JPH04344454A - Electrode for detecting halogen ion - Google Patents

Abstract

PURPOSE:To prevent silver surfaces from corroding even when an electrode comprising silver layers, silver halide layers and an ion selective layer laminated on a support is preserved for a long period and to enable stable potential measurement by providing the ion selective layer not in contact with the silver layers. CONSTITUTION:A V-shaped insulating groove 12 is formed at the center of the longitudinal direction of a support 11 and silver layers 13, 13 are laid on the upper surface of the support 11 with the insulating groove 12 and its nearby portion uncovered. Silver halide layers 14, 14 are laid on the overall upper surfaces of the silver layers 13, 13 with the outside end portion b of each layer 13 uncovered. An ion selective layer 15 is laid over the overall surfaces of the silver halide layers 14, 14 with the outside end portion c of each silver halide layer 14, 14 uncovered. Therefore, the ion selective layer 15 does not make contact with the silver layers 13, 13, so preventing corrosion of the silver layers 13, 13.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a halogen ion detection electrode for potentiometrically measuring the halogen ion concentration in body fluids such as aqueous fluids, blood, and serum, and particularly for halogen ion detection with improved storage stability. It is related to electrodes.

0002

2. Description of the Related Art Generally, a film-like dry type electrode is used to measure the ion concentration of blood or the like because it requires only a small amount of sample liquid. Such electrodes are disclosed in Japanese Patent Application Laid-Open No. 52-142584 and U.S. Patent No. 4,
As disclosed in No. 053,381, a metal layer, a water-insoluble salt layer of the same kind of metal as the metal of the metal layer, and a water-soluble salt having a common anion with the water-insoluble salt are dissolved on an insulating film. A dried electrolyte layer containing a hydrophilic binder matrix and an ion-selective membrane layer are laminated in this order.

[0003] In order to measure the ion concentration in a sample solution using this electrode, the two electrodes are paired, connected via a bridge, and connected to a potentiometer. This is done by placing each dot on a film and measuring the potential difference.

Dry-type ion-selective electrodes can measure specific ions by changing the type of ion-selective membrane on the top layer.
There are many types, such as those for + measurement and those for Cl- measurement.

As shown in FIGS. 7 and 8, the specific structure of the above-mentioned electrode is, for example, as shown in FIGS. Two silver layers 3, 3 are laminated on both sides with the groove 1 in between, silver chloride layers 4, 4 are laminated on each silver layer 3 leaving both ends, and the entire surface of both silver chloride layers 4, 4 is laminated. , 1 using trialkylammonium halide in a part of the silver layer 3 and the groove 1
Two ion selective layers 5 are stacked.

[0006] To create such an electrode, first, a silver layer is deposited on a polyester support, and then the central silver layer including the polyester support is removed. Then, both sides of the silver layer are protected, the remaining surface is made into a silver chloride layer, and an ion selective membrane containing tetraalkylammonium halide is provided on the silver chloride layer and a part of the silver layer.

[0007]

[Problems to be Solved by the Invention] However, when the conventional electrodes mentioned above are left at room temperature, they begin to corrode within 2 to 3 months, and even when the probe is brought into contact with the silver surface to measure the potential, it is difficult to generate enough electricity. Measurement could not be carried out because the target bond could not be formed.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide an electrode for detecting halogen ions that does not cause corrosion of the silver surface even after long-term storage and is capable of stable potential measurement.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the present inventor has conducted extensive research into the corrosion of the silver layer, and found that the cause of the corrosion is that the ion selective layer is partially connected to the silver layer (part a in the figure). I found out that this is due to contact.

The present invention was first completed based on the above findings, and is based on an electrode in which a silver layer, a silver halide layer, and an ion selective layer are laminated on a support, in which the ion selective layer does not come into contact with the silver layer. The feature is that it is provided in a state.

The halogen ion detection electrode of the present invention is provided with the ion selection layer not in contact with the silver layer. In order to provide the ion selective layer by coating without contacting the silver layer, by controlling the Giesser width, the viscosity of the coating solution and the width of the silver halide layer can be adjusted to provide the ion selective layer.

[0012] The support used in the electrode of the present invention can be made of a material that can support other parts of the electrode and is electrically insulating and electrically inert. There are no particular restrictions on the material, and a wide variety of materials can be selected and used. Preferred are those constructed from film-forming polymers such as cellulose acetate, polyethylene terephthalate, polycarbonate, and polystyrene. The support generally has a thickness of about 0.05 to 0.
．． It is preferable to form it to a thickness of 5 mm.

[0013] The silver layer can be provided by vacuum deposition or the like. The silver halide layer provided on the silver layer can be provided by a conventionally known method. For example, silver halide is deposited under vacuum, the silver layer is deposited in a K2Cr2O7-HX solution or a K3Fe(CN)4]-NaOH-KX solution (X
There are a method of converting silver into a halide by treatment with halogen (eg, chlorine, bromine, iodine), a method of coating a silver halide-aqueous protective colloid emulsion, etc. Among these, the one in which silver is treated with a K2Cr2O7-HX solution has the best stability.

[0014] The thickness of the silver halide layer is generally from 50 nm to
It is 10 μm, preferably 50 nm to 1 μm.

In order to make a part of the silver layer function as an electrical connection terminal, a method of masking by applying a known resist to prevent the vicinity of the side edges from being converted into metal halide;
"Research Disclosure" magazine, #1
9445 (June 1980 issue), a method of masking by applying a resist that can be removed with an alkali, and a method of masking by applying a resist that can be removed with an alkali, a method of masking by applying a resist that can be removed with an alkali, and a method of masking a thin film of nickel or chromium with a thickness of 5 nm to 20 nm, as disclosed in JP-A-56-33537. Method of providing and masking, palladium thickness 1.5 nm to 1
5 nm vapor deposited thin film or 3 nm to 20 nm of indium
A method of masking by providing a vapor-deposited thin film of nm thickness, a method of masking by using a removable film such as a Freon mask (manufactured by Furuto Sangyo), etc. can be applied.

[0016] The ion selective layer can select a specific ion, and preferably is electrically insulating in a dry state before coming into contact with the reference liquid or test liquid. the above"
"Specific ions can be selected" refers not only to cases in which only specific ions are selectively transmitted or sensitive, but also to cases in which specific ions are selected from other non-measurable substances with a sufficient time difference for measurement. Including cases where you get it. Additionally, depending on the material used in the ion-selective layer, potentiometric responses corresponding to changes in ion activity in the liquid may be measured through ion exchange, resulting in the same function as selecting a specific ion. In the present invention, it is said that "a specific ion can be selected".

[0017] In the ion-selective electrode of the present invention, since both the sample liquid and the optional reference liquid are aqueous liquids, the ion-selective layer must be water-insoluble. The ion selective layer may be hydrophilic or hydrophobic as long as it is water insoluble, but is preferably hydrophobic.

The most typical ion selective layer is:
It consists of an ion carrier, an ion carrier solvent, and a hydrophobic organic binder (or a matrix consisting of a hydrophobic organic binder). Ion carriers include valinomycin, cyclic polyether, tetralactone, macrolide actin, enninatine group, monensins, gramicidins, nonactin group, tetraphenyl ether, 3-methoxyphenylphenyl ether, 4-methoxyphenylphenyl ether, dimethyl Phthalate, dibutyl phthalate, dioctyl phthalate, dioctyl phenyl phosphate, bis(2-ethylhexyl) phthalate, octyl diphenyl phosphate, tritolyl phosphate, dibutyl sepacate, and the like.

Hydrophobic organic binders include hydrophobic natural or synthetic polymers capable of forming thin films, such as cellulose esters, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyurethane, polycarbonate, vinyl chloride, vinyl acetate. There are copolymers, etc.

The ion carrier, the ion carrier solvent, the hydrophobic organic binder, and the ion selective layer comprising them are described in Japanese Patent Application Laid-open No. 142584/1984, US Pat. No. 4,053,381, US Pat. No. 4,171, No. 246 and No. 4,214,968, as well as “Re
"Search Disclosure" magazine, Report No.
16113 (September 1977) can be used.

The ion selective layer can be provided by a conventionally known method. For example, an ion carrier dissolved in a solvent is applied to a binder solution and dried. The ion carrier concentration is generally between 0.05g and 10g/m
2. The thickness of the ion selective layer is about 3 μm to about 125 μm,
Preferably it is 5 μm to 50 μm.

Measurement of ion activity using the ion-selective electrode of the present invention is carried out by using two bridges separated by a groove to generate and promote the ion transfer between liquid and liquid required for potentiometric measurement. This is done by placing a bridge between the electrodes, dropping a coating liquid and a reference liquid simultaneously on each electrode (specifically, an ion selective layer or a protective layer), and reading the potential change according to the ion activity with a potentiometer. be exposed.

[0023] Known materials can be used as the material for the bridge, such as bolus paper (filter paper/blotting paper), binder, membrane, filter, cotton material (cotton cloth), thickener and polycarbonate or polyamide. formed of a porous material such as a mixture of Preferred examples of bridges and how to provide them are disclosed in Japanese Patent Application Laid-Open No. 52-1
No. 42584 (U.S. Pat. No. 4,053,381, 4
, 214,968 and 4,171,246),
No. 55-59326, No. 55-71942, No. 55
-20499 (corresponding to U.S. Pat. No. 4,148,936), Japanese Utility Model Application Publication No. 55-64759, etc.

[0024] As the chemical analysis slide in which the electrode of the present invention is incorporated, all conventionally known slides can be used.
For example, JP-A-58-211648, JP-A-62-9
There is a chemical analysis slide described in Publication No. 264.

[0025]

[Operation] In the halogen ion detection electrode of the present invention, the ion selective layer does not come into contact with the silver layer, thereby preventing corrosion of the silver layer.

[0026]

EXAMPLE An example of the electrode for detecting halogen ions according to the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a perspective view of a halogen ion detection electrode according to the present invention, FIG. 2 is a front view of the same, and FIG. 3 is a plan view of the same.

In these figures, reference numeral 11 denotes a support, and a "V"-shaped insulating groove 12 is formed in the center of the support 11 in the longitudinal direction. Silver layers 13, 13 are laminated on the upper surface of the support 11, leaving the insulating groove 12 and its vicinity, and a silver halide layer 14 is laminated on the entire upper surface of the silver layers 13, 13, leaving the outer edge b. , 14 are stacked. An ion selective layer 15 is laminated over the entire surface of the silver halide layers 14, 14, except for the outer ends c of each silver halide layer 14, 14.

In order to manufacture the electrode for detecting halogen ions as described above, as shown in FIG. 4, first, a support 11 on which a silver layer 13 is laminated by vapor deposition is prepared (FIG. 4(a)),
Next, a protective film 16 is applied to both ends, and an insulating groove 12 is bored (FIG. 4(b)). Then, a silver halide layer 14 is formed on the exposed surface of the silver layer 13 by treatment with a predetermined solution (FIG. 4(c)), and then the protective film 16 is removed (FIG. 4(d)). . Finally, the ion selective layer 15 is applied leaving the vicinity of the side edges of the halogenated layer 14 (Fig. 4
(e)). Then, this laminate is cut into a predetermined width to complete the electrode (FIG. 4(d)).

Next, an example of a chemical analysis slide incorporating the above-described electrode for detecting halogen ions will be explained based on FIGS. 5 and 6. FIG. 5 is a sectional view of the chemical analysis slide, and FIG. 6 is an exploded perspective view of the same.

In these figures, reference numeral 21 denotes a support frame plate, and a halogen ion detection electrode 22 is mounted on this support frame plate 21.
is fixed. Then, on the upper surface of this electrode 22,
A water-impermeable member 23, a porous liquid distribution member 24, and a liquid reservoir member 25 are provided, and an upper lid 27 is provided with a bridge 26 at the top.

Example 1 Polyethylene terephthalate (PET) with a thickness of 100 μm
) Silver is deposited to a thickness of approximately 800 nm on the film, and the width is 32 m.
m, cut into lengths of 10 cm along the center line in the length direction with a cutter (NT cutter A-300 type Nippon Transfer Paper K.K)
Without cutting the film, a single scratch-like insulating groove was made approximately in the center of the film surface. Electrical insulation test with a tester showed perfect insulation. Next, a liquid masking agent was applied to both lengthwise ends of this silver-deposited PET film in a width of 5 mm, dried, and then diluted with hydrochloric acid (36%).
5 g of potassium dichromate and 1 liter of water at 35°C for 60 seconds (halogenation treatment) to change the surface and vicinity of the silver layer to silver chloride, then washed with water and dried to form a liquid mask. The agent was removed.

[0033] And, VYNS
0.9g trioctylmethylammonium chloride
1.35g didodecyl phthalate
0.03g
M.E.K.
a solution consisting of 5 g is applied leaving the edges of the silver halide layer;
A chloro ion selective layer with a dry film thickness of 28 μm was formed.

Example 2 A silver vapor-deposited PET film (width 32 mm x
2m long) at a speed of 6m/min in the longitudinal direction of the silver-deposited film, using a cutter knife to remove the silver-deposited PET film.
Insulating grooves were provided in the longitudinal direction of the film to a depth sufficient to provide electrical insulation. The depth of the insulation trench ranged from approximately 1 to 50 μm.

The silver chloride layer and the chloro ion selective layer are the same as in Example 1.

Comparative Example 1 This was the same as Example 1 except that the layer structure was such that the chloro ion selective layer and the silver layer were in contact with each other.

Comparative Example 2 This was the same as Example 2 except that the layer structure was such that the chloro ion selective layer and the silver layer were in contact with each other.

Test I Method: Immediately after electrode preparation, using Catan system as a bridge, VERSATOL (103 meq/l) was used as a standard solution,
Cl- ion concentration is 77 meq/l, 120 meq/l
The solution was measured. Results: There was no difference in the measured data between Examples 1 and 2 and Comparative Examples 1 and 2.

Test II Method: Six months after electrode preparation, measurements were made in the same manner as in Test 1. Results: Comparative Examples 1 and 2 were unmeasurable, but Example 1 and
2 was successfully measured.

[0040]

According to the present invention, the silver surface does not corrode even after long-term storage of one year or more, and the halogen ion concentration can always be measured stably.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an electrode for detecting halogen ions according to the present invention.

FIG. 2 is a front view of an electrode for detecting halogen ions according to the present invention.

FIG. 3 is a plan view of an electrode for detecting halogen ions according to the present invention.

FIG. 4 is a diagram showing the manufacturing process of a halogen ion detection electrode according to the present invention.

FIG. 5 is a cross-sectional view of a chemical analysis slide incorporating an electrode for detecting halogen ions according to the present invention.

FIG. 6 is an exploded perspective view of a chemical analysis slide incorporating an electrode for detecting halogen ions according to the present invention.

FIG. 7 is a perspective view of a conventional halogen ion detection electrode.

FIG. 8 is a front view of a conventional halogen ion detection electrode.

[Explanation of symbols]

11...Support 13...Silver layer 14...Silver halide layer 15...Ion selective layer

Claims (1)

[Claims] 1. An electrode for detecting halide ions, comprising a silver layer, a silver halide layer, and an ion selective layer laminated on a support, the ion selective layer being provided without contacting the silver layer.