JPH0743337A - Anion selective electrode with manganese porphyrin complex as sensitive substance - Google Patents

Abstract

PURPOSE:To measure chlorine ion with an improved selectivity quickly and stably especially under severe conditions of serum for a long time by forming a film material using a sensitive substance of porphyrin complex with manganese as a central metal. CONSTITUTION:Tetraxysphenylporphyrinmanganese complex, nitrophenyloxchileter plasticizer, and polyvinylchloride support material are melted in ratrahydrofuran to create a film material. The film material is applied to the tip surface of an internal electrode 1 where silver chloride is coated on, for example, silver surface to form a sensitive film 3. A part where no film material is applied to is covered with a body 4 and a cap 5 where a lead wire is inserted is placed on the tip of the body 4. When measuring chlorine ion concentration using it, potential is reduced by approximately 60mV when ion concentration becomes ten times larger, thus achieving a high-sensitivity detection. Further, according to the load test of an electrode using control serum, no serum protein is adhered, thus achieving a stable measurement for a long time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anion selective electrode suitable for measuring chloride ion concentration by potentiometry.

[0002]

2. Description of the Related Art Conventionally, as a selective electrode for measuring anions, there are one using a solid film and one using a liquid film. It is known to use silver chloride, silver sulfide or the like for the solid film. As an example of using a liquid film, the use of thiocyanate (α, β, γ, δ-tetraphenylporphyrinate) cobalt (III) is known as CHEMIST.
RYLETTERS, (1989), The Chem
ical Society of Japan, PP. 9
93-996).

[0003]

However, the above-mentioned conventional selective electrode has a drawback that the response speed when the anion concentration changes is extremely slow and the measurement time is long. Moreover, in the conventional anion-selective electrode using a liquid membrane, since quaternary ammonium salts are used as a sensitive substance, proteins are attached to the electrode when applied to serum analysis, resulting in a response speed. And the life of the electrode are shortened. Furthermore, when a quaternary ammonium salt is used as a sensitive substance, the selectivity for chloride ions contained in serum, particularly for chloride ions, is poorer than that for nitrate ions and the like. An object of the present invention is to provide an anion-selective electrode which can stably use chloride ions, particularly anions, under stable conditions such as serum for a long period of time and with good selectivity in a short time. is there.

[0004]

The anion-selective electrode of the present invention comprises a porphyrin complex having a porphyrin ring such as tetraphenylporphyrin, tetraethylporphyrin, water-insoluble protoporphyrin derivatives as a basic skeleton and manganese as a central metal. This is a structure in which a film material obtained by forming a sensitive material and a plasticizer on a support is made to face the noble metal electrode.

[0005]

[Operation] In an aqueous solution containing anions to be measured,
When the selective electrode with the above-mentioned structure is immersed, the ligand of the central metal of the porphyrin complex changes and the anion (chlorine ion)
Can be measured selectively in a short time and stably over a long period of time.

[0006]

EXAMPLES Examples of the present invention will be described below.

<Example 1> First, a porphyrin complex (tetrakis (p-chloro) phenylporphyrin manganese complex;
A method for synthesizing n (p-Cl) TPPCl) will be described.

(P-Chloro) benzaldehyde (0.4
~ 0.8 mol) to refluxing propionic acid (100
0 ml) and pyrrole (0.4-0.8 mol)
Was slowly added to the boiling solution. The solution turns black,
Reflux for 30 minutes to 1 hour. After refluxing, the mixture was left overnight at room temperature, and purple crystals were collected by filtration.

Then, the product was purified by column chromatography on activated alumina using dichloromethane as an eluent, recrystallized from dichloromethane-n-hexane and dried to obtain H ₂ (pCl) TPP.

Further, the H ₂ (p-Cl) TPP was dissolved in acetic acid, manganese acetate was added and the mixture was refluxed to obtain Mn (p
-Cl) TPP was synthesized. The reaction compares two Soret band peaks (420 and 470 nm) and
Was repeated until the peak of disappeared. Dichloromethane was added to this solution, which was washed 2-3 times with water and finally 1
A tetrakis (p-chloro) phenylporphyrin manganese complex Mn (p-Cl) TPPCl in which a chlorine group was coordinated was obtained by contacting with a mol-KCl aqueous solution. Then, it was recrystallized from dichloromethane-n-hexane to obtain the desired product.

Next, a selective electrode using the above-mentioned tetrakis (p-chloro) phenylporphyrin manganese complex as a sensitive substance will be described.

Tetrakis (p-chloro) phenylporphyrin manganese complex 0.2-4 wt%, nitrophenyl octyl ether (NPOE) 50-70 as a plasticizer
wt%, polyvinyl chloride (PVC) 26 as a support material
49.8 wt% was well dissolved in tetrahydrofuran (THF) to prepare a membrane material. Then, the noble metal electrode was immersed in the film agent 10 to 15 times, and the film agent was applied to the surface of the noble metal electrode to manufacture a selective electrode.

FIG. 2 shows a cross-sectional explanatory view of the selective electrode thus manufactured. As shown in the figure, platinum, gold, silver,
Silver chloride or an alloy selected from the group consisting of platinum, gold and silver,
Alternatively, the sensitive film 3 is formed by coating the above-mentioned film material on the tip surface of the internal electrode 1 made of any one of a silver surface coated with silver chloride. In addition, the internal electrode 1
A portion of the surface of (1) not coated with the film material is covered with the body 4. The tip of the body 4 is covered with a cap 5 having a lead wire inserted therethrough. As the material of the body 4, polystyrene resin, polypropylene resin, polyacetal resin, epoxy resin, polyvinyl chloride resin, polyimide resin or the like can be used.

<Example 2> As another aspect of the present invention, a selective electrode having a structure in which the film material is opposed to a noble metal electrode through an internal liquid will be described below with reference to FIG. . In the present embodiment shown in the cross-sectional explanatory view of FIG.
Was poured into a petri dish for the same day as in Example 1 to allow the THF to completely evaporate, and then the sheet-shaped film was punched out into a desired shape, and a hollow structure having a hollow structure 16 described later could be filled. It was adhered to the tip of the body 14 using an adhesive.

The internal electrode 11 is made of silver chloride and has a lead wire 12 soldered to the upper portion thereof, and is firmly fixed to the body 14 by a fixing portion 17 opposite to the sensitive film 13. There is.

The internal liquid 16 is an aqueous solution of inorganic salts, and K
Cl, NaCl, NH ₄ Cl or the like can be used.

On the tip of the body 14 opposite to the sensitive film 13, a cap 15 having the lead wire is inserted. As the material of the body 14, polystyrene resin, polypropylene resin, polyacetal resin, epoxy resin, polyvinyl chloride resin, polyimide resin or the like can be used.

The results of measuring the chlorine ion concentration using the two types of selective electrodes according to <Examples 1 and 2> are shown in FIG.
Shown in. As can be seen from the figure, when the chloride ion concentration is increased 10 times, the potential is decreased by about 60 mV.
It was confirmed that the selective electrode of this example detects the chloride ion concentration with high sensitivity.

Further, when a load test of the above two kinds of electrodes was carried out using a 10-fold diluted control serum, adhesion of serum proteins was not recognized, and it was confirmed that stable measurement was performed for a long time.

Example 3 In this example, a tetrakis (p-methoxy) phenylporphyrin manganese complex;
Mn of (p-OCH ₃₎ TPPCl is a photosensitive material of membrane material.

First, a method for synthesizing a tetrakis (p-methoxy) phenylporphyrin manganese complex will be described.

First, as in Example 1, H ₂ (p-OCH ₃ ) TPP was obtained using (p-methoxy) benzaldehyde as a raw material instead of (p-chloro) benzaldehyde. Further, as in Example 1, H ₂ (p-OC
H ₃ ) TPP was dissolved in acetic acid and the same operation was carried out to obtain tetrakis (p-methoxy) phenylporphyrin complex: Mn
It was obtained (p-OCH ₃₎ TPPCl.

Next, the above-mentioned tetrakis (p-methoxy)
A selective electrode using a phenylporphyrin complex as a sensitive material is described. Tetrakis (p-methoxy) phenylporphyrin manganese complex 0.2-4 wt%, nitrophenyl octyl ether (NPOE) 50 as a plasticizer
~ 70wt%, polyvinyl chloride (PVC) as support material
26-49.8 wt% of tetrahydrofuran (THF)
Dissolved well into a film material. The plasticizer mentioned above is N
In addition to POE, tributyl sebacate (TBS), tributyl phthalate (TBP), and the like can exhibit similar characteristics. Using this film material, a chloride ion electrode having the structure shown in FIGS. 2 and 3 can be manufactured in the same manner as in Example 1.

[0024]

As described above, the selective electrode of the present invention can quantify a trace amount of anion, particularly chloride ion, with high selectivity. Further, in the case of serum analysis and the like, since the protein does not adhere to the electrode surface, the response speed of measurement is as fast as that of a neutral carrier, and the electrode life is long. Therefore, the present invention provides an anion-selective electrode which is capable of stably using chloride ions among anions, particularly under severe conditions such as serum for a long period of time and with good selectivity in a short time.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a tetrakis (p-chloro) phenylporphyrin manganese complex.

FIG. 2 is an explanatory sectional view showing the structure of a selective electrode according to the present invention.

FIG. 3 is an explanatory sectional view showing the structure of a selective electrode according to another embodiment of the present invention.

FIG. 4 is a graph showing the results of measuring the chlorine ion concentration using the electrode of the present invention.

FIG. 5 is a structural explanatory view of a tetrakis (p-methoxy) phenylporphyrin manganese complex.

[Explanation of symbols]

 1, 11 ... Internal electrode 2,12 ... Lead wire 3,13 ... Membrane material 4,14 ... Body 5,15 ... Cap 16 ... Internal liquid 17 ... Fixing part

Claims (4)

[Claims] 1. A porphyrin complex having tetraphenylporphyrin, tetraethylporphyrin, water-insoluble protoporphyrin derivatives and the like as a basic skeleton, and a porphyrin complex containing manganese as a central metal as a sensitive substance, and the sensitive substance and a plasticizer as a support material. An anion-selective electrode having a structure in which the film material formed in the above is opposed to a noble metal electrode. 2. The anion-selective electrode according to claim 1, wherein the membrane material is opposed to the noble metal electrode via an internal liquid. 3. The noble metal electrode is platinum, gold, silver, silver chloride, or an alloy selected from the group consisting of platinum, gold and silver, or
The anion-selective electrode according to claim 1 or 2, wherein the anion-selective electrode is formed of any one of a silver surface coated with silver chloride. 4. A membrane material containing a porphyrin complex in an amount of 0.2 to 4 w.
The anion-selective electrode according to any one of claims 1 to 3, which contains t% and a plasticizer in an amount of 50 to 70 wt%, respectively.