JP2016211927A - Ion Sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the ion sensor that prevents an internal solution (internal gel liquid) inside an ion sensor from being vaporized with a simple structure, and covered by a packing member for preventing an internal electrode from being affected by vaporization.SOLUTION: Inside an ion sensor main body 1, there are provided a flow passage 2 into which a solution of a measurement object flows, an ion-sensitive film 3 provided in the flow passage so as to contact the flowing solution, an internal electrode 4 for outputting a potential generated in the ion-sensitive film 3, and a space 5 for storing an internal solution (internal gel liquid) for electrically conducting the internal electrode 4 and the ion-sensitive film. An automatic analysis device obtains the potential from the internal electrode 4 of the mounted ion sensor and executes an analysis of the measurement object. Thus, the internal electrode 4 is arranged so as to be exposed outside of the ion sensor, and the periphery of the electrode is covered by an internal electrode connector 7.SELECTED DRAWING: Figure 2

Description

The present invention relates to an ion sensor used for electrolyte analysis.

  Electrolyte analyzers are applied to the quantification of specific ion components such as sodium ions, potassium ions, and chlorine ions contained in biological samples such as blood and urine (hereinafter referred to as samples). The specific ion concentration in the biological fluid is closely related to the metabolic reaction of the living body, and measurement of the specific ion concentration enables various diagnoses such as hypertension symptoms, renal diseases, and neurological disorders. One known method for detecting ions in a sample is to measure specific ions in a sample by using an ion sensor having a flow path through which the reagent and the sample pass.

  In order to maintain the stability of such an ion sensor, Patent Document 1 discloses ion exchange in order to prevent water in the internal solution from entering the microscopic pores of the ion exchange membrane and moving to the sample channel side. An ion sensor is disclosed in which a surface that does not come into contact with a sample of a film is coated with a two-component mixed epoxy resin.

Patent Document 2 discloses that an anion selective electrode is made of water, a hydrophilic polymer, an electrolyte, a hydrophobic compound on the surface in contact with the sample of the anion selective electrode for the purpose of providing a stable storage container for the anion selective electrode. An anion-selective electrode storage container in which an anion-selective electrode provided with a moisturizing member containing any one of them and sealed with a member serving as a water vapor supply source is sealed in a space in which a sample is provided. Is disclosed.

JP 2003-207476 A JP 2000-329728 A

  In the method of Patent Document 1, since it is necessary to apply an adhesive to one surface of the ion exchange membrane, the manufacturing process of the ion sensor is complicated.

  Further, in the method of Patent Document 2, since the water vapor supply source is placed in the sealed container, the inside of the storage container can be maintained in a moist environment and the characteristics of the ion sensitive membrane can be maintained. May occur. In particular, since the internal electrode provided in the ion sensor uses metal, there is a possibility that the performance of the ion sensor may be affected if rusting due to condensation occurs.

In view of the above problems, the present invention provides an ion sensor covered with a packing member for preventing volatilization of an internal solution (internal gel solution) in an ion sensor with a simple configuration and not affecting internal electrodes. With the goal.

Means of the present invention for solving the above-mentioned problems are as follows. That is, the bottom case includes: a flow type ion sensor main body; a bottom case that covers an outer periphery of the flow type ion sensor main body and has at least one opening; and a lid that covers the opening of the bottom case. Includes a sensor housing portion having a depth corresponding to the thickness of the flow type ion sensor, and a rib that is formed in a part of the sensor housing portion and that engages with a recess provided around the flow path of the flow type ion sensor. It is characterized by having.

  According to the present invention, it is possible to prevent moisture evaporation of the internal solution (internal gel solution) from the ion sensor flow path by simple packaging, and to keep the water content in the internal solution constant until it is opened once packed. An ion sensor can be provided.

Furthermore, by preventing the volatilization of moisture from the ion sensor flow path, it is possible to provide an ion sensor that prevents condensation inside the packaging container and prevents adhesion of water droplets and rust to the internal electrode exposed on the surface of the ion sensor. it can.

Ion sensor body diagram Cross section of ion sensor (front) Ion sensor cross section (side view) Ion sensor perspective view Ion sensor packing example front view in the first embodiment Side view (vertical) of ion sensor packing example in the first embodiment Side view of the ion sensor packaging example in the first embodiment (horizontal) Mass change in the ion sensor packing state in the first embodiment Example of ion sensor packaging in the second embodiment Example of ion sensor packaging in the second embodiment

  Hereinafter, the present invention will be described in detail with reference to the drawings. First, an ion sensor packaging embodiment according to the present invention will be described.

  FIG. 1 is a diagram showing a rectangular parallelepiped flow cell ion sensor according to the present invention. 1 is a cross-sectional view of the surface connecting the upper end a-a 'and the lower end a-a' of FIG. 1, and FIG. 3 is a cross-sectional view of the surface connecting bb of FIG.

  Inside the ion sensor body 1, there are a flow path 2 through which the liquid to be measured flows, an ion sensitive film 3 provided in the flow path so as to contact the flowing liquid, an internal electrode 4 that outputs a potential generated in the ion sensitive film 3, A space 5 is provided for containing an internal solution (internal gel solution) that electrically connects the internal electrode 4 and the ion sensitive membrane. In the automatic analyzer, a potential is acquired from the internal electrode 4 of the ion sensor mounted, and the measurement object is analyzed. Therefore, the internal electrode 4 is disposed so as to be exposed to the outside of the ion sensor, and the periphery of the electrode is covered with the internal electrode connector 7.

  The flow path 2 is formed so as to cross the sensor body 1 in a direction perpendicular to the paper surface of FIG. 1 and has a diameter of about 1 mm. An internal electrode 4 made of Ag / AgCl is installed inside the ion sensor main body 1, and the internal electrode 4 is electrically connected to the ion sensitive membrane 3 through the internal solution (internal gel solution) in the space 5. doing. By measuring the potential of the internal electrode, the ion concentration contained in the liquid flowing through the flow path 2 can be measured.

  Concave portions 6 and convex portions 8 are formed around the end of the flow path 2 in FIG. When an ion sensor is installed in the automatic analyzer, a flow path connector (convex flow path connector and concave flow path connector) having a shape mating with the concave portion 6 and the convex portion 8 is provided on the automatic analyzer side. By engaging the convex flow channel connector and the concave portion 6 and engaging the concave flow channel connector and the convex portion 8, it becomes possible to flow the liquid to be measured into the flow channel 2. It is also possible to connect a plurality of ion sensors having the same shape and measure different ion components with each ion sensor. In that case, the convex portion 8 of another adjacent ion sensor is engaged with the concave portion 6 so that the measurement object can be analyzed by a plurality of ion sensors via the flow path.

  The ion sensitive membrane 3 is disposed so as to protrude toward the flow path. One side of the ion sensitive membrane 3 is in contact with the liquid flowing in the flow channel through the hole of the flow channel 2, and the other side of the ion sensitive membrane 3 is an internal solution (internal gel filled in the space 5). Liquid).

  FIG. 4 is a perspective view when the ion sensor is placed with the convex portion 8 facing upward. A flow path 2 having a diameter of 1 mm is formed inside the convex portion 8, and an O-ring 9 for preventing liquid leakage is provided therearound.

  In contrast to such an ion sensor, a conventional package includes a rectangular parallelepiped hard case that covers the entire ion sensor 1 and a rubber cap that covers the opening of the flow path. With the hard case, it is possible to prevent the ion sensor from being damaged due to an impact transmitted from the outside to the ion sensor main body during transportation and storage. Moreover, volatilization of the internal solution (internal gel solution) inside the ion sensor can be prevented by closing the opening of the flow path 2 with a rubber cap.

  Even with the conventional packing method, of course, the effect of securing the current storage life has been achieved. However, for example, when there is a need to reduce the size of the ion sensor in the future, it is necessary to extend the storage life of the ion sensor. In such a case, the current packing method may not sufficiently prevent volatilization of the internal gel solution. In particular, when the water in the internal gel solution volatilizes, the volume of the internal gel solution is reduced, and the electrical conductivity between the internal electrode and the ion sensitive membrane may be lost. With the miniaturization of the ion sensor, it is considered that the decrease in the volume of the internal solution (internal gel solution) has a great influence on the performance.

Furthermore, since the metal which is easy to rust is used for the material of the internal electrode provided in the ion sensor, the performance of the electrode may deteriorate if dew condensation occurs in the packing container. In particular, ion sensors may undergo large temperature changes during storage and transportation. Specifically, after being transported in a temperature environment close to about 40 ° C., it may be stored in an environment cooled to about 7 ° C. (such as a user's refrigerator). When the storage temperature changes with this width, if a large amount of water vapor is contained in the packaging container, dew condensation occurs on the surface of the ion sensor, and rusting occurs due to water droplets adhering to the internal electrode exposed on the ion sensor. This may cause noise and prevent accurate measurement. Moreover, since the dew condensation inside the packing material may damage the landscape of the ion sensor main body, it is necessary to prevent the dew condensation.

  FIG. 5 is a front view of an ion sensor packed in a packing container according to the present invention. The packaging container includes a bottom case 10 and a lid (top sheet) 11. The bottom case 10 has a sensor housing portion 18 having a shape along the outer shape of the ion sensor formed therein, and one surface is greatly opened. The sensor accommodating portion 18 has a shape that can accommodate the ion sensor in the horizontal direction, and the depth thereof is substantially equal to the thickness of the ion sensor. More specifically, when the ion sensor is placed sideways in the sensor housing portion 18 with the side surface provided with the concave portion down, the upper surface of the convex portion is disposed at the height of the housing portion. .

  When packing, the ion sensor is put in the sensor housing portion of the bottom case 10, and the top sheet 11 made of aluminum or the like is placed on the opening, and the outer periphery is sealed with heat to seal the ion sensor. It is also possible to describe the ion sensor information such as the date of manufacture and the storage deadline on the top sheet 11, and the operator who purchased the ion sensor according to the present invention refers to the matters described on the top cover, It is possible to acquire information on ion sensors included in the sensor and to make a use plan. When using an ion sensor, the operator peels off the top sheet 11 and takes out the ion sensor from the bottom case 10 and sets it in the apparatus.

  FIG. 6 is a cross-sectional view (vertical) of the ion sensor packed by the above method, and FIG. 7 is a cross-sectional view (horizontal) of the packed ion sensor. Ribs 12 are formed in the bottom case 10 at positions corresponding to the concave portions 6 of the ion sensor. When the ion sensor is stored in the bottom case 10, the rib 12 is engaged with the concave portion 6 of the ion sensor, thereby closing one end of the flow path 2. The other end of the flow path 2 is blocked by the top sheet 10. Since both the bottom case and the top sheet are formed of a material having a high water vapor barrier property, it is possible to prevent the water in the internal solution from evaporating from the flow path 2 by simply storing the bottom case and the top sheet. It can be stored with good stability. Specific materials for the bottom case and the top cover will be described later.

Further, the bottom case and the top sheet 10 are configured to accommodate the ion sensor without providing a large space along the outer shape of the ion sensor housing. The volume of the internal solution (internal gel solution) in the ion sensor is about ³ to 10 cm ^{3. In} order to prevent volatilization of water in the internal solution (internal gel solution), the space provided around the ion sensor is internal. It is because it is desirable that it is about 110-180% with respect to the volume of a solution (internal gel liquid). Thereby, it becomes possible to suppress the moisture of the internal gel solution from volatilizing as much as possible from a portion other than the flow path 2 (for example, the ion sensor housing portion, the connection portion between the ion sensor housing and the electrode connector, etc.).

  Further, two gaps 13 are provided in the bottom case with the rib 12 interposed therebetween. An operator who uses the ion sensor can easily take out the ion sensor from the bottom case 10 by putting a finger into the gap 13. Note that only one gap portion 13 may be provided, or three or more gap portions 13 may be formed. However, if the gap portion 13 is formed too much, a space in which the internal gel solution volatilizes is allowed by that amount. Therefore, there are preferably two places.

  Further, in the bottom case 10, an electrode housing portion 14 that houses an electrode connector is formed separately from the gap portion 13. Since the electrode connector is formed so as to protrude from the housing of the ion sensor, fixing the electrode connector ensures that the ion sensor does not move in the bottom case during storage or transportation, and stabilizes the ion sensor. Can be stored and transported.

  Further, the bottom case is provided with a collar 15 on its outer periphery. Handling can be prepared by having an operator and this collar 12.

  Furthermore, it is desirable that the bottom case is formed of a permeable material. By being formed of a permeable material, it is possible to observe the state of the internal ion sensor from the side surface or the bottom surface of the bottom case. For example, it is possible to visually confirm information described on the side surface of the ion sensor or to confirm the color of the casing of the ion sensor.

  In the present embodiment, the bottom case 10 and the top cover 11 are formed of a material having high airtightness and have a shape that closes the entrance / exit of the flow path 2, so that the internal solution ( The volatilization of water in the internal gel solution) can be prevented, and the amount of water after filling the internal solution (internal gel solution) can be maintained for a long time. Further, by preventing the volatilization of moisture from the ion sensor flow path, condensation inside the packing container can also be prevented, and water droplets are formed on the terminals of the internal electrode connector 7 made of Ag / AgCl exposed on the top of the ion sensor. It is possible to prevent adhesion and deterioration of performance. Furthermore, by providing a storage portion for holding an electrode portion provided as a shape protruding at one end of the ion sensor, the posture of the ion sensor stored in the packaging container is stabilized during transportation and storage.

The bottom case is made of a material having a water vapor permeability of 12.0 g / m ² · 24 h or less. Specific examples of materials include polyvinyl chloride, polypropylene, polyvinylidene chloride, polyethylene, polyacrylonitrile (crystallization), vinylidene chloride copolymer, polyethylene terephthalate (biaxial stretching), polyethylene terephthalate, polyvinyl chloride (unplasticized), poly Examples thereof include chlorotrifluoroethylene, polytetrafluoroethylene, polyethylene (density 0.92), polyethylene (density 0.955), polypropylene, nylon 11, nylon 12, hydrochloric acid rubber, polyphenyl sulfide, and the like. The bottom case may be formed of a single material of these materials, or a plurality of materials may be combined to form a multilayer.

In this example, a polyvinyl chloride, polypropylene, polyvinylidene chloride, and polyethylene film material was used, and an ion sensor packaging container was prepared by thermoforming with a thickness of 1 mm or less. The water vapor permeability of this material is 0.5 g / m ² · 24 h.

In order to confirm the effect of storage stabilization by the container, ions using a rectangular hard cover formed of polystyrene resin or the like (water vapor permeability is 12.2 g / m ² · 24 h) which is a general packing material Comparison of weight change in packaging state over the elapsed days using an ion sensor (Comparative Example 1) housed in a sensor packaging container and an ion sensor (Comparative Example 2) with both ends of the flow path covered with rubber caps Went. In addition, if the water in the internal solution (internal gel solution) inside the ion sensor volatilizes, the volume of the internal solution (internal gel solution) contracts, so that there is a possibility that the continuity between the internal electrode and the ion sensitive membrane may be lost. . Therefore, maintaining the moisture inside the ion sensor greatly contributes to the maintenance of the lifetime of the ion sensor.

  FIG. 8 is a diagram showing a change in mass (mg) of the ion sensor housed in the packing container and the ion sensors of Comparative Examples 1 and 2 in this example.

  After the product storage life (14 months) elapsed, Comparative Example 1 had a mass loss of 40 mg, and Comparative Example 2 had a mass decrease of 110 mg. These mass changes are almost synonymous with the amount of water evaporation inside the ion sensor, and it can be considered that the amount of water corresponding to the weight change has volatilized from the internal gel solution.

On the other hand, when the packaging container in the present example was used, the mass change during the two weeks after packaging was about 10 mg, but the same mass could be maintained even after two years. Therefore, it can be said that the amount of water evaporation of the internal solution (internal gel solution) inside the ion sensor is suppressed to about 10 mg. By using the packing abandonment in this example, it becomes possible to maintain almost the same amount as the internal solution (internal gel solution) immediately after manufacture even during the conventional storage period, and even if the ion sensor is downsized, the performance Can be maintained. In addition, when stored for about two years, the amount of water evaporation of the ion sensor of Comparative Example 2 increases to 160 mg, but when this example is used, the amount of water evaporation can be suppressed to 10 mg. From the above, it is possible to extend the storage life of the conventional ion sensor by using the packing method according to the present method.

  Another embodiment of the present invention will be described with reference to FIGS.

  9 and 10 are diagrams showing a case where a humidity control unit made of a highly water-absorbent resin is provided in the packing container of the ion sensor.

  The highly water-absorbent resin has the property of repeating water absorption and dehydration according to the surrounding humidity, which absorbs moisture under high humidity conditions and gradually releases moisture under low humidity conditions. Therefore, a constant storage humidity can always be maintained by repeating the water absorption and dehydration of the air inside the packing material due to the change in the storage temperature of the ion sensor. Such superabsorbent resins include polyacrylates, polysulfonates, maleic anhydrides, polyacrylamides, polybutylene oxides, polyaspartate, polyglutamate, polyalginic acid. Examples thereof include a salt system, a starch system, and a cellulose system.

  In FIG. 9, the superabsorbent resin is made into a thin sheet, and the superabsorbent resin humidity control unit 16 is provided in the gap 13. Even when the ion sensor storage location is at a high temperature and the water in the internal gel solution is likely to volatilize, the high water-absorbing resin humidity control unit 16 absorbs the water vapor generated. Condensation water does not adhere. Furthermore, the humidity in the packing container is always controlled within a certain range due to the effect of the highly water-absorbing resin humidity adjusting unit 13, so even if the ion sensor is left in a high temperature environment for a long time. The water in the internal gel solution does not volatilize in large quantities.

  The humidity control part may be formed of a material other than the highly water absorbent resin. Other examples include B-type silica gel. B-type silica gel, like the highly water-absorbing resin, has the property of absorbing moisture in the space under high humidity conditions and gradually releasing moisture under low humidity conditions. FIG. 10 shows a configuration in which a B-type silica gel humidity control unit 17 is provided in the gap 13 of the bottom case. Since it has a humidity control effect similar to that of the sheet-shaped humidity control unit 16, the amount of water evaporation in Example 1 can be further reduced, and adhesion of water droplets to the internal electrode 4 can be prevented.

According to this embodiment, since the humidity control unit maintains the humidity inside the packaging material constant, the humidity inside the packaging container is kept constant until the operator opens the packaging container without being affected by the storage temperature. It is possible to prevent evaporation of water in the internal gel solution.

1: Ion sensor body 2: Channel 3: Ion sensitive membrane 4: Internal electrode 5: Space 6: Concave part 7: Internal electrode connector 8: Convex part 9: O-ring 10: Bottom case 11: Lid part 12: Rib 13 : Gap part 14: Electrode housing part 15: Brim 16: High water absorption resin humidity control part 17: B type silica gel humidity control part

Claims (8)

A container for containing an internal solution, a channel that penetrates from one side surface of the container to the other side surface and circulates the liquid to be measured, an ion exchange membrane that is at least partially exposed on the inner surface of the channel, and a part of A flow having a metal internal electrode that is in contact with the internal solution and the other part is exposed to the outside of the container, and is formed on the side surface of the container, with recesses and protrusions formed around both ends of the channel. Type ion sensor body,
A bottom case that covers the outer periphery of the flow type ion sensor body and has at least one opening;
A cover for covering the opening of the bottom case,
The bottom case is an ion sensor having a sensor housing portion having a depth corresponding to the thickness of the flow type ion sensor, and a rib formed in a part of the sensor housing portion and engaged with the concave portion.
The ion sensor according to claim 1.
The bottom case and the lid portion are ion sensors formed of a material having a water vapor permeability of 12.0 g / m ² · 24 h or less.
The ion sensor according to claim 1.
The bottom case includes at least one gap formed around the housing;
An ion sensor having an electrode housing portion for housing an internal electrode exposed to the outside of the housing.
The ion sensor according to claim 1.
The bottom case is made of polyvinyl chloride, polypropylene, polyvinylidene chloride, polyethylene, polyacrylonitrile (crystallization), vinylidene chloride copolymer, polyethylene terephthalate (biaxial stretching), polyethylene terephthalate, polyvinyl chloride (unplasticized), polychlorotri Fluoroethylene, polytetrafluoroethylene, polyethylene (density 0.92), polyethylene (density 0.955), polypropylene, nylon 11, nylon 12, hydrochloric acid rubber or polyphenyl sulfide, or a combination of these materials , Ion sensor.
The ion sensor according to claim 1.
The said cover part is an ion sensor which is formed with aluminum and has an ion sensor information recording part on the surface.
The ion sensor according to claim 1.
The bottom case is an ion sensor in which a humidity control member for keeping the humidity in the container within a certain range is disposed at least partially.
The ion sensor according to claim 6.
The humidity sensor is an ion sensor made of a highly water-absorbent resin or B-type silica gel.
The ion sensor according to claim 7.
The superabsorbent resin is a polyacrylate, polysulfonate, maleate, polyacrylamide, polyethylene oxide, polyaspartate, polyglutamate, polyalginate, An ion sensor that is either starch-based or cellulose-based.

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