JPH0552804A - Chorine ion selective electrode, sensitive film and field effect transistor - Google Patents

Abstract

PURPOSE:To maintain electrode performance for a long term by using quaternary ammonium salt as an in exchanger of a chlorine ion sensitive film and replacing hydrogen ions of an alkyl radical coupling its nitrogen atoms with a hydroxyl radical. CONSTITUTION:A chlorine ion selective electrode comprises a chlorine ion sensitive film having a high polymer substance as a support film and using quarternary ammonium salt as a chlorine ion sensitive substance, wherein the sensitive substance is exhibited by a formula while at least one of four organic radicals of X, Y, Z, V has a hydroxyl radical. For example an electrode body 1 is filled with internal solution 2 containing sodium chloride of 10mmol/l into which an internal electrode 3 is soaked. An ion sensitive film 4 is fixed inside the body 1 so that it is in contact with a flow path 5, while polyvinyl chloride, a chloride ion sensitive substance and plasticizer are dispersed in the sensitive film 4. This electrode can maintain electrode performance for long term.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chloride ion sensitive film suitable for use in analysis of chloride ions in biological fluids, a chloride ion selective electrode using the same, and a field effect transistor.

[0002]

2. Description of the Related Art Conventionally, various quaternary ammonium salts have been used for the purpose of improving the electrode performance of chloride ion electrodes. For example, JP-A-57-77952 discloses a methyltridodecylammonium salt, and JP-A-59-137851 discloses a dimethyldioctadecyl ammonium salt.
No. 23151 uses a tetraoctadecyl ammonium salt. Thus, all the organic groups bonded to the nitrogen atom of the quaternary ammonium salt are composed of straight chain alkyl groups.

[0003]

A polymer-supporting membrane-type chloride ion-selective electrode is a polymer material containing polyvinyl chloride,
Composed of plasticizer and sensitive material. Japanese Patent Application Sho 64-23151
As described in No. 1, X, Y, Z, and U in Chemical Formula 1, Chemical Formula 2, and Chemical Formula 3 have a carbon number of 10 to 24 as a sensitive substance.
It is considered that when a quaternary aluminium salt having the same normal or isoalkyl group selected from the above is used, there are four bulky alkyl groups around the nitrogen atom, and therefore it is difficult to be attacked by a bulky anion. Therefore,
The chloride ion-selective electrode using the quaternary ammonium salt as a sensitive material has high selectivity for hydrophilic hydrogen phosphate ions, hydrogen carbonate ions, lipophilic perchlorate ions and the like. However, in the chlorine ion electrode using the above-mentioned conventional technique, the quaternary ammonium salt, which is a chlorine ion-sensitive substance, does not have a sufficiently high lipophilicity with respect to the plasticizer, so that the function as an ion exchange site does not always function sufficiently. .. Therefore, there is a problem that the performance may be deteriorated in a relatively short time as compared with a sodium ion electrode or a potassium ion electrode using a neutral carrier as an ion sensitive substance.

An object of the present invention is to provide a chloride ion-selective electrode, a chloride ion-selective field effect transistor and a chloride ion-selective sensitive film whose electrode performance is maintained for a long term in practical use. is there.

[0005]

Means for Solving the Problems The above object is to provide a cation-containing quaternary ammonium salt as an ion exchanger in a chloride ion sensitive membrane in which a chloride ion sensitive substance is contained in a polymer supporting membrane containing a polymer substance and a plasticizer. Is achieved by substituting a hydrogen atom of an alkyl group bonded to the nitrogen atom with a hydroxyl group.

[0006]

The quaternary alumonium salt of the present invention has a hydroxyl group and therefore has a property of sufficiently high compatibility with alcohol which is a plasticizer. Therefore, there is almost no elution of the constituents, the compound efficiently functions as an ion exchange site, and the life is long. Further, the quaternary ammonium salt of the present invention has a high responsiveness of chlorine ion to various interfering ions such as hydrogen carbonate ion existing in biological fluids such as blood and urine. By using it as an ion-sensitive membrane of a selective electrode, blood,
It is possible to quantify chloride ions present in biological fluids such as urine extremely accurately, and its industrial value is great.

[0007]

EXAMPLES The present invention will be described below with reference to examples. Figure 1
The schematic diagram of the chloride ion selective electrode to which the present invention is applied is shown in FIG.

The electrode body 1 was filled with an internal solution 2 containing 10 mmol / l sodium chloride, and the internal solution 2
The silver / silver chloride internal electrode 3 is dipped in. Electrode body 1
An ion-sensitive film 4 is fixed inside the chamber so as to come into contact with the channel 5. The ion sensitive film 4 has polyvinyl chloride, a chloride ion sensitive substance and a plasticizer dispersed therein.

In the first embodiment, chloride ion-selective electrode was obtained by using N, N, N-trioctadecyloctanol ammonium bromide 2 as the quaternary ammonium salt.

[0010]

[Chemical 4]

16% by weight of the above ion-sensitive substance, 11% by weight of ortho-nitrophenyloctyl ether as a plasticizer, 26% by weight of tetradecyl alcohol, 5% by weight of tridecyl alcohol, and 42% of polyvinyl chloride as a polymer substance. The evaporation film 4 was prepared by weighing so as to have a weight%, adding a certain amount of a solvent (tetrahydrofuran) to dissolve it, and then evaporating the solvent. This was bonded to the end of the electrode body 1 of FIG.

From the viewpoint of the responsiveness and selectivity of the chloride ion electrode, it is appropriate that the aliphatic alcohol having a low dielectric constant has a total content of 5 to 40% by weight. The content of the high dielectric constant organic compound in the sensitive film is suitably 0 to 15% by weight. Further, the content of the quaternary ammonium salt dispersed in the sensitive film is appropriately 5 to 20% by weight from the viewpoint of responsiveness, selectivity and reduction of membrane impedance. If the content of the polymer substance supporting the sensitive substance or the plasticizer is 35% by weight or less due to the relation with other compositions, the mechanical strength becomes weak. On the other hand, when the content of the polymer substance is 60% by weight or more, the membrane impedance becomes high and it becomes difficult to obtain a stable electrode. Therefore, the content of the polymer substance is preferably 35 to 60% by weight.

In the second embodiment, a chloride ion-selective electrode was obtained using N, N-dioctadecyl N, N-dioctanol ammonium bromide 3 as the quaternary ammonium salt.

[0014]

[Chemical 5]

16% by weight of the above ion-sensitive substance, 11% by weight of ortho-nitrophenyloctyl ether as a plasticizer, 26% by weight of tetradecyl alcohol, 5% by weight of tridecyl alcohol, and 42% of polyvinyl chloride as a polymer substance. Used by weight%. The method for preparing the sensitive film is the same as in the first embodiment. This example differs from the first example in that the number of hydroxyl groups is increased to two.

In the third embodiment, a chloride ion selective electrode was obtained by using N, N-trioctadecyl octadecanol ammonium bromide 4 as the quaternary ammonium salt.

[0017]

[Chemical 6]

16% by weight of the above ion-sensitive substance, 11% by weight of ortho-nitrophenyloctyl ether as a plasticizer, 26% by weight of tetradecyl alcohol, 5% by weight of tridecyl alcohol, and 42% of polyvinyl chloride as a polymer substance. Used by weight%. The method for preparing the sensitive film is the same as in the first embodiment. This example is different from the first example in that the carbon number of the hydroxyl group is increased.

As a fourth embodiment, a field effect transistor was manufactured using a chlorine ion sensitive film. FIG. 2 shows a sectional configuration diagram thereof.

The n-type source and drain are formed on a silicon substrate, and the SiO ₂ film and the Si ₃ N ₄ insulating film are formed on the n-type source and drain. Then, the sensitive film 4 according to the first embodiment is coated with Si ₃
A chloride ion selective field effect transistor was manufactured by forming it on the N ₄ insulating film. In this embodiment, the same composition as the sensitive film in the first embodiment was used, but an ion sensitive film having another composition according to the present invention may be used.

Next, the effect of the embodiment according to the present invention will be described.

Here, a conventional example will be shown in order to correspond to the present invention. The conventional example is a chloride ion-selective electrode disclosed in JP-A-64-23151, in which the composition ratio of the sensitive film is 16% by weight of the ion sensitive material and ortho-nitrophenyl as a plasticizer as in the first embodiment. Octyl ether is 11% by weight, tetradecyl alcohol is 26% by weight, tridecyl alcohol is 5% by weight, and polyvinyl chloride is 42% as a polymer substance.
Including% by weight. That is, the present invention is different from the present invention in that all four organic groups of the quaternary ammonium salt are alkyl groups.

FIG. 3 shows the chloride ion selective electrodes of the first and third embodiments of the present invention and the above-mentioned conventional example.
The result of having measured the selection coefficient with respect to various anions on the basis of chloride ion is shown. In FIG. 3, (a) and (b) show the results of the first and third embodiments according to the present invention, and (c) shows the results of the conventional example.
As is clear from FIG. 3, the chlorine ion electrode according to the present invention has excellent selectivity as compared with the conventional ion selective electrode.

Next, FIG. 4 shows a change with time in slope sensitivity in the measurement of a 10 mmol sodium chloride aqueous solution using a chloride ion selective electrode according to the first embodiment of the present invention and a chloride ion selective electrode according to the conventional example. The results of examination are shown below.
The chloride ion-selective electrode based on the conventional example has a decreased slope sensitivity in a relatively short time, while the first based on the present invention.
The slope sensitivity of the chloride ion-selective electrode according to the example of Example 1 was kept at a high value for a long period of time as compared with the conventional example. Similar results were obtained with other electrodes.

As described above, the chloride ion-selective electrode according to the present invention is characterized in that the electrode performance lasts for a long period of time as compared with the conventional example, so that a practical chloride ion-selective electrode can be obtained.

[0026]

EFFECTS OF THE INVENTION According to the present invention, since the accuracy as a characteristic of a chloride ion selective electrode is improved, it is possible to use it for a long period of time and obtain a high reliability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structure of a chloride ion selective electrode.

FIG. 2 is a cross-sectional view of a structure of a chloride ion selective field effect transistor.

FIG. 3 is a diagram of selectivity coefficients for various anions.

FIG. 4 is a diagram showing changes over time in slope sensitivity.

[Explanation of symbols]

1 ... Electrode body, 2 ... Internal solution, 3 ... Internal electrode, 4 ... Sensitive film, 5 ... Flow path, 6 ... N-type source, 7 ... N-type drain,
8 ... Silicon substrate, 9 ... SiO ₂ film, 10 ... Si ₃ N ₄ insulating film.

Claims (7)

[Claims] 1. A chlorine ion-sensitive membrane comprising a polymeric material as a supporting membrane and a quaternary ammonium salt as a chlorine ion-sensitive material, an internal solution storage container provided with the sensitive membrane, and an interior arranged in the container. In a chloride ion-selective electrode provided with an electrode, the sensitizer is represented by the following formula: And at least one of the four organic groups of X, Y, Z and U is an alkyl group having a hydroxyl group and having a carbon number of 2 to 20, and the remaining organic groups have a carbon number of A chloride ion-selective electrode, which is an alkyl group having the same carbon number selected from 10 to 24. 2. A chloride ion selective electrode according to claim 1, wherein a linear aliphatic alcohol is dispersed in the sensitive film. 3. The chloride ion selective electrode according to claim 1, wherein a plurality of linear aliphatic alcohols having different carbon numbers are dispersed in the sensitive film. 4. A chloride ion selective electrode according to claim 3, wherein ortho nitrophenyl octyl ether is dispersed in the sensitive film. 5. The chloride ion-selective electrode according to claim 4, wherein the support film contains 5 to 20% by weight of an ion-sensitive substance and 5 to 40% by weight of a plurality of aliphatic alcohols in total.
A chloride ion-selective electrode comprising 0 to 15% by weight of orthonitrophenyl octyl ether and 35 to 60% by weight of a polymer substance. 6. A chloride ion-selective electrode provided with a chloride ion sensitive membrane comprising a polymeric material as a supporting membrane and a quaternary ammonium salt as a chloride ion sensitive material, wherein the sensitive material is represented by the following formula: And at least one of the four organic groups of X, Y, Z and U is an alkyl group having a hydroxyl group and having a carbon number of 2 to 20, and the remaining organic groups have a carbon number of A chloride ion-selective sensitive film, which is an alkyl group having the same carbon number selected from 10 to 24. 7. A field effect transistor comprising a chloride ion sensitive film comprising a polymeric material as a supporting film and a quaternary ammonium salt as a chloride ion sensitive material, wherein the sensitive material is represented by the following formula: And at least one of the four organic groups of X, Y, Z and U is an alkyl group having a hydroxyl group and having a carbon number of 2 to 20, and the remaining organic groups have a carbon number of A field effect transistor, which is an alkyl group having the same carbon number selected from 10 to 24.