Application of menthol-organic acid eutectic solvent in organophosphorus detection

Abstract

The invention belongs to the technical field of detection and analysis, and particularly relates to application of a menthol-organic acid eutectic solvent in organophosphorus detection. According to the present invention, the technical scheme is provided that the menthol-organic acid eutectic solvent is adopted as the analysis protective agent when the gas chromatography-mass spectrometry method is adopted to detect a variety of organic phosphorus, and the detection lower limit of a variety of target organic phosphorus can be significantly reduced by using the technical scheme. Performance test experiments show that when the menthol-butyric acid eutectic solvent is used for detecting various organophosphorus, the response signal of omethoate is increased by more than 20 times and reaches 35.5 times. When the menthol-hexanoic acid eutectic solvent is adopted, the peak areas of the omethoate, the octamethylphos, the metolafos and the isometon-methyl are respectively increased by 71.9 times, 70.4 times, 28.4 times and 20.5 times. When the menthol-octanoic acid eutectic solvent is adopted, the response signal of omethoate is increased by more than 100 times and reaches 101.1 times, and unexpected technical effects are achieved.

Description

Technical Field

[0001] The present application belongs to the field of detection and analysis technology, and specifically relates to the application of a menthol-organic acid low eutectic solvent in the detection of organophosphorus. Background Art

[0002] Organophosphorus pesticides are widely used in agricultural production due to their superior insecticidal and weed-killing abilities. However, their excessive use will cause residues in agricultural products and the environment, and accumulate in the human body through the food chain enrichment effect, causing human poisoning. Therefore, strengthening the monitoring of organophosphorus pesticide residues is an important measure to ensure human health and safety.

[0003] Gas chromatography-mass spectrometry is a common method for detecting organophosphorus pesticides. However, in the process of detecting organophosphorus by gas chromatography-mass spectrometry, it was found that the chromatographic peak response of some varieties of organophosphorus was weak and the detection sensitivity was low, especially for organophosphorus pesticides such as octamethoxam, oxydemeton-methyl, and bromophos. This is because organophosphorus molecules containing P=O or P=S groups are easily adsorbed by the active sites of the injection port or column head, resulting in a decrease in the number of organophosphorus molecules entering the analyzer and a decrease in the chromatographic peak response signal. Studies have found that analytical protective agents such as 3-ethoxy-1,2-propanediol, gulolactone, and sorbitol can preferentially occupy the active sites in the gas phase through hydrogen bonds, block the interaction between organophosphorus and the active sites, and significantly improve the gas chromatography signal of organophosphorus pesticides. However, the analytical protective agents currently studied are generally polyhydroxy compounds with high polarity and must be soluble in polar solvents such as acetonitrile and water, which limits their application in gas chromatography-mass spectrometry analysis.

[0004] In recent years, considering that analytical protectants and analytes mainly interact with active sites in the gas phase through hydrogen bonds, relevant research and development using low eutectic solvents to replace analytical protectants has begun to appear in the analysis and detection of other substances such as pyrethroids and quinolones. For example, patent application number 202310740715.X discloses the use of a low eutectic solvent formed by menthol as a hydrogen bond acceptor and p-methylphenol as a hydrogen bond donor to detect quinolone drug residues. In addition, there are related studies on the detection of pyrethroid residues using a low eutectic solvent formed by menthol as a hydrogen bond acceptor and decanoic acid as a hydrogen bond donor. However, on the one hand, different analytes have different functional groups and molecular structures. For example, organophosphorus pesticides contain P=O or P=S groups, while pyrethroids may contain functional groups such as C=O or C=C double bonds. These differences determine the strength and mode of interaction between them and hydrogen bond acceptors and donors in the low eutectic solvents, as well as the difference in solubility, which will directly affect the detection sensitivity. On the other hand, the adsorption capacity of active sites in gas chromatography-mass spectrometry is selective, and the role of low eutectic solvents is to reduce the nonspecific adsorption of the analytes to be tested by competitively occupying these active sites. Therefore, for those skilled in the art, it is difficult to transfer the low eutectic solvents set for a certain analytical substrate to the analysis of other substrates, and it is expected that the detection sensitivity of the transferred analytical substrates can be improved. Summary of the invention

[0005] In order to solve the above technical problems faced by organophosphorus detection, the present application proposes a technical solution for using a menthol-organic acid system deep eutectic solvent as an analytical protective agent in the process of detecting organophosphorus as an analyte to be detected by gas chromatography-mass spectrometry to improve the sensitivity of organophosphorus detection. Specifically:

[0006] A menthol-organic acid deep eutectic solvent is used in the detection of organic phosphorus, wherein the deep eutectic solvent uses menthol as a hydrogen bond acceptor and an organic acid as a hydrogen bond donor; the organic acid includes one or more of propionic acid, butyric acid, hexanoic acid and octanoic acid; the detection adopts gas chromatography-mass spectrometry; the organic phosphorus includes mefenphos, omethoate, chlorpyrifos, methyl isothiocarb, ethoprophos, chlorpyrifos, phorate, dimethoate, octamphos, terbufos, fenthiophos, chlorpyrifos, diazinon, disulfothion, isoflavone One or more of the group consisting of chlorpyrifos-methyl, chlorpyrifos-sodium, chlorpyrifos-methyl, malathion, fenthion, chlorpyrifos-sodium, dichlorvos, bromophos, chlorpyrifos-sodium, isoflavone, quinalphos, chlorpyrifos-sodium, bromophos-ethyl, chlorpyrifos-sodium, chlorpyrifos-sodium, fenamiphos, chlorpyrifos-sodium, bromophos-ethyl, chlorpyrifos-sodium, chlorpyrifos-sodium, fenamiphos, chlorpyrifos-sodium, propylthion, propylthion, defoliation, ethylthion, ethylthion, chlorpyrifos-sodium, propylthion, triazophos, trithion, fenamiphos sulfoxide, phosmet, phenylphos, thiophos, thiophos, chlorpyrifos, bromophos, and azophos.

[0007] Preferably, when the organic acid includes one or more of propionic acid, butyric acid, and caproic acid, the organic phosphorus also includes chloranil. The applicant found that in the process of using menthol-octanoic acid low eutectic solvent as an analytical protective agent to detect chloranil by gas chromatography-mass spectrometry, the peak area of ​​chloranil could not be effectively improved, which shows that the system cannot improve the detection sensitivity of chloranil. However, in further research, it was found that when short-chain organic acids such as propionic acid, butyric acid, and caproic acid were used to replace octanoic acid and menthol to form a low eutectic solvent, the response of chloranil increased significantly, which was specifically manifested as an increase of 3.5 times, 6.6 times, and 11.89 times in peak area, respectively, which shows that different organic acids have obvious differences in the detection effect of target compounds when used as analytical protective agents.

[0008] Preferably, the organic acid includes propionic acid, and the organophosphorus includes one or more of chlorfenthion and omethoate. In this technical solution, chlorfenthion and omethoate are detected by gas chromatography-mass spectrometry by using menthol-propionic acid deep eutectic solvent as analytical protective agent, and the peak areas increase by 6.85 and 13.75 times respectively, and the sensitivity of organophosphorus detection is effectively improved.

[0009] Preferably, the organic acid includes butyric acid, and the organophosphorus includes one or more of omethoate, octamidine, chlorpyrifos, methyl isothiocarb, and ethoxyproline. This technical solution uses menthol-butyric acid deep eutectic solvent as an analytical protective agent to detect the above-mentioned organophosphorus by gas chromatography-mass spectrometry, and the peak area increases by 10.23 to 35.47 times, and the sensitivity of organophosphorus detection is effectively improved, which has unexpected technical effects.

[0010] Preferably, the organic acid is butyric acid, and the organophosphorus includes one or more of chlorpyrifos, chlorpyrifos, phorate, dimethoate, terbufos, chlorpyrifos, diazinon, disulfothion, isothiocyanate, chlorpyrifos, methyl pirimiphos, fenthion, dimethoate, pirimiphos, isofos, quinalphos, bromothion-ethyl, chlorpyrifos, fenamiphos and profenofos. This technical solution uses menthol-butyric acid deep eutectic solvent as an analytical protective agent to detect the above-mentioned organophosphorus by gas chromatography-mass spectrometry, and the peak area increases by 5.18 to 8.83 times, and the sensitivity of organophosphorus detection is effectively improved.

[0011] Preferably, the organic acid is hexanoic acid, and the organophosphorus includes one or more of omethoate, octamphos, cypermethrin, methyl isothioate, ethoxyphos, chlorpyrifos, dimethoate, terbufos, chlorpyrifos, diazinon, ethsulfuron, isothiocyanate, chlorpyrifos, methyl pirimiphos, fenthion, pirimiphos, isoflavone, quinalphos, baclofos, ethyl bromothion, chlorpyrifos, fenamiphos, bromophos-ethyl, chlorpyrifos, fenamiphos, bromophos-ethyl, fenthiocyanate, fenamiphos, bromophos-ethyl, and chlorpyrifos. This technical solution uses menthol-hexanoic acid deep eutectic solvent as an analytical protective agent to detect the above-mentioned organophosphorus by gas chromatography-mass spectrometry, and the peak area increases by 10.13 to 71.88 times, and the sensitivity of organophosphorus detection is effectively improved, which has unexpected technical effects.

[0012] Preferably, the organic acid is hexanoic acid, and the organophosphorus includes one or more of chlorpyrifos, phorate, chlorpyrifos, methyl chlorpyrifos, chlorpyrifos, chlorpyrifos, chlorcarbamide, chlorfenapyr, bromophos, chlorpyrifos, chlorpyrifos, chlorfenapyr, bromophos, chlorpyrifos, chlorpyrifos, chlorfenapyr, bromophos, chlorpyrifos, chlorpyrifos, chlorfenapyr, chlorfenapyr, chlorfenapyr, bromophos, chlorpyrifos, chlorfenapyr ...

[0013] Preferably, the organic acid is octanoic acid, and the organophosphorus includes one or more of omethoate, mefenphos, methyl isothioate, ethoxyphos, thiophanate-methyl, octamidine, diazinon, isothioate, methyl pirimiphos, fenthion, pirimiphos-methyl, isoflavone, isoflavone, baclofos, chlorpyrifos and profenofos, cypermethrin, phorate, dimethoate, terbufos, chlorpyrifos, ethylsulfophos, chlorpyrifos-methyl, chlorpyrifos, chlorpyrifos, chlorpyrifos, bromothion, quinalphos, methidathion, ethyl bromothion, chlorpyrifos, fenamiphos, propylthiophos, defoliant, cypermethrin, sulfothiophos, triazophos, fenamiphos sulfoxide, phosmet, phosphamidon and bromophenylphos. This technical solution uses menthol-octanoic acid low eutectic solvent as an analytical protective agent to detect the above-mentioned organophosphorus by gas chromatography-mass spectrometry. The peak area increases by 10.7 to 101.08 times, and the sensitivity of organophosphorus detection is effectively improved, with unexpected technical effects.

[0014] Preferably, the organic acid is octanoic acid, and the organophosphorus includes one or more of fofophos, fenitrothion, malathion, defoliant, trithion, safflower, phosalone and azophos. In this technical solution, the menthol-octanoic acid deep eutectic solvent is used as an analytical protective agent to detect the above-mentioned organophosphorus by gas chromatography-mass spectrometry, and the peak area increases by 5.63 to 9.73 times, and the sensitivity of organophosphorus detection is effectively improved.

[0015] Preferably, the molar ratio of menthol to organic acid is (1-3):(1-3); more preferably, the molar ratio of menthol to organic acid is 1:1.

[0016] Compared with the prior art, this application has the following beneficial effects:

[0017] The present application proposes a technical solution using menthol-organic acid low eutectic solvent as an analytical protective agent when detecting a variety of organophosphorus by gas chromatography-mass spectrometry, which can significantly reduce the detection limit of a variety of target organophosphorus. Performance test experiments have found that when menthol-propionic acid is used to detect omethoate, the peak area increases by 13.75 times, and when chlorpyrifos is detected, the peak area increases by 6.85 times. When menthol-butyric acid low eutectic solvent is used to detect a variety of organophosphorus, the response signal of omethoate increases by more than 20 times, reaching 35.5 times, and the signals of the four organophosphorus, octamidine, chlorpyrifos, methyl isothiocarb, and chlorpyrifos also increase by 17.09, 13.47, 10.26 and 10.23 times, respectively, and 21 of the remaining organophosphorus have a signal growth multiple of 5-10 times. When using menthol-caproic acid deep eutectic solvent, the peak areas of omethoate, octamethylenetetramine, chlorpyrifos, and methyl isoenide increased by 71.9, 70.4, 28.4, and 20.5 times, respectively. The peak area of ​​21 kinds of organophosphorus increased by 10-20 times, and the peak area of ​​21 kinds of organophosphorus increased by 5-10 times. When using menthol-octanoic acid deep eutectic solvent, the response signal of omethoate increased by more than 100 times, reaching 101.1 times, and the peak area of ​​14 other organophosphorus pesticides increased by more than 20 times, the peak area of ​​26 kinds of organophosphorus increased by 10-20 times, and the peak area of ​​8 kinds of organophosphorus increased by 5-10 times. These results show that by adjusting the above-mentioned technical scheme of the present application, the detection limit of different organophosphorus compounds in gas chromatography-mass spectrometry detection can be significantly improved, with unexpected technical effects. DETAILED DESCRIPTION

[0018] The present application will be further described below in the form of specific embodiments. Those of ordinary skill in the art will be able to implement the present application based on these descriptions. In addition, the embodiments of the present application involved in the following description are generally only embodiments of a part of the present application, rather than all embodiments. Therefore, based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work should fall within the scope of protection of the present application.

[0019] The relevant parameters of the gas chromatography-mass spectrometry in the following embodiments are as follows: gas chromatography: using a DB-5MS weak polar capillary column with a specification of 30m×0.25mm×0.25μm; injection volume: 1.0μL, non-split injection; injection port temperature: 300°C, septum purge: 3mL / min; program temperature conditions: initial temperature: 60°C, increased to 120°C at a rate of 20°C / min, maintained for 1min, and then increased to 280°C at a rate of 5°C / min, maintained for 3min; carrier gas: high-purity nitrogen, purity ≥99.999%; constant flow mode, flow rate 1mL / min; mass spectrometry: using an EI ion source, source temperature 230°C, electron bombardment energy: 70eV, gas transfer rod temperature: 280°C; quadrupole 1 and quadrupole 2 temperature: 150°C; multiple reaction monitoring mode (MRM), specific monitoring ion pairs and collision energies are shown in the table below.

[0020] Table 1. GC-MS / MS mass spectrometry parameters

[0021]

[0022]

[0023] Example 1

[0024] This embodiment discloses a method for detecting organophosphorus using gas chromatography-mass spectrometry, comprising the following steps:

[0025] S1. Preparation of menthol-propionic acid deep eutectic solvent. 78.13 g menthol and 37.04 g propionic acid were weighed in a flask (250 mL) equipped with a magnetic stirring rotor according to a 1:1 molar ratio, and a magnetic stirrer with a heating function was used to stir at a constant temperature of 600 rpm in an 80°C water bath until the solid and liquid phases were mixed into a uniform, transparent liquid (about 15 min), which was the menthol-propionic acid deep eutectic solvent. After cooling to room temperature, it was set aside for use. Its structure was confirmed by nuclear magnetic resonance spectrometer and infrared spectrometer.

[0026] S2. Prepare a mixed standard solution with an organic phosphorus concentration of 100 ng / mL by adding 10% (v / v) menthol-propionic acid low eutectic solvent. Take 100 μL of the 1 μg / mL organic phosphorus mixed standard stock solution, add 100 μL of menthol-propionic acid low eutectic solvent, and then dilute to 1 mL with dichloromethane to prepare an organic phosphorus mixed standard working solution with a concentration of 100 ng / mL containing 10% (v / v) low eutectic solvent.

[0027] S3. According to the above-mentioned gas chromatography triple quadrupole mass spectrometry detection conditions, the chromatographic peak retention time and chromatographic peak area of ​​52 organophosphorus pesticides in the organophosphorus mixed standard working solution containing 10% (v / v) low eutectic solvent (concentration 100 ng / mL) are determined.

[0028] Example 2

[0029] This embodiment discloses a method for detecting organic phosphorus using gas chromatography-mass spectrometry. The only difference between this method and Example 1 is that menthol-butyric acid deep eutectic solvent is used to replace menthol-propionic acid in Example 1. When preparing menthol-butyric acid deep eutectic solvent, the feeding amount of butyric acid is 44.05 g.

[0030] Example 3

[0031] This example discloses a method for detecting organic phosphorus using gas chromatography-mass spectrometry. The only difference between this method and Example 1 is that menthol-caproic acid deep eutectic solvent is used to replace menthol-propionic acid in Example 1. When preparing menthol-caproic acid deep eutectic solvent, the feeding amount of caproic acid is 58.08 g.

[0032] Example 4

[0033] This embodiment discloses a method for detecting organic phosphorus using gas chromatography-mass spectrometry. The only difference between this embodiment and embodiment 1 is that menthol-octanoic acid deep eutectic solvent is used to replace menthol-propionic acid in embodiment 1. When preparing menthol-octanoic acid deep eutectic solvent, the feeding amount of octanoic acid is 72.10 g.

[0034] Comparative Example 1

[0035] The difference between this comparative example and Example 1 is that the menthol-propionic acid deep eutectic solvent is not added. Specifically, in this comparative example, a 100 μg / mL organophosphorus pesticide mixed standard solution is diluted with dichloromethane to a 1 μg / mL mixed standard stock solution, 100 μL is taken and fixed to 1 mL, and a 100 ng / mL mixed standard working solution is prepared, and the chromatographic peak retention time and chromatographic peak area of ​​52 organophosphorus pesticides are obtained according to the above-mentioned gas chromatography triple quadrupole mass spectrometry conditions.

[0036] Performance Test 1

[0037] This performance test summarizes the chromatographic peak retention times and chromatographic peak areas of 52 organophosphorus pesticides obtained from Examples 1 to 4 and Comparative Example 1, and the table is as follows:

[0038] Table 2. Effect of adding different types of deep eutectic solvents on the signal enhancement of organophosphorus

[0039]

[0040]

[0041]

[0042] By observing the above table, it can be found that in addition to using menthol-octanoic acid low eutectic solvent to detect organophosphorus, adding different low eutectic solvents to 100 ng / mL organophosphorus mixed standard working solution can improve the response of organophosphorus in GC-MS detection to varying degrees. Specifically, when 10% (v / v) menthol-propionic acid deep eutectic solvent was added as an analytical protective agent in Example 1, the detection signals of 50 kinds of organophosphorus increased by less than 5 times, and the signals of chlorpyrifos and omethoate increased by 6.8 times and 13.7 times respectively; when 10% (v / v) menthol-butyric acid deep eutectic solvent was added as an analytical protective agent in Example 2, the response signal of omethoate increased by more than 20 times, reaching 35.47 times, and the signals of the four organophosphorus, octamidine, chlorpyrifos, methyl isothiocarb, and anthiocarb increased by 17.09, 13.47, 10.62 and 10.23 times respectively, and 21 of the remaining organophosphorus had a signal increase multiple between 5 and 10 times, and 26 peak areas increased by less than 5 times; when 10% (v / v) menthol-hexanoic acid was added as an analytical protective agent in Example 3, the response signal of omethoate increased by more than 20 times, reaching 35.47 times, and the signals of the four organophosphorus, chlorpyrifos, methyl isothiocarb, and anthiocarb increased by 17.09, 13.47, 10.62 and 10.23 times respectively. When the deep eutectic solvent is used as the analytical protective agent, the peak areas of omethoate, octamidine, chlorpyrifos and methyl isodemeton-methyl increase by 71.9, 70.4, 28.4 and 20.5 times, respectively; the peak areas of 21 organophosphorus increase by 10-20 times, the peak areas of 21 organophosphorus increase by 5-10 times, and the peak areas of 6 increase by less than 5 times; when 10% (v / v) menthol-octanoic acid deep eutectic solvent is added as the analytical protective agent in Example 4, the response signal of omethoate increases by more than 100 times, reaching 101.1 times; the peak areas of 14 other organophosphorus pesticides increase by more than 20 times, the peak areas of 26 organophosphorus increase by 10-20 times, the peak areas of 8 organophosphorus increase by 5-10 times, and the peak areas of 2 increase by less than 5 times.

[0043] Performance Test 2

[0044] In order to examine the stability of the signal enhancement effect, this performance test compares the slopes of the standard curves of Example 3 and Comparative Example 1, and evaluates the stability of the signal enhancement effect by comparing the slope growth ratio of the standard curve and the peak area growth ratio of the single point concentration. The integrated table is as follows:

[0045] Table 3. Slope and growth ratio of the standard curve with / without deep eutectic solvent

[0046]

[0047]

[0048] By comparing the slopes of the calibration curves of the two groups of standard solutions, it can be seen that the slope growth multiples of the four pesticides, methyl isothiophos, octamphos, cypermethrin, and oxydemeton-methyl, reached more than 20 times, the slope growth multiples of 18 pesticides were between 10-20 times, the slope growth multiples of 21 pesticides were between 5-10 times, and the slope growth multiples of the nine pesticides, phosalone, azophos, chlorpyrifos, ethion, triazophos, fenamiphos sulfoxide, phorate, fenitrothion, and cypermethrin, were less than 5 times. In addition, the slope growth multiples were basically consistent with the area growth multiples, indicating that the addition of menthol-caproic acid deep eutectic solvent had a stable signal enhancement effect on 52 target organophosphorus pesticides.

Claims

1. Application of a menthol-organic acid deep eutectic solvent in organophosphorus detection, characterized in that: The low eutectic solvent uses menthol as a hydrogen bond acceptor and an organic acid as a hydrogen bond donor; the organic acid includes one or more of propionic acid, butyric acid, hexanoic acid, and octanoic acid; the detection adopts gas chromatography-mass spectrometry; the organic phosphorus includes chlorpyrifos, oxydemeton-methyl, chlorpyrifos, chlorpyrifos-methyl, chlorpyrifos, chlorpyrifos, chlorpyrifos, terbufos, chlorpyrifos, chlorpyrifos, chlorpyrifos, chlorpyrifos, One or more of chlorpyrifos, methyl pirimiphos, malathion, fenthion, chlorpyrifos, chlorpyrifos, dimethoate, bromophos, pirimiphos, isofos, quinalphos, baclofos, methidathion, ethyl bromophos, chlorpyrifos, chlorpyrifos, fenamiphos, chlorpyrifos, propylthion, propylbromophos, defoliation, ethylthion, ethion, chlorpyrifos, propylthion, triazophos, trithion, fenamiphos sulfoxide, phosmet, fenthion, piperophos, silyphos, phosalone, bromophos, and azophos.

2. The use of a menthol-organic acid deep eutectic solvent according to claim 1 in the detection of organophosphorus, characterized in that: When the organic acid includes one or more of propionic acid, butyric acid, and caproic acid, the organic phosphorus further includes chloranil.

3. Use of a menthol-organic acid deep eutectic solvent according to claim 1 or 2 in the detection of organophosphorus, characterized in that: The organic acid includes propionic acid, and the organic phosphorus includes one or more of chlorpyrifos and omethoate.

4. Use of a menthol-organic acid deep eutectic solvent according to claim 1 or 2 in organophosphorus detection, characterized in that: The organic acid includes butyric acid, and the organic phosphorus includes one or more of omethoate, octamidine, mefenphos, methyl isothioate and anthiosulfuron.

5. Use of a menthol-organic acid deep eutectic solvent according to claim 1 or 2 in the detection of organophosphorus, characterized in that: The organic acid is butyric acid, and the organophosphorus includes one or more of cypermethrin, chlorpyrifos, phorate, dimethoate, terbufos, chlorpyrifos, diazinon, ethophos, isothiocyanate, chlorpyrifos, methyl pirimiphos, fenthion, dimethoate, pirimiphos-methyl, isoflurane, chlorpyrifos, pirimiphos-methyl, isoflurane, quinalphos, baclofos, ethyl bromothion, chlorpyrifos, fenamiphos and propylbromophos.

6. Use of a menthol-organic acid deep eutectic solvent according to claim 1 or 2 in the detection of organophosphorus, characterized in that: The organic acid is hexanoic acid, and the organophosphorus includes one or more of omethoate, octamphos, mefenphos, methyl isothioate, ethoxyphos, chlorpyrifos, dimethoate, terbufos, chlorpyrifos, diazinon, disulfothion, isothiocyanate, chlorpyrifos, methyl pirimiphos, fenthion, pirimiphos, isoflavone, quinalphos, baclofos, ethyl bromothion, chlorpyrifos, chlorpyrifos, fenamiphos, propylfenthion, and defoliant.

7. Use of a menthol-organic acid deep eutectic solvent according to claim 1 or 2 in the detection of organophosphorus, characterized in that: The organic acid includes hexanoic acid, and the organophosphorus includes one or more of chlorpyrifos, phorate, chlorpyrifos, methyl chlorpyrifos, chlorpyrifos, chlorpyrifos, chlorpyrifos, chlorcarb, chlorpyrifos, bromothion ...chlorpyrifos, chlorpyrifos, chlorpyrifos, chlorpy 8. Use of a menthol-organic acid deep eutectic solvent according to claim 1 in the detection of organophosphorus, characterized in that: The organic acid includes octanoic acid, and the organophosphorus includes one or more of omethoate, mefenphos, methyl isothioate, ethoxyphos, thiophanate-methyl, octamidine, diazinon, isothioate, methyl pirimiphos, fenthion, pirimiphos, isoflavone, baclofos, chlorpyrifos and propylbromophos, cypermethrin, phorate, dimethoate, terbufos, chlorpyrifos, ethylsulfophos, chlorpyrifos-methyl, chlorpyrifos, chlorpyrifos, chlorpyrifos, chlorfenapyr, bromophos, quinalphos, methidathion, ethyl bromophos, chlorpyrifos, fenamiphos, propylphos, defoliant, cypermethrin, sulfophos, triazophos, fenamiphos sulfoxide, phosmet, phosphamidon and bromophenylphos.

9. Use of a menthol-organic acid deep eutectic solvent according to claim 1 in the detection of organophosphorus, characterized in that: The organic acid includes octanoic acid, and the organic phosphorus includes one or more of fofophos, fenitrothion, malathion, defoliant, trithion, safflower, phosalone and azophos.

10. Use of a menthol-organic acid deep eutectic solvent according to claim 1 in the detection of organophosphorus, characterized in that: The molar ratio of menthol to organic acid is (1-3): (1-3).

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