layer 15 does not contain a plasticizer, a hard side is formed in η-, j, and il)2J,
There is almost no stone count property as seen in polyvinyl chloride resin films containing i'll, and I'll from the silver chloride layer I4.
The silver chloride layer 14, the epoxy resin, and the polyvinyl chloride resin film layer fixed to the inner peripheral surface of the temporary 14 through hole 12 are coated with the same material. By covering the ion-sensitive membrane layer 1G, its density and fluff properties are further improved.

〔Effect of the invention〕

The present 5 and Ming's incent bodies have excellent adhesion to the ion-sensitive membrane, and therefore exhibit stable potential and long life, and have extremely great industrial value.

[Embodiments of the invention]

Hereinafter, the flow type ion centimeter of the present invention will be explained in detail along with examples.

Example 6 and Comparative Example A lead wire was connected to a part of the inner peripheral surface of a 2.5-diameter through hole drilled in the center of an epoxy resin disk with a diameter of 15 fins and a thickness of 3 m. exposed area 24-1 thickness Q, l IIg
After depositing a silver layer, a silver chloride layer was obtained on the surface of the silver layer by electrolysis using this silver as an anode.

In this way, four epoxy resin disks having silver arranged on the inner peripheral surface of the through hole were prepared.

On the other hand, in 20 g of tetrahydrofuran, 1 g of polyvinyl chloride resin, 2 g of orthonitrophenyl octyl ether, and 130 g of monensin were dissolved respectively to form a sodium ion-sensitive membrane forming solution, 1.1 g of polyvinyl chloride resin,
Dissolve 1.7 g of dioctyl adipate, 2 to 10 g of potassium tetraphenylborate, and 10 da of palinomycin to prepare a bath solution for forming a potassium ion-sensitive membrane, and 1.1 g of polyvinyl chloride resin.
5g.

Meburu tridodecylammonium chloride 500■
A solution for forming a chloride ion-sensitive membrane was prepared by dissolving 3 g of potassium chloride and 1 g of polyvinyl chloride resin, which will serve as a base film for the ion-sensitive membrane.

Next, add each of the above solutions for the base film of the ion-sensitive membrane.
A small amount of the mixture was applied to the circumferential surface of the through hole of two epoxy resin disks and dried to form a polyvinyl chloride resin layer containing potassium chloride with a thickness of 150 pm.

Next, the obtained sodium, potassium, and chlorine ion-sensitive single conversion forming solutions were first applied on the base layer of the through holes of three epoxy resin disks, dried, and the film thickness was 250 μm.
An ion-sensitive membrane of m was formed to obtain an ion-selective electrode according to the present invention. Further, a silicone rubber film (FL'I'V) was formed on the base layer of the remaining epoxy resin disk to serve as a reference electrode.

These ion-selective electrodes and reference electrodes had a diameter of 15nφ.
2.5cm thick silicone/rubber disc with 3H thickness
As shown in FIG. 3, each through hole is integrally connected to each other via an insulating member in which a through hole of the fin φ is formed to form a flow path for the chamber fluid. The ionic centiform of the present invention was obtained.

On the other hand, for comparison, an ion-selective electrode without a polyvinyl chloride resin membrane layer containing potassium chloride (ion-sensitive membrane base l17i) (an ion-sensitive membrane was applied directly to the through-hole of an epoxy resin disk) A comparative ion sensor body was prepared by the same method C2 as above except that the same method as above was used.

Next, a solution containing 50 m+nol/E of each of disodium, potassium, and chlorine ions was continuously passed through the measurement liquid flow passage of the ion centimeter of the present invention and the comparison ion centimeter prepared as described above, and a life test was conducted. went.

As a result, the ion centimeter of the present invention showed normal measurement values even after continuous measurement for 230 days, while the comparative ion centimeter showed ion sensitivity and the membrane peeled off within 11 days, and the ion concentration decreased. Measurement became impossible.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of one aspect of the sodium ion selective rq electrode according to the present invention. FIG. 2 is a conceptual diagram of a -J'b-like crystal plane of a reference electrode used in a preferred embodiment of Akira Kizuko. FIG. 3 is intended to show a cross section of one embodiment of the ion centimeter of the present invention. 11.21...Epoxy resin 12.22...Through hole 13.23...Silver plate 14,24...Silver chloride layer 1
5.25...KC! 3-containing polyvinyl chloride resin film layer (first layer) 16...halogen compound-containing polyvinyl chloride resin layer (
211η) 26... Silicon-based polymer protective film 31... Sodium ion selective electrode 32... Potassium ion selective electrode 33... Chlorine ion selective electrode 34... Reference electrode 35... Silicone rubber sea bream insulation member 26...Measurement liquid inlet 37...Measurement liquid outlet 3
8. 38', 38', 38'''...'Electrode line 39...Exterior agent Patent attorney Noriyuki Takashi Chika (1 other person)

Claims (2)

[Claims] (1) A conductive member disposed along a through hole drilled in a plate made of an insulating material so as to form at least a part of the inner circumferential surface of the through hole; forming the inner surface of the through hole; an ion-sensitive membrane made of a polyvinyl chloride resin film that covers at least a part of the surface of the isoelectric member and the surface of a plate made of an insulating material adjacent to the surface of the conductive member; a lead wire connected to the conductive member; a plurality of ion-selective electrodes comprising;
In a flow-type ion sensor body in which through-holes are integrally connected to each other via an electrically insulating member to form a flow path for a liquid to be measured, the ion-sensitive membrane is composed of a halogen compound and a polyvinyl chloride-based membrane. a first layer consisting of a resin;
The layer is made of a laminate including a second layer made of a polyvinyl chloride resin containing at least an ion-sensitive substance, and the polyvinyl chloride resin layer containing the ion-sensitive substance is provided to form a flow path for the liquid to be measured. A flow-through type ion sensor body characterized by the following. (2) A reference electrode provided on the inner circumferential surface of the through-hole drilled in the plastic plate, together with the plurality of ion-selective electrodes, connects each through-hole to a flow path for the liquid to be measured through an electrically insulating member. A flow-through type ion sensor body according to claim 1, which is integrally connected to each other to form a flow-through ion sensor body.