JP3321461B2 - Solution for ion-selective electrode with improved storage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a solution for an ion-selective electrode. More specifically, the present invention relates to an ion-selective electrode solution containing an aminoglycoside antibiotic. More specifically, the present invention relates to an ion-selective electrode solution containing gentamicin or a salt thereof.

[0002]

2. Description of the Related Art An ion-selective electrode is an electrode capable of measuring the concentration of a specific ion contained in a solution, and is widely used in a pH meter, a device for measuring ions in a biological sample, and the like.

[0003] An ion-selective electrode typically includes an ion-sensitive membrane capable of reacting to a desired specific ion and an internal electrode. The membrane potential generated when the ion-sensitive membrane is brought into contact with a test solution is measured by the ion concentration. By converting to, the ion concentration can be measured.

For the ion-selective electrode, various solutions such as an electrode preserving solution and a diluent (hereinafter, various solutions used for the ion-selective electrode are collectively referred to as an ion-selective electrode solution) are used. However, when stored for more than one year, there is a problem that microorganisms are generated in these solutions and cannot be used.

In order to prevent the generation of microorganisms in the electrode solution, it is useful to add a substance that suppresses the generation of microorganisms to the ion-selective electrode solution.
It has been difficult to select a substance that does not affect the measurement by the ion-selective electrode and has a sufficient preservative action.

For example, sodium azide, which is frequently used for such a purpose, ionizes into azide ion and sodium ion in an ion-selective electrode solution and affects the measurement of sodium ion. Not suitable for use in selective electrode solutions.

[0007] Formalin (formaldehyde aqueous solution) which is also frequently used to suppress the growth of microorganisms
Reacts with ammonium ions present in the sensitive membrane to form a Schiff base, thereby significantly reducing the durability of the ion-selective electrode.

For this reason, it has been proposed to add an alcohol which does not cause deterioration of the electrode to the solution for the ion-selective electrode.

However, since alcohol alone cannot withstand long-term storage on a yearly basis, it is desired to find a more suitable substance.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a solution for an ion-selective electrode which has improved storage stability and does not affect the measurement by the ion-selective electrode.

[0011]

In order to solve the above-mentioned problems, the present invention provides an ion-selective electrode solution containing an aminoglycoside antibiotic.

Further, the present invention provides a method for preparing gentamicin and / or
Alternatively, there is provided an ion-selective electrode solution containing a salt thereof.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a solution for an ion-selective electrode, which comprises an aminoglycoside antibiotic.

Since the solution for an ion-selective electrode of the present invention contains an aminoglycoside antibiotic, it can be used at room temperature (15 to
At 35 ° C.), microorganisms such as bacteria and fungi do not occur for a long period of one year or more. In addition, since aminoglycoside antibiotics do not contain a group that reacts with the ion-selective electrode to deteriorate the electrode, the aminoselective electrode does not deteriorate the ion-selective electrode.

As used herein, the term "ion-selective electrode"
What is the measurement of the concentration of a specific ion by generating a potential corresponding to the ion concentration (more precisely, the activity) in response to a specific ion such as hydrogen ion, sodium ion, potassium ion, chloride ion, etc. Refers to an electrode that can be used.

[0016] The ion-selective electrode typically comprises a sensitive membrane and an internal electrode.

The sensitive membrane is a membrane having selectivity for specific ions, and includes a glass electrode, an organic ion-sensitive membrane (liquid membrane electrode), an inorganic ion-sensitive membrane (fixed membrane electrode), and the like. It is. More specifically, an electrode composed of an ionophore such as valinomycin can be included, but is not limited thereto.

Generally, an ion-selective electrode, together with a reference electrode (reference electrode), a salt bridge, an electrometer, and the like, constitute an apparatus for measuring a specific ion concentration.

As used herein, the term "aminoglycoside antibiotic" refers to any antibiotic containing glucosamine in its structural formula, its derivative, its stereoisomer, its polymorph, its salt, or its solvate. A thing. Aminoglycoside antibiotics include gentamicin, streptomycin, kanamycin, neomycin, biomycin, tobramycin, spectinomycin, and methylmycin, and their derivatives, stereoisomers, polymorphs, salts, or solvates. Including, but not limited to.

Preferred aminoglycoside antibiotics to be added to the solution of the present invention are gentamicin and its sulfates (hereinafter gentamicin and its derivatives, its stereoisomers, its polymorphs, its salts, or its solvents). The sums are collectively referred to as gentamicins).

Aminoglycoside antibiotics are water-soluble because they have a plurality of amino groups and are well soluble in commonly used ion-selective electrode solutions. In addition, since the aminoglycoside antibiotic does not adversely affect any of the glass electrode, the organic ion-sensitive membrane, and the inorganic ion-sensitive membrane, the ion-selective electrode solution of the present invention can be used for any ion-selective electrode. It can be applied to a non-polar electrode.

In the present invention, the aminoglycoside antibiotic is added to an “ion-selective electrode solution”.
“Ion-selective electrode solution” is any solution used for measurement with an ion-selective electrode, storage, maintenance, or maintenance of an ion-selective electrode, and a standard solution for creating a standard curve for measurement. A diluent for diluting a test solution to be subjected to measurement with an ion-selective electrode, an internal standard solution used as an internal standard when measuring an electrolyte, and for storing an electrode when the ion-selective electrode is not used. Electrode preservation solution,
And a selectivity check solution for checking the selectivity of the ion-selective electrode, and a solution such as a reference electrode solution which is an auxiliary solution of the reference electrode internal solution, but are not limited thereto.

The solution for an ion-selective electrode is usually an aqueous solution, and often contains buffer components such as phosphate and carbonate. When a buffer component is contained, microorganisms such as bacteria are extremely liable to be generated.However, even when the solution for an ion-selective electrode of the present invention contains a buffer component, the microorganism is almost or completely not generated. do not do.

In order to be able to store at room temperature for a long period of time, an aminoglycoside antibiotic must be added to the solution for the ion-selective electrode at a concentration that can substantially exhibit preservative action.
Here, "concentration capable of substantially exhibiting a preservative effect" means one month, preferably six months, more preferably one year, and most preferably two years at room temperature, the measured value The concentration at which the change is maintained at ± 10% or less, preferably ± 5%, more preferably ± 1% or less.

When gentamicins are used as aminoglycoside antibiotics, at least 0.001 w /
When added to a solution to a concentration of v%, a preservative effect can be substantially exhibited. In order to enhance the preservative action, 0.
Gentamicin of 005 w / v% or more may be added. In particular, when 0.001 w / v% or more of gentamicin is added, no microorganisms are generated in the ion-selective electrode solution even when left at room temperature for two years (see Examples). However, if an aminoglycoside antibiotic is added in a large amount, the ion-selective electrode may be deteriorated. Therefore, an excessive amount should not be added. Normally,
Concentrations below 0.01 w / v% will show sufficient preservative action.

Now, the present invention will be described in further detail with reference to Examples.

Example 1 In this example, the durability of the ion-selective electrode in the solution for an ion-selective electrode of the present invention and the ion-selective electrode in a solution for an ion-selective electrode containing formalin were used. And durability.

In this example, in order to demonstrate that the solution for an ion-selective electrode of the present invention does not deteriorate the ion-selective electrode, a solution for an ion-selective electrode containing 0.001 w / v% of gentamicin sulfate was used. Using 40,000
The change with time of the relative potential (potential (%) when the potential of the ion-selective electrode at the time of 0 sample was taken as 100%) when the sample was measured was measured. As the ion-selective electrode, a chloride-selective electrode (quaternary ammonium salt electrode), a sodium electrode (glass electrode), and a potassium electrode (valinomycin electrode) were used. Using two ion-selective electrodes, measurement results were obtained for each (labeled as gentamicin 1 and 2 in the table).

As a control, an ion-selective electrode solution containing 0.25 w / v% formalin was used. Similarly, measurement results were obtained for each of the two ion-selective electrodes (in the table, they are indicated as formalin 1 and 2).

The results are shown in Tables 1 and 2 below and FIGS. 1 and 2.

[0031]

[Table 1]

[0032]

[Table 2]

As is apparent from the table and the figure, a chloride ion-selective electrode, a sodium ion-selective electrode using an ion-selective electrode solution containing gentamicin sulfate,
Also, with the potassium ion selective electrode, the relative potential hardly changed even after measuring 40000 samples.

On the other hand, a chloride ion-selective electrode using an ion-selective electrode solution containing formalin is one of
When 0000 to 15000 samples were measured, the relative potential decreased by tens of percent. Sodium and potassium ion-selective electrodes using an internal standard solution containing formalin
At the stage of measuring 0000 samples, the relative potential decreased by about 10%.

According to the present embodiment, unlike the conventional solution for an ion-selective electrode, the solution for an ion-selective electrode of the present invention does not deteriorate various ion-selective electrodes at all even after performing many measurements. Proven.

[Embodiment 2] In this embodiment, 0.001 w
The durability of a sodium electrode, a potassium electrode, and a chlorine electrode using an internal standard solution containing gentamicin sulfate / v% was examined.

The types of the internal standard solution and the electrodes used in this embodiment are the same as those in the first embodiment.

The results are shown in Table 3.

[0039]

[Table 3]

As is evident from Table 3, for all the electrodes,
The measured values of ion concentration showed almost perfect reproducibility. The results of this example demonstrate that the solution for an ion-selective electrode of the present invention can provide stable measured values without deteriorating various electrodes even after performing many measurements.

Example 3 In this example, the preservability of the solution for an ion-selective electrode of the present invention was examined by a constant temperature storage test corresponding to two years.

The ion-selective electrode solution used was:
(1) Solution A containing gentamicin sulfate or formalin (buffer and electrolyte components at pH 8: internal standard solution and diluent for electrolyte measurement), (2) Solution B containing gentamicin sulfate or formalin (potassium chloride solution: electrolyte) Comparative electrode solution for measurement).

The concentration of gentamicin sulfate was 0.001 w / v% in solution A, and 0.001 w / v% in solution B.
1 w / v%. The concentration of formalin is 0.25 w / v% for both solution A and solution B.

As a control, solution A and solution B containing no preservative were used.

Using these solutions, a storage test corresponding to two years at room temperature was performed.

The results are shown in Table 4 below.

[0047]

[Table 4]

As is evident from Table 4, no microorganisms were generated in the solutions A and B to which formalin and gentamicin sulfate were added for 2 years. On the other hand, in the control, microorganisms are generated in one year in both the solutions A and B, and particularly in the solution A containing the buffer component, a very large number (10,000 to 10,000)
17000 microorganisms / mL).

According to this example, it was clarified that the solution for an ion-selective electrode of the present invention had the same preservative effect as the solution for an ion-selective electrode containing formalin.

[0050]

The solution for an ion-selective electrode of the present invention can be stored at room temperature for a long period of time and does not adversely affect the measurement using the ion-selective electrode.

[Brief description of the drawings]

FIG. 1 is a diagram showing the durability of a chloride ion-selective electrode when the solution for an ion-selective electrode of the present invention is used.

FIG. 2 is a diagram showing the durability of a sodium ion selective electrode and a potassium electrode when the solution for an ion selective electrode of the present invention is used.

────────────────────────────────────────────────── ─── Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 27/333 G01N 27/28 G01N 27/416 JICST file (JOIS)

Claims (2)

(57) [Claims] 1. An ion-selective electrode solution containing an aminoglycoside antibiotic. 2. The solution for an ion-selective electrode according to claim 1, wherein the aminoglycoside antibiotic is gentamicin and / or a salt thereof.