JPH0915190A - Multi-sensor - Google Patents

Abstract

PURPOSE: To enable the continuous measurement of a measuring item, to reduce the replacing frequency of a multi-sensor and to enhance economical efficiency and handling simplicity by providing a plurality of sensors corresponding to certain measuring items and changing over a plurality of waste fluid passages to use only one sensor in measurement at once. CONSTITUTION: When the concn. of a sample soln. is calculated, the sample soln. supplied from a passage 6 to come into contact with ion selective electrodes (a)-(c) and, therefore, the electrode (c) is gradually deteriorated. Electrodes c', c" having the same ion selectivity as the electrode (c) to objective ions come into contact only with the reference electrode soln. from a passage 7 and does not come into contact with the sample soln. to be prevented from deterioration, When the life of the electrode (c) is exhausted, waste fluid passages 8, 8" are closed and a waste fluid passage 8' is opened to use the electrode c' and, when the life of the electrode c' is exhausted, the passages 8, 8' are closed and the fluid 8" is opened to start the use of the electrode c". By this constitution, the whole of the multi-sensor can be used up to the sum total of the lives of a plurality of the electrodes c, c', c" to the same objective ions and can be extended in life by the arranging number of the electrodes (c).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-sensor in which a plurality of sensors are housed in a single package, and in particular, a sensor such as an ion selective electrode suitable for measuring biochemical components in blood is packaged in a single package. The present invention relates to a multi-sensor housed in plural.

[0002]

2. Description of the Related Art Conventionally, as a multi-sensor in which a plurality of sensors such as ion selective electrodes are contained in one package,
There is a multi-sensor in which an ion-selective electrode for sodium, potassium, and chloride ions and a reference electrode are integrated, which are reported in Metrology Control, 35, 31, (1986).

[0003]

In the conventional multi-sensor described above, if the sensors corresponding to individual measurement items have different lifespans, even if the sensor corresponding to one measurement item reaches the end of its service life and becomes unusable, Even if the above sensor can be used, there is a problem that it is uneconomical and complicated because it is necessary to replace the multi-sensor if it is necessary to measure the measurement item detected by the sensor that has reached the end of its life.

It is an object of the present invention that even if a sensor corresponding to each measurement item contained in a multi-sensor has a different life, and a sensor corresponding to one measurement item reaches the end of its service life, the sensor cannot be used. It is to make it possible to continuously measure the measurement item detected by the sensor, reduce the frequency of replacing the multi-sensor, and improve the economical efficiency and the ease of handling.

[0005]

The object is to provide a plurality of sensors corresponding to at least one measurement item (having a shorter sensor life than others) in the package of the multi-sensor, and to start using the multi-sensor at the beginning. For this measurement item, only one of these multiple sensors is brought into contact with the measurement sample solution for measurement, the other is preserved, and the next sensor is measured one after another at the end of the life of this sensor. The contacting with the sample solution and the measurement are repeated for all the plurality of sensors corresponding to the measurement item.

[0006]

[Function] When there is only one sensor of the measurement item having a shorter sensor life than the sensor of other measurement items in the package of the multi-sensor, when the life of this sensor is reached, this measurement item is measured unless the multi-sensor is replaced. It becomes impossible. However, multiple sensors for measurement items whose sensor life is shorter than those of other measurement items are provided in the multi-sensor package,
By limiting the number of sensors to be used for measurement by contacting with the measurement sample solution and saving the other ones, even if the life of each sensor expires, switch to another saved sensor for use By doing so, this measurement item can be used up to the total life of the individual sensors. Therefore, even if the life of one sensor corresponding to a specific measurement item is short, the number of short-life sensors corresponding to the life of a sensor having a longer life corresponding to another measurement item is reduced to a multi-sensor package. It is possible to continuously measure this measurement item by using it by sequentially switching it as described in the section of the above means, reducing the frequency of replacing the multi-sensor, economical and easy to handle. Can be improved.

[0007]

Embodiments of the present invention will be described below. FIG. 1 is an example of a sectional view of the configuration of a multi-sensor to which the present invention is applied. A flow channel is formed in the flow cell type electrode body 1, and an opening protruding in a curved shape is provided to the flow channel, and one or more sensitive films 2a, 2b, 2c, 2 are provided along the curved surface.
c ', 2c "are adhered. The sensitive film 2 contains a polymer substance and the sensitive film components such as the sensitive substance and the plasticizer are dispersed. The surface of the individual sensitive film opposite to the flow path. An internal electrode 4 is formed on the inner electrode 4 via an internal electrolyte layer 3. As the internal electrolyte layer 3, a polymer gel containing an electrolyte such as sodium chloride is preferably used, and an example of a polymer that is preferably used as this polymer Examples thereof include polyvinyl alcohol, polyethylene glycol, agarose, etc. In addition, a moisturizing material such as polyol may be added to these, and the internal electrode 4 is a curved plate electrode made of silver silver chloride or the like. It is also possible to use a mesh-shaped electrode that is easy to bend and adhere to .. Connect a lead wire etc. to this internal electrode to take out a signal to the outside of the flow cell type electrode body. Since the inner electrolyte layer 3 and the inner electrode 4 corresponding to the individual sensitive membranes 2a, 2b, etc. are formed to be electrically insulated from each other, the ion electrodes a, b, c, c ', c independent of each other are formed. ″ Functions. Further, in this example, the reference electrode 5 was also formed in the same flow cell type electrode body.

In the present invention, as the sensitive films 2a, 2b, 2c, etc., hydrogen ions, sodium ions, potassium ions,
An ion-selective sensitive film that responds to ions such as lithium ion, calcium ion, magnesium ion, and chlorine ion is preferably used, and by combining each with an independent internal electrolyte layer, internal electrode, lead wire, etc.,
Hydrogen ion, sodium ion, potassium ion, lithium ion, calcium ion, magnesium ion,
It functions as ion-selective electrodes a, b, c, etc. that respond to target ions a, b, c, etc., such as chlorine ions. Each of these sensitive films is formed by a conventionally known method. Further, in this embodiment, the reference electrode salt 5 is an ion-selective electrode using a sensitive membrane for chlorine ions or potassium ions, and an aqueous solution having a constant concentration such as potassium chloride is used for the flow path 7 for the reference electrode solution. It was made to function as a reference electrode by circulating it as a reference electrode liquid. Of course, a silver-silver chloride electrode may be used in place of the above-mentioned ion-selective electrode using a sensitive film for chloride ion or potassium ion to form a reference electrode.

As schematically shown in the figure, the flow path provided inside the multi-sensor of this embodiment is basically a measurement sample solution for supplying the measurement sample solution to a plurality of ion-selective electrodes. Flow channel 6, a reference electrode liquid flow channel 7 for supplying the reference electrode liquid to the reference electrode, and a waste liquid flow channel 8 in which a mixed solution of the measurement sample solution and the reference electrode liquid flows. It is roughly divided into three types. However, in the present embodiment, a plurality of waste liquid flow paths are provided like 8, 8 ′, 8 ″, and a plurality of confluence points at which the measurement sample solution and the reference electrode solution meet are also provided correspondingly, which is a conventional point. Fundamentally different from multi-sensor.

Next, the outline of the operation of the embodiment according to the present invention will be described with reference to FIG. At the beginning of use of the multi-sensor, only the waste liquid flow path 8 is used and the remaining 8 ′ and 8 ″ are closed. Selection of such a flow path is performed, for example, by a solenoid valve provided outside the multi-sensor. The measurement sample solution is supplied from the flow path 6 for the measurement sample solution to the ion selective electrodes a, b, c, and the reference electrode liquid is supplied from the flow path 7 for the reference electrode liquid to the reference electrode. 5, and then merges with the measurement sample solution via the ion-selective electrodes c ′ and c ″. Then, a free-flow liquid junction is formed at this confluence point, which is proportional to the logarithm of the activity of the target ions a, b, c in the measurement sample solution at the ion-selective electrodes a, b, c.
An electromotive force is generated with reference to the reference electrode 5. The concentration of the unknown measurement sample solution is obtained by comparing the electromotive forces of the measurement sample solution of unknown concentration and the measurement sample solution of known concentration. After the measurement is completed, the measurement sample solution and the reference electrode solution are discharged to the outside of the multi-sensor via the waste liquid channel 8.

Since the sample solution does not come into contact with the ion selective electrodes c'and c ", only the reference electrode solution comes into contact therewith,
The sensitive membrane is not deteriorated by the proteins, lipids, sugars and other contaminants contained in the sample solution, and the electrode performance is hardly deteriorated, and the performance is preserved. On the other hand, since the ion-selective electrode c comes into contact with the sample solution, it is affected by these substances contained in the sample solution, so that the sensitive membrane is gradually deteriorated and the electrode performance is gradually deteriorated.

In this way, finally the ion-selective electrode c
When the liquid deteriorates and reaches the end of its life, the waste liquid flow path 8 (and the waste liquid flow path 8 ″) is closed next, and only the waste liquid flow path 8 ′ is used instead.
At the same time, stop using the ion-selective electrode c,
Instead, the use of the ion-selective electrode c ′ is started, and the measurement is performed in the same manner as above. Then, only the ion selective electrode for measuring the target ion c is changed from c to c ′,
The measurement can be continued in exactly the same manner, and the measurement can be continued until the life of the ion-selective electrode c'is reached. When the life of the ion-selective electrode c'is reached, the waste liquid flow path 8 '(and the waste liquid flow path 8) is similarly closed and only the waste liquid flow path 8 "is used instead, and at the same time, the ion selective electrode c'is used. The use of ′ is stopped, the use of the ion-selective electrode c ″ is started instead, and the measurement is performed as described above.

As described above, by sequentially supplying the preserved electrodes to the measurement, the entire multi-sensor can be used up to the total life of the individual ion-selective electrodes c, c ', c ". As compared with the case where only one ion-selective electrode is provided for the target ion c as described above, the life can be extended by the number of installed ion electrodes c.

Although the present embodiment has been described by taking as an example a mode in which only a plurality of ion-selective electrodes c for the target ion c having the shortest life are provided, the spirit of the present invention is not limited to this example. It is naturally possible to extend the life of these multi-sensors by installing a plurality of ion-selective electrodes a and b having a longer life in the same manner.

Further, in the present embodiment, a plurality of waste liquid flow paths are provided to save the unused electrodes, but it is of course possible to save the used electrodes by another method. For example, a plurality of measurement sample solution introducing channels are provided, ion selective electrodes are separately provided for the respective measurement sample solution introducing channels, and the measurement sample solution introducing channels are sequentially switched and used. Due to
Similar effects can be obtained.

[0016]

According to the present invention, a plurality of sensors are provided in a package of a multi-sensor in correspondence with at least one measurement item (having a shorter sensor life than others), and the measurement is performed at the beginning of use of the multi-sensor. For items, only one of these sensors is put in contact with the measurement sample solution for measurement, and the other is preserved.Whenever this sensor reaches the end of its life, only the next sensor is added to the measurement sample solution. By repeating contacting and performing measurements for all of the multiple sensors corresponding to this measurement item, even if the sensors corresponding to the individual measurement items contained in the multi-sensor have different lifespans, one measurement item Even if one corresponding sensor reaches the end of its service life and becomes unusable, the measurement items detected by that sensor can be continuously measured, and the frequency of replacing multiple sensors can be reduced. Hesi, can improve the convenience of the economy and handling.

[Brief description of the drawings]

FIG. 1 is a sectional view of a flow cell type multi-sensor according to the present invention.

[Explanation of symbols]

1 ... Flow cell type electrode body, 2a, 2b, 2c, 2
c ', 2c "... Sensitive membrane, 3 ... Internal electrolyte layer, 4 ... Internal electrode, 5 ... Reference electrode, 6 ... Flow path for measurement sample solution, 7 ... Flow path for reference electrode solution, 8, 8', 8 ″ ... Waste liquid flow path.

Claims (5)

[Claims] 1. A multi-sensor in which sensors corresponding to a plurality of measurement items are individually provided in one package, and a plurality of sensors corresponding to a certain measurement item are provided, and only one sensor at a time is provided for this measurement item. It is used for measurement by contacting with the sample solution, the remaining sensor is saved without contacting the sample solution, and it is used by switching to the sensor that was saved at the stage when the sensor used for measurement reached the end of its life. A multi-sensor. 2. The method according to claim 1, wherein a plurality of flow paths provided in the multi-sensor are switched by a valve provided externally so that only one sensor is brought into contact with the sample solution at a time for measurement. Multi-sensor to serve. 3. The multi-sensor according to claim 2, wherein the flow path used by switching is a waste liquid flow path. 4. The multi-sensor according to claim 3, wherein each waste liquid flow path is provided between each flow path connecting a plurality of sensors corresponding to a certain measurement item. 5. The multi-sensor according to claim 2, wherein the flow channel used by switching is a flow channel through which the measurement sample solution flows.