JP7421774B2 - Component measurement method and strip for component measurement - Google Patents

Description

The present invention relates to a component measuring method and a component measuring strip for measuring components in a liquid sample.

Generally, in a plant factory, hydroponic cultivation is performed using a nutrient solution in which nutrients necessary for plants (crops such as vegetables) are dissolved in water. Examples of hydroponic cultivation include circulating hydroponic cultivation in which nutrient solution is circulated.
In the case of such circulating hydroponic cultivation, the composition of the nutrient solution held in the cultivation tank changes as the nutrient solution circulates. Since the growth of plants is affected by the components of the nutrient solution, the nutrient solution is adjusted as necessary based on the results of the nutrient solution analysis.
Patent Document 1 discloses a technique for detecting the physical quantity of a nutrient solution in hydroponic cultivation using a circulating system, and adjusting cultivation environmental conditions such as the pH and nutrient concentration of the nutrient solution based on the detection results. There is.

Japanese Patent Application Publication No. 2015-53882

Examples of liquid analysis devices include high performance liquid chromatography (HPLC) devices that can analyze multiple components contained in a liquid sample. However, since the HPLC apparatus itself is large-scale, it is necessary to once collect a liquid sample to be measured and send it to an analysis site equipped with analytical equipment. Moreover, HPLC measurement also takes time.

Therefore, if you want to perform component analysis in a relatively short period of time, especially near a site where liquid samples are handled, for example, you can use the color reaction (chemical reaction that causes color development or color change) of the components in the liquid sample to analyze the components of the liquid sample. Analyzing the components in the sample is performed. As the analysis method, a colorimetric method, a spectrophotometric method, etc. are adopted. Such measurements are particularly effective for early-stage screening tests of liquid samples.

However, in a liquid sample component measurement method using a color reaction, the color reaction does not occur just by mixing one type of reagent with the liquid sample, and in order to cause the color reaction to occur, it is necessary to add the first reagent. It may be necessary to mix a second reagent that is different from the first reagent.
In this case, first, a test paper holding a first reagent is immersed in a liquid sample to generate a chemical reaction between the liquid sample and the first reagent. Next, the test paper on which the chemical reaction product has been generated is immersed in or added to a second reagent to cause a chemical reaction between the chemical reaction product and the second reagent, and a predetermined amount is determined according to the component concentration of the liquid sample. Produces a reaction product that exhibits color. By performing optical measurements (such as spectroscopic measurements) on the test paper on which this reaction product has been produced, the concentration of the components in the liquid sample is measured.

However, in the above measurement method, it is necessary to immerse or add the test paper twice to the liquid sample and the second reagent, and the measurement takes time. Furthermore, since a plurality of liquids (liquid sample, second reagent) are handled, it takes time and effort to handle each liquid (eg, prevent leakage to the outside) and dispose of each liquid. Furthermore, the number of containers for holding each liquid is equal to the number of liquids, and management becomes complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a component measuring method and a component measuring strip that can easily measure components in a liquid sample in a short time.

In order to solve the above problems, one aspect of the component measuring method according to the present invention is such that a first reagent pad holding a first reagent and a second reagent pad holding a second reagent are provided on a base sheet. a first step of preparing a sample strip; a second step of bringing a liquid sample into contact with the strip; and a second step of contacting the strip with a liquid sample; The method includes a third step of mixing two reagents to cause a color reaction, and a fourth step of comparing the colors of the color region where the color reaction has occurred.

In this way, the first reagent pad holding the first reagent and the second reagent pad holding the second reagent can be properly coated by simply bringing the strip provided on one base sheet into contact with the liquid sample once. can cause a color reaction. Therefore, even if it is necessary to generate a color reaction using the first reagent and the second reagent, the measurement can be performed in a short time. Furthermore, since the first reagent and the second reagent are each held in a reagent pad, there is no need for handling (for example, preventing leakage to the outside) or disposal of both reagents, and there is no need for a container for holding both reagents. Therefore, reagent management becomes easy.

Further, in the above component measuring method, the third step includes a step of causing a first reaction between the liquid sample and the first reagent, and a step of causing a reaction between the reactant produced by the first reaction and the second reagent. and a step of generating a second reaction, wherein the result of the second reaction may be the result of the coloring reaction.
In this case, an appropriate color reaction result can be obtained depending on the component concentration in the liquid sample.

Furthermore, in the above component measuring method, in the first step, the strip in which the first reagent pad and the second reagent pad are provided adjacently on the base sheet may be prepared. . In this case, the liquid sample, the first reagent, and the second reagent can be easily mixed in the second step.
Further, in the above component measuring method, in the first step, the strip may be prepared in which the first reagent pad and the second reagent pad are provided in an overlapping manner on the base sheet. In this case, the liquid sample, the first reagent, and the second reagent can be mixed more appropriately in the second step.

Furthermore, in the above component measuring method, the second reagent may be either an acid reagent or an alkaline reagent. In this case, since pH such as acidity and alkalinity can be adjusted by mixing the second reagent, a pH-dependent coloring reaction can be appropriately generated in the third step.
Moreover, in the above component measuring method, the second reagent may be a nonvolatile acid. In this case, the components can be appropriately measured using the strip fixed on the reagent pad without the second reagent being volatilized.

Furthermore, in the above component measuring method, the first reagent or the second reagent may be either an oxidizing agent or a reducing agent. In this case, oxidation and reduction actions can be appropriately generated in the third step.
Moreover, in the above component measuring method, the first reagent may be a chlorinating reagent. If the first reagent is an oxidizing agent, the oxidizing agent is often unstable in an aqueous solution, but the chlorinated reagent is relatively stable, so the strip fixed on the reagent pad can be removed without being decomposed. can be used to appropriately measure components.

Furthermore, one aspect of the component measuring strip according to the present invention includes a first reagent pad holding a first reagent provided on a base sheet, and a first reagent pad provided on the base sheet adjacent to the first reagent pad. a second reagent pad for holding a second reagent, and the first reagent pad and the second reagent pad are arranged so that when the liquid sample is brought into contact with the liquid sample, the second reagent pad holds a second reagent. The first reagent held by the first reagent pad and the second reagent held by the second reagent pad are mixed to cause a color reaction.
In this way, since the first reagent pad holding the first reagent and the second reagent pad holding the second reagent are provided adjacently on one base sheet, the component measurement strip A color reaction can be appropriately generated by just one contact with a liquid sample. Therefore, it is possible to provide a strip that allows the components in a liquid sample to be easily measured in a short time.

Moreover, in the above strip for measuring components, the first reagent pad and the second reagent pad may be formed of test paper. In this case, the reagents can be held appropriately.
Further, in the component measurement strip described above, when the first reagent pad and the second reagent pad are brought into contact with the liquid sample, a first reaction between the liquid sample and the first reagent occurs. However, the arrangement may be such that next, a second reaction between the reactant produced by the first reaction and the second reagent occurs. In this case, a color reaction can be appropriately generated depending on the concentration of components in the liquid sample.

Moreover, in the above strip for measuring components, the first reagent pad and the second reagent pad may be provided on the base sheet in an overlapping manner. In this case, the liquid sample, the first reagent, and the second reagent can be appropriately mixed when brought into contact with the liquid sample.
Furthermore, in the component measurement strip described above, the first reagent pad and the second reagent pad are provided on the base sheet in an overlapping manner in the order of the second reagent pad and the first reagent pad. You can. In this case, the first reagent pad on which the colored region appears will be placed on the outermost surface. Therefore, it becomes easier to compare the colors of the colored regions.

Moreover, in the above strip for measuring components, the first reagent pad and the second reagent pad may be arranged in contact with each other on the same surface of the base sheet. In this case, the liquid sample, the first reagent, and the second reagent can be appropriately mixed when brought into contact with the liquid sample.
Furthermore, the above-mentioned component measurement strip has a plurality of first reagent pads each holding a different first reagent, and each of the plurality of first reagent pads and the second reagent pad are mutually different from each other. They may be provided on the base sheet in contact with each other. In this case, it becomes possible to measure multiple different components at once. Furthermore, since the second reagent pad is shared, costs can be reduced accordingly.

Moreover, in the above strip for measuring components, the second reagent may be either an acid reagent or an alkaline reagent. In this case, a pH-dependent color reaction can be appropriately generated.
Furthermore, in the above strip for measuring components, the second reagent may be a nonvolatile acid. In this case, a strip can be obtained in which the second reagent is fixed on the reagent pad without being volatilized.

Moreover, in the above component measuring strip, the first reagent or the second reagent may be either an oxidizing agent or a reducing agent. In this case, oxidation or reduction can be appropriately generated in the third step.
Furthermore, in the above strip for measuring components, the first reagent may be a chlorinated reagent. When the first reagent is an oxidizing agent, the oxidizing agent is often unstable in an aqueous solution, but the chlorinating reagent is relatively stable, so it is possible to use a strip fixed to the reagent pad without being decomposed. , the components can be measured appropriately.

Further, one aspect of the method for manufacturing a component measurement strip according to the present invention includes a first step of manufacturing a first reagent pad that holds a first reagent, and a second step of manufacturing a second reagent pad that holds a second reagent. and a third step of installing the first reagent pad and the second reagent pad adjacently on a base sheet, and in the third step, when a liquid sample is brought into contact with The liquid sample, the first reagent held by the first reagent pad, and the second reagent held by the second reagent pad are mixed and a color reaction occurs. and a second reagent pad.
Thereby, it is possible to manufacture a strip that can easily measure components in a liquid sample in a short time.

Furthermore, in the method for manufacturing a component measuring strip described above, the second step includes a step of impregnating the main body of the second reagent pad with the solution of the second reagent, and a step of impregnating the main body of the second reagent pad with the solution of the second reagent. drying the second reagent pad, the second reagent may be a non-volatile acid.
In this case, in the second step of producing the second reagent pad, the second reagent can be properly fixed to the reagent pad even after the drying step.

Further, in one embodiment of the component measuring device according to the present invention, a strip holding strip is provided on a base sheet, and a first reagent pad holding a first reagent and a second reagent pad holding a second reagent are provided on a base sheet. a coloring region where a coloring reaction occurs when a holding part, the liquid sample, a first reagent held by the first reagent pad of the strip, and a second reagent held by the second reagent pad are mixed; and a measurement unit that measures the concentration of the component in the liquid sample.
Thereby, the component concentration in the liquid sample can be appropriately measured.

According to the present invention, components in a liquid sample can be easily measured in a short time.

It is a figure showing an example of a component measurement strip in this embodiment. It is a figure which shows the manufacturing process example of the strip for a component measurement. It is a figure which shows the contact process in a component measuring method. It is a figure which shows another example of the colorimetric process in a component measuring method. It is a figure which shows another example of the strip for a component measurement. It is a figure which shows another example of the strip for a component measurement. It is a figure which shows another example of the strip for a component measurement. It is a figure which shows another example of the strip for a component measurement. FIG. 1 is a diagram for explaining an example of the basic configuration of a component analysis system. It is a figure which shows an example of the conventional strip for a component measurement. It is a figure which shows the 1st contact process in the conventional component measurement method. It is a figure which shows the 2nd contact process in the conventional component measuring method. It is a figure which shows the colorimetric process in the conventional component measurement method.

Embodiments of the present invention will be described below based on the drawings.
In this embodiment, a component measuring device that measures components in a liquid sample using a coloring reaction between a coloring reagent and a liquid sample will be described.
This component measuring device is used, for example, in a liquid analysis system that analyzes the components of a nutrient solution in which nutrients necessary for plants (crops such as vegetables) are dissolved in water in a plant factory.

FIG. 9 is a diagram showing an example of a liquid analysis system in a plant factory.
Generally, in a plant factory, hydroponic cultivation is performed using a nutrient solution in which nutrients necessary for plants (crops such as vegetables) are dissolved in water. FIG. 9 shows an example of a circulating hydroponic culture in which a nutrient solution 91 is circulated as a hydroponic culture.
As shown in FIG. 9, the nutrient solution 91 supplied to the cultivation tank 93 in which crops 92 are grown is circulated through a circulation channel 95 by a liquid pump 94. As shown in FIG. A part of the circulating nutrient solution 91 is automatically collected, for example, through a liquid sample collection channel 96 branched from a part of the circulation channel 95, and the components of the collected nutrient solution 91 are analyzed by a liquid analyzer 97. be analyzed.

In the case of circulating hydroponic cultivation, the composition of the nutrient solution held in the cultivation tank changes as the nutrient solution circulates. Since the growth of plants is affected by the components of the nutrient solution, the nutrient solution is adjusted as necessary based on the results of the nutrient solution analysis.
The liquid analyzer 97 can be, for example, a component measuring analyzer that employs high performance liquid chromatography (HPLC) to analyze the nutrient solution 91. In this case, the liquid analyzer 97 can accurately analyze multiple components in the nutrient solution 91, but the measurement takes time and the device itself becomes large-scale.
Therefore, when it is desired to measure the components in the nutrient solution 91 in a relatively short time, a method is used in which the components in the nutrient solution 91 are measured using a color reaction between a coloring reagent and the nutrient solution 91.

Hereinafter, a method for measuring components of a liquid sample using a conventional color reaction will be explained.
First, a strip (test piece) holding a reagent is prepared.
An example of the structure of the strip is shown in FIG. As shown in FIG. 10, the strip 10' has a structure in which a reagent pad 11 for holding a reagent is provided on one surface of a rectangular base sheet 13 and near one end of the base sheet 13.

Then, as shown in FIG. 11(a), a liquid sample 31 (for example, the nutrient solution 91 for hydroponic cultivation shown in FIG. 9) held in the sample container 31a is prepared. Then, a strip 10' shown in FIG. 10 is immersed in the liquid sample 31 (contact step). At this time, at least a portion of the reagent pad 11 is always immersed in the liquid sample 31. Note that it is preferable that all of the reagent pads 11 be immersed in the liquid sample 31.
In this contact step, as shown in FIG. 11(b), the strip 10' shown in FIG. It may also be dripped onto the pad 11 portion.
Through this step, the liquid sample 31 and the reagent react on the reagent pad 11, and a color reaction occurs depending on the concentration of the components in the liquid sample 31. Therefore, the concentration of the component in the liquid sample 31 can be measured based on the degree of color of the reagent pad 11.

However, some fertilizer components in plant factories do not cause a coloring reaction when reacted with only one type of reagent as described above.
In order to measure such fertilizer components, first, a liquid sample and a first reagent are reacted, and then a chemical reaction product of the liquid sample and the first reagent is mixed with a second reagent different from the first reagent. A color reaction occurs by reacting with
In this case, the component measurement of the liquid sample is performed in the following procedure.

First, a strip 10' including a reagent pad 11 holding a first reagent is prepared. Then, as shown in FIG. 11(a) or FIG. 11(b) described above, the strip 10' is immersed in the liquid sample 31 (first contact step). This causes the liquid sample 31 and the first reagent to react.

Next, as shown in FIG. 12(a), the second reagent 22 held in the second reagent container 22a is prepared. Then, the strip 10' that has gone through the steps shown in FIG. 11(a) or FIG. 11(b) is dried, and the dried strip 10' is immersed in the second reagent 22 (second contact step). At this time, at least a portion of the reagent pad 11 is always immersed in the second reagent 22. Note that it is preferable that all of the reagent pads 11 be immersed in the second reagent 22.
In addition, in this second contact step, as shown in FIG. 12(b), the strip 10' is arranged so that the reagent pad 11 is located on the upper surface side, and the second reagent 22 is added to the reagent using a pipette or the like. It may also be dripped onto the pad 11 portion.

Through this step, a chemical reaction occurs between the chemical reaction product of the liquid sample 31 and the first reagent and the second reagent 22, and a reaction product is generated. The generated reaction product exhibits a predetermined color depending on the component concentration of the liquid sample 31.
In this way, by mixing the liquid sample, the first reagent, and the second reagent, a color reaction can occur. Here, as the first reagent or the second reagent, a pH adjuster such as an acid reagent or an alkaline reagent, a redox agent, or the like can be used.

The strip 10' on which the color reaction has been obtained is set in a component measuring device 100' as shown in FIG. 13, and the component concentration in the liquid sample 31 is measured (colorimetric step). The component measuring device 100' is, for example, an optical measuring device (spectrophotometer). The component measuring device 100' can measure the component concentration in the liquid sample 31 by comparing the colors of the colored regions on the reagent pad 11 of the strip 10'. Note that when comparing the colors of the colored regions, the colored regions may be visually observed and the concentration of components in the liquid sample 31 may be estimated by referring to, for example, a color comparison table.

In this way, in the conventional component measuring method described above, it is necessary to bring the liquid sample 31 and the second reagent 22 into contact with the strip 10' twice. Therefore, measurement takes time. Furthermore, since a plurality of liquids (liquid sample 31, second reagent 22) are handled, it takes time and effort to handle each liquid (eg, prevent leakage to the outside) and dispose of each liquid. Furthermore, containers for holding each liquid are required as many as the number of liquids, and management becomes complicated.

In this embodiment, the components in the liquid sample 31 can be easily measured in a short time without requiring complicated management of the liquid.
In the component measurement method in the embodiment, for example, a first reagent pad (in this embodiment, a test paper) that holds a first reagent and a second reagent that holds a second reagent are placed on one base sheet in the form of a rectangle. A strip provided with a pad (in this embodiment, a test strip) is used.

FIG. 1 is a diagram showing an example of the configuration of a strip 10 for component measurement in this embodiment.
As shown in FIG. 1, the strip 10 includes a first test paper (a first reagent pad) that holds a first reagent on one surface of a rectangular base sheet 13 and near one end of the base sheet 13. ) 11 and a second test paper (second reagent pad) 12 holding a second reagent are provided adjacent to each other. In this embodiment, the first test paper 11 and the second test paper 12 are stacked on the base sheet 13 in the order of the second test paper 12 and the first test paper 11 from the bottom.

The base sheet 13 can be made of polyester, for example.
The pad main bodies, which are the main bodies of the first test strip 11 and the second test strip 12, can be constructed from a hygroscopic sheet (hygroscopic sheet). As the hygroscopic sheet, for example, a filter paper or a porous membrane made of cellulose, cellulose nanofiber (CNF), glass fiber, or the like is used.

Next, an example of the manufacturing process of the strip 10 will be described with reference to FIG. 2.
The manufacturing process shown in FIG. 2 includes [A] a manufacturing process of the first test paper 11 (first step), [B] a manufacturing process of the second test paper 12 (second process), and [C] a first test paper 11 and the step of installing the second test paper 12 (third step).

[A] Production process of first test paper 11 The first test paper 11 is produced through the following steps.
First, the test strip body 11a made of a small hygroscopic sheet is immersed in a solution of the first reagent 21 held in the first reagent container 21a, thereby impregnating the test strip body 11a with the solution of the first reagent 21. (impregnation process). In addition, in this impregnation process, the solution of the 1st reagent 21 may be dripped at the test paper main body 11a, and the test paper main body 11a may be impregnated with the solution of the 1st reagent 21.
Next, the test paper 11b impregnated with the solution of the first reagent 21 is dried to remove the solvent 21b (drying step). Here, as the drying method, for example, a heating drying method can be adopted. Note that drying may be performed at room temperature. Further, the drying method is not limited to the above, and for example, freeze drying, vacuum drying, blow drying by blowing dry air, etc. can also be adopted.
In this way, the first test paper 11 holding the first reagent 21 is produced through the impregnation process and the drying process.

[B] Manufacturing process of second test paper 12 The second test paper 12 is produced through the following steps.
First, the test paper main body 12a made of a small hygroscopic sheet is immersed in a solution of the second reagent 22 held in the second reagent container 22a, so that the test paper main body 12a is impregnated with the solution of the second reagent 22. (impregnation process). In addition, in this impregnation process, the solution of the 2nd reagent 22 may be dripped at the test paper main body 12a, and the test paper main body 12a may be impregnated with the solution of the 2nd reagent 22.
Next, the test paper 12b impregnated with the solution of the second reagent 22 is dried to remove the solvent 22b (drying step). Here, as the drying method, for example, a heating drying method can be adopted. Note that drying may be performed at room temperature. Further, the drying method is not limited to the above, and for example, freeze drying, vacuum drying, blow drying by blowing dry air, etc. can also be adopted.
In this way, the second test paper 12 holding the second reagent 22 is produced through the impregnation process and the drying process.

[C] Installation Step The first test paper 11 obtained in step [A] and the second test paper 12 obtained in step [B] are installed adjacent to one side of the base sheet 13. Specifically, the second test paper 12 and the first test paper 11 are placed on one surface of the base sheet 13 near one end of the base sheet 13 so as to be stacked in this order from the bottom.
The first test paper 11 and the second test paper 12 are fixed to the base sheet 13 using an adhesive, for example. Any adhesive may be used as long as it does not affect the reaction between the liquid sample 31 and the first reagent 21 or the reaction between the chemical reaction product of the liquid sample 31 and the first reagent 21 and the second reagent 22. The type doesn't matter.

For example, when the liquid sample 31 is a nutrient solution for hydroponic cultivation, the components to be measured include potassium (K), phosphorus (P), ammonium (NH ₄ ), nitrate (NO ₃ ), and calcium (Ca). , magnesium (Mg), boron (B), iron (Fe), etc.

For example, when the liquid sample 31 is a nutrient solution for hydroponic culture and potassium in the nutrient solution is to be measured, the first reagent 21 held by the first test paper 11 may be dipicrylamine sodium (Dipicrylamine sodium). Sodium Salt) and sodium hydroxide (NaOH) are used. Further, as the second reagent 22 held by the second test paper 12, a nonvolatile acid such as trichloroacetic acid (CCl ₃ COOH) is used.
Note that the term "nonvolatile acid" as used herein means an acid having a boiling point of 100°C or higher.

Some acid reagents are volatile, but when a volatile acid reagent is used as the second reagent 22, the drying step in the manufacturing process (step [B]) of the second test paper 12 shown in FIG. In this case, the second reagent 22 itself is volatilized in addition to the solvent 22b. As a result, the amount of the second reagent 22 held by the second test paper 12 decreases or disappears.
Therefore, in this embodiment, when an acid reagent is used as the second reagent 22, a nonvolatile acid is used. Note that for the first reagent 21 as well, it is preferable to use a nonvolatile reagent for the same reason.

Examples of nonvolatile acids include trichloroacetic acid mentioned above, as well as boric acid, metasilicic acid, phosphoric acid, sulfuric acid, thiosulfuric acid, perchloric acid, chloric acid, chromic acid, dichromic acid, arsenic acid, and arsenic acid. Acids include bromate acid, iodic acid, hexachloride platinic (IV) acid, tetrachloride (III) acid, and the like.
Here, in consideration of safety, cost, ease of handling (powder at room temperature), it is preferable to use trichloroacetic acid, boric acid, metasilicic acid, phosphoric acid, thiosulfuric acid, bromic acid, and iodic acid.
In addition, when the liquid sample 31 is a nutrient solution for hydroponic cultivation, trichloroacetic acid, metasilicic acid, thiosulfuric acid, bromate, iodine, Acids are preferred.
In this way, as the second reagent 22, a pH adjuster that adjusts acidity can be used.

Further, for example, when the liquid sample 31 is a nutrient solution for hydroponic cultivation and phosphorus in the nutrient solution is to be measured, the first reagent 21 held by the first test paper 11 is heptamolybdate hexa Ammonium (English chemical _name : Ammonium molybdate _tetrahydrate : ( _NH4 ) _6Mo7O24.4H2O ) and trichloroacetic _acid are used. Further, as the second reagent 22 held by the second test paper 12, reducing agents such as tin (II) chloride (STANNOUS CHLORIDE: SnCl ₂ ), hydrazine sulfate, ascorbic acid, tetramethylbenzidine, hydroquinone, and sodium sulfite are used. It will be done.

For example, when the liquid sample 31 is a nutrient solution for hydroponic cultivation and ammonia in the nutrient solution is to be measured, the first reagent 21 held by the first test paper 11 is sodium dichloroisocyanurate. A chlorinating reagent that is an oxidizing agent such as sodium dichloroisocyanurate (C ₃ Cl ₂ N ₃ NaO ₃ ) or trichloroisocyanuric acid (C ₃ Cl ₃ N ₃ O ₃ ) is used. Further, the second reagent 22 held by the second test strip 12 includes sodium salicylate (C ₇ H ₅ NaO ₃ ), phenol (Phenol: C ₆ H ₅ OH), and naphthol (Naphthol: C ₁₀ H _{8 )} . O) is used.

Note that the first reagent 21 and the second reagent 22 can be appropriately selected depending on the component to be measured. For example, a case has been described in which an acid reagent is used as the second reagent 22 when the component to be measured is potassium, but an alkaline reagent may be used depending on the component to be measured.

Hereinafter, a component measuring method using the strip 10 in this embodiment will be explained.
[First step]
A strip 10 shown in FIG. 1 is prepared.
[Second step]
As shown in FIG. 3(a), the strip 10 is immersed in the liquid sample 31 held in the sample container 31a, and the liquid sample 31 is brought into contact with the strip 10. At this time, at least a portion of the first test paper 11 and at least a portion of the second test paper 12 are always immersed in the liquid sample 31. Note that it is preferable that both the first test paper and the second test paper 12 be immersed in the liquid sample 31.
In this second step, as shown in FIG. 3(b), the strip 10 shown in FIG. 1 is arranged so that the first test paper 11 and the second test paper 12 are located on the upper side, Alternatively, the liquid sample 31 may be dropped onto the first test paper 11 and second test paper 12 using a dropper. Specifically, in the case of the strip 10 shown in FIG. 1, the liquid sample 31 is dropped onto the first test paper 11, which is the outermost test paper.

[Third step]
In the stacked first test paper 11 and second test paper 12, the liquid sample 31, the first reagent 21, and the second reagent 22 are mixed to cause a chemical reaction and a color reaction to occur.
Specifically, first, a chemical reaction (first reaction) occurs between the liquid sample 31 and the first reagent 21, and then a chemical reaction product generated by this chemical reaction (first reaction) and the second reagent 22 are generated. A chemical reaction (second reaction) with The reaction product produced by this chemical reaction (second reaction) exhibits a predetermined color depending on the concentration of the components in the liquid sample 31.
In this way, by just going through one step (second step) of bringing the liquid sample 31 into contact with the test paper provided on the strip 10, the liquid sample 31, the first reagent 21, and the second reagent 22 are mixed, and coloring is achieved. A reaction can occur.

Here, as an example of a color reaction, a case where the measurement target is potassium in a nutrient solution will be described.
In this case, as described above, dipicrylamine sodium is used as the first reagent 21 and trichloroacetic acid is used as the second reagent 22.
Here, dipicrylamine sodium itself is a red reagent, and the reaction product produced by reacting with potassium is also red. In other words, there is no color change just by the reaction between sodium dipicrylamine and potassium. However, when the second reagent 22, trichloroacetic acid, is mixed therein, a color change appears. Specifically, the color changes from red to yellow to orange. At this time, the color after the change is determined depending on the degree of reaction between sodium dipicrylamine and potassium.
For example, if potassium is not present in the nutrient solution, mixing sodium dipicrylamine and trichloroacetic acid will change the color from red to yellow. On the other hand, if potassium is present in the nutrient solution, the color changes from red to orange by mixing trichloroacetic acid. The shade of orange is determined by the degree of reaction between potassium and sodium dipicrylamine, that is, the concentration of potassium.

[STEP 4]
After STEP 3, as shown in FIG. 4, the strip 10 is set in the component measuring device 100. The component measuring device 100 includes a holding section 101 that holds the strip 10, and a measuring section 102 that performs optical measurement on the strip 10 held by the holding section 101 and measures the concentration in the liquid sample 31. The measurement unit 102 includes an optical measuring device. As the optical measuring device, an RGB camera or a spectrophotometer can be used. The measuring unit 102 measures the color of the colored region of the strip 10 on the first test paper 11 using an optical measuring device, and measures the concentration of the liquid sample 31 using a colorimetric method.
When a color reaction occurs in STEP 3, the color region appears on the first test paper 11. Therefore, the strip 10 is held by the holding unit 101 so that the first test paper 11 and the second test paper 12 are located on the upper surface side, and the measuring unit 102 measures the color of the colored area from the first test paper 11 side. Measure.
Note that when comparing the colors of the colored regions, the colored regions may be visually observed and the concentration of components in the liquid sample 31 may be estimated by referring to, for example, a color comparison table.

As explained above, the component measuring method according to the present embodiment includes the first step of preparing the strip 10, the second step of bringing the liquid sample 31 into contact with the strip 10, and the step of bringing the liquid sample 31 and the first test paper 11 into contact with each other. A third step of mixing the first reagent 21 held and the second reagent 22 held by the second test paper 12 to generate a color reaction, and colorimetrically measuring the color of the color area where the color reaction has occurred. A fourth step of doing so. Here, the "contact" in the second step includes at least one of the operation of immersing the strip 10 in the liquid sample 31 and the operation of dropping the liquid sample 31 onto the strip 10.

As described above, in this embodiment, the strip 10, in which the first test paper 11 holding the first reagent 21 and the second test paper 12 holding the second reagent 22 are provided on one surface, is placed in the liquid sample 31. Used to measure the components of Therefore, by just going through one step of bringing the liquid sample 31 into contact with the strip 10, first a first reaction occurs between the liquid sample 31 and the first reagent 21, and then a reactant produced by the first reaction and a second reaction are generated. A second reaction with two reagents 22 can occur. Then, the result of the second reaction can be obtained as the result of the color reaction.

For example, when the measurement target is phosphorus in a nutrient solution, ammonium molybdate is used as the first reagent 21 and tin chloride is used as the second reagent 22, as described above. If the ammonium molybdate contained in the first reagent 21 is mixed with tin chloride before reacting with phosphorus, it will be reduced first, so ammonium molybdate and tin chloride should not be mixed in advance. Can not.
The strip 10 in this embodiment is held by the first test paper 11 and the second test paper 12 to prevent the first reagent 21 and the second reagent 22 from being mixed, respectively, before the liquid sample 31 is brought into contact with the strip 10. The strip 10 is configured so that the samples 21 and 22 and the liquid sample 31 are mixed for the first time when the liquid sample 31 is brought into contact with the strip 10. Therefore, a color reaction can be appropriately generated.

In this way, in the present embodiment, even if the first reagent 21 and the second reagent 22, which cannot be mixed in advance, are required as reagents for generating a color reaction, as shown in FIG. By using the strip 10 as shown in FIG. 10, it is possible to appropriately generate a color reaction just by bringing the liquid sample 31 into contact with the strip 10 once, and the measurement method using the strip 10' shown in FIG. Measurements can be made in a shorter time compared to
In addition, since the first reagent 21 and the second reagent 22 are each held in a test paper, there is no need to handle (for example, prevent leakage to the outside) or dispose of both reagents, and there is no need for a container to hold both reagents. Become. Therefore, reagent management becomes easy.

Here, in the strip 10 used for component measurement in this embodiment, specifically, the first test paper 11 holding the first reagent 21 and the second test paper 12 holding the second reagent 22 are It has a structure that is provided adjacently on the material sheet 13. That is, the strip 10 is arranged in a first test such that when the liquid sample 31 is brought into contact with the liquid sample 31, the liquid sample 31, the first reagent 21, and the second reagent 22 are mixed and a color reaction occurs. A paper 11 and a second test paper 12 are provided.
The first test paper 11 and the second test paper 12 can be provided on the base sheet 13 in an overlapping manner. By arranging the first test paper 11 and the second test paper 12 in contact with each other in this manner, when the liquid sample 31 is brought into contact, the liquid sample 31, the first reagent 21, and the second reagent 22 are connected to each other. Easy to mix.

Further, the first test paper 11 and the second test paper 12 can be provided on the base sheet 13 in the order of the second test paper 12 and the first test paper 11. When the liquid sample 31 is brought into contact and a color reaction occurs, a color region appears on the first test paper 11 . Therefore, by stacking the first test paper 11 and the second test paper 12 on the base sheet 13 so that the first test paper 11 is on the outermost surface, it is easy to compare the colors of the colored regions. Become.
In addition, when the base material sheet 13 is made of a transparent material, the first test paper 11 and the second test paper 12 may be provided on the base material sheet 13 to be stacked in this order. In this case, the color of the colored region can be compared from the back side of the base sheet 13 (the side where the test papers 11 and 12 are not provided).

Here, the method for manufacturing the strip 10 includes a first step of producing the first test strip 11 holding the first reagent 21, a second step of producing the second test strip 12 holding the second reagent 22, A third step of installing the first test paper 11 and the second test paper 12 adjacently on the base sheet 13 is included. The process of producing the first test paper 11 and the process of producing the second test paper 12 include a process of impregnating the test paper body with a reagent solution and a process of drying the test paper impregnated with the reagent solution. and, including.

In this way, the process of producing the first test paper 11 and the second test paper 12 includes a drying process. Therefore, if a volatile reagent is used, the reagent will volatilize during the strip manufacturing process and will not be fixed on the test paper.
Therefore, in this embodiment, nonvolatile reagents are used as the first reagent 21 and the second reagent 22. For example, when using an acid reagent as the second reagent 22, a nonvolatile acid is used. Thereby, the second reagent 22 can be properly fixed on the test paper, and can be held on the strip 10 together with the first test paper 11 holding the first reagent 21.

As described above, in this embodiment, components in a liquid sample can be easily measured in a short time, and management of reagent solutions can be made unnecessary.

(Modified example)
In the above embodiment, a case has been described in which the strip 10 having the configuration shown in FIG. 1 is used to measure the components of the liquid sample 31. However, the component measuring strip is not limited to the above configuration, and in the contact process of the liquid sample 31 shown in FIGS. 3(a) and 3(b), the liquid sample 31 is Any configuration is sufficient as long as it is always absorbed by at least a portion of the second test paper 12 and a color reaction can occur.

For example, like a strip 10A shown in FIG. 5, a first test strip 11 and a second test strip 12 are arranged side by side on one surface of a rectangular base sheet 13 near one end of the base sheet 13. It may have a similar structure. In this case, as shown in FIG. 5, the first test strip 11 and the second test strip 12 can be arranged side by side on the same surface of the base sheet 13 in contact with each other. Although not particularly illustrated, a slight gap may be formed between the first test paper 11 and the second test paper 12.
As shown in FIG. 5, the first test paper 11 and the second test paper 12 are arranged side by side on the same surface of the base sheet 13, and the liquid sample 31 is dropped as shown in FIG. 3(b). In this case, the liquid sample is dropped so that the liquid sample 31 contacts both the first test paper 11 and the second test paper 12.

Furthermore, like the strip 10B shown in FIG. 6, a plurality of first test strips 11 and second test strips 12 are placed on one surface of the rectangular base sheet 13 near one end of the base sheet 13. A configuration in which they are arranged adjacent to each other may also be used. In this case, as shown in FIG. 6, the second test strip 12 may be sandwiched between the plurality of first test strips 11. Here, the plurality of first test strips 11 may hold the same first reagent, or may hold different first reagents.
When there are multiple components to be measured and the first reagents used for component measurement are different and the second reagents are the same, a plurality of first test strips 11 each holding a different first reagent; By using the strip 10B provided with one common second test paper 12, it becomes possible to measure a plurality of components with one strip.
In addition, also in this case, a slight gap may be formed between the first test paper 11 and the second test paper 12.

Furthermore, the configuration using the common second test strip 12 is not limited to the configuration shown in FIG. 6 above.
For example, like a strip 10C shown in FIG. 7, a plurality of first test strips 11 may be arranged on top of one second test strip 12. In this case, three or more first test strips 11 may be placed on one second test strip 12. Also, as in the strip 10D shown in FIG. They may be arranged side by side. In this case, a slight gap may be formed between the adjacent first test paper 11 and second test paper 12.
Although FIGS. 6 to 8 show an example in which two first test strips 11 are used, it is also possible to use three or more first test strips 11 and one common second test strip 12. .

DESCRIPTION OF SYMBOLS 10... Strip for component measurement, 11... First reagent pad, 12... Second reagent pad, 21... First reagent, 22... Second reagent, 31... Liquid sample, 100... Component measuring device

Claims (16)

A component measurement method for measuring components of a liquid sample for growing plants, the method comprising:
a first step of preparing a strip in which a first reagent pad holding a first reagent and a second reagent pad holding a second reagent are stacked on a base sheet;
a second step of contacting the liquid sample with the strip;
a third step of mixing the liquid sample, a first reagent held by the first reagent pad, and a second reagent held by the second reagent pad to generate a color reaction;
a fourth step of comparing the color of the coloring region where the coloring reaction has occurred ;
The first reagent pad and the second reagent pad are provided on the base sheet in an overlapping manner in the order of the second reagent pad and the first reagent pad, and the first reagent pad is on the outermost surface of the strip. The component measuring method is characterized in that the colored region appears on the first reagent pad . The third step is
generating a first reaction between the liquid sample and the first reagent;
generating a second reaction between a reactant produced by the first reaction and the second reagent,
2. The component measuring method according to claim 1, wherein the result of the second reaction is the result of the color reaction. 3. The component measuring method according to claim 1, wherein the second reagent is one of an acid reagent and an alkaline reagent. 4. The component measuring method according to claim 3 , wherein the second reagent is a nonvolatile acid. 3. The component measuring method according to claim 1, wherein the first reagent or the second reagent is one of an oxidizing agent and a reducing agent. 6. The component measuring method according to claim 5 , wherein the first reagent is a chlorinating reagent. A component measurement strip for measuring components of a liquid sample for growing plants,
comprising a first reagent pad holding a first reagent and a second reagent pad holding a second reagent provided on a base sheet,
The first reagent pad and the second reagent pad are configured to separate the liquid sample, a first reagent held by the first reagent pad, and a second reagent held by the second reagent pad when the liquid sample is brought into contact with each other. The two reagents are arranged so that a color reaction occurs when they are mixed ,
The first reagent pad and the second reagent pad are provided on the base sheet in the order of the second reagent pad and the first reagent pad, and the first reagent pad is located at the top of the strip. A strip for measuring components , wherein a colored region on the surface where the coloring reaction occurs appears on the first reagent pad . 8. The component measuring strip according to claim 7 , wherein the first reagent pad and the second reagent pad are made of test paper. The first reagent pad and the second reagent pad are
When the liquid sample is brought into contact, a first reaction occurs between the liquid sample and the first reagent, and then a second reaction occurs between the reactant produced by the first reaction and the second reagent. The component measuring strip according to claim 7 or 8 , wherein the strip is arranged so that a reaction occurs. 9. The component measuring strip according to claim 7 , wherein the second reagent is one of an acid reagent and an alkaline reagent. The component measuring strip according to claim 10 , wherein the second reagent is a nonvolatile acid. 9. The component measuring strip according to claim 7 , wherein the first reagent or the second reagent is one of an oxidizing agent and a reducing agent. 13. The component measuring strip according to claim 12 , wherein the first reagent is a chlorinating reagent. A method for producing a component measuring strip for measuring components of a liquid sample for growing plants, the method comprising:
A first step of producing a first reagent pad holding a first reagent;
a second step of producing a second reagent pad holding a second reagent;
a third step of placing the first reagent pad and the second reagent pad on a base sheet,
In the third step,
When the liquid sample is brought into contact with the liquid sample, the liquid sample, the first reagent held by the first reagent pad, and the second reagent held by the second reagent pad are mixed, and a color reaction occurs. the first reagent pad and the second reagent pad are installed as shown in FIG .
The first reagent pad and the second reagent pad are provided on the base sheet in the order of the second reagent pad and the first reagent pad, and the first reagent pad is on the outermost surface of the strip. A method of manufacturing a strip for measuring a component , wherein a colored region in which the coloring reaction occurs appears on the first reagent pad . The second step is
impregnating the main body of the second reagent pad with a solution of the second reagent;
drying the second reagent pad impregnated with the second reagent solution;
15. The method of manufacturing a component measuring strip according to claim 14 , wherein the second reagent is a nonvolatile acid. A component measuring device for measuring components of a liquid sample for growing plants,
a holding part that holds a strip in which a first reagent pad holding a first reagent and a second reagent pad holding a second reagent are provided on a base sheet;
Comparing the colors of a colored region where a color reaction occurs when the liquid sample, a first reagent held by the first reagent pad of the strip, and a second reagent held by the second reagent pad are mixed. a measuring unit that measures the concentration of the component in the liquid sample ;
The first reagent pad and the second reagent pad are provided on the base sheet in the order of the second reagent pad and the first reagent pad, and the first reagent pad is provided on the outermost surface of the strip. The component measuring device is characterized in that the colored region appears on the first reagent pad .

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