JP2011007725A - Method and apparatus for measuring residual agricultural chemical - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly sensitively detect most agricultural chemicals by a simple constitution.SOLUTION: A lipid film sensor formed by mixing prescribed ratios of lipid, a plasticizer, and a polymer agent is immersed in a plurality of sample liquids in which different concentrations of a surfactant used in an agricultural chemical as an auxiliary agent is dissolved to measure its membrane potential (S1-S7). On the basis of its result, an estimate equation for estimating the concentration of agricultural chemical having the surfactant as an auxiliary agent is determined to the response of the lipid film sensor (S8, S9). The lipid film sensor is immersed in a liquid to be inspected in which deposits in the surface of a body to be inspected are dissolved to measure its membrane potential. The concentration of remaining agricultural chemical of the body to be inspected is estimated on the basis of both of the response of the lipid film sensor obtained to the liquid to be inspected and the estimate expression.

Description

  The present invention relates to a technique for highly sensitively detecting residual agricultural chemicals adhering to agricultural products.

  In recent years, interest in agricultural chemical residues is increasing. In particular, the revised Food Sanitation Law was enforced on May 29, 2006, and the standard value of residual pesticides was set for all foods, and a standard value of 0.01 ppm was set for pesticides with no standard value for residual pesticides. is what happened.

  Conventionally, as a general analysis method for pesticides, an analysis device such as a high-speed chromatographic mass spectrometer (HPLC-MS) or a gas chromatography mass spectrometer (GC-MS) has been used. It requires skill and time, and is not suitable for testing a large amount of agricultural products.

  Therefore, it is desirable to detect the presence or absence of residual pesticides efficiently by a simpler method, and to perform detailed analysis using the above-described analyzer on those determined to have residual pesticides in the inspection.

  As methods for simply detecting residual agricultural chemicals, methods for detecting the presence or absence of a cholinesterase inhibitor, methods using enzyme immunoreaction, and the like have been known.

  However, the method for detecting the presence or absence of a cholinesterase inhibitory substance is effective against organic phosphorus, chlorine and carbamate pesticides having cholinesterase inhibition, but these pesticides are about 20 of the number currently registered as pesticides. The detection sensitivity is as low as about 0.1 to several ppm.

  In the method using enzyme immunoreaction, the detection sensitivity is as high as several ppb to several tens ppb, but the pesticides that can be detected are limited to those for which test antibodies have been developed, and currently only used for about 30 types of pesticides. Can not.

  In addition, although not intended for agricultural chemicals, the applicants have also proposed using a lipid membrane sensor to detect toxic substances such as cyanide, which have an adverse effect on the human body in the same way as agricultural chemicals ( Patent Document 1), the inventors also tried an experiment to determine whether or not pesticide detection is possible using this technique.

Japanese Patent Laid-Open No. 10-267878

  However, as described later, it was found that lipid membrane sensors hardly responded to various pesticides, and it was considered difficult to detect pesticides using lipid membrane sensors.

  This invention is made | formed in view of the said situation, and it aims at providing the residual agrochemical measurement method and apparatus which can detect with high sensitivity with respect to the majority of the registered agrochemical.

  In addition, the present invention uses the fact that the lipid membrane sensor hardly responds to various pesticides as described above, and the surfactant lipid membrane sensor contained in the pesticide in a certain ratio together with the active ingredient. This is based on the idea of estimating the concentration of the drug substance from the response to.

In order to achieve the above object, the pesticide residue measuring method of the present invention comprises:
Immerse a lipid membrane sensor formed by mixing lipids, plasticizers, and polymer agents in a predetermined ratio in multiple sample solutions in which surfactants used as auxiliary agents for agricultural chemicals are dissolved at different concentrations. Measuring the membrane potential (S1 to S7);
Based on the measurement result, obtaining an estimation formula for estimating the concentration of the agrochemical using the surfactant as an auxiliary to the response of the lipid membrane sensor (S8, S9);
Steps (S11 to S15) of immersing the lipid membrane sensor and measuring its membrane potential with respect to the liquid to be inspected in which the deposit on the surface of the test object is dissolved,
A step (S16) of estimating the concentration of the residual pesticide in the object to be inspected from the response of the lipid membrane sensor obtained with respect to the liquid to be examined and the estimation formula.

Moreover, the residual pesticide measuring apparatus of the present invention is
A lipid membrane sensor (25) formed by mixing a lipid, a plasticizer, and a polymer agent at a predetermined ratio;
Response of the lipid membrane sensor based on the membrane potential of the lipid membrane sensor when the lipid membrane sensor is immersed in a plurality of sample solutions in which surfactants used as auxiliary agents for agricultural chemicals are dissolved at different concentrations In addition, an estimation formula for estimating the concentration of the agrochemical using the surfactant as an auxiliary agent is obtained, and the lipid membrane sensor is immersed in a liquid to be inspected in which deposits on the surface of the test object are dissolved. Computing means (37) for calculating the estimated concentration of the residual pesticide of the subject to be inspected from the response at the time and the estimation formula.

Moreover, the residual pesticide measuring apparatus according to claim 3 of the present invention is the residual pesticide measuring apparatus according to claim 2,
The surfactant is anionic,
In the lipid membrane sensor, 800 mg of polyvinyl chloride (PVC) as a polymer agent, 1 ml of 2-nitrooctyl ether (NPOE) as a plasticizer, and tetradodecyl ammonium bromide (TDAB) as a lipid are 0.1 to 0. It is contained in the range of 8 mg.

Moreover, the residual pesticide measuring apparatus according to claim 4 of the present invention is the residual pesticide measuring apparatus according to claim 2,
The surfactant is anionic,
The lipid membrane sensor is in the range of 800 mg of polyvinyl chloride (PVC) as a polymer agent, 0.1 mg of tetradodecyl ammonium bromide (TDAB) as a lipid, and 0.75 to 1 mlg of dioctylphenyl phosphonate (DOPP) as a plasticizer. It is characterized by being included.

Moreover, the residual pesticide measuring apparatus according to claim 5 of the present invention is the residual pesticide measuring apparatus according to claim 2,
The surfactant is anionic,
The lipid membrane sensor is composed of 800 mg of polyvinyl chloride (PVC) as a polymer agent, 1 ml of 2-nitrooctyl ether (NPOE) as a plasticizer, and 0.1 to 0 tridodecylmethylammonium chloride (TDAC) as a lipid. It is contained in the range of 3 mg.

Moreover, the residual agricultural chemical measuring apparatus according to claim 6 of the present invention is the residual agricultural chemical measuring apparatus according to claim 2,
The surfactant is anionic,
The lipid membrane sensor is composed of 800 mg of polyvinyl chloride (PVC) as a polymer agent, 1 ml of 2-nitrooctyl ether (NPOE) as a plasticizer and 0.1 to 0 of didodecyldimethylammonium bromide (DDAB) as a lipid. It is contained in the range of 4 mg.

  As described above, in the present invention, the formula for estimating the concentration of residual pesticide from the membrane potential of the lipid membrane sensor based on the concentration of the surfactant contained as an auxiliary agent in the agricultural chemical and the membrane potential of the lipid membrane sensor. From the membrane potential of the lipid membrane sensor with respect to the sample liquid of the test subject and the estimation formula, the concentration of the residual pesticide in the test subject is estimated.

  This is because the concentration of residual agricultural chemicals and the concentration of surfactant contained as an auxiliary agent are approximately proportional to each other, and from the types of agricultural chemicals used for the test subject, This is because the ratio of the surfactant to the surfactant can be almost specified, and the lipid membrane sensor for the pesticide has not responded to the active ingredient of the pesticide, but mainly responds to the surfactant.

  Therefore, by obtaining the response of the lipid membrane sensor to the surfactant concentration as described above, and using the estimation formula obtained from the relationship, the concentration of the residual pesticide can be accurately estimated. Sensitive detection is possible.

  In the case where the surfactant is anionic, the lipid membrane sensor is composed of lipid tetradodecyl ammonium bromide (TDAB) with respect to 800 mg of the polymer agent polyvinyl chloride (PVC) and 1 ml of the plasticizer 2-nitrooctyl ether (NPOE). ) In a range of 0.1 to 0.8 mg can be detected with particularly high sensitivity and stability.

  In addition, when the lipid TDAB was 0.1 mg as a lipid membrane sensor, the one containing the plasticizer DOPP in the range of 0.75 to 1 mlg was confirmed to have effective sensitivity to the surfactant. .

  A lipid membrane sensor containing 0.1 to 0.3 mg of lipid tridodecylmethylammonium chloride (TDAC) with respect to 1 ml of the plasticizer NPOE has an effective sensitivity to the surfactant. It was confirmed that

  A lipid membrane sensor that contains lipid didodecyldimethylammonium bromide (DDAB) in the range of 0.1 to 0.4 mg per 1 ml of the plasticizer NPOE has an effective sensitivity to the surfactant. It was confirmed that

Configuration diagram of an embodiment of the present invention Diagram showing the composition of commercially available pesticides The flowchart which shows the process sequence of embodiment Diagram showing the response of the active ingredient glyphosate only to the sample fluid The figure which shows the response with respect to the sample liquid containing an active ingredient glyphosate and SDS Figure showing the response of the active ingredient chlorfenapyr alone to the sample solution The figure which shows the response with respect to the sample liquid containing the active ingredient chlorfenapyr and SDS Diagram showing the response of the active ingredient imazalil alone to the sample solution The figure which shows the response with respect to the samble liquid containing an active ingredient imazalil and SDS The figure which shows the relative response value of the lipid membrane sensor with respect to surfactant SDS The figure which shows the CPA response value of the lipid membrane sensor with respect to surfactant SDS The figure which shows an example of the density | concentration of surfactant SDS, and the response characteristic of a lipid membrane sensor The flowchart which shows the procedure of the inspection process of embodiment The figure which shows the relative response value of the lipid membrane sensor which changed content of the plasticizer Diagram showing the response of the original glyphosate alone to the sample fluid when using different lipids The figure which shows the response with respect to the samble liquid containing an active ingredient glyphosate and SDS when another lipid is used. Diagram showing the response of the original chlorfenapyr alone to the sample fluid when using different lipids The figure which shows the response with respect to the sample liquid containing the active ingredient chlorfenapyr and SDS when another lipid is used. Diagram showing the response to the original imazalil-only samble solution using different lipids The figure which shows the response with respect to the sample liquid containing the active ingredient imazalil and SDS when another lipid is used The figure which shows the relative response value of the lipid membrane sensor using another lipid The figure which shows the relative response value of the lipid membrane sensor using another lipid

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of a residual agricultural chemical measuring apparatus 20 according to the embodiment.

  In FIG. 1, the residual pesticide measuring apparatus 20 includes a container 21 for containing a reference solution, a sample solution, and a test target solution, a probe 22, a voltage detector 35 that detects a potential difference between the probes 22, and a voltage detector 35. An A / D converter 36 that converts the output into a digital value, an arithmetic unit 37 that performs processing such as storage, calculation, and comparison determination on the output of the A / D converter 36, and an output that outputs a processing result of the arithmetic unit 37 It is comprised by the apparatus 38.

  The probe 22 is used by being immersed in a liquid placed in a container 21 and has a reference electrode 23 and a lipid membrane sensor 25 for outputting a reference potential for measurement.

  The surface of the reference electrode 23 is covered with a buffer layer 24 in which 100 mMole of potassium chloride is fixed with agar so as not to react with lipid in the liquid, and a lead wire 22a is connected thereto.

  The lipid membrane sensor 25 is fixed in a state where one surface side is exposed on the surface of a base material 26 such as acrylic, and the opposite surface of the lipid membrane sensor 25 is equivalent to the buffer layer 24 of the reference electrode 23. An electrode 28 is provided via the buffer layer 27, and a lead wire 22 b is connected to the electrode 28.

  The lipid membrane sensor 25 is integrated so that a lipid having a non-polar and hydrophobic portion and a polar and hydrophilic portion forms a membrane with the hydrophilic portion facing the surface side. Therefore, when immersed in a liquid, the potential of the membrane changes according to the components in the liquid.

  The lipid membrane sensor 25 is prepared by mixing a base polymer, a plasticizer, and a lipid in a predetermined ratio.

  Here, a mixture of 800 mg of polyvinyl chloride (PVC) as a polymer, 1 ml of 2-nitrooctyl ether (NPOE) having a positive charge as a plasticizer, and a predetermined amount of tetradodecyl ammonium bromide (TDAB) as a lipid is mixed with 10 cc of THF. It is dissolved in a flat-bottomed container (for example, a petri dish of 85 mmφ), and kept at about 30 ° C. for 2 hours on a uniform heated plate to volatilize THF to form a lipid membrane having a thickness of about 200 μm. It has gained. In addition, although the ratio of lipid TDAB is mentioned later, it sets to the ratio which has responsiveness with respect to surfactant as an adjuvant of an agricultural chemical.

  When the probe 22 is immersed in a liquid, the distance between the reference electrode 23 and the lipid membrane sensor 25 is kept constant so that the measurement conditions do not change. You may support by a fixed space | interval.

Lead wires 22 a and 22 b of the probe 22 are connected to a voltage detector 35.
The voltage detector 35 is configured by, for example, a differential amplifier, detects a difference (voltage) between the potential of the reference electrode 23 and the potential of the lipid membrane sensor 25 and outputs the difference to the A / D converter 36.

  The A / D converter 36 converts the output voltage of the voltage detector 35 into a digital value and outputs it to the arithmetic unit 37.

  The arithmetic unit 37 is constituted by a microcomputer, and stores an output value of the A / D converter 36 in the memory 37a when receiving a storage command from an operation unit (not shown), and stores the stored value in the memory 37a when receiving the arithmetic command. Based on the output value of the A / D converter 36, arithmetic processing necessary for measuring the concentration of residual agricultural chemicals is performed, and the result is output to an output device (for example, a display) 38.

  Next, the principle of the residual pesticide measuring method using this residual pesticide measuring apparatus 20 will be described. First, FIG. 2 shows the composition of agricultural chemicals currently on the market. As is apparent from this figure, general pesticides consist of an active ingredient as an active ingredient exhibiting agrochemical activity, a carrier as an additive that retains the active ingredient and provides ease of handling in application, and an interface. It consists of an activator.

  Among these, anionic surfactants are used for many agricultural chemicals. From various experiments, it was confirmed that the components of the agrochemical substance were not substantially sensitive by the measurement using the probe 22 described above.

  Therefore, the inventors of the present application have further experimented and found that effective sensitivity can be obtained by measurement using the probe 22 for the surfactant used as an auxiliary agent for most of these agricultural chemicals.

  In other words, this measurement method does not directly measure the concentration of the pesticide residue in agricultural products, but measures the concentration of the surfactant contained in the pesticide along with the active ingredient, and estimates the pesticide concentration from the measurement result. It is to do.

The method will be specifically described below.
First, in addition to the reference solution and the cleaning solution, sample solutions having concentrations of 10 ppb, 30 ppb, 50 ppb, and 100 ppb of SDS (Sodium Dodecyl Sulfate) widely used as an anionic surfactant are prepared. did.

  In addition, as a sample used for measurement to confirm that the lipid membrane sensor does not respond to the active ingredient of the agrochemical and shows remarkable responsiveness to the surfactant, three typical active ingredients glyphosate, chlorfenapyr, and imazalil Were used to prepare a sample solution containing only the three original materials and a sample solution containing each of these original materials and SDS.

  Here, the standard solution is 30 mM potassium chloride + 0.3 mM tartaric acid, in which 0.045 g of tartaric acid and 2.24 g of potassium chloride are dissolved in pure water to make the total amount to 1 liter. The cleaning solution for the plus membrane is a solution of 10 mM potassium hydroxide + 100 mM potassium chloride + 30 vol% ethanol. 7.46 g of potassium chloride is dissolved in about 500 ml of pure water, and 300 ml of ethanol with a purity of 95% or more is added and stirred. And further. 10 ml of 1M potassium hydroxide solution was added, and the total volume was made up to 1 liter with pure water. Other cleaning solutions are equivalent to the reference solution.

  Moreover, the lipid membrane sensor 25 used for the probe 22 was prepared with different lipid TDAB contents, and the difference in response was confirmed.

Actual measurement is performed according to the flowchart of FIG.
That is, first, the probe 22 is immersed in the reference solution, and the membrane potential V1 of the lipid membrane sensor 25 with respect to the reference electrode 23 is measured and stored (S1).

  Next, the probe 22 is immersed in the sample solution, the membrane potential V2 of the lipid membrane sensor 25 with respect to the reference electrode 23 is measured, and (V2-V1) is calculated and stored as the relative response value Va for the sample solution. (S2).

  Next, the probe 22 is immersed in a cleaning solution to gently clean the sensor surface (leaving components adsorbed on the sensor surface), and then immersed in a reference solution (same composition as the first reference solution) to form a lipid membrane for the reference electrode 23. The membrane potential V3 of the sensor 25 is measured, and (V3-V1) is calculated and stored as the CPA response value (response value due to the adsorbed component) Vcpa for the sample liquid (S3, S4).

Finally, the probe 22 is immersed in a cleaning solution to clean the sensor surface, and components adsorbed on the surface are washed away (S5).
The above processes S1 to S5 are repeated for sample solutions having different concentrations (S6, S7).

  Among the results obtained in this manner, the response of the sample solution containing only the agrochemical raw material and the response of the sample solution containing the active material and SDS are shown in FIGS.

  4, 6, and 8 show responses (relative response values) of only three kinds of drug substances, which are almost constant and sensitive to changes in the drug substance concentration and the lipid content of the sensor. It turns out that there is no.

  On the other hand, FIG. 5, FIG. 7 and FIG. 9 show the response (relative response value) of the sample solution obtained by adding the same amount of SDS to the above three kinds of original materials, which is clearly the response of the original material alone. In contrast, the response increases with the concentration of SDS, and it can be seen that the degree of change varies depending on the lipid content of the sensor.

  From the above, the probe 22 does not respond to the active ingredient in pesticides, has a remarkable response to the SDS of the surfactant, and its response characteristics vary depending on the lipid content. I understand.

  Therefore, if the lipid content of the probe 22 is set to an appropriate value and the relationship between the concentration and the response to the surfactant is obtained in advance, the concentration can be estimated from the measurement result of the pesticide whose concentration is unknown. Can do.

  Next, the measurement result with respect to the sample liquid from which the density | concentration differs only by SDS is shown in FIG. 10, FIG.

  FIG. 10 shows changes in the relative response value Va when the lipid TDAB content of the lipid membrane sensor 25 is changed, and FIG. 11 shows changes in the CPA response value Vcpa.

  From these results, the lipid membrane sensor having a lipid TDAB content in the range of 0.01 mg to 0.8 mg has an output corresponding to the concentration of the surfactant SDS sample solution. Recognize.

  However, as a result of repeating the experiment, reproducibility tends to be poor when the content of lipid TDAB is less than 0.1 mg, and the content of lipid TDAB is 0 for an anionic surfactant SDS. A sensitivity of 10 ppb or more can be stably obtained in the range of 1 mg to 1 mg. In particular, when the lipid TDAB content is 0.1 mg, both the relative response value and the CPA response value are highly sensitive.

  The results obtained by using the lipid membrane sensor 25 showing high sensitivity to the anionic surfactant SDS in this way (the relative response value Va is desirable in terms of characteristics. From Va), for example, the relationship between the surfactant concentration q and the response value Va of the lipid membrane sensor 25 is obtained as shown in FIG. Therefore, for example, when a measurement result using the lipid membrane sensor 25 having a lipid TDAB content of 0.1 mg is obtained, an arithmetic command is issued to the arithmetic device 37 to approximate the above relationship (straight line). The coefficient of the equation or curve equation is obtained and stored (S8).

  Then, the content ratio α (known) of the raw material of the agricultural chemical expected to be used in the actual test object, the content ratio β (known) of the surfactant of the agricultural chemical, and the above coefficient From this, the formula for estimating the concentration of the pesticide (raw material) is determined (S9).

For example, the relationship between the surfactant concentration q and the response value Va of the lipid membrane sensor 25 is expressed by the linear equation Va = A · q.
When the estimated concentration of the pesticide residue in the test subject is γ,
β / α = q / γ
Therefore, the relationship between the estimated concentration γ and the response value Va is
Va = A · (β / α) γ
It becomes.

Therefore, the estimated concentration γ of residual pesticide is
γ = Va / [A · (β / α)] (1)
Can be obtained by the following calculation.

  Here, the coefficient A is known from the value obtained by the experiment on the SDS sample solution, and (β / α) is the content ratio α of the pesticide active ingredient that is expected to be used in the actual test object. And the content ratio β of the surfactant are known, and this is manually input to the calculation device 37 or registered in advance in the database inside the calculation device 37 for each pesticide, By performing the designation operation, the above estimation formula can be calculated.

  Thus, after the concentration estimation formula of the residual agricultural chemical is obtained, the process proceeds to the inspection process of FIG. In this inspection process, a liquid to be inspected (which is set so as to be a liquid having the same weight as the weight of the object to be inspected) in which deposits on the surface of the object to be inspected, such as agricultural crops, are prepared.

  Then, as described above, the probe 22 is immersed in the reference solution, and the membrane potential 1 of the lipid membrane sensor 25 with respect to the reference electrode 23 is obtained and stored, and then the probe 22 is immersed in the inspection target solution to obtain the relative response value Va. After washing lightly, the sample is immersed in a reference solution to obtain a CPA response value Vcpa, and finally immersed in a cleaning solution for cleaning (S11 to S15).

  Then, the obtained response value (in this case, the relative response value) Va is substituted into the estimation formula (1) to obtain the estimated concentration γ of the residual pesticide (S16).

  Then, the obtained density γ is compared with a preset threshold value R. When the estimated density γ is larger than the threshold value R, a failure (NG) display is performed together with the density γ, and the estimated density γ is When the value is equal to or less than the threshold value R, a pass (OK) display is performed together with the concentration γ (S17 to 19).

  In the above processing, the relative response value and the CPA response value are obtained. However, in the results of the experiments so far, the relative response value Va shows a more stable characteristic. Therefore, the response value is changed to only the relative response value. It may be limited.

  The characteristics shown in FIGS. 4 to 11 were sensitivity characteristics of a lipid membrane sensor in which the content of lipid TDAB was varied with respect to 800 mg of polymer PCV and 1 ml of plasticizer NPOE, but the content of lipid TDAB was 0.1 mg. Then, the sensitivity characteristic of the lipid membrane sensor with variable content of the plasticizer dioctylphenyl phosphonate (DOPP) to the surfactant SDS was measured by the same procedure as described above, and the result of FIG. 14 was obtained.

  In FIG. 14, it can be seen that a relative response value Va corresponding to the concentration of the surfactant SDS is obtained when the content of the plasticizer DOPP is in the range of 0.75 to 1 ml.

  Therefore, a lipid membrane sensor formed with the plasticizer DOPP in the range of 0.75 to 1 ml with respect to the polymer PCV 800 mg and the lipid TDAB 0.1 mg is also effective for the measurement of residual agricultural chemicals.

  In the above example, TDAB was used as the lipid of the probe 22, but similar results could be obtained even when tridodecylmethylammonium chloride (TDAC) was used as the lipid.

  FIGS. 15 to 20 show the responses (relative response values) of each of the three kinds of drug substances and the drug substance and SDS to the sample liquid when lipid TDAC is used. As shown in FIG. 19, it can be seen that there is no sensitivity to the sample solution of only the original substance.

  On the other hand, as shown in FIGS. 16, 18, and 20, a remarkable responsiveness can be confirmed in the same manner as described above with respect to a sample solution containing the same amount of SDS as the original substance, and a probe using lipid TDAC. 22 can estimate the concentration of the agricultural chemical as described above.

  In FIG. 15 to FIG. 20, for the convenience of the experiment, the content of lipid TDAC is shown in units of millimolar (mM) on the horizontal axis. What is necessary is just to make 01 mM correspond to 0.057 mg.

  FIG. 21 shows the sensitivity characteristics of the lipid membrane sensor with the lipid TDAC content varied with respect to 800 mg of the polymer PCV and 1 ml of the plasticizer NPOE with respect to the surfactant SDS.

  From the experimental results in FIG. 21, it can be seen that the relative response value Va corresponding to the concentration of the surfactant SDS is obtained when the content of the lipid TDAC is in the range of 0.1 to 0.3 mg.

  Therefore, it can be seen that a lipid membrane sensor formed with a lipid TDAC content in the range of 0.1 to 0.3 mg based on 800 mg of the polymer PCV and 1 ml of the plasticizer NPOE is also effective for the measurement of residual agricultural chemicals.

  FIG. 22 shows the sensitivity characteristics of the lipid membrane sensor with respect to the surfactant SDS in which the content of lipid didodecyldimethylammonium bromide (DDAB) is varied with respect to 800 mg of the polymer PCV and 1 ml of the plasticizer NPOE.

  From the experimental results shown in FIG. 22, it can be seen that a relative response value Va corresponding to the concentration of the surfactant SDS is obtained when the lipid DDAB content is in the range of 0.1 to 0.4 mg.

  Therefore, it can be understood that a lipid membrane sensor formed with a polymer DD of 800 mg and a plasticizer NPOE in the range of 0.1 to 0.4 mg of lipid DDAB is also effective for the measurement of residual agricultural chemicals.

  Although not shown, it has been confirmed that no sensitivity to the drug substance can be obtained even when the lipid DDAB is used. From these facts, it can be sufficiently estimated that a sensor using lipids is not responsive to a representative active ingredient of an agricultural chemical and exhibits a remarkable responsiveness to a surfactant.

  20 ... Residual pesticide measuring device, 21 ... Container, 22 ... Probe, 23 ... Reference electrode, 25 ... Lipid membrane sensor, 35 ... Voltage detector, 36 ... A / D converter, 37 ... Arithmetic unit, 38 …… Output device

Claims (6)

Immerse a lipid membrane sensor formed by mixing lipids, plasticizers, and polymer agents in a predetermined ratio in multiple sample solutions in which surfactants used as auxiliary agents for agricultural chemicals are dissolved at different concentrations. Measuring the membrane potential (S1 to S7);
Based on the measurement result, obtaining an estimation formula for estimating the concentration of the agrochemical using the surfactant as an auxiliary to the response of the lipid membrane sensor (S8, S9);
Steps (S11 to S15) of immersing the lipid membrane sensor and measuring its membrane potential with respect to the liquid to be inspected in which the deposit on the surface of the test object is dissolved,
A method for measuring residual agricultural chemicals, comprising: estimating the concentration of residual agricultural chemicals in the subject to be inspected from the response of the lipid membrane sensor obtained with respect to the liquid to be inspected and the estimation formula (S16). A lipid membrane sensor (25) formed by mixing a lipid, a plasticizer, and a polymer agent at a predetermined ratio;
Response of the lipid membrane sensor based on the membrane potential of the lipid membrane sensor when the lipid membrane sensor is immersed in a plurality of sample solutions in which surfactants used as auxiliary agents for agricultural chemicals are dissolved at different concentrations In addition, an estimation formula for estimating the concentration of the agrochemical using the surfactant as an auxiliary agent is obtained, and the lipid membrane sensor is immersed in a liquid to be inspected in which deposits on the surface of the test object are dissolved. A residual pesticide measuring apparatus comprising a calculation means (37) for calculating an estimated concentration of the residual pesticide of the subject to be inspected from a response when the test is performed and the estimation formula. The surfactant is anionic,
In the lipid membrane sensor, 800 mg of polyvinyl chloride (PVC) as a polymer agent, 1 ml of 2-nitrooctyl ether (NPOE) as a plasticizer, and tetradodecyl ammonium bromide (TDAB) as a lipid are 0.1 to 0. The residual pesticide measuring apparatus according to claim 2, which is contained in a range of 8 mg. The surfactant is anionic,
The lipid membrane sensor is in the range of 800 mg of polyvinyl chloride (PVC) as a polymer agent, 0.1 mg of tetradodecyl ammonium bromide (TDAB) as a lipid, and 0.75 to 1 mlg of dioctylphenyl phosphonate (DOPP) as a plasticizer. The residual pesticide measuring apparatus according to claim 2, wherein The surfactant is anionic,
The lipid membrane sensor is composed of 800 mg of polyvinyl chloride (PVC) as a polymer agent, 1 ml of 2-nitrooctyl ether (NPOE) as a plasticizer, and 0.1 to 0 tridodecylmethylammonium chloride (TDAC) as a lipid. The residual pesticide measuring apparatus according to claim 2, which is contained in a range of .3 mg. The surfactant is anionic,
The lipid membrane sensor is composed of 800 mg of polyvinyl chloride (PVC) as a polymer agent, 1 ml of 2-nitrooctyl ether (NPOE) as a plasticizer and 0.1 to 0 of didodecyldimethylammonium bromide (DDAB) as a lipid. The residual pesticide measuring apparatus according to claim 2, which is contained in a range of .4 mg.

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