Liquid phase-tandem mass spectrometry analysis method of triazine herbicide

Abstract

The invention belongs to the field of analysis and detection, and provides a liquid chromatography-tandem mass spectrometry analysis method of triazine herbicides. According to the invention, MON-2OH is grafted to carboxyl modified Fe3O4 through a room temperature synthesis method, and abundant long-chain hydroxyl functionalized magnetic MON nanoparticles (MMON-2OH) are covalently constructed and are used for enriching triazine herbicides. The invention also provides an MSPE-LC-MS / MS method based on the magnetic composite material, the MSPE-LC-MS / MS method is used for accurately capturing and sensitively determining eight triazine herbicides in water and honey samples, the LODs of water is 0.03-0.6 ng.L <-1 >, and the LODs of honey is 0.006-0.13 ug.kg <-1 >. And the adding standard recovery rate of the two samples is 72.1%-116.2%. According to the invention, the application of MMON-2OH in enrichment of trace pesticide residues in sample pretreatment is greatly enriched.

Description

Technical Field

[0001] The invention belongs to the field of analysis and detection, and particularly relates to a liquid phase-tandem mass spectrometry analysis method for triazine herbicides. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Triazine herbicides were introduced in the 1950s and are mainly used to control the growth of broadleaf weeds before and after the emergence of crops such as corn, sorghum and sugarcane. Its mechanism of action is to inhibit electron transfer in photosynthesis by destroying the D1 protein in plant photosystem II (PSII). Due to the large-scale use of triazine herbicides and their long environmental half-life, these compounds will remain in water, soil and agricultural products. This persistence may lead to the "three-hazard" effects of carcinogenesis, teratogenesis and mutagenesis, as well as endocrine disruption and other irreversible side effects. The U.S. Environmental Protection Agency (EPA) has listed triazine herbicides such as simazine and atrazine as priority pollutants and stipulated that the concentration of atrazine in drinking water should be less than 3μg·L -1 , the concentration of simazine is less than 4 μg·L -1 The European Union (EU) has set the maximum residue limit of triazine herbicides in honey and its bee products at 0.01-0.1 mg kg. -1 Therefore, there is an urgent need to develop an accurate, sensitive, and convenient method for the quantitative detection of triazine herbicide residues in agricultural products and environmental water samples.

[0004] Due to the complex matrix effects of triazine herbicides in food and the environment and their low residual concentrations in actual samples, it is very difficult to directly separate and instrumentally determine triazine herbicides in actual complex samples. Therefore, sample pretreatment is crucial to eliminate matrix interference and ensure the accuracy and precision of analysis. At present, traditional sample pretreatment methods include dispersive solid phase extraction (d-SPE), solid phase extraction (SPE) and solid phase microextraction (SPME). However, these methods are usually complicated and time-consuming. Magnetic solid phase extraction (MSPE) is an advanced sample pretreatment technology derived from d-SPE, which has attracted widespread attention due to its high efficiency in enriching trace targets in complex matrices. In MSPE, the complex pre-designed functionalized sites on the magnetic adsorption material play a vital role in its enrichment efficiency. In recent years, the development of porous organic polymers such as COFs (covalent organic frameworks) and MOFs (metal organic frameworks) has significantly accelerated the development of magnetic nanoadsorbents. The functionalized properties of these materials improve enrichment efficiency and recyclability. However, developing magnetic materials with stable covalent bonds and specific functionalization to further improve efficiency and recyclability remains a necessary and challenging task.

[0005] Microporous organic networks (MONs) are lattice frameworks constructed from alkynyl-containing monomers as "backbones" and aromatic halides as "linkers" via Sonogashira-Hagihara coupling using palladium as a catalyst under alkaline conditions. MONs have a customizable internal network through strong covalent bonds, good thermal stability, tunable porosity, high surface area, and a highly conjugated π backbone. These properties make them highly promising for use in sample pretreatment. In 2020, Du et al. modified a uniform MON-NH2 shell on a magnetic Fe3O4 core through a simple in situ growth method to prepare a magnetic amino-functionalized microporous organic network composite (Fe3O4@MON-NH2) for efficient MSPE and enriched four endocrine disrupting chemicals (EDCs) in water, juice, and beverage bottle samples. Du et al. also used it as a magnetic solid phase extraction adsorbent for the adsorption of tetrabromobisphenol A (TBBPA), a typical brominated flame retardant (BFR), from aqueous solutions. In 2024, Xu et al. prepared Fe3O4 nanoparticles doped β-cyclodextrin microporous organic network composites (MCD-MON) by a simple one-pot solvothermal synthesis method for four phenolic endocrine disrupting chemicals in food takeout boxes and water samples. In 2022, Li et al. synthesized amino-functionalized microporous organic network MON-NH2 and used it as an SPME coated fiber for the analysis of parabens, bisphenols and triclosan in saliva simulant samples. However, the magnetic MONs reported so far are usually prepared using MONs with no or little modification (short-chain functional groups) or physical doping between MON and Fe3O4. The lack of binding sites and covalent bonds limits the widespread application of magnetic MONs in sample pretreatment. Therefore, the development of hydrophilic covalent magnetic MONs functionalized with covalent long chains to provide abundant and effective adsorption sites will be very valuable for improving the sensitivity of triazine herbicide enrichment. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a liquid phase-tandem mass spectrometry analysis method for triazine herbicides. According to the -Cl and -NH groups of the triazine herbicide structure, based on the possible pre-designed hydrogen bonds, halogen bonds and π stacking, the present invention grafts MON-2OH onto carboxyl-modified Fe3O4 through a room temperature synthesis method, and covalently constructs rich long-chain hydroxyl-functionalized magnetic MON nanoparticles (MMON-2OH) for enriching triazine herbicides. MMON-2OH with long-chain hydroxyl groups provides sufficient contact with triazine herbicides, while carboxyl-modified Fe3O4 ensures good dispersibility in aqueous solution throughout the MSPE process, such as Figure 1 shown.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] The first aspect of the present invention provides an MMON-2OH for triazine herbicide analysis, comprising:

[0009] MON-2OH was obtained by polymerization reaction using 5-amino-2,4,6-triiodo-N,N'-bis(2,3-dihydroxypropyl)-1,3-benzenedicarbamide and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine as monomers;

[0010] After COOH-Fe3O4 is activated, it is mixed with the MON-2OH to react to obtain MMON-2OH.

[0011] In some embodiments, the molar ratio of 5-amino-2,4,6-triiodo-N,N'-bis(2,3-dihydroxypropyl)-1,3-benzenedicarboxylic acid amide to 2,4,6-tris(4-aminophenyl)-1,3,5-triazine is 1:1-1.1.

[0012] In some embodiments, the mass ratio of COOH-Fe3O4 to MON-2OH is 1:1-1.1.

[0013] In some embodiments, the catalyst used in the polymerization reaction is a bistriphenylphosphine palladium dichloride catalyst and cuprous iodide, and the co-catalyst is triethylamine.

[0014] In some embodiments, the mass volume ratio of the bistriphenylphosphine palladium dichloride catalyst, cuprous iodide and triethylamine is 40 mg:21 mg:6.0-6.5 mL.

[0015] In some embodiments, the specific method of COOH-Fe3O4 activation is:

[0016] COOH-Fe3O4, N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were sequentially added to the MES buffer solution, and the mixture was ultrasonically treated at room temperature and then shaken to obtain the product.

[0017] In some embodiments, the mass ratio of COOH-Fe3O4, N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 35-40:170:110.

[0018] The second aspect of the present invention provides MMON-2OH prepared by the above method.

[0019] The third aspect of the present invention provides a liquid phase-tandem mass spectrometry analysis method for triazine herbicides, comprising:

[0020] The MMON-2OH described above is used to perform magnetic solid phase extraction on the sample to be tested to obtain a concentrated sample;

[0021] The concentrated sample is detected by liquid chromatography-tandem mass spectrometry to obtain the product.

[0022] In some embodiments, the sample includes: water sample, honey.

[0023] Beneficial effects of the present invention

[0024] (1) The present invention designs a method for preparing MON-2OH (627.24 m2) with a large specific surface area by reacting ADTB and TEPT within 24 h at room temperature. 2 / g). This material combines the excellent adsorption performance of MON-2OH and the advantages of magnetic particles that are easy to separate from water. After the successful carboxylation modification of Fe3O4, the carboxyl groups on it interact with the amino groups of MON-2OH in MES-NH S -EDC buffer system is covalently linked to form a structure with "capillary network surrounding alveoli". The present invention optimizes six parameters for enriching triazine herbicides and finds that the material is slightly affected by pH and salt ions, the enrichment process can be completed within 4 minutes, the adsorbent dose of 4 mg and the elution liquid of 2 mL show the characteristics of "green chemistry", and the high recovery rate and reusability have the potential to be extended to other pesticide residue analysis.

[0025] (2) The present invention developed an MSPE-LC-MS / MS method based on this magnetic composite material for accurate capture and sensitive determination of eight triazine herbicides in water and honey samples, with LODs of 0.03-0.6 ng·L for water. -1 , the LODs of honey are 0.006-0.13ug·kg -1 The spiked recoveries of the two samples were between 72.1% and 116.2%. The present invention greatly enriches the application of MMON-2OH in enriching trace pesticide residues in sample pretreatment. The preparation and extraction process of MMON-2OH embodies the concept of "low carbon and environmental protection", which contributes to ensuring food safety, environmental quality and human health.

[0026] (3) The method of the present invention is simple, practical and easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the exemplary embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] Figure 1The figure is a flow chart of the synthesis process of MMON-2OH and its use as a magnetic solid phase extraction material to extract triazine herbicides.

[0029] Figure 2 Infrared spectra of TEPT, ADTB, MON-2OH, MMON-2OH and COOH-Fe3O4.

[0030] Figure 3 :(A)(B)(C) are scanning electron microscope images of COOH-Fe3O4, MON-2OH and MMON-2OH, respectively; (D) water contact angles of COOH-Fe3O4, MON-2OH and MMON-2OH; (E) specific surface areas of COOH-Fe3O4, MON-2OH and MMON-2OH; (F) hysteresis loops of COOH-Fe3O4 and MMON-2OH.

[0031] Figure 4 The MSPE parameters (n=3) were optimized by single factor method: solution pH (A); salt concentration (B); adsorption time (C); adsorbent dosage (D); desorption time (E); acetonitrile volume (F). DETAILED DESCRIPTION

[0032] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0033] The present invention will be further described in detail below in conjunction with specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0034] Example 1: Synthesis of MMON-2OH

[0035] 1) Synthesis of COOH-Fe3O4

[0036] A mixture of ferric chloride hexahydrate (1.95 g), sodium acetate (NaAC, 3.6 g) and sodium citrate (0.6 g) was weighed and placed in a beaker containing ethylene glycol (EG, 60 mL), stirred for 30 min, and the mixed solution was transferred to a 100 mL polytetrafluoroethylene-lined reactor, placed in a 200 ° C oven, reacted for 10 h, and naturally cooled to room temperature. The obtained material was washed twice with pure water and ethanol (EtOH), and then dried in a vacuum drying oven at 100 ° C for 10 h to obtain COOH-Fe3O4 nanoparticles.

[0037] 2) Synthesis of MON-2OH

[0038] In a three-necked flask, 5-amino-2,4,6-triiodo-N,N'-bis(2,3-dihydroxypropyl)-1,3-benzenedicarbamide (ADTB, 0.25mmol, 176mg) and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TEPT, 0.25mmol, 95mg), tetrahydrofuran (THF, 6.0mL) and triethylamine (Et3N, 6.0mL) were added in sequence. Then, argon was passed through the flask under vacuum for three cycles. Then, bistriphenylphosphine palladium dichloride catalyst (PdC12(PPh3)2, 0.057mmol, 40mg), cuprous iodide (CuI, 0.10mmol, 21mg) and tetrahydrofuran (THF, 3.0mL) were added thereto, and the mixed solution immediately changed from brown to black. Finally, three vacuum-argon cycles were performed, and the resulting solution was stirred at room temperature for 24h. The reddish brown precipitated product was filtered and washed thoroughly twice with water, methanol and acetonitrile in sequence to remove excess impurities, and finally dried in a vacuum oven at 60° C. for 24 h to obtain a reddish brown powder (126 mg).

[0039] 3) Synthesis of MMON-2OH

[0040] Preparation of MES buffer: Weigh 4-morpholineethanesulfonic acid (MES, 2.5 mmol, 490 mg) in a beaker, add 50 mL of ultrapure water, dissolve by ultrasonication, and then slowly add a small amount of sodium hydroxide solution to the above solution until the pH is adjusted to 6.0.

[0041] Transfer 20 mL of MES buffer solution to a 60 mL glass tube and add COOH-Fe3O4 (35 mg), N-hydroxysuccinimide (NH S , 170 mg) and 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC, 110 mg), the above mixture was ultrasonically treated for 5 min at room temperature, then placed in a rotary mixer and vibrated for 30 min to activate the carboxyl group in COOH-Fe3O4. Then, MON-2OH (35 mg) was added, the mixed system was ultrasonically treated for 1 min, and then placed in a mixing rotary instrument and vibrated for 30 min. Finally, the product was separated with a magnet, washed with water and ethanol, and dried under vacuum to obtain MMON-2OH (dark brown, 30 mg).

[0042] Example 2: Magnetic solid phase extraction process

[0043] Weigh 4 mg of MMON-2OH prepared in Example 1 into a 60 mL glass tube, and add 50 mL of sample solution containing a standard solution of triazine herbicides. The mixture is placed in a rotary mixer (80 rpm) and rotated for 2 min to complete the enrichment process, and the adsorbent loaded with triazine herbicides is quickly collected by a magnet, and the sample solution is poured; the MMON-2OH loaded with triazine herbicides is eluted with 2 mL of acetonitrile, and the elution step is the same as the enrichment step, and the elution time is 2 min. The eluent is separated from MMON-2OH with a magnet, and the eluent is collected; the eluent is blown dry with a water bath nitrogen blower, and the concentrated sample is redissolved in 500 μL of acetonitrile. Finally, the composite solution is injected into the LC-MS / MS system for analysis of triazine herbicides.

[0044] Example 3: Collection and pretreatment of water and honey samples

[0045] Environmental samples: surface water and groundwater. Water samples were filtered with a 0.22 μm filter and then subjected to magnetic solid phase extraction.

[0046] Honey samples, including acacia honey, osmanthus honey and multi-flower honey, were purchased from a farmer's market (Jinan, China). Honey sample processing steps: 0.5 g honey was weighed in a 50 mL centrifuge tube, 40 mL of purified water was added, ultrasonic treatment was performed for 10 min, and vortexing was performed for 5 min to completely dissolve the honey in water. The honey aqueous solution was adjusted to a neutral pH, filtered through a 0.22 μm filter head, and transferred to a 60 mL glass vial for magnetic solid phase extraction experiments using the method of Example 2.

[0047] Example 4: Liquid chromatography-tandem mass spectrometry conditions

[0048] HPLC-MS / MS instrument: Ultimate 3000 liquid chromatograph connected to QTRAP 5500 mass spectrometer. Liquid chromatography conditions: ThermoFisher C18 column (100 mm x 2.1 mm, 2.6 μm); column temperature: 30 °C; mobile phase: acetonitrile (A) and 0.1% formic acid water (B); gradient elution: 0-6.0 min, 25-75% A; 6.0-6.1 min, 25% A and 6.1-8.0 min, 25% A; flow rate: 0.3 mL min -1 ; Injection volume: 5μL.

[0049] Mass spectrometry conditions: ion source: electrospray ionization (ESI) in positive ion mode; scan mode: multiple reaction monitoring mode (MRM); ion source temperature was 500°C; other parameters are shown in the table.

[0050] Table 1 Mass spectrometry parameters of 8 triazine herbicides

[0051]

[0052]

[0053] * is the quantitative ion

[0054] Experimental Example 1: Structural Analysis of MMON-2OH

[0055] FT-IR analysis, such as Figure 2 As shown. TEPT at 3292cm -1 The characteristic peaks at (-C≡CH) and ADTB at 471cm -1 The characteristic peak (CI) at 2195 cm-1 disappeared at the same time, and a peak at 2195 cm-1 appeared in the FT-IR of MON-2OH. -1 The new characteristic peak (-C≡C-) of the prepared COOH-Fe3O4 nanoparticles was confirmed to have undergone a Sonogashira-Hagihara coupling reaction. -1 It shows a strong characteristic absorption peak, which corresponds to the stretching vibration signal of Fe-O. Finally, the product MMON-2OH was characterized. The characteristic peak of MMON-2OH -C≡C-(2195cm -1 ) and the characteristic peak Fe-O (635cm-1) in COOH-Fe3O4 appeared simultaneously, indicating that COOH-Fe3O4 was loaded on MON-2OH nanoparticles to form a nanocomposite MMON-2OH.

[0056] Scanning electron microscopy images Figure 3 As shown in Figures AC, COOH-Fe3O4 is a dense regular sphere with a diameter of about 200 nm; MON-2OH is a sponge gourd mesh structure; 3C shows that COOH-Fe3O4 nanoparticles loaded with MON-2OH on the sponge gourd mesh structure form a huge "capillary network wrapped around the alveoli".

[0057] Water contact angle measurement diagram Figure 3 As shown in D. The water contact angle of COOH-Fe3O4 is 23°, which is hydrophilic, and the water contact angle of MON-2OH is 137°, which is hydrophobic. The covalent connection of hydrophilic COOH-Fe3O4 and hydrophobic MON-2OH leads to a slight decrease in the water contact angle of MMON-2OH (water contact angle = 92°), which enhances its hydrophilicity and improves its dispersion in water, which is beneficial for the adsorption of large volume water samples.

[0058] The N2 adsorption-desorption measurements showed that the three curves exhibited typical type II isotherms, and the specific surface areas of the three curves were 63.93, 287.86, and 627.24 m 2 / g( Figure 3E). However, its value is much higher than the specific surface area of ​​COOH-Fe3O4 (63.93m 2 / g), indicating that the prepared MMON-2OH has a good specific surface area and is more suitable as a MSPE adsorbent than mesoporous COOH-Fe3O4.

[0059] Hysteresis loop, such as Figure 3 As shown in F. There is no obvious hysteresis in both, and the VSM curves have similar shapes and symmetries. The saturation magnetization (Ms) of COOH-Fe3O4 is 60.78emu / g, while that of MMON-2OH is 33.24emu / g. Its value has decreased slightly, but it still has high magnetic sensitivity and can achieve rapid magnetic separation within 10s.

[0060] Experimental Example 2: Optimization and Methodological Verification of Magnetic Solid Phase Extraction for Detection of Triazine Herbicides 1) Single Factor Optimization of Extraction Conditions of Magnetic Solid Phase Extraction

[0061] Six experimental parameters (solution pH, salt concentration, adsorption time, adsorbent dose, desorption time and desorption volume) were optimized by single factor. The recovery rate of phenylurea herbicides under different optimized conditions was used to evaluate the efficiency of MSPE, so as to obtain the optimal experimental parameters. In the single factor MSPE optimization experiment, the water sample volume was 50 mL, and the spiked concentration of 8 triazine herbicides in the water sample was 500 ng·L -1 Each group of experiments was performed in triplicate.

[0062] Since triazine herbicides have -NH in their structure and MMON-2OH has -OH in its structure, changes in pH affect their protonation and ionization. Figure 4 In Figure A, when the pH is between 6 and 10, the spiked recoveries of the eight triazine herbicides remain basically unchanged, about 90%. The reasons are as follows: the pKa range of triazine herbicides is 2.28-7.68. Under acidic conditions, they will be protonated, and the existence form of MMON-2OH will remain unchanged. The mechanism of action of MMON-2OH with triazine herbicides is mainly OH···N- and halogen bonds, but the stability of hydrogen bonds is reduced under acidic conditions. Under alkaline conditions, MMON-2OH will ionize to form MMON-2O - The mechanism of action of MMON-2OH and triazine herbicides is mainly NH···O - and halogen bonds; although the pH changes, the type of interaction between triazine herbicides and MMON-2OH changes, but the weak interaction forces of hydrogen bonds and halogen bonds always exist, so the optimal pH is 6.0.

[0063] In the optimization experiment of ionic strength, the potential effect of ionic strength (0, 0.2, 0.4, 0.6, 0.8 M) in the samples on the recovery of 8 triazine herbicides was systematically studied. Figure 4 As shown in B. The ionic strength in the sample was changed by adding NaCl. The experimental results showed that the recovery rates of the eight triazine herbicides were basically around 90%, indicating that the adsorption of the synthesized material MMON-2OH on the eight triazine herbicides was not restricted by the influence of ionic strength, which expanded its application prospects in actual samples. Therefore, NaCl was not added in this experiment.

[0064] The adsorption time determines the MSPE adsorption efficiency, such as Figure 4 As shown in Figure C, the present invention selects an adsorption time range of 2-30 min to investigate its effect on the recovery rate of 8 triazine herbicides. The present invention surprisingly found that an adsorption time of 2 min is sufficient to achieve adsorption equilibrium, and the extraction efficiency remains basically unchanged when the extraction time is extended, indicating that MMON-2OH can quickly achieve the enrichment of 8 phenylurea herbicides in a very short time, thereby indicating that the halogen bond and hydrogen bond in the adsorption force play a key role, which is conducive to achieving rapid enrichment. Therefore, from the perspective of improving the extraction efficiency of MSPE, the extraction time is 2 min.

[0065] The increase of adsorbent dosage is beneficial to increase adsorption sites and improve adsorption capacity, however, excessive adsorbent is useless. Therefore, the present invention investigates the effect of adsorbent dosage (4, 6, 8, 10, 12 mg) on ​​the extraction of triazine herbicides. Figure 4 As shown in Figure D, when the adsorbent dosage is 4 mg, the recovery rate of the target is as high as 90%, indicating that 4 mg of MMON-2OH is sufficient to achieve the enrichment of 8 triazine herbicides, which shows that the prepared MMON-2OH material has abundant adsorption sites, and the interaction forces of halogen bonds and hydrogen bonds are relatively strong, which is conducive to achieving high-capacity enrichment. Therefore, from the perspective of saving materials, the adsorbent dosage is 4 mg.

[0066] During the MSPE analysis process, the present invention selects the analysis time and volume to examine their effects on the analysis efficiency. Figure 4 Figure E shows that when the desorption time is 2 min, the desorption efficiency of 8 triazine herbicides is 90%. When the desorption time is increased, the recovery rate remains basically unchanged. Figure 4 As shown in Figure F, the volume of the analytical solvent acetonitrile was optimized (2-10 mL), and the recovery rate of triazine herbicides gradually increased with the increase of acetonitrile volume, reaching a peak at 6 mL, and then remained basically unchanged. In order to save nitrogen purging time, the volume of acetonitrile was selected as 2 mL in subsequent studies.

[0067] 2) Methodological parameters

[0068] Combined with the optimized six experimental parameters, the present invention established a quantitative method for LC-MS / MS analysis of eight triazine herbicides by magnetic solid phase extraction of triazine herbicides in sample solutions in water and honey matrices. It can be clearly seen from Tables 2 and 3 that the method has good linearity in the concentration range (water: simazine: 2.5-2000 ng·L -1 , other 7 triazine herbicides: 1-2000ng·L -1 ; Honey: Simazine: 0.8-160μg·kg -1 , other 7 triazine herbicides: 0.08-160 μg·kg -1 ). The regression coefficient is good, R 2 >0.991, low detection limit (LOD) (water: 0.03-0.6ng·L -1 ; Honey: 0.006-0.13·ug·kg -1 ), limit of quantification (LOQ) (water: 0.12-2.0 ng·L -1 ; Honey: 0.02-0.44ug·kg -1 ), intra-day standard deviation (RSD) <10%, matrix effect (ME) between ±20%. The above results show that this method has a wide linear range, high sensitivity, good reproducibility, high precision, and little influence by the matrix.

[0069] Table 2 Parameters for magnetic solid phase extraction analysis of triazine herbicides in water based on MMON-2OH

[0070]

[0071] Table 3 Parameters for magnetic solid phase extraction analysis of triazine herbicides in honey based on MMON-2OH

[0072]

[0073] Experimental Example 3: Detection of triazine herbicides in actual water and honey samples by magnetic solid phase extraction combined with LC / MS / MS

[0074] In order to verify the reliability of the method, the established MSPE analysis method was applied to the determination of triazine herbicides in environmental samples (groundwater and surface water) and food honey samples (acacia honey, osmanthus honey and multi-flower honey). The determination results are analyzed and listed in Tables 4 and 5. By performing magnetic solid phase extraction on blank samples, the present invention can find that in surface water, atrazine and amethoxazole are detected, and their contents are 21.2 ng·L -1 and 1ng·L -1 The residual amount of atrazine in acacia honey was 0.36 μg kg -1; The residual amount of atrazine in osmanthus honey was 0.128 μg·kg -1 ; The residual amount of azomethin in honey was 0.96 μg·kg -1 .

[0075] On this basis, three spike concentrations (10 ng·L -1 , 500ng·L -1 , 1500ng·L -1 ) was used to perform spike recovery experiments on triazine herbicides in water and honey samples for further confirmation. The results of the spike recovery experiments showed that the recovery rates of the eight triazine herbicides were between 72.1% and 116.2%, which was in line with the EU pesticide residue identification guidance document, indicating that this method can quickly, accurately and sensitively analyze trace triazine herbicides in real water samples and honey.

[0076] Table 4 Analytical data of triazine herbicides in environmental water samples (n=3).

[0077]

[0078]

[0079] Spike concentration: (a) 10 ng L -1 (b) 500ng L -1 、(c)1500ng L -1 、(d)ND d Not detected

[0080] Table 5 Analysis data of triazine herbicides in honey samples (n=3).

[0081]

[0082] Spiked concentration: (a) 0.8ug kg -1 (b) 40ug kg -1 、(c)120ug kg -1 、(d)ND d Not detected.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A MMON-2OH for triazine herbicide analysis, characterized in that: include: MON-2OH was obtained by polymerization reaction using 5-amino-2,4,6-triiodo-N,N'-bis(2,3-dihydroxypropyl)-1,3-benzenedicarbamide and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine as monomers; After COOH-Fe3O4 is activated, it is mixed with the MON-2OH to react to obtain MMON-2OH.

2. MMON-2OH for triazine herbicide analysis according to claim 1, characterized in that: The molar ratio of the 5-amino-2,4,6-triiodo-N,N'-bis(2,3-dihydroxypropyl)-1,3-benzenedicarboxylic acid amide to 2,4,6-tris(4-aminophenyl)-1,3,5-triazine is 1:1-1.

1.

3. MMON-2OH for triazine herbicide analysis according to claim 1, characterized in that: The mass ratio of the COOH-Fe3O4 to MON-2OH is 1:1-1.

1.

4. MMON-2OH for triazine herbicide analysis according to claim 1, characterized in that: The catalysts used in the polymerization reaction are bistriphenylphosphine palladium dichloride catalyst and cuprous iodide, and the co-catalyst is triethylamine.

5. MMON-2OH for triazine herbicide analysis according to claim 4, characterized in that: The mass volume ratio of the bistriphenylphosphine palladium dichloride catalyst, cuprous iodide and triethylamine is 40 mg:21 mg:6.0-6.5 mL.

6. MMON-2OH for triazine herbicide analysis according to claim 1, characterized in that: The specific method of COOH-Fe3O4 activation is: COOH-Fe3O4, N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were sequentially added to the MES buffer solution, and the mixture was ultrasonically treated at room temperature and then shaken to obtain the product.

7. MMON-2OH for triazine herbicide analysis according to claim 1, characterized in that: The mass ratio of the COOH-Fe3O4, N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 35-40:170:

110.

8. MMON-2OH prepared by the method described in any one of claims 1 to 7.

9. A liquid phase-tandem mass spectrometry analysis method for triazine herbicides, characterized in that: include: Using the MMON-2OH described in claim 8 to perform magnetic solid phase extraction on the sample to be tested to obtain a concentrated sample; The concentrated sample is detected by liquid chromatography-tandem mass spectrometry to obtain the product.

10. The liquid phase-tandem mass spectrometry analysis method for triazine herbicides according to claim 9, characterized in that: The samples include: water samples and honey.

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