JP7587270B2 - Method for diagnosing deterioration of monitored object - Google Patents

Description

The present invention relates to a method for diagnosing deterioration of monitored objects, particularly wooden buildings.

One of the causes of deterioration of buildings, particularly wooden buildings, is damage caused by wood pests. Known wood pests include termites, wood beetles, wood beetles, long-horn beetles, and weevils. These wood pests damage the beauty of wooden buildings and feed on the structural materials of buildings, causing the structural materials to lose their functionality, resulting in the instability of the buildings.
In particular, in the conservation of traditional wooden buildings such as cultural properties, preventing damage caused by wood pests is an urgent and important issue.

Among wood pests, termites have the tendency to breed by securing feeding sites and nests (hereafter referred to as "feeding sites") inside wood or underground. This makes it difficult to visually confirm feeding sites. Furthermore, when termites invade buildings from the outside, they use underground tunnel-like passages called "ant trails" to move around, making it rare for adult insects to be seen with the naked eye, and specialized knowledge and experience are required to determine whether damage has occurred. This difficulty in monitoring is one of the factors that causes the spread of damage to buildings caused by termites and other wood pests.

In light of the above, technology to detect the presence of wood pests early and monitor their presence is considered important in terms of minimizing damage and making control easier.

As a monitoring technology for such wood pests targeting termites, Patent Document 1 describes "a termite monitoring device having a bait storage space capable of storing termite bait containing a termite killing component, a buried body that is buried underground in a state that allows termites to invade the bait storage space, and a station box with a lid member that allows the bait storage space to be opened and closed from above ground, and a gas detection element facing the bait storage space of the station box that detects metabolic gases resulting from the intrusion of termites into the termite bait."

Patent Document 2 also describes a termite detection device that includes "an artificial bait (50) having a membrane material (51) eaten by termites and an interior enclosed by the membrane material and containing a gas emitter (52) that emits a target gas, a storage space (13) for storing the artificial bait, a main body (10) having an entry port (14) through which termites can enter the storage space, and a gas sensor (30) for detecting the target gas emitted from the artificial bait."

As for devices targeting wood pests, Patent Document 3 describes a wood pest detector that "includes a feeding sensor that detects wood pests and an alarm device that issues an alarm when a wood pest is detected by the feeding sensor, the feeding sensor being characterized in that it includes a support, a feeding member made of a feeding-damaging material that is mounted on the support in an energized state and is cut by feeding damage from wood pests, with one of the cut pieces moving in the energized direction, and a detection means that detects the movement of the cut piece."

JP 2003-144029 A JP 2017-42134 A Japanese Patent Application Publication No. 9-299009

The device described in Patent Document 1 is a device that is buried underground and includes a main body that contains bait and a detection element for termite metabolic gases, and detects termites by their metabolic gases.

The device described in Patent Document 2 detects termites by feeding them artificial bait that contains a gas emitter that releases the target gas, thereby releasing the target gas.

In addition, the device described in Patent Document 3 is designed so that a component made of a food-harming material is cut by wood pests, and a sensor detects the movement of the cut pieces and issues an alarm.

The problem with the above-mentioned wood pest detection devices and methods is that, due to the principle of detecting the metabolic activity and feeding behavior of wood pests, they cannot detect the presence of wood pests such as termites unless they are actually active in the area.

As already mentioned, wood pests have the tendency to secure feeding grounds inside wood or underground, making it difficult to detect their own activity. If the location of the device is not selected appropriately, there is a risk that wood pests will not be detected even if they are present in the vicinity.

Considering the above circumstances, the present invention aims to provide a deterioration diagnosis method that can provide information for determining whether the monitored object may be deteriorated by wood pests such as termites, without detecting the wood pests themselves.

As a result of extensive research into achieving the above object, the inventors have discovered that the above object can be achieved by the following configuration.

[1] A method for diagnosing deterioration of an object to be monitored, comprising: collecting a specimen from the object to be monitored or its surroundings; contacting a mixed liquid containing the specimen and water with an electrode; and performing electrochemical measurement in an anaerobic environment in the presence of at least one compound selected from the group consisting of cellulose, cellulose derivatives, and cellobiose; and providing information for determining that deterioration of the object to be monitored is progressing when current generation is detected as a result of the electrochemical measurement.
[2] The deterioration diagnosis method for an object to be monitored according to [1], wherein the compound is at least one selected from the group consisting of cellulose and cellulose derivatives.
[3] The deterioration diagnosis method according to [1] or [2], wherein the monitored object is a wooden building.
[4] The degradation diagnosis method according to any one of [1] to [3], wherein the electrochemical measurement method is a method of controlling the potential of the electrode and measuring the current flowing through the electrode as a function of time.
[5] The deterioration diagnosis method according to any one of [1] to [4], wherein the controlled potential of the electrode is within a range exceeding 0 V with respect to a standard hydrogen electrode and less than an upper limit value of a potential window.
[6] The deterioration diagnosis method according to [5], wherein the potential is +0.3 to +1.0 V with respect to the standard hydrogen electrode.
[7] The degradation diagnosis method according to any one of [1] to [6], wherein the specimen includes at least one selected from the group consisting of environmental water, soil, and garbage.
[8] The degradation diagnosis method according to any one of [1] to [6], wherein the information for making the judgment includes at least one measurement result selected from the group consisting of a time from the start of the electrochemical measurement to the detection of the current generation, a slope of a current increase curve, and a maximum value of a current density of the generated current.
[9] The degradation diagnosis method according to [8], wherein the information for making the judgment includes comparison information between a predetermined reference value and the measurement result.
[10] The degradation diagnosis method according to [9], further comprising the steps of: collecting a control sample; obtaining a preliminary measurement result for the control sample in a similar manner to that for the sample; and determining the reference value based on the preliminary measurement result.

The deterioration diagnostic method of the present invention (hereinafter also referred to as "this method") includes collecting a sample from the object to be monitored or its surroundings, contacting a mixed liquid containing the sample and water with an electrode, and performing an electrochemical measurement in an anaerobic environment in the presence of cellulose, and providing information for determining that deterioration of the object to be monitored is progressing if current generation is detected as a result of the electrochemical measurement.

As shown in the examples below, the present inventors have discovered for the first time that microorganisms derived from the intestines of wood pests have the property of generating an electric current in an anaerobic environment (i.e., in a condition similar to that in the intestines) in the presence of at least one compound selected from the group consisting of cellulose, cellulose derivatives, and cellobiose (hereinafter also referred to as "cellulose, etc."). The present method utilizes the above characteristic.

That is, detection of current generation from a sample suggests the presence of a microbial group derived from the intestinal tract of a wood pest in the sample. Specifically, the presence of a microbial group derived from the intestinal tract in a sample means that the sample contains wood pests themselves, wood pest carcasses, or parts of these, as well as wood pest excrement, etc.
This provides information for judging the progress of deterioration of the monitored object. According to this method, even if wood pests themselves are not actually contained in the sample, if the sample contains, for example, parts of the carcasses or excrement of wood pests, information for judging the progress of deterioration of the monitored object can be provided.

In addition, when the cellulose or the like is at least one type selected from the group consisting of cellulose and its derivatives, it is easier to more specifically detect the generation of electric current from microorganisms originating from the intestines of wood pests. In other words, it is less susceptible to the influence of impurities contained in the sample.

Furthermore, when the object to be monitored using this method is a wooden building, it is susceptible to damage from wood pests, and this method is particularly useful for diagnosing deterioration. This method does not require installing a device and waiting for wood pests to be attracted. Therefore, since samples can be collected from the object to be monitored or its surroundings, there is no need to damage the object to be monitored or install a large number of devices around the object that would spoil its appearance. Therefore, this method is particularly suitable for monitoring the deterioration of wooden buildings such as historical buildings.

With conventional methods, after installing a monitoring device, wood pests could not be detected until they were actually attracted to the device and began to be active (feed) within the device. In other words, wood pests could not be detected until they were actually present within the device and engaged in specific behavior.

However, when the electrochemical measurement method in this method involves controlling the potential of an electrode and measuring the current flowing through the electrode as a function of time, results can be obtained immediately by contacting the sample with the electrode to control the potential, or by contacting the sample with an electrode whose potential has been previously controlled. The time it takes to obtain results varies depending on the sample, but is, for example, between 5 seconds and 24 hours.

In addition, when the potential of the controlled electrode exceeds +0.3 V (vs. SHE) and is within the range below the upper limit of the potential window, it is easier to distinguish the current generated by microorganisms, making it easier to provide information for determining whether deterioration is progressing.

In addition, when the controlled electrode potential is +0.3 to +1.0 V (vs. SHE), the transfer of electrons from the intestinal microorganisms to the electrode becomes smoother, resulting in a clearer signal generated by current.

In addition, when the specimen contains at least one selected from the group consisting of environmental water, soil, and dust, this is preferable in that deterioration can be diagnosed without damaging the monitored object. In addition, environmental water, soil, and dust are likely to contain microbial groups derived from the intestines of wood pests via excrement, etc., making diagnosis easier.

In addition, it is preferable that the information for the above judgment includes at least one measurement result selected from the group consisting of the time from the start of the electrochemical measurement to the detection of the current generation, the slope of the current increase curve (time-current curve), and the maximum current density of the generated current, since quantitative evaluation is easier. For example, samples may be collected at multiple locations around the object to be monitored, and differences in the measurement results may be used to identify locations that are particularly likely to have deteriorated. In addition, the results of samples collected at different times at the same location can be compared, making it easier to judge changes in the deterioration state over time.

In addition, if the information for the above judgment includes the difference between a predetermined reference value and the above measurement result, this is preferable in that it makes it easier to prevent erroneous diagnosis. Even if the measurement result obtained is affected by characteristics such as the type of sample or the location of the monitored object, the inclusion of information for comparison with a corresponding predetermined reference value allows the results to be understood more accurately, and as a result, a more accurate diagnosis is possible.

In addition, when the method further includes collecting a control sample and obtaining preliminary measurement results for the control sample in the same procedure as for the sample, and determining the reference value, for example, by collecting a control sample that reflects the local characteristics of the installation environment of the monitored object and using the reference value determined based on the preliminary measurement results, a more accurate diagnosis can be achieved.

2 is a flowchart of a degradation diagnosis method according to an embodiment of the present invention. These are recipes for "CMC539 medium" and "CMC539 medium" in which cellobiose is replaced with carboxymethylcellulose. 1 is a time-current curve showing the change in generated current over time when CMC539 medium is used as the cellulose source. 5 is a time-current curve showing the time change in generated current when 539 medium (containing cellobiose) was used. This is a time-current curve when the electrode potential is +0.3V. This is a time-current curve when the electrode potential is +0.4V. This is a time-current curve when the electrode potential is +0.5V. This is a time-current curve when the electrode potential is +0.6V. This is a time-current curve when the electrode potential is +0.7V. This is a time-current curve when the electrode potential is +0.8V. This is a time-current curve when the electrode potential is +0.9V. This is a time-current curve when the electrode potential is +1.0V.

The present invention will be described in detail below.
The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment.
In this specification, a numerical range expressed using "to" means a range that includes the numerical values before and after "to" as the lower and upper limits.

FIG. 1 is a flowchart of a degradation diagnosis method according to one embodiment of the present invention (hereinafter, also referred to as "the method").
First, a sample is collected from the monitored object or its surroundings, and a corresponding control sample is also collected (step S11).
The object to be monitored is not particularly limited, but is preferably a building or structure that may be damaged by wood pests. In particular, if the object to be monitored is a wooden building, the effect of the deterioration diagnosis method according to the present invention is greater.

The specimen may be a part of the monitored object, such as a corroded structural material, or may be environmental water, soil, trash, etc. collected from around the monitored object. When the monitored object is a building, the soil may be soil under the floor, and the environmental water may be rainwater drainage.
Environmental water, soil, and garbage collected from around the object to be monitored often contain microbial groups derived from the intestines of wood pests, making them particularly suitable as test subjects.

Furthermore, samples may be collected from one location or multiple locations. When samples are collected from multiple locations, they may be measured individually or mixed together. Because this method has excellent sensitivity, sufficient sensitivity can be obtained even when samples are mixed together for measurement. When multiple samples are measured individually, the obtained information for determining the progress of deterioration can be compared with the collection locations of the corresponding samples to determine the positional distribution of the degree of deterioration in the monitored object.

Control samples (hereinafter also referred to as "C samples") contribute to the determination of reference values, which will be described later, and by collecting C samples appropriately, it is possible to negate the effects on measurements due to factors such as the location of the monitored object. For example, if the monitored object is a building and the sample is the soil under the floor, soil collected at a location a certain distance away from the building can be used as the C sample. The C sample and the sample do not need to be of the same type, but if they are of the same type (for example, soil and soil), more accurate information can be provided.

In FIG. 1, a control sample is collected in step S11, but in the method according to the embodiment of the present invention, it is not necessary to collect a control sample.

Next, the mixture containing the specimen and water is brought into contact with the electrodes, and electrochemical measurement is performed in the presence of cellulose or the like in an anaerobic environment (step S12).
The mixture may contain the specimen and water, and when the specimen is environmental water, it may be used as it is without adding water, whereas when the specimen is soil or dust, it may be subjected to measurement as it is after adding water, or the supernatant obtained by centrifugation may be used.

The water used to prepare the mixed liquid may contain other components as necessary. Examples of other components include metal salts (e.g., salts of alkali metals or alkaline earth metals). Examples of such salts include NaCl, KH ₂ PO ₄ , MgCl ₂ , KCl, and Na ₂ CO _3. The content of the metal salt is not particularly limited, but is preferably 10 to 50% by mass when the total content of the solids in the mixed liquid is 100% by mass.

The mixed liquid may contain a carbon source, a nitrogen source, and a sulfur source other than cellulose, etc., but from the viewpoint of being able to more specifically detect the microbial groups derived from the intestines of wood pests, it is preferable that the total content of these sources is 10 mass% or less of the total solid content.

The mixed liquid may contain cellulose, etc. When the mixed liquid contains cellulose, etc., electrochemical measurement can be performed "in the presence of cellulose, etc." by contacting the mixed liquid with an electrode. In this specification, cellulose, etc. means at least one compound selected from the group consisting of cellulose, cellulose derivatives, and cellobiose. As the cellulose derivative, a cellulose derivative such as carboxymethyl cellulose is preferable from the viewpoint of easy dispersion in the mixed liquid.
The molecular weight of the cellulose is not particularly limited, but is preferably from 500 to 1,000,000.

In particular, it is preferable that the cellulose, etc. contained in the mixed solution is at least one type selected from the group consisting of cellulose and cellulose derivatives, since it is less susceptible to the influence of impurities contained in the sample.

When cellulose or the like is contained in the mixed liquid, the content of the cellulose or the like in the mixed liquid is not particularly limited, but is preferably 10 to 70 mass % when the total mass of the solid content of the mixed liquid is 100 mass %.
When the mixed liquid contains two or more kinds of cellulose, etc., the total content thereof is preferably within the above numerical range.

If the mixed solution does not contain cellulose, etc., measurements may be performed "in the presence of cellulose, etc." by using a cellulose, etc.-immobilized electrode on which cellulose, etc. is immobilized by a known method.

As a method for electrochemical measurement, a method in which the potential of the electrode is controlled and the current is measured as a function of time is preferred. Examples of such methods include amperometry, cyclic voltammetry, linear sweep voltammetry, and square wave voltammetry.

The material of the electrode is not particularly limited, and electrodes known for electrochemical measurements can be used. Examples of the electrode material include ITO (indium tin oxide), precious metals (gold (Au), silver (Ag), platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir), ruthenium (Ru), etc.), copper (Cu), aluminum (Al), tungsten (W), molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), etc. Also, so-called "carbon electrodes" such as carbon materials, such as carbon and graphite (graphene), may be used. In addition, boron-doped diamond electrodes can be used because of their wide potential window. Among them, carbon electrodes are preferable.

For the electrochemical measurement, a general electrochemical measurement device can be used, for example, a three-electrode electrochemical measurement device in which a working electrode, a counter electrode, and a reference electrode are housed in a cell.
The temperature at which the electrochemical measurement is performed is not particularly limited, but may be the same as the temperature at which the sample is collected, or may be controlled. In this case, the temperature of the test solution is preferably 10 to 40° C.
The measurement may be carried out in a general anaerobic glove box (anaerobic chamber), preferably in an oxygen-free state.

If current generation is detected by this electrochemical measurement (step S13: Yes), the presence of a group of microorganisms derived from the intestines of wood pests is suggested. Therefore, water containing sample C is then brought into contact with an electrode, and electrochemical measurement is performed in the presence of cellulose in an anaerobic environment (step S14).
At this time, the conditions for the electrochemical measurement are the same as those for the measurement of the specimen already described.

In this embodiment, the measurement of the control specimen is started when current generation is detected, but it is also possible to provide information for determining that deterioration of the monitored object is progressing when current generation is detected (S13: Yes) without measuring the control specimen. In this case, for example, the information provided may include the time from the start of electrochemical measurement until current generation is detected, and the maximum current density of the generated current. As the measurement of the C specimen and comparison with the reference value are not performed, results can be obtained more quickly.

On the other hand, a preliminary measurement result may be obtained by electrochemical measurement of sample C before the electrochemical measurement of the sample. In this case, a reference value may be determined in advance before the measurement of the sample.

Returning to the flow of FIG. 1, after electrochemical measurement is performed on sample C (step S14), a reference value is then determined based on the preliminary measurement result of sample C (step S15).
An example of a method for determining the reference value may be a method in which the reference value is the time from the start of electrochemical measurement of sample C until current generation is detected, the slope of the current increase curve (time-current curve), and the maximum current density of the generated current.

In addition, although this embodiment has a procedure for determining the reference value based on the preliminary measurement results of the C sample, the reference value may be determined in advance. By determining the reference value in advance, the procedure for measuring the C sample can be omitted, and results can be obtained more quickly.

Next, comparison information between the measurement result of the sample and the reference value is provided as information for determining whether deterioration of the monitored object is progressing (step S16). This comparison information may be the difference between the measurement result of the sample and the reference value, etc. For example, from the difference in the maximum current density of the generated current, it is possible to determine whether the sample may contain microorganisms originating from the intestines of wood pests, and the amount thereof, etc.

The deterioration diagnosis method of the present invention will be described in detail below based on examples. Note that the deterioration diagnosis method of the present invention should not be interpreted as being limited to the specific examples below.

[Current generation test using bacteria derived from the intestines of termites]
The following test confirmed that electric current generation could be detected using a specimen containing bacteria derived from the intestines of termites.

(Test Method)
The bacterial strain used was Ruminiclostridium cellobioparum subsp. termitidis (DSM 5398, hereinafter referred to as "R.C. termitidis") obtained from DSMZ (Deutsche Sammlung von Microorganismen und Zellkulturen). This bacterial strain was isolated from the hindgut of the termite Nasutitermes lujae.

R. C. termitidis [DSM no. 5398] was placed in a Hungate tube with a butyl rubber stopper containing 10 ml of Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ) 539 medium (hereinafter referred to as "CMC539 medium"), which was modified by replacing 5 g/L cellobiose in the recipe with 5 g/L sodium carboxymethylcellulose (CMC, approximately 250,000, degree of substitution 0.7), and pre-cultured at 37°C with an anoxic headspace of CO ₂ /N ₂ (20:80, v/v).
After 3 days, the culture medium reached a cell OD600nm of 0.1 and was used for electrochemical measurements.
FIG. 2 shows recipes for 539 medium and "CMC539 medium" in which cellobiose is replaced with carboxymethylcellulose.

Electrochemical measurements were performed in a single-cell/three-electrode electrochemical reactor placed in a COY anaerobic chamber filled with 100% nitrogen.
The working electrode was an ITO (sheet resistance 8 Ω/□, thickness 1.1 mm, surface area 3.1 cm ² ) prepared by spray pyrolysis deposition on a glass substrate, and placed at the bottom of the reactor. A platinum wire was used as the counter electrode, and Ag/AgCl (sat. KCl) was used as the reference electrode.

For electrochemical measurements in the presence of CMC, anoxic "CMC539 medium" was used as the electrolyte. A total of 5 ml of sterile anoxic medium was added to the electrochemical reactor as electrolyte. The reactor was operated without stirring during electrochemical measurements. R. C. termitidis cells precultured for 3 days in CMC539 medium were harvested from 6 ml of cell culture by centrifugation at 12,022 g for 12 min in an anaerobic COY chamber, resuspended in 0.5 ml of anoxic electrolyte, and added to the reactor to a final OD 600 nm of 0.1.

Using a potentiostat (VMP3, Bio-Logic Science Instruments), the ITO electrode was set to +0.4 V relative to the SHE and measurements were performed using the chronoamperometric method. The electrolyte solution to which no cells were added was used as a sterile control.

Next, the same test was carried out using cellobiose instead of CMC, that is, R. C. termitidis was cultured under the same conditions as above using 539 medium originally containing 5 g/L of cellobiose (see FIG. 2).
After one day, the culture had a cell OD600nm of 0.592 and was used for electrochemical measurements.

For electrochemical measurements in the presence of cellobiose, 539 medium was used as the electrolyte. A total of 5 ml of sterile, anoxic medium was added to the electrochemical reactor as the electrolyte. The reactor was operated without stirring during the electrochemical measurements. R. C. termitidis cells pre-cultured for 1 day in medium 539 were harvested from 6 ml of cell culture by centrifugation at 12,022 g for 12 min in an anaerobic COY chamber, resuspended in 0.5 ml of anoxic electrolyte, and then added to the reactor to a final OD600nm of 0.5.

Using a potentiostat (VMP3, Bio-Logic Science Instruments), the ITO electrode was set to +0.4 V relative to the SHE and measurements were made using the chronoamperometric method. The electrolyte solution to which no cells were added was used as a sterile control.

(result)
Figure 3 is a time-current curve showing the time change of the generated current when CMC539 medium was used as the cellulose source. From the results in Figure 3, it can be seen that the current was generated immediately when R. C. termitidis was added. On the other hand, no current was generated in the control sample.

Figure 4 is a time-current curve showing the change in current generated over time when 539 medium (containing cellobiose) was used. From the results in Figure 4, it was confirmed that current was generated even when cellobiose was used.

The above results show that when electrochemical measurements are performed on a sample containing microorganisms derived from the intestines of termites under anaerobic conditions, current generation can be detected using cellulose, which has a molecular weight of 250,000, a much larger molecular weight than cellobiose (a disaccharide), as an electron source.

[Verification of the relationship between electrode potential and current generation]
The bacterial solution used was R. C. termitidis (OD600 = 0.23) that had been cultured for 2 days in 16 mL of medium (DSM.539) placed in an anaerobic glass tube (diameter 18 mm, length 150 mm).

For the current measurement, an 8-series carbon printed electrode (Metrohm, working electrode and counter electrode: carbon, reference electrode: silver) was used. 150 μL of an electrolyte solution containing 5 g/L Cellobiose was added, and current measurement was started at each potential.
Next, the above-mentioned bacterial liquid was centrifuged, the supernatant was discarded, and 50 μL of the resuspension was added, and an increase in current was observed.

Figures 5 to 12 show the results of the above test. In each case, the horizontal axis represents time, and the vertical axis represents the magnitude of the generated current. The arrows in the figures indicate the timing when the bacterial liquid was added. Figure 5 shows the time-current curve when the electrode potential was +0.3 V (vs SHE), Figure 6 shows +0.4 V (vs SHE), Figure 7 shows +0.5 V (vs SHE), Figure 8 shows +0.6 V (vs SHE), Figure 9 shows +0.7 V (vs SHE), Figure 10 shows +0.8 V (vs SHE), Figure 11 shows +0.9 V (vs SHE), and Figure 12 shows +1.0 V (vs SHE).

The results of Figures 5 to 12 show that a current sufficient for detection can be obtained at any potential (+0.3 to +1.0 V). In particular, it was found that the maximum current value tends to be larger when the electrode potential exceeds +0.6 V (vs. SHE) and is equal to or lower than +1.0 V.

This method can provide information to determine whether a monitored object may be deteriorating due to wood pests, without detecting wood pests themselves. It is not necessary to install many monitoring devices around the monitored object, and it is possible to determine the risk of deterioration in a desired location when desired. This method can be applied to monitoring the deterioration of traditional wooden buildings, etc., where prevention of damage by wood pests is an urgent and important issue.

Claims (9)

Taking a sample from the monitored object or its surroundings;
bringing the mixture containing the specimen and water into contact with an electrode, and performing electrochemical measurement in an anaerobic environment in the presence of at least one compound selected from the group consisting of cellulose, cellulose derivatives, and cellobiose;
and providing information for determining that deterioration of the object to be monitored is progressing when current generation is detected as a result of the electrochemical measurement ;
A deterioration diagnosis method for a monitored object , wherein the monitored object is a wooden building . The deterioration diagnosis method for a monitored object according to claim 1, wherein the compound is at least one selected from the group consisting of cellulose and cellulose derivatives. 3. The degradation diagnosis method according to claim 1 , wherein the electrochemical measurement method is a method of controlling a potential of the electrode and measuring a current flowing through the electrode as a function of time. 4. The degradation diagnosis method according to claim 3 , wherein the controlled potential of the electrode is within a range exceeding 0 V with respect to a standard hydrogen electrode and less than an upper limit of a potential window. 5. The deterioration diagnosis method according to claim 4 , wherein the potential is +0.3 to +1.0 V with respect to the standard hydrogen electrode. The degradation diagnostic method according to any one of claims 1 to 5 , wherein the specimen includes at least one selected from the group consisting of environmental water, soil, and garbage. The degradation diagnosis method according to any one of claims 1 to 6, wherein the information for making the judgment includes at least one measurement result selected from the group consisting of a time from the start of the electrochemical measurement to the detection of the current generation, a slope of a current increase curve, and a maximum value of a current density of the generated current. 8. The degradation diagnosis method according to claim 7 , wherein the information for making the judgment includes information obtained by comparing the measurement result with a predetermined reference value. further comprising collecting a control sample;
9. The degradation diagnosis method according to claim 8 , further comprising: obtaining a preliminary measurement result for the control sample in a similar procedure to that for the sample; and determining the reference value based on the preliminary measurement result.