Determination method for clethoxamid, flumetsulam and / or ipfencarbazone in feed and application of determination method for clethoxamid, flumetsulam and / or ipfencarbazone

Abstract

The invention discloses a method for determining novel herbicides such as clethoxamid, flumetsulam and / or ipfencarbazone in feed and application of the novel herbicides. Belongs to the technical field of pesticide residue detection. The invention provides a method for determining novel herbicides such as clethoxamid, flumiflusulam and ipfencarbazone in feed, which is based on a dispersive solid-phase extraction pretreatment technology, does not need a solid-phase extraction small column, is low in reagent cost, realizes effective purification and enrichment of the three novel herbicides, and is suitable for large-scale industrial production. According to the present invention, with the combination of the ultra-high performance liquid chromatography-tandem mass spectrometry UPLC-MS / MS, whether the animal feed contains the pyriflusulam, the pethoxamid, the ipfencarbazone and other herbicides and the corresponding residual quantity can be rapidly and accurately determined, and the method has advantages of high sensitivity, good specificity, accurate and reliable detection result, and high sensitivity. The technical support is provided for the simultaneous detection of three novel herbicides, namely the clethoxamid, the flumiflusulam and the ipfencarbazone.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide residue detection, and more particularly to a method for determining pethodiac, fluazifop and / or triazone in feed and application thereof. Background Art

[0002] Pethodiamide is a new type of acetylchloroanilide herbicide, mainly used to control grass weeds and broadleaf weeds in corn and soybean fields. Fomesulfuron is a second-generation sulfonamide rice field herbicide, which has extremely high control effect on annual weeds such as barnyard grass and perennial difficult-to-control weeds, and has excellent effect on resistant weeds. Triazoline is a triazolinone rice field herbicide, which is highly effective against grass weeds, annual weeds and some annual broadleaf weeds, especially barnyard grass, with a long lasting effect, and is highly safe even when used during rice transplanting. At present, these three new farmland herbicides have been widely used abroad, especially in the planting of grain crops such as rice, wheat, corn, soybeans, and sorghum. These grain crops are the main raw materials for making feed, which leads to the high possibility of large amounts of residues of these three herbicides in feed. These herbicide residues enter and accumulate in animals through feed, and while endangering animal health, they are ingested by humans along with animal-derived foods, thereby endangering human health.

[0003] At present, the European Union, the United States, Japan and other countries have stipulated the residue limits of these three herbicides in plant-derived foods. For example, Japan stipulates that the limit of fluazifop in rice is ≤0.05ppm, and the limit of triazolam is ≤0.05ppm; the European Union stipulates that the limit of pethamide in fresh or frozen fruits, root and tuberous vegetables, bulb vegetables, sunflower seeds, rapeseed, soybeans, pumpkin seeds, and corn grains is ≤0.01ppm, and pethamide in tea is ≤0.05ppm. It can be seen that the residues of these three herbicides are harmful to the human body. Therefore, it is of great significance to the health of livestock and the safety of human animal-derived food by measuring and controlling the residues of the above three herbicides in feed.

[0004] At present, there are few detection standards for herbicides in feed. Among them, the DB34 / T 3102-2018 "Determination of sulfonylurea herbicides in feed-liquid chromatography tandem mass spectrometry" standard uses a purification technology based on gel chromatography, which is complicated to operate and has high cost. It requires the purchase of a gel permeation chromatograph, which has high requirements on the operator's operating level. Its detection range does not include the three herbicides of pethodiola, fluazifop and triazolam; in the GB / T 23744-2009 "Determination of 36 pesticide residues in feed by gas chromatography-mass spectrometry" standard, the determination of four low-boiling point herbicides, namely, cypermethrin, cyfluthrin, herbicide and cyfluthrin, is achieved based on gas chromatography-mass spectrometry, but its gas chromatography-mass spectrometry is not suitable for the three high-boiling point (425.7°C to 550.8°C) herbicides detected by the present invention. At present, there is no corresponding detection method for the above three new herbicides, especially for the residual detection of these three herbicides in feed.

[0005] Therefore, how to provide a method for quickly and accurately determining the residues of fluazifop, pethodiola and triazone in animal feed is a technical problem that those skilled in the art need to solve urgently. Summary of the invention

[0006] In view of this, the present invention provides a method for determining pethoamid, fluazifop and / or triazolam in feed and its application. Based on dispersed solid phase extraction pretreatment technology and combined with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS / MS), it can quickly and accurately determine whether animal feed contains herbicides such as fluazifop, pethoamid and triazolam and the corresponding residues. The method has high sensitivity and good specificity, can determine three herbicides at the same time, and the detection results are accurate and reliable.

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

[0008] A method for determining pethodiola, fluazifop and / or triazone in feed comprises the following steps:

[0009] (1) Sample pretreatment: Take the sample to be tested, add water to mix, let it stand for 15-30 minutes, then add the extraction solvent and homogenizer, shake well to obtain the primary extract;

[0010] (2) Adsorption of impurities and water: Add adsorbent to the primary extract, shake at high speed, centrifuge and take the supernatant to obtain the secondary extract;

[0011] (3) Purification of the extract: add a purification reagent to the secondary extract, vortex shake, centrifuge, take the supernatant, filter, and obtain the test solution;

[0012] (4) High performance liquid chromatography tandem mass spectrometry detection: The test solution is injected into a high performance liquid chromatography tandem mass spectrometer for qualitative and quantitative detection.

[0013] Preferably, the extraction solvent in step (1) is an acetic acid-acetonitrile solution with a concentration of 1%, and the addition amount is 15 mL / 5 g of the sample to be tested; and the shaking time is 5 min.

[0014] Preferably, the adsorbents in step (2) are anhydrous magnesium sulfate and sodium acetate, and the added amounts are 6.0 g / 5 g of the sample to be tested and 1.5 g / 5 g of the sample to be tested, respectively; the speed of high-speed oscillation is 250 times / min, and the time is 2 min; the centrifugal speed is 5000 r / min, and the centrifugal time is 5 min.

[0015] Preferably, the purification reagents in step (3) are anhydrous magnesium sulfate, C18 and PSA, and the added amounts are 150 mg / mL secondary extract, 50 mg / mL secondary extract, and 50 mg / mL secondary extract, respectively; the vortex oscillation speed is 250 times / min, and the time is 2 min; the centrifugal speed is 5000 r / min, and the centrifugation time is 5 min; the filtration is performed using a microporous filter membrane with a pore size of 0.22 μm.

[0016] Preferably, the chromatographic conditions of the high performance liquid chromatography in step (4) are as follows:

[0017] Chromatographic column: ACQUITY UPLC HSS T3 1.8 μm; 2.1 × 100 mm;

[0018] Mobile phase: Phase A is 0.1% formic acid aqueous solution; Phase B is acetonitrile solution;

[0019] Elution: Gradient elution, the elution program is as follows:

[0020] 0-0.5min, mobile phase A is 50%, mobile phase B is 50%;

[0021] 0.5-4min, the amount of mobile phase A is gradually decreased from 50% to 20%, and the amount of mobile phase B is gradually increased from 50% to 80%;

[0022] 4-5min, mobile phase A is 20%, mobile phase B is 80%;

[0023] 5-5.5min, the amount of mobile phase A increased from 20% to 50% at a uniform rate, and the amount of mobile phase B decreased from 80% to 50% at a uniform rate;

[0024] 5.5-7min, the amount of mobile phase A is 50%, and the amount of mobile phase B is 50%.

[0025] Preferably, during the HPLC elution in step (4), the flow rate of the mobile phase is 0.3 mL / min, the column temperature is 40° C., and the injection volume is 1.0 μL.

[0026] Preferably, the mass spectrometry conditions of the tandem mass spectrometry in step (4) are as follows:

[0027] Ion source type: electrospray ion source;

[0028] Scanning mode: positive ion mode;

[0029] Capillary voltage: 3.0kV;

[0030] Desolvation temperature: 500°C;

[0031] Desolvation gas flow rate: 600L / Hr;

[0032] Atomizer pressure: 7.0bar;

[0033] Multiple reaction monitoring (MRM).

[0034] Another object of the present invention is to provide an application of the above-mentioned determination method in detecting pethodiac, fluazifop and / or triazone residues in feed.

[0035] It can be seen from the above technical scheme that compared with the prior art, the present invention has the following beneficial effects: the present invention provides a method for determining the new herbicides of pethoamid, fluazifop and / or triazolam in feed, and adopts dispersed solid phase extraction pretreatment technology to pretreat the sample, without the need for solid phase extraction cartridges, and the reagents used have low cost, thereby achieving effective purification and enrichment of the three new herbicides. Combined with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS / MS), it can quickly and accurately determine whether animal feed contains fluazifop, pethoamid and triazolam and the corresponding residues. The method has high sensitivity and good specificity, and the detection results are accurate and reliable, which provides technical support for the simultaneous detection of the three new herbicides of pethoamid, fluazifop and triazolam. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0037] Figure 1 The following are the changes in the amount of mobile phase B over time in the elution procedure;

[0038] Figure 2For: MRM mass spectrum of pethodiamide;

[0039] Figure 3 For: MRM mass spectrum of fluazifop-sulfuron;

[0040] Figure 4 The following is the MRM mass spectrum of triazolam;

[0041] Figure 5 The TIC diagrams are: Pyrimisulfan, Pethoxamid and Ipfencarbazone;

[0042] Figure 6 This is: the standard working curve diagram of pethodiola matrix matching;

[0043] Figure 7 It is: the standard working curve diagram of the matrix matching of pyrifossulacean;

[0044] Figure 8 The following is the standard working curve diagram of triazolam matrix matching;

[0045] Fig. 9 The calculation formula for the content of pethodiola, fluazifop and triazone is:

[0046] Fig.10 The following are: mass chromatogram of pethodiamide (1: 296.39>250.22; 2: 296.39>131.14; 3: TIC);

[0047] Fig.11 The mass chromatogram of fluazifop-sulfuron is shown as follows: (1: 420.37>370.19; 2: 420.37>255.22; 3: TIC);

[0048] Fig.12 The following are: mass chromatogram of triazolam (1: 427.297>198.18; 2: 427.29>198.18; 3: TIC). DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] The instruments and equipment used in the embodiments of the present invention are as follows:

[0051] UPLC Iclass-XEVOTQ-XS liquid chromatography-tandem mass spectrometer (Waters, USA); electronic balance (BSA223S, Sartorius, Germany); high-speed refrigerated centrifuge (Sigma, Germany); nitrogen-blown parallel concentrator (Biotage); ultrapure water purification system (Millipore, USA); XW-80A micro vortex mixer (Shanghai Huxi); high-speed sample oscillator (TAITEC SR-1, Japan); 0.22 μm organic phase microporous filter membrane.

[0052] The reagents, materials and standard solutions used in the embodiments of the present invention are configured as follows:

[0053] 1) Acetonitrile (chromatographic grade, CAS No.: 75-05-8);

[0054] 2) Formic acid (chromatographically pure, CAS No.: 64-18-6);

[0055] 3) Acetic acid (chromatographically pure, CAS No.: 64-19-7);

[0056] 4) Sodium acetate (analytical grade, CAS No.: 127-09-3);

[0057] 5) Anhydrous magnesium sulfate (analytical grade, CAS No.: 7487-88-9);

[0058] 6) Ethylenediamine-N-propylsilane silica gel (PSA): particle size 40μm-60μm;

[0059] 7) Octadecylsilane bonded silica gel (C18): particle size 40 μm-60 μm;

[0060] 8) Standard substances: pethodiamide (purity 99.5%); fluazifop-sodium (purity 99.6%); triazolam (92.4%);

[0061] 9) Preparation of standard stock solution: accurately weigh 1 mg of standard substance using a 1 / 100,000 balance, dissolve it in acetonitrile and dilute to 10 mL using a volumetric flask to prepare a standard stock solution with a concentration of 100 μg / mL, store it in a freezer at -18°C, and the shelf life is 1 year;

[0062] 10) Preparation of mixed standard stock solution: Take 1 mL of each of pethodiac, fluazifop, and triazone standard stock solutions into a 10 mL volumetric flask, dilute to 10 mL with acetonitrile, and prepare a mixed standard stock solution with a concentration of 10 μg / mL.

[0063] Example 1

[0064] A method for determining pethodiola, fluazifop and / or triazone in feed comprises the following steps:

[0065] (1) Sample pretreatment: Take 5 g of sample (accurate to 0.01 g) and place it in a 50 ml plastic centrifuge tube, add 10 ml of water, vortex to mix, let stand for 30 min, add 15 ml of 1% acetic acid-acetonitrile solution and 1 homogenizer, and shake vigorously on a shaker for 5 min to obtain the primary extract;

[0066] (2) Adsorption of impurities: Add 6 g of anhydrous magnesium sulfate and 1.5 g of sodium acetate to the primary extract, place it on a high-speed sample shaker and shake it vigorously for 2 min, then place it in a centrifuge and centrifuge it at 5000 r / min for 5 min to obtain the supernatant, which is the secondary extract;

[0067] (3) Purification of the extract: Accurately pipette 5 ml of the secondary extract, add 750 mg of anhydrous magnesium sulfate, 250 mg of C 18 , 250 mg PSA, vortexed for 2 min, centrifuged at 5000 r / min for 5 min, took the supernatant, and filtered it through a 0.22 μm organic phase microporous filter to obtain the test solution;

[0068] (4) High performance liquid chromatography tandem mass spectrometry detection: injecting the test solution into a high performance liquid chromatography tandem mass spectrometer for qualitative and quantitative detection;

[0069] The chromatographic conditions were as follows:

[0070] Chromatographic column: ACQUITY UPLC HSS T3 1.8 μm; 2.1 × 100 mm;

[0071] Mobile phase: Phase A is 0.1% formic acid aqueous solution; Phase B is acetonitrile solution;

[0072] Elution: Gradient elution, the elution program is as follows:

[0073] 0-0.5min, mobile phase A is 50%, mobile phase B is 50%;

[0074] 0.5-4min, the amount of mobile phase A is gradually decreased from 50% to 20%, and the amount of mobile phase B is gradually increased from 50% to 80%;

[0075] 4-5min, mobile phase A is 20%, mobile phase B is 80%;

[0076] 5-5.5min, the amount of mobile phase A increased from 20% to 50% at a uniform rate, and the amount of mobile phase B decreased from 80% to 50% at a uniform rate;

[0077] 5.5-7min, mobile phase A is 50%, mobile phase B is 50%;

[0078] The amount of mobile phase B changes with time. Figure 1shown.

[0079] The flow rate of the mobile phase was 0.3 mL / min, the column temperature was 40 °C, and the injection volume was 1.0 μL.

[0080] The mass spectrometry conditions were as follows:

[0081] Ion source type: electrospray ion source;

[0082] Scanning mode: positive ion mode;

[0083] Capillary voltage: 3.0kV;

[0084] Desolvation temperature: 500°C;

[0085] Desolvation gas flow rate: 600L / Hr;

[0086] Atomizer pressure: 7.0bar;

[0087] Multiple reaction monitoring (MRM).

[0088] The retention time, parent ion, daughter ion and ion pair mass spectrometry parameters of each target are shown in Table 1. The MRM mass spectrum of each target is shown in Figure 2-Figure 4 As shown; the total ion current (TIC) diagram is as follows Figure 5 As shown:

[0089] Table 1 Target ion pair parameters

[0090]

[0091]

[0092] Qualitative determination: When conducting sample determination, if the relative error between the detected chromatographic peak retention time and the chromatographic peak retention time of the blank sample and the reference substance added is less than 2%, and the selected ion pairs appear in the sample mass spectrum after background subtraction, and the relative abundance ratio of the selected ion pairs and the relative abundance ratio of the ion pairs added with the reference substance is within the range specified in Table 2, then it can be determined that the compound exists in the sample.

[0093] Table 2 Maximum allowable error of relative ion abundance in qualitative confirmation (%)

[0094] Relative ion abundance ＞50 ＞20-50 ＞10-20 ≤10 Allowable relative error ±20 ±25 ±30 ±50

[0095] Quantitative determination: Select a blank sample with the same or similar properties as the sample to be tested and perform pretreatment according to the sample pretreatment method of step (1) to obtain a blank matrix solution. Accurately aspirate a certain amount of the mixed standard stock solution, and dilute it step by step with the blank matrix solution to form a matrix-matched standard working solution with a mass concentration of 0.5ng / mL, 1ng / mL, 2ng / mL, 5ng / mL, 10ng / mL, 20ng / mL, 50ng / mL and 100ng / mL. Select no less than 5 concentration points for instrument determination based on instrument performance and detection needs. Use the mass chromatogram peak area of ​​the target substance quantification product ion as the ordinate and the corresponding matrix-matched standard working agricultural mass concentration as the abscissa to draw a matrix-matched standard working curve, and quantify using the external standard method. The standard curves of pethoxydim, fluazifop-sodium and triazolam are as follows: Figure 6-Figure 8 The linear equation is shown in Table 3. According to the results, the standard curve has good linearity in the concentration range of 0.5 to 100 ng / mL, and the correlation coefficient r>0.999.

[0096] The contents of pethodiac, fluazifop and triazone in the samples were Fig. 9 The formula shown calculates:

[0097] Where:

[0098] ω—the content of the substance being tested in the sample, in milligrams per kilogram (mg / kg);

[0099] ρ—the value of the mass concentration of the substance to be measured in the sample solution obtained from the matrix matching standard working curve, in milligrams per liter (mg / L);

[0100] V—the value of the volume of the extract, in milliliters (mL);

[0101] m—the numerical value of the sample mass, in grams (g);

[0102] The calculation result shall be rounded to three significant figures.

[0103] Table 3 Linear equations for fluazifop, pethodiola and triazone

[0104] Compound Name Regression equation Concentration range (ng / mL) Correlation coefficient Fomesulam Y=56373.6*x-120.977 0.5–100 ng / mL 0.999812 Pethodiamide Y=79066.9*x+9957.33 0.5–100 ng / mL 0.999125 Triazolam Y=12776*x-357.229 0.5–100 ng / mL 0.999029

[0105] The mass chromatograms of standard samples of pethodiac, fluazifop and triazone are shown in Figure 1. Figure 10-12 shown.

[0106] The detection limit and quantification limit of the calculation method are calculated using the signal-to-noise ratio S / N ≥ 3 and S / N ≥ 10, and it is obtained that the detection limit of pethodiola and fluazifop in the present invention is 0.005 mg / kg, and the quantification limit is 0.01 mg / kg; the detection limit of triazole is 0.01 mg / kg, and the quantification limit is 0.02 mg / kg.

[0107] Assay precision determination

[0108] Spike recovery and relative standard deviation

[0109] A blank feed sample was selected for spike recovery experiment, and pethodiola and fluazifop were added at 0.01 mg / kg, 0.02 mg / kg, and 0.1 mg / kg, respectively; three concentration levels of standard substances of triazolam were added at 0.02 mg / kg, 0.04 mg / kg, and 0.2 mg / kg, and 6 replicates were made for each addition level. After spiking, the sample was vortexed and allowed to stand for 30 minutes. After the standard substance and the feed sample to be tested were fully mixed, the pretreatment and UPLC-MS / MS method were performed according to the corresponding steps, and the recovery rate and precision were calculated respectively. The results are shown in Table 4.

[0110] Table 4 Recovery and precision of blank feed samples when analytes were added

[0111]

[0112]

[0113] Example 2

[0114] Determination of new herbicides such as pethodiola, fluazifop and triazone in different feeds:

[0115] 1. Feed containing a large amount of starch: Weigh 5g of feed sample (feed with wheat, rice, corn and potato as the main ingredients), add 0.1μg of pethoamid, fluazifop and triazolam, and process and measure according to the operating steps of the present invention, and the pethoamid is 0.0180mg / kg; fluazifop 0.0156mg / kg; triazolam 0.0214mg / kg. The recovery rates are 90%, 78% and 107% respectively, which meet the detection requirements.

[0116] 2. Oil-containing feed: Weigh 5g of feed sample (feed with high oil content such as soybean, peanut, rapeseed, etc. as the main component), add 0.1μg of pethoamid, fluazifop and triazolam, and process and measure according to the operating steps of the present invention, and measure 0.0230mg / kg of pethoamid; 0.0166mg / kg of fluazifop; 0.0221mg / kg of triazolam. The recovery rates are 115%, 83% and 110.5% respectively, which meet the detection requirements.

[0117] 3. Feed containing sugar: Weigh 5g of feed sample (feed with sugarcane stalks, beets and other crops with high sugar content as the main ingredients), add 0.1μg of pethoamid, fluazifop and triazolam, and process and measure according to the operating steps of the present invention, and the pethoamid is 0.0191mg / kg; fluazifop 0.0216mg / kg; triazolam 0.0176mg / kg. The recovery rates are 95.5%, 108% and 88% respectively, which meet the detection requirements.

[0118] 4. High-protein feed: Weigh 5g of feed sample (feed with defatted soybean, soybean meal and other crops with high protein content as the main ingredients), add 0.1μg of pethoamid, fluazifop and triazolam, and process and measure according to the operating steps of the present invention, and measure 0.0187mg / kg of pethoamid, 0.0194mg / kg of fluazifop and 0.0196mg / kg of triazolam. The recovery rates are 95.5%, 108% and 88% respectively, which meet the detection requirements.

[0119] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0120] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining pethodiola, fluazifop and / or triazone in feed, characterized in that: The steps include: (1) Sample pretreatment: Take the sample to be tested, add water to mix, let it stand for 15-30 minutes, then add the extraction solvent and homogenizer, shake well to obtain the primary extract; (2) Adsorption of impurities and water: Add adsorbent to the primary extract, shake at high speed, centrifuge and take the supernatant to obtain the secondary extract; (3) Purification of the extract: add a purification reagent to the secondary extract, vortex shake, centrifuge, take the supernatant, filter, and obtain the test solution; (4) High performance liquid chromatography tandem mass spectrometry detection: The test solution is injected into a high performance liquid chromatography tandem mass spectrometer for qualitative and quantitative detection.

2. The measuring method according to claim 1, characterized in that The extraction solvent in step (1) is 1% acetic acid-acetonitrile solution, and the addition amount is 15 mL / 5 g of the sample to be tested; the shaking time is 5 min.

3. The measuring method according to claim 1, characterized in that The adsorbents in step (2) are anhydrous magnesium sulfate and sodium acetate, and the added amounts are 6.0 g / 5 g of the sample to be tested and 1.5 g / 5 g of the sample to be tested, respectively; the speed of the high-speed oscillation is 250 times / min, and the time is 2 min; the centrifugal speed is 5000 r / min, and the centrifugal time is 5 min.

4. The measuring method according to claim 1, characterized in that The purification reagent in step (3) is anhydrous magnesium sulfate, C 18 and PSA, the addition amounts were 150 mg / mL secondary extract, 50 mg / mL secondary extract, and 50 mg / mL secondary extract, respectively; the vortexing speed was 250 times / min, and the time was 2 min; the centrifugal speed was 5000 r / min, and the centrifugal time was 5 min; The filtration is performed using a microporous filter membrane with a pore size of 0.22 μm.

5. The measuring method according to claim 1, characterized in that The chromatographic conditions of the high performance liquid chromatography in step (4) are as follows: Chromatographic column: ACQUITY UPLC HSS T3 1.8 μm; 2.1 × 100 mm; Mobile phase: Phase A is 0.1% formic acid aqueous solution; Phase B is acetonitrile solution; Elution: Gradient elution, the elution program is as follows: 0-0.5min, mobile phase A is 50%, mobile phase B is 50%; 0.5-4min, the amount of mobile phase A is gradually decreased from 50% to 20%, and the amount of mobile phase B is gradually increased from 50% to 80%; 4-5min, mobile phase A is 20%, mobile phase B is 80%; 5-5.5min, the amount of mobile phase A increased from 20% to 50% at a uniform rate, and the amount of mobile phase B decreased from 80% to 50% at a uniform rate; 5.5-7min, the amount of mobile phase A is 50%, and the amount of mobile phase B is 50%.

6. The measuring method according to claim 1, characterized in that In step (4), the flow rate of the mobile phase during the HPLC elution is 0.3 mL / min, the column temperature is 40° C., and the injection volume is 1.0 μL.

7. The measuring method according to claim 1, characterized in that The mass spectrometry conditions of the tandem mass spectrometry in step (4) are as follows: Ion source type: electrospray ion source; Scanning mode: positive ion mode; Capillary voltage: 3.0kV; Desolvation temperature: 500°C; Desolvation gas flow rate: 600L / Hr; Atomizer pressure: 7.0bar; Multiple reaction monitoring (MRM).

8. Use of the determination method according to any one of claims 1 to 7 in detecting pethodiac, fluazifop and / or triazone residues in feed.

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