JPH1082759A - Composite electrode both for suction and circulation measurements - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive composite electrode which can easily perform both circulation measurement and suction measurement. SOLUTION: A double tube 4 comprising an inner tube 1 forming a flow path of sample liquid and an outer tube 2 branched from the middle of the inner tube 1 for surrounding the inner tube 1 so that a ring-like space 3 is formed between the inner tube 1 and it is integrally formed of glass, a response film 5 is formed on a part of the inner tube 1 surrounded by the outer tube 2, the space 3 between the inner tube 1 and the outer tube 2 is filled with glass electrode internal liquid 6, and an inner electrode 7 is provided at a position corresponding to the response film 5 in the glass electrode internal liquid 6. On the other hand, the double tube 4 is surrounded by an outer cylinder 8 so that a ring-like gap 9 is formed between the double tube 4 and it, the gap 9 is filled with reference electrode internal liquid 10, a liquid junction 11 is provided on a part of the inner tube 1 in contact with the reference electrode internal liquid 10, and a reference electrode inner pole 12 is provided in the reference electrode internal liquid 10 corresponding to the liquid junction 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composite electrode capable of performing suction measurement and flow measurement.

[0002]

2. Description of the Related Art Conventionally, a pH electrode for flow measurement has been known in which a flow path a for a sample liquid is formed in a lateral direction as shown in FIG. In addition, in FIG. 5, b is a pH-responsive membrane, c
Denotes a glass electrode inner electrode, d denotes a glass electrode inner liquid, e denotes a liquid junction, f denotes a reference electrode internal liquid, g denotes a reference electrode inner electrode, and h denotes an output cable.

[0003]

In the above-mentioned conventional pH electrode for flow measurement, the ratio of glass processing in the manufacturing process is large, skill is required, and the cost is high.
Particularly, in the structure of the double tube as described above, it is difficult for a skilled person to process a thick response glass tube having a large outer diameter, and only a small-diameter capillary can be obtained. The length could not be too long, and the degree of freedom in designing the glass part was extremely low.

When only a small amount of sample solution is obtained, it is desirable to easily perform suction measurement using a dropper or bellows. However, as described above, the sample solution flow path a is formed in the lateral direction. Therefore, it is necessary to separately attach suction means such as a curved tube to the suction side,
The operation was troublesome. In addition, if the flow path a has a small diameter, it may be difficult to mount a suction means such as a dropper on the suction side.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a low-cost composite electrode that can easily perform both flow measurement and suction measurement.

[0006]

According to the present invention, means for solving the above-mentioned problems are constituted as follows. In the invention according to claim 1, an inner tube forming a flow path of the sample liquid;
A double tube comprising an outer tube surrounding the inner tube integrally formed of glass so as to branch off from the middle of the inner tube so as to form an annular space between the inner tube and the outer tube; Forming a responsive film in a part of the inner tube surrounded by, and filling a space between the inner tube and the outer tube with a glass electrode internal liquid, and the responsive film in the glass electrode internal liquid. While the internal electrode is provided at a corresponding position, the double tube is surrounded by an outer cylinder so as to form an annular gap between the double tube and the double tube, and the gap is filled with a reference electrode internal liquid. A liquid junction is provided in a part of the inner tube in contact with the electrode internal liquid, and a comparison electrode inner electrode is provided in the comparison electrode internal liquid corresponding to the liquid junction.

For the outer cylinder, for example, a synthetic resin molded pipe having an appropriate shape-retaining property is used, and rubber packing or the like is used for joining the outer cylinder to a double pipe integrally formed of glass. With a simple configuration, the flow path of the sample liquid can be formed in the vertical direction along the outer cylinder, and suction measurement with a dropper, bellows, or the like becomes extremely easy.

[0008] The processing of the glass double tube itself is relatively easy, and in order to integrate a pipe-shaped responsive film into a part of the inner tube, the joining operation is performed by fusion welding using a burner. Can be carried out effectively, and skill is not required for glass processing. Further, the diameter and length of the inner tube can be set to appropriate values, and the degree of freedom in designing the glass portion is significantly improved.

In the invention according to claim 2, the inner tube according to the invention according to claim 1 is directly introduced into a sample container,
It is characterized by aspirating a sample.

According to a third aspect of the present invention, a sample is aspirated by directly attaching a suction means to the inner tube in the first aspect of the invention.

According to a fourth aspect of the present invention, the outer cylinder and the inner cylinder in the first aspect of the invention are integrated by a seal member.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a composite electrode according to a first embodiment of the present invention; FIG. 1 is a configuration diagram of a combined electrode for suction and flow, and FIG. 2 is a partially enlarged view of the composite electrode. In these figures, reference numeral 1 denotes an inner tube forming a flow path of a sample liquid, An outer tube surrounding the inner tube 1 so as to form an annular space 3 between the inner tube 1 and the inner tube 1. A double tube 4 including the inner tube 1 and the outer tube 2 is integrally formed of glass. Is formed.

Reference numeral 5 denotes a pipe-shaped pH responsive film integrally connected to a part of the inner tube 1 by fusion welding with a burner, etc. The space 3 is filled with a glass electrode internal liquid 6, An internal electrode 7 is provided in the glass electrode internal liquid 6 so as to correspond to the pH responsive film 5.

Reference numeral 8 denotes an outer cylinder made of a synthetic resin molded article having shape-retaining properties, which surrounds the outer tube 2 so as to form an annular gap 9 with the double pipe 4, and the gap 9 has A liquid junction portion 11 is provided in a part of the inner tube 1 which is filled with the reference electrode internal solution 10 and is in contact with the reference electrode internal solution 10. A reference electrode inner pole 12 is provided therein.

13 is a packing (seal member) interposed between the inner tube 1 and the outer tube 8, 14 is a packing interposed between the outer tube 2 and the outer tube 8, and 15 is an inner tube 1 And a lead wire 121 connected to the reference electrode inner pole 12.
The packing 15 has lead wires 7 connected to the internal electrodes 7.
1 are respectively inserted and held. Reference numeral 16 denotes a rubber stopper which is fitted in a stopper hole for replenishing the internal liquid, which is opened in the outer cylinder 8, and 17 denotes an output cable.

As described above, by forming the flow path of the sample liquid and forming the inner tube 1 in which the pH responsive membrane 5 is integrated in the vertical direction along the outer tube 8, as shown in FIG. Then, a suction means such as a dropper 18 or a bellows 19 is inserted into the upper part of the inner tube 1, and the lower part is directly introduced into the sample container.
Suction measurements can be performed very easily. In addition, more preferably, by attaching a suction adapter 20 to the tip of the inner tube 1 in accordance with the size or shape of the sample container or the standard solution container, the tip is protected and the suction measurement is performed more efficiently. Can be performed.

On the other hand, when the flow measurement is performed, FIG.
As shown in (2), tubes 21 and 22 for flowing sample liquid may be connected to both ends of the inner tube 1, respectively, and the sample (standard solution) may be flowed through a pump. In this flow measurement, the outer cylinder 8 may be held vertically by an electrode stand (not shown), or may be horizontally installed. Alternatively, the liquid may be inverted, and in this case, it is possible not to be affected by the liquid inside the comparative electrode leaking into the sample liquid from the liquid junction 11. It should be noted that the air bubbles can easily escape upward in both cases of vertical placement and inversion, making it less likely to be affected by the bubbles.

A pipe-like pH integrated with the inner tube 1
Since the entire periphery of the response film 5 is covered with the liquid inside the comparison electrode, a high electrostatic shielding effect is obtained, and the electrostatic interference effect can be effectively prevented. In addition, the pH-responsive membrane 5
Needless to say, since the liquid contact area can be set large, high detection sensitivity and quick responsiveness can be obtained.

The glass double tube 4 including the pH responsive film 5 can be obtained relatively easily without requiring a skilled person, and in particular, the diameter and length of the inner tube 1 It is a major feature that the degree of freedom of design can be dramatically improved because it can be set to a large value, and that it can flexibly cope with a wide range of required specifications, such as large ones for plants and the like. The present invention is not limited to the composite electrode for measuring pH, but can be applied to a composite electrode for measuring ions other than pH (for example, Na ⁺ ) by using another ion responsive membrane instead of the pH responsive membrane 5. Is also applicable, and the same operation and effect can be obtained.

[0020]

As described above, according to the suction / distribution combined electrode of the present invention, the response film is formed integrally with a part of the inner tube of the double glass tube, and the response films are compared. Since the electrodes are covered with the liquid inside the electrodes, a high electrostatic shielding effect can be obtained. In addition, since the glass double tube is housed in a synthetic resin-molded outer cylinder via a packing or the like, the number of glass processing portions is reduced, the configuration is simplified, the production is facilitated, and the cost is reduced. Can be planned. Further, the diameter and length of the inner tube forming the flow path of the sample liquid can be set to be large, so that it is possible to flexibly cope with a wide range of required specifications.

By arranging the flow path of the sample liquid vertically, the flow path inlet can be directly inserted into the sample container or the standard liquid container without connecting a pipe such as a tube. It can be easily performed, and in flow measurement, by connecting tubes to both ends of the flow path, measurement can be performed in any of vertical, horizontal, and inverted postures.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing one embodiment of a combined suction / distribution electrode of the present invention.

FIG. 2 is an enlarged sectional view of the main part.

FIG. 3 is an explanatory diagram at the time of the suction measurement.

FIG. 4 is an explanatory diagram during the flow measurement.

FIG. 5 is a cross-sectional view showing an example of a conventional flow-type pH electrode.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inner tube, 2 ... Outer tube, 3 ... Space, 4 ... Double tube, 5 ... Response membrane, 6 ... Glass electrode internal liquid, 7 ... Internal electrode, 8 ... Outer cylinder,
9: gap, 10: reference electrode internal liquid, 11: liquid junction, 12
... Internal electrode of reference electrode.

Continued on the front page (72) Inventor Toshiyuki Baba 2 Higashi-cho, Kichijoin-gu, Minami-ku, Kyoto, Kyoto Inside Horiba, Ltd.

Claims (4)

[Claims] 1. An inner tube forming a flow path of a sample liquid, and an outer tube branching from the middle of the inner tube and surrounding the inner tube so as to form an annular space between the inner tube and the inner tube. A double tube made of glass is formed integrally with glass, a responsive membrane is formed on a part of the inner tube surrounded by the outer tube, and a glass electrode is provided in a space between the inner tube and the outer tube. While filling the internal liquid, the internal electrode is provided at a position corresponding to the response film in the glass electrode internal liquid, and the double tube is formed into an outer cylinder so as to form an annular gap between the internal tube and the double tube. And the gap is filled with the reference electrode internal liquid, a liquid junction is provided in a part of the inner tube in contact with the comparison electrode internal liquid, and the comparison electrode internal liquid is made to correspond to the liquid junction. A composite electrode for both suction and distribution, characterized in that a reference electrode inner electrode is provided in the inside. 2. The aspiration / suction device according to claim 1, wherein the inner tube is directly introduced into the sample container to suck the sample.
Combined distribution electrode. 3. The combined suction / distribution electrode according to claim 1, wherein a sample is sucked by directly attaching suction means to the inner tube. 4. The combined suction / distribution electrode according to claim 1, wherein the outer cylinder and the inner cylinder are integrated by a seal member.