JPS634659B2 - - Google Patents
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- Publication number
- JPS634659B2 JPS634659B2 JP55162225A JP16222580A JPS634659B2 JP S634659 B2 JPS634659 B2 JP S634659B2 JP 55162225 A JP55162225 A JP 55162225A JP 16222580 A JP16222580 A JP 16222580A JP S634659 B2 JPS634659 B2 JP S634659B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- potential
- polymer membrane
- ion
- sample solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- 229920005597 polymer membrane Polymers 0.000 claims description 25
- 239000012488 sample solution Substances 0.000 claims description 25
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 14
- 239000007788 liquid Substances 0.000 description 13
- 150000002500 ions Chemical class 0.000 description 11
- 239000007864 aqueous solution Substances 0.000 description 10
- 235000011164 potassium chloride Nutrition 0.000 description 7
- 239000001103 potassium chloride Substances 0.000 description 7
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 6
- 239000012528 membrane Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000001681 protective effect Effects 0.000 description 5
- 229940075397 calomel Drugs 0.000 description 4
- ZOMNIUBKTOKEHS-UHFFFAOYSA-L dimercury dichloride Chemical compound Cl[Hg][Hg]Cl ZOMNIUBKTOKEHS-UHFFFAOYSA-L 0.000 description 4
- 239000000523 sample Substances 0.000 description 4
- GTKRFUAGOKINCA-UHFFFAOYSA-M chlorosilver;silver Chemical compound [Ag].[Ag]Cl GTKRFUAGOKINCA-UHFFFAOYSA-M 0.000 description 3
- 239000010408 film Substances 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229920000915 polyvinyl chloride Polymers 0.000 description 3
- 239000004800 polyvinyl chloride Substances 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 3
- 229920000742 Cotton Polymers 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 2
- 229910052753 mercury Inorganic materials 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 238000004313 potentiometry Methods 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- HSYWOEKSALFBEK-UHFFFAOYSA-N 2,2-dioctyldecanedioic acid Chemical compound CCCCCCCCC(CCCCCCCC)(C(O)=O)CCCCCCCC(O)=O HSYWOEKSALFBEK-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 229910021607 Silver chloride Inorganic materials 0.000 description 1
- 108010067973 Valinomycin Proteins 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 239000002671 adjuvant Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- FCFNRCROJUBPLU-UHFFFAOYSA-N compound M126 Natural products CC(C)C1NC(=O)C(C)OC(=O)C(C(C)C)NC(=O)C(C(C)C)OC(=O)C(C(C)C)NC(=O)C(C)OC(=O)C(C(C)C)NC(=O)C(C(C)C)OC(=O)C(C(C)C)NC(=O)C(C)OC(=O)C(C(C)C)NC(=O)C(C(C)C)OC1=O FCFNRCROJUBPLU-UHFFFAOYSA-N 0.000 description 1
- 238000000840 electrochemical analysis Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000002779 inactivation Effects 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229920006254 polymer film Polymers 0.000 description 1
- 229920005990 polystyrene resin Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 229910001414 potassium ion Inorganic materials 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 description 1
- FCFNRCROJUBPLU-DNDCDFAISA-N valinomycin Chemical compound CC(C)[C@@H]1NC(=O)[C@H](C)OC(=O)[C@@H](C(C)C)NC(=O)[C@@H](C(C)C)OC(=O)[C@H](C(C)C)NC(=O)[C@H](C)OC(=O)[C@@H](C(C)C)NC(=O)[C@@H](C(C)C)OC(=O)[C@H](C(C)C)NC(=O)[C@H](C)OC(=O)[C@@H](C(C)C)NC(=O)[C@@H](C(C)C)OC1=O FCFNRCROJUBPLU-DNDCDFAISA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
- G01N27/301—Reference electrodes
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Molecular Biology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Sampling And Sample Adjustment (AREA)
Description
【発明の詳細な説明】
(イ) 産業上の利用分野
本発明は、イオン選択性電極に用いる電極に関
するものである。DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an electrode used as an ion-selective electrode.
(ロ) 従来技術
電気化学分析法のなかでとくにポテンシヨメト
リー（Potentiometry）という名称で分類されて
いる分析方法においては、試料溶液に指示電極
（イオン選択性電極）を挿入し、その電極と溶液
との界面に発生する電位が当該試料溶液の成分と
濃度に関係するという現象に着目して電位計測手
段によつて試料成分濃度を分析している。また、
この手法の実施に当つては、界面電位の直接計測
は不可能であるから、基準電極（Reference
Electrode）を指示電極の対として同じ試料溶液
中に挿入し、基準電極電位は常に一定であるとい
う仮定のもとに、両電極間電位差を測定し、指示
電極電位を推測している。一般に基準電極として
用いられている電極は、甘汞（カロメル）電極、
銀−塩化銀電極などであるが、難溶性の金属塩で
ある甘汞や塩化銀もまたそれが接触する溶液中の
塩素イオン活量によつて電位が変化するので、具
体的にはそれらの電極を塩素イオン濃度が一定で
ある水溶液に浸漬し、その溶液と試料溶液との境
界壁に部分的に液絡部を設け両溶液を接触させ電
位差測定を可能ならしめている。また他の例で
は、基準電極に塩素イオン濃度が一定である水溶
液を小量づつ流し、試料溶液が混入した塩素イオ
ン濃度一定の水溶液が基準電極に接触しないよう
にしている。(b) Prior art Among electrochemical analysis methods, an analysis method classified under the name potentiometry involves inserting an indicator electrode (ion-selective electrode) into a sample solution, and connecting the electrode and the solution. Focusing on the phenomenon that the potential generated at the interface with the sample solution is related to the component and concentration of the sample solution, the sample component concentration is analyzed using a potential measuring means. Also,
When implementing this method, since it is impossible to directly measure the interfacial potential, a reference electrode (Reference
An indicator electrode is inserted into the same sample solution as a pair of indicator electrodes, and on the assumption that the reference electrode potential is always constant, the potential difference between the two electrodes is measured and the indicator electrode potential is estimated. Calomel electrodes are commonly used as reference electrodes.
Silver-silver chloride electrodes, etc., but the potential of poorly soluble metal salts such as chlorine and silver chloride also changes depending on the chloride ion activity in the solution with which they come into contact, so specifically, these electrodes The electrode is immersed in an aqueous solution with a constant chlorine ion concentration, and a liquid junction is partially provided on the boundary wall between the solution and the sample solution to bring the two solutions into contact, making it possible to measure the potential difference. In another example, a small amount of an aqueous solution with a constant chlorine ion concentration is flowed over the reference electrode, so that the aqueous solution with a constant chlorine ion concentration mixed with the sample solution does not come into contact with the reference electrode.
第３図は従来のポテンシヨメトリー用分析機器
の概要を示す。図において１は指示電極（イオン
選択性電極）であり、２は基準電極であつて、ピ
ンホール形液絡部２１を有する容器２２内の内部
液中に挿入されている。３は試料液で指示電極１
及び基準電極２の容器２２が挿入されている。４
は増幅器で指示電極１と基準電極２との間の電位
差を増幅し、その出力がメータ５によつて表示さ
れる。増幅器４は高入力抵抗の増幅器であるか
ら、指示電極１と増幅器４とを接続するリード線
にはシールド６が施してある。 FIG. 3 shows an outline of a conventional analytical instrument for potentiometry. In the figure, 1 is an indicator electrode (ion-selective electrode), and 2 is a reference electrode, which is inserted into the internal liquid in a container 22 having a pinhole type liquid junction 21. 3 is the sample solution and the indicator electrode 1
and the container 22 of the reference electrode 2 is inserted. 4
The amplifier amplifies the potential difference between the indicator electrode 1 and the reference electrode 2, and the output thereof is displayed by the meter 5. Since the amplifier 4 is an amplifier with high input resistance, a shield 6 is applied to the lead wire connecting the indicator electrode 1 and the amplifier 4.
(ハ) 発明が解決しようとする問題点
しかしこれらの手段は、液絡部に発生する電位
の変動（一般にジヤンクシヨンポテンシアルと呼
ばれている）や、内外両液の交流による塩素イオ
ン活量の変化のために、精密なイオン選択性電極
電位の測定を困難にし、ひいては生化学分析のよ
うな精密な化学分析に誤差を与えている。(c) Problems to be solved by the invention However, these methods do not deal with fluctuations in potential generated at the liquid junction (generally referred to as junction potential) and changes in chloride ion activity caused by alternating current between the internal and external liquids. These changes make it difficult to measure precise ion-selective electrode potentials and, in turn, introduce errors in precise chemical analyzes such as biochemical analyses.
(ニ) 問題点を解決するための手段
本発明は、特殊な高分子膜によつて、試料溶液
と基準電極の内部液等との間を隔離することによ
つて、液絡部を除外した構造の電極対を可能にし
て、上述した従来の電極系の欠点が根本的に解消
されることを見出し、本発明に想到したものであ
る。(d) Means for solving the problem The present invention eliminates the liquid junction by isolating the sample solution from the internal liquid of the reference electrode using a special polymer membrane. The inventors have discovered that the drawbacks of the conventional electrode systems described above can be fundamentally eliminated by making it possible to form electrode pairs in this structure, and have conceived the present invention.
具体的には、本発明は、保護管内に基準電極内
部液を収容し、該内部液と試料液とを高分子膜に
より隔離するイオン選択性電極用基準電極におい
て、該高分子膜が無孔性の不活性な分子構造から
なることを特徴とする。 Specifically, the present invention provides a reference electrode for an ion-selective electrode in which a reference electrode internal solution is contained in a protection tube and the internal solution and a sample liquid are separated by a polymer membrane, wherein the polymer membrane is non-porous. It is characterized by consisting of an inert molecular structure.
(ホ) 作用
本発明は、無孔性の不活性高分子膜により対接
部に界面電位の変化を生じないようにするもので
ある。(e) Effect The present invention prevents changes in interfacial potential between contacting parts using a non-porous inert polymer membrane.
(ヘ) 実施例
以下、実施例によつて本発明について具体的に
説明する。第１図は、本発明の一実施例に係る基
準電極部分の縦断面図を示す。２３は保護管で先
端部に高分子膜（通前10〜1000μｍ）２４が気密
に接着してあり、保護管２３と高分子膜２４とに
よつて基準電極内部液の容器が構成されている。
２５はカロメル保持用ガラス管で、下流孔には綿
栓等多孔性栓１２がしてあり、管内には下半にカ
ロメル７を充填し、上半に水銀８を充し、上方よ
り水銀８中に白金線９が挿入され、白金線９の上
端にリード線１０が接続してある。保護管２３内
には一定濃度のkcl（塩化カリ）水溶液１１が充し
てあり、ガラス管２５はこのkcl水溶液中に浸漬
されており、kcl水溶液は綿栓１２を通してカロ
メル７と接触している。このような構造でイオン
不活性高分子膜２４の部分が試料液３中に浸漬さ
れる。イオン不活性高分子膜２４には孔がなく、
すなわち無孔性のイオン不活性高分子膜で保護管
２３内のkcl水溶液１１と試料液３とは完全に隔
離されている。(f) Examples Hereinafter, the present invention will be specifically explained using examples. FIG. 1 shows a longitudinal sectional view of a reference electrode portion according to an embodiment of the present invention. Reference numeral 23 denotes a protective tube, and a polymer membrane (10 to 1000 μm in diameter) 24 is airtightly adhered to the tip thereof, and the protective tube 23 and the polymer membrane 24 constitute a container for the internal liquid of the reference electrode. .
25 is a glass tube for holding calomel, and the downstream hole is equipped with a porous stopper 12 such as a cotton plug. The lower half of the tube is filled with calomel 7, the upper half is filled with mercury 8, and mercury 8 A platinum wire 9 is inserted therein, and a lead wire 10 is connected to the upper end of the platinum wire 9. The protective tube 23 is filled with a KCl (potassium chloride) aqueous solution 11 of a certain concentration, the glass tube 25 is immersed in this KCl aqueous solution, and the KCl aqueous solution is brought into contact with the calomel 7 through a cotton plug 12. . With this structure, a portion of the ion-inactive polymer membrane 24 is immersed in the sample liquid 3. The ion-inactive polymer membrane 24 has no pores;
That is, the KCl aqueous solution 11 and the sample liquid 3 in the protection tube 23 are completely isolated by a non-porous ion-inactive polymer membrane.
このイオン不活性高分子膜２４は少くとも試料
溶液と接触する外面と試料溶液との界面には、試
料溶液中のイオン種やそれらの活量によつて界面
電位が発生しないか、あるいは電位が発生しても
変化しない無孔性の不活性な分子構造を有する高
分子膜であつて（たとえば、表面のイオン解離基
密度の小さい物質はこれに属する）その抵抗値は
10MΩないし5000MΩ程度のものが多い。このよ
うな性質の高分子膜は、たとえば、弗素樹脂、ポ
リスチレン樹脂、ポリ塩化ビニールなどを高純度
のテトラヒドロフランのような溶媒にて溶解して
成形したのち、高純度不活性気体中にて溶媒を蒸
発乾固してえられる。膜のこの製法は任意の形状
の高純度膜を形成するため非常に好適であるが、
本発明はこの製法による膜に限定されるものでは
ない。なお高分子膜に多孔性処理を施したものを
液絡部に用いることも提案されているが、このよ
うな膜は本発明の趣旨と合致しない。すなわち、
本発明の高分子膜は無孔性に限定される。 At least at the interface between the outer surface of the ion-inert polymer membrane 24 that comes into contact with the sample solution and the sample solution, no interfacial potential is generated or no potential is generated depending on the ionic species in the sample solution and their activities. It is a polymer membrane with a non-porous and inert molecular structure that does not change even when generated (for example, substances with a small density of ionic dissociative groups on the surface belong to this category), and its resistance value is
Most of them are around 10MΩ to 5000MΩ. Polymer membranes with such properties can be formed by dissolving fluororesin, polystyrene resin, polyvinyl chloride, etc. in a high-purity solvent such as tetrahydrofuran, and then dissolving the solvent in a high-purity inert gas. Obtained by evaporation to dryness. This method of manufacturing membranes is very suitable for forming high-purity membranes of arbitrary shapes;
The present invention is not limited to membranes produced by this method. Although it has been proposed to use a porous polymer membrane for the liquid junction, such a membrane does not meet the spirit of the present invention. That is,
The polymer membrane of the present invention is limited to non-porous properties.
第１図の構造において保護管２３内の水溶液１
１と不活性高分子膜２４の内面との間の界面電位
は外面と同様の理由によつて一定である。また不
活性高分子膜２４の外面と試料液３との間の界面
電位は、上記手段によつて試料溶液３に含まれる
イオンに対して一定となる。保護管２３内は無孔
性のイオン不活性高分子膜でシヤツトアウトされ
ていることから試料液に対して完全に閉じている
ので試料溶液が動いたり、内外圧力差や温度差が
生じてもそのために試料溶液が保護管内に侵入し
てkcl水溶液１１の濃度を変えて基準電位を変動
させるとか、保護管内のkcl水溶液１１が試料液
中に漏出して試料液を汚染すると云うようなこと
も完全に防止されている。 In the structure shown in FIG. 1, the aqueous solution 1 in the protective tube 23
The interfacial potential between 1 and the inner surface of the inert polymer film 24 is constant for the same reason as the outer surface. Further, the interfacial potential between the outer surface of the inert polymer membrane 24 and the sample solution 3 becomes constant with respect to the ions contained in the sample solution 3 by the above-mentioned means. The inside of the protective tube 23 is shut out with a non-porous, ion-inert polymer membrane, so it is completely closed to the sample solution, so even if the sample solution moves or there is a pressure difference or temperature difference between the inside and outside, it will not be affected. There is no possibility that the sample solution may enter the protection tube and change the concentration of the KCl aqueous solution 11 and fluctuate the reference potential, or that the KCl aqueous solution 11 inside the protection tube leaks into the sample solution and contaminates the sample solution. is prevented.
第２図は、第１図の実施例装置による不活性高
分子膜電極について、実際に得られた電位応答に
関する性能を示すデータである。電位応答の性能
は不活性であることに主眼をおいて、従来形の液
絡部を有する銀−塩化銀基準電極と、本発明にも
とづく無孔性の不活性高分子膜電極とを対にして
両電極間の電位差を測定した。 FIG. 2 shows data showing the performance regarding the potential response actually obtained for the inert polymer membrane electrode produced by the example device shown in FIG. Focusing on inert potential response performance, we paired a conventional silver-silver chloride reference electrode with a liquid junction with a non-porous inert polymer membrane electrode based on the present invention. The potential difference between both electrodes was measured.
第２図において、データ３１はポリ塩化ビニー
ルをテトラハイドロフランで溶解後薄膜成形して
固化した無孔性の膜に関するもので、内部極にも
銀塩化銀電極を使用している。データ３２は弗素
樹脂膜に関するものである。いづれも、試料溶液
中のk+濃度に無関係に一定の電位を与えること
がわかる。図はk+に対する一例を示したが、
Na+、Cl-、HCo3 -など通常の工業的あるいは生
化学的用途の試料溶液中に存在する一般的な物質
に対しても不活性であつた。これに対し、ポリ塩
化ビニールに、K+活性物質であるバリノマイシ
ンと適当な補助剤であるジオクチルセバシン酸と
の混合物質をテトラハイドロフランで溶解し薄膜
成形して固化した膜を同様の手法で測定した電位
応答はデータ３３のようであつて、この膜を具備
した電極は明らかにK+に対するイオン選択性電
極となる。また不適当な溶媒や微量の不純物ある
いは不適切な補助剤の混入は、本発明の要点であ
る不活性化を防害する。 In FIG. 2, data 31 relates to a non-porous membrane made by dissolving polyvinyl chloride in tetrahydrofuran, forming a thin film, and solidifying it, and a silver-silver chloride electrode is also used for the internal electrode. Data 32 relates to the fluororesin film. It can be seen that in both cases, a constant potential is given regardless of the k + concentration in the sample solution. The figure shows an example for k + ,
It was also inactive against common substances such as Na + , Cl - , and HCo 3 - that are present in sample solutions for common industrial and biochemical applications. In contrast, a film obtained by dissolving a mixture of valinomycin, a K + active substance, and dioctyl sebacic acid, an appropriate adjuvant, in polyvinyl chloride with tetrahydrofuran, forming a thin film, and solidifying it was measured using the same method. The potential response is as shown in data 33, and the electrode equipped with this membrane clearly becomes an ion-selective electrode for K + . Furthermore, the incorporation of unsuitable solvents, trace amounts of impurities, or unsuitable auxiliaries prevents inactivation, which is the key point of the present invention.
第２図のデータ３０は不活性膜としてガラスを
用いた場合の電極特性を示しており、活性電極３
３に比しかなり不活性ではあるが、本発明により
不活性高分子膜を用いた電極の場合データ３１，
３２は目的のイオン濃度の変化に対してほとんど
変化がなく、基準電極としてきわめて安定である
ことを示している。 Data 30 in FIG. 2 shows the electrode characteristics when glass is used as the inactive film, and the active electrode 3
Although it is considerably inert compared to data 31, in the case of an electrode using an inert polymer membrane according to the present invention, data 31,
No. 32 shows almost no change with respect to changes in the target ion concentration, indicating that it is extremely stable as a reference electrode.
次に、上記不活性高分子膜電極を実用するため
の測定システムを説明する。 Next, a measurement system for putting the inert polymer membrane electrode into practical use will be explained.
通常この高分子膜は比較的高い固有抵抗を有す
るので、一般の電圧測定法ではノイズや不安定性
のために精密な電極間電位差を測定することがで
きない。本発明はこのような困難を排除するため
に微小な第３電極を試料溶液内に挿入し、しかも
試料溶液の種類に応じて変動する第３電極の電極
電位を差動電気計測によつて自動的に補正する方
法を採用する。 Since this polymer membrane usually has a relatively high resistivity, common voltage measurement methods cannot accurately measure the potential difference between the electrodes due to noise and instability. In order to eliminate such difficulties, the present invention inserts a minute third electrode into the sample solution, and automatically measures the electrode potential of the third electrode, which varies depending on the type of sample solution, by differential electrical measurement. Adopt a method to correct the situation.
第４図は、この三電極示差測定システムの概要
を示す。図においてイオン選択的活性電極７１は
指示電極として作動し、任意の第３電極７３（た
とえば微小白金電極）との電位差が第１差動増幅
器７４によつて増幅される。一方、上記のイオン
不活性高分子膜電極７２と第３電極７３との電位
差が第２差動増幅器７５によつて増幅される。い
ま指示電極７１がK+イオン選択的活性電極であ
る場合、その電極電位E1は
E1＝E0＋RT／Ｆ2.303log aK + ……(1)
である。式中aK +は試料溶液中のK+の活量、E0は
標準酸化還元電位系によつて決まる定数、Ｆ、Ｒ
およびＴはそれぞれフアラデ−定数、ガス定数お
よび絶対温度である。イオン不活性高分子膜電極
７２の電位E2は既述のように や他の共存イオ
ンに無関係に一定であるから
E2＝E0′ ……(2)
となる。第３電極７３の白金電極はそれ自身内部
抵抗は小さいけれども、その電位E3は試料溶液
中に存在するイオンによつて電位が変化し、一般
に
E3＝E0″＋
〓i
RT／niＦ2.303log｛ai FIG. 4 shows an overview of this three-electrode differential measurement system. In the figure, the ion-selective active electrode 71 operates as an indicator electrode, and the potential difference with an arbitrary third electrode 73 (for example, a minute platinum electrode) is amplified by a first differential amplifier 74. On the other hand, the potential difference between the ion-inactive polymer membrane electrode 72 and the third electrode 73 is amplified by the second differential amplifier 75. When the indicator electrode 71 is a K + ion selective active electrode, its electrode potential E 1 is E 1 =E 0 +RT/F2.303log a K + (1). In the formula, a K + is the activity of K + in the sample solution, E 0 is a constant determined by the standard redox potential system, F, R
and T are Faraday's constant, gas constant, and absolute temperature, respectively. Since the potential E 2 of the ion-inactive polymer membrane electrode 72 is constant regardless of and other coexisting ions, E 2 =E 0 ' (2). Although the platinum electrode of the third electrode 73 itself has a small internal resistance, its potential E 3 changes depending on the ions present in the sample solution, and generally E 3 =E 0 ″+ 〓 i RT/n i F2.303log{a i
Claims (1)
液と試料液とを高分子膜により隔離するイオン選
択性電極用基準電極において、該高分子膜が無孔
性の不活性な分子構造からなることを特徴とする
イオン選択性電極用基準電極。1. In a reference electrode for an ion-selective electrode in which a reference electrode internal solution is contained in a protection tube and the internal solution and sample solution are separated by a polymer membrane, the polymer membrane has a non-porous and inert molecular structure. A reference electrode for an ion-selective electrode characterized by:
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55162225A JPS5786037A (en) | 1980-11-17 | 1980-11-17 | Electrode for electrochemical analysis applied apparatus |
| PCT/JP1981/000334 WO1982001772A1 (en) | 1980-11-17 | 1981-11-16 | Reference electrode |
| EP81903068A EP0068025B1 (en) | 1980-11-17 | 1981-11-16 | Reference electrode |
| DE8181903068T DE3176510D1 (en) | 1980-11-17 | 1981-11-16 | Reference electrode |
| DK317782A DK159861C (en) | 1980-11-17 | 1982-07-15 | REFERENCE ELECTRODE WITH INACTIVE POLYMER MEMBRANE AND PROCEDURE FOR PREPARING IT |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55162225A JPS5786037A (en) | 1980-11-17 | 1980-11-17 | Electrode for electrochemical analysis applied apparatus |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61180678A Division JPS6276448A (en) | 1986-07-30 | 1986-07-30 | Method and instrument for continuous analysis of liquid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5786037A JPS5786037A (en) | 1982-05-28 |
| JPS634659B2 true JPS634659B2 (en) | 1988-01-29 |
Family
ID=15750341
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP55162225A Granted JPS5786037A (en) | 1980-11-17 | 1980-11-17 | Electrode for electrochemical analysis applied apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5786037A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0365127A (en) * | 1989-08-01 | 1991-03-20 | Kobayashi Kankyo Kagaku Kenkyusho:Kk | Sanitary water culture |
| JPH03297331A (en) * | 1990-04-13 | 1991-12-27 | Kyushu Kagaku:Kk | Medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3505196A (en) * | 1966-07-15 | 1970-04-07 | Ibm | Reference electrode |
| JPS5481897A (en) * | 1977-12-12 | 1979-06-29 | Kuraray Co | Fet comparison electrode |
| JPS54128791A (en) * | 1978-03-30 | 1979-10-05 | Shingijutsu Kaihatsu Jigyodan | Ion sensor using semiconductor field effect |
-
1980
- 1980-11-17 JP JP55162225A patent/JPS5786037A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3505196A (en) * | 1966-07-15 | 1970-04-07 | Ibm | Reference electrode |
| JPS5481897A (en) * | 1977-12-12 | 1979-06-29 | Kuraray Co | Fet comparison electrode |
| JPS54128791A (en) * | 1978-03-30 | 1979-10-05 | Shingijutsu Kaihatsu Jigyodan | Ion sensor using semiconductor field effect |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0365127A (en) * | 1989-08-01 | 1991-03-20 | Kobayashi Kankyo Kagaku Kenkyusho:Kk | Sanitary water culture |
| JPH03297331A (en) * | 1990-04-13 | 1991-12-27 | Kyushu Kagaku:Kk | Medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5786037A (en) | 1982-05-28 |
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