JPS6010164A - Flow communication type ion sensor - Google Patents

Abstract

PURPOSE:To obtain a long life ion sensor generating no delamination of an ion responsive film, in forming the ion responsive film to the inner peripheral surface of the through-hole provided to an insulating board, by providing polyvinyl chloride (PVC) resin plates provided with through-holes to both sides of the insulating board. CONSTITUTION:A through-hole 12 is provided to an insulating board 11 comprising an epoxy resin disc and a Ag-layer 13 is formed to a part of the inner peripheral surface of said through-hole 12 while a AgCl-layer 14 is formed to the surface layer 13 by an electrolytic process and an ion responsive film 16 is formed so as to cover the layer 14 and the inner peripheral surface of the insulating board 11. In this case, recessed parts are formed to both sides of the insulating board 11 around the through-hole 12 and polyvinyl chloride resin rings 15, 15 having through-holes are inlaid with the recessed parts while the responsive film 16 consisting of ion selective substances, a plasticizer and a PVC resin is formed so as to cover the surfaces of the rings 15, the surface of the insulating board 11 and the layer 14. By this method, K<+>, Na<+> and Cl<->-selective electrodes 31, 32, 33 are formed and received in a case along with a similarily fabricated reference electrode 34 through an insulating material. By this method, a small long life flow communication type sensor capable of simultaneously measuring ions in serum is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an ion sensor capable of selectively measuring specific ion concentrations.

More specifically, the adhesion of the ion-sensitive blade is different.

Therefore, the present invention relates to a flow 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 the characteristic of being able to selectively quantify the concentration of ions in tube feet in liquids.

Until now, it has been used in a wide range of fields such as monitoring the concentration of specific ions and analyzing water quality.

For example, in the case of a cation-selective electrode, there is a difference between the activity a of the cation of interest and the potential E shown by the cation selectivity + Kame 4.

E = E' + 2.303 (RT/zF) 10g a (
1) As in 10, and in the case of an anion-selective electrode, the relationship between the ion activity fL a- and the potential exhibited by the anion-selective electrode is E = E. ' -2,303 (几T/zF) 10
g a - Since a relationship is established in which the logarithm of active:A is proportional to the potential as shown in (2), the total activity of the target ion can be easily calculated from the measured value of the potential by 3·f.

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

In this way, by using an ion-selective electrode, it becomes possible to quantify the ion concentration over a wide concentration range simply by measuring the potential. Furthermore, by using an ion-selective electrode and making the electrode part smaller, it becomes possible to measure a small amount of sample. As described above, the ion-selective 7W electrode is convenient and has recently been used for medical purposes, especially for ions present in blood, such as Na.
, K.

Attempts to use it for quantifying various ions such as CI are becoming more popular.

In fact, various types of analyzers using the ion-selective electrodes have been devised, and their use as medical analyzers for blood and the like is expanding.

Among these ion-selective electrodes, recently there is no internal electrolyte solution, especially the ion-selective mirror electrode, which has a partial structure in which the metal north directly forms an ion-sensitive membrane.

The electrode is attracting attention because it is easy to manufacture, handle, and maintain.

Further, as a method for rapidly measuring the concentration of each of the ions of a plurality of barges in the liquid to be measured, a plurality of ion-selective γt poles are arranged in parallel in the flow path of the constant liquid.

Analyze the electrical signals from each electrode. It is known that the so-called flow cell system is convenient.

Furthermore, recently, a flow-type ion sensor body has been developed in which the ion-selective electrodes having no internal electrolyte solution are integrally combined in a flow cell manner.

This flow-type ion sensor body has multiple ion-selective flow paths for the liquid to be measured. a. Since it is formed by the electrode surface of the pole, it is compact and multifunctional, and has the advantage that only a small amount of liquid to be measured is required for ion analysis.

As such a flow-type ion sensor body, y-
It is known that a single-metal continuous pipe is coated with an ion-sensitive membrane.

However, a flow-through type ion sensor body made of a precious metal pipe is expensive because it uses a large amount of precious metal material.
Moreover, it has the disadvantage that the adhesion between the metal and the ion-sensitive membrane is poor and its life is short.

For this reason, gold 11.i) Instead of a pipe, a through hole is provided on the surface of the plastic plate through which the liquid to be measured flows, and an electrode using a thin metal film coated on a part of the inner surface of the through hole is used. is proposed.

The flow-through type ion sensor body uses a plastic plate, so it is inexpensive because it uses less metal material, and the ion-sensitive membrane is only on the metal surface.
47 Improving the adhesion of the ion-sensitive membrane by spreading the damage to the plastic surface that comes into contact with it Phase 1:! I can do j.

Plastic plates that have been used to date for this purpose have been made of acrylic resin, phenol TLB-1 resin, epoxy resin, and the like.

However, the adhesion between these plastic plates and the polyvinyl chloride resin film of the ion-sensitive membrane base material was not as good as expected, and peeling often occurred.

There is a problem in that short-circuiting of the liquid to be measured to the metal plate causes the potential to become unstable, significantly shortening the life of the ion sensor body.

[Purpose of the invention]

An object of the present invention is to provide a flow-through type ion sensor body that has an 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 extensive research, and as a result, we have developed a flow-through type ion sensor in which a through hole drilled in a plate of insulating material serves as a flow path for the liquid to be measured. If a polyvinyl chloride resin plate with through holes is provided on both sides of the plate and an ion-sensitive trace made of a polyvinyl chloride resin film is applied to the surface, the adhesion of the ion-sensitive membrane will be significantly improved. They discovered the facts and completed the present invention. That is, the flow-through type ion sensor body of the present invention is disposed along a through hole formed 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. v'1 Denberi; A polyvinyl chloride resin plate with through holes arranged on both sides of the board of Ka Zetsu Ka C1'II; Kai Zetsu &1
) rA conductive member surface forming the inner circumferential surface of the through hole drilled in the old plate, the cotton feeding material plate surface adjacent to the conductive member surface, and the insulation material plate disposed on both sides of the plate. an ion-sensitive membrane made of a polyvinyl chloride resin film covering at least a portion of the polyvinyl chloride resin plate; and a plurality of ion-selective electrical connections connected to the conductive parts. G: Electrical insulation g1! It is characterized in that the respective through holes are integrally connected to each other through a material so as to form a δ11 mark of the liquid to be measured.

Next, the ion sensor body of the present invention will be explained with reference to the drawings.

11 is a cross-sectional conceptual diagram of one embodiment of a sodium ion selective electrode according to the great invention; FIG.

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 a part of the inner peripheral surface of the through hole 12. There is.

The surface of this silver 13 is covered with a silver chloride layer 14.

The epoxy resin plate 11 had a 4'M structure in which rings 15 made of polyvinyl chloride resin were embedded on both sides.

In the present invention, the ring 15 made of polyvinyl chloride resin is an essential 4111 component that plays a role in improving the adhesion of the polyvinyl chloride resin film of the ion-sensitive membrane base material, and its shape is not limited to a ring shape. It may be square, triangular, star-shaped, etc.

Further, the method of disposing the device is not limited to burying, but any method such as screwing may be used. This silver chloride layer 14 and the epoxy resin plate 1
1 and a polyvinyl chloride resin ring 15, the inner peripheral surface of the through hole 12 is covered with an ion-sensitive membrane 16 made of a polyvinyl chloride resin, monensin, and a plasticizer, orthotrophenyl octyl ether. The ions of the liquid to be measured flowing through it form a constant state.

FIG. 2 is a conceptual cross-sectional view of one embodiment of a reference electrode used in a preferred embodiment of the present invention.

In the figure, a through hole 22 is bored in the center of the epoxy resin plate 21, and the silver 23 deposited along the voice through hole 22 forms part of the inner peripheral surface of the ft through hole. ing.

Polyvinyl chloride resin rings 25 are embedded on both sides of the epoxy resin plate 21. The inner peripheral surface of the Jj through hole 22, which is made up of the silver chloride layer 24, the epoxy resin plate 21, and the polyvinyl chloride resin ring 25, is covered with a polyvinyl chloride resin film 26 containing potassium chloride. The vinyl resin 41 and the resin 26 are protected by a protective film 27 made of silicone polymer.

FIG. 3 is a concept N showing a cross section of one embodiment of the ion sensor body of the present invention.

In the figure, ladle numbers 31, 32, 33 and 34 are respectively.

Represents a sodium, potassium, and chloride ion selective electrode and a reference electrode.

Through these ion-selective th electrodes and reference T44%34k'r,%%Ml'Iq,sound1-tr)835, each through hole forms a flow path for the liquid to be measured. They are integrally connected to each other.

Furthermore, this flow type ion sensor body is surrounded by an exterior 39 having a liquid to be measured inlet 36 connected to the through hole and an electric signal output port for guiding the outflow of the liquid to be measured to the outside.

In order to form the ion-sensitive membrane portions of the four ion-selective electrodes, for example, the following method can be used (this will be explained with reference to FIG. 1).

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

Next, this solution is applied to the through holes 12 of the epoxy resin plate 11, the silver chloride layer 14, and the inner circumferential surfaces of the polyvinyl chloride thread and the resin ring 15 and dried to obtain an ion-sensitive membrane layer.

In the present invention, since the polyvinyl chloride resin ring 15 is coated with the ion-sensitive membrane 16 made of polyvinyl chloride resin, its adhesion is extremely good. In particular, when an ion-sensitive film-forming solution containing a solvent such as tetrahydrofuran is applied to a polyvinyl chloride ring to form an ion-sensitive layer 16, the surface layer of the polyvinyl chloride resin ring 15 is dissolved by the solvent. and ion sensitive membrane 1
This will further enhance the adhesion with 6.

〔Effect of the invention〕

The ion sensor body of the present invention has excellent adhesion of the ion-sensitive membrane, and therefore exhibits stable potential and long life, and has extremely great industrial value.

[Embodiments of the invention]

EMBODIMENT OF THE INVENTION Hereinafter, the flow type ion sensor body of this invention is explained in detail along with an Example.

Examples and Comparative Examples A through hole with a diameter of 6 mm centered on a 2.5 mm diameter through hole drilled in the center of an epoxy resin disk with a diameter of 15 mm and a thickness of 3 mm,
Recesses with a depth of 9.5 x m were provided on both sides of the epoxy resin disk, and a lead wire was connected to a part of the inner peripheral surface of the 5 through holes, with an exposed area of 24 mm', thickness U, and 1 mm silver. After the layer was deposited, a silver chloride layer was irradiated on the surface of the silver layer by an electrolytic method using the pot as an anode. Next, outer diameter 5.8mm, inner diameter 3
A polyvinyl chloride resin ring with a thickness of 9.5 mm was fitted into the recesses on both sides of the epoxy resin disk. In this way, four epoxy resin disks having silver chloride arranged on the inner peripheral surface of the oil producing hole were prepared.

Meanwhile, 20 g of tetrahydrofuran, respectively.

Dissolve 1 g of polyvinyl chloride resin, 2 g of orthonitrophenyl octyl ether, and 130 mg of monensin to create a sodium ion-sensitive membrane forming solution, 1.1 g of polyvinyl chloride resin, 1.7 g of adipine dioctyl, 2 mg of potassium tetraphenylporate, and palinomycin. 10 m
Prepare a chloride ion sensitive membrane forming solution by dissolving potassium ion sensitive membrane forming solution, 1.5 g of polyvinyl chloride resin, and 500 mg of methyltridodecylammonium chloride. did.

Next, the obtained sodium, potassium, and chlorine ion-sensitive membrane forming solutions were respectively applied to the through holes of the three epoxy resin disks and the inner peripheral surface of the polyvinyl chloride ring, and dried. An ion-selective electrode according to the present invention was obtained by forming an ion-sensitive membrane having a thickness of 300 μm. A silicone rubber film (R
TV)! (100 μm) was formed in the same manner and used as a reference electrode.

These ion-selective electrodes and reference electrodes have a diameter of 15 mm.
, 2.5 in the center of a silicone rubber disk with a thickness of 3
As shown in FIG. 3, the through holes are integrally connected to each other to form a flow path for the liquid to be measured through an insulating member having through holes of mmψ. I got a body.

On the other hand, for comparison, a comparative ion sensor body was created by the same method as above except that an epoxy resin ring was used instead of the polyvinyl chloride resin ring.

Next, a solution containing 50 mmol/l of each of sodium, potassium, and chlorine ions was continuously passed through the flow path of the liquid to be measured of the ion sensor bodies of the present invention and for comparison prepared as described above, and a life test was conducted. Ta.

Results 1: The ion sensor body of the present invention showed normal measurement values even after continuous measurement for 230 days, but the ion sensitive membrane of the comparative ion sensor body peeled off within 11 days, making it impossible to measure ion concentration. It became.

[Brief explanation of drawings]

FIG. 1 is a conceptual cross-sectional view of one embodiment of a sodium ion selective electrode according to the present invention. FIG. 2 is a conceptual cross-sectional view of one embodiment of a reference electrode used in a preferred embodiment of the present invention. FIG. 3 is a conceptual diagram showing a cross section of one embodiment of the ion sensor body of the present invention. 11.21...Epoxy resin plate, 12.22...Through hole. 13.23...Silver plate, 14%24...Silver chloride layer. 15.25...Polyvinyl chloride resin ring, 16.
...Ion-sensitive membrane, 26..KCl-containing polyvinyl chloride 81 resin. 27...Silicon-based polymer protective film. 31... Sodium ion selective pole, 32... Potassium ion selective intussusception, 33...'4N, k,'
/r On-selective sapling, 34... Reference electrode, 35 - P bond member made of silicone rubber. 36...Measurement liquid inlet, 37...Measurement liquid outlet. Representative Patent Attorney Rules Kensuke Chika (1 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 peripheral surface of the through hole; and a plate made of an insulating material. a polyvinyl chloride resin plate with through holes provided on both sides of the insulating material;
a polyvinyl chloride resin film covering at least a portion of a polyvinyl chloride resin plate disposed on the conductive part surface, the surface of an insulating material plate adjacent to the surface of the conductive part 1, and both sides of the insulating material plate; A plurality of ion-selective electrodes each comprising: an ion-sensitive garment consisting of; and a lead wire connected to the conductive member; A flow-through type ion sensor body characterized by being integrally connected to each other. (2) A reference electrode provided on the inner circumferential surface of a through-hole drilled in the plastic plate is connected to the plurality of ion-selective electrodes via an electrically insulating member, so that each through-hole connects the flow path of the liquid to be measured. A flow-through type ion sensor body according to claim 1, which is interconnected to form a flow-through ion sensor body.