A method for separating and determining isomers of chlorfenvinphos and methyl chlorfenvinphos by reversed phase liquid chromatography tandem mass spectrometry

Abstract

A method for separating and determining isomers of chlorfenvinphos and methyl chlorfenvinphos by reversed phase liquid chromatography tandem mass spectrometry belongs to the technical field of analytical chemistry. The method comprises the following steps: 1) pre-treating a sample to be tested to obtain a solution to be tested; 2) detecting the solution to be tested by reversed phase liquid chromatography tandem mass spectrometry; 3) calculating the content of chlorfenvinphos and methyl chlorfenvinphos isomers in the sample to be tested according to a standard working curve; in step 2), the chromatographic column used for reversed phase liquid chromatography detection is Lux ® Amylose-1, which uses silica gel coated with amylose-tris (3,5-dimethylphenylcarbamate) as filler, and the mobile phase is acetonitrile-formic acid aqueous solution (0.1% volume fraction). The present invention can realize the separation and rapid quantitative analysis of cis and trans isomers of chlorfenapyr and methyl chlorfenapyr, and the method has high sensitivity and accuracy and good separation degree.

Description

Technical Field

[0001] The invention relates to a method for separating and detecting isomers of chlorfenvinphos and methyl chlorfenvinphos, in particular to a method for separating and determining isomers of chlorfenvinphos and methyl chlorfenvinphos by reversed phase liquid chromatography tandem mass spectrometry, belonging to the technical field of analytical chemistry. Background Art

[0002] Cis-trans isomerism is an important stereoisomerism phenomenon, which belongs to the problem of diastereoisomerism. Due to the factors that restrict rotation in the compound molecules, the different arrangements of the groups in space lead to cis-trans isomerism. The properties of these isomers are not exactly the same, and their digestion and fate in the environment are often significantly different. There may be huge differences in their activity, toxicity, absorption, metabolism, degradation and many other aspects in the natural environment and organisms.

[0003] Chlorfenapyr and methyl chlorfenapyr are highly toxic to humans and animals and are highly toxic pesticides. The molecular structure of chlorfenapyr and methyl chlorfenapyr contains a C=C bond and a pair of cis-trans isomers, with the following structure:

[0004]

[0005] At present, the pesticides sold on the market are all mixtures of chlorfenapyr and chlorfenapyr methyl cis-trans isomers, which have a small amount of residues after use in the process of crop planting and storage. However, the existing technology can only measure the total amount of chlorfenapyr and chlorfenapyr methyl when detecting chlorfenapyr and chlorfenapyr methyl. For example, the document "Analysis of 29 Organophosphorus Pesticide Residues in Tobacco by Gas Chromatography-Mass Spectrometry" (Journal of Chinese Tobacco Science, 2008, 14 (Z1)) discloses a method for detecting organophosphorus pesticide residues in tobacco. This method uses gas chromatography-mass spectrometry for analysis after sample pretreatment, and can analyze the chlorfenapyr residues in tobacco. However, since the gas chromatography and the corresponding chromatographic column have no specific selectivity for chlorfenapyr isomers, it is impossible to separate and quantitatively analyze the cis-trans isomers of chlorfenapyr and chlorfenapyr methyl. Since the activities of the cis and trans isomers of chlorfenvinphos and methyl chlorfenvinphos have certain differences, it is very necessary to establish a method for determining the isomer content of chlorfenvinphos and methyl chlorfenvinphos for the development and production of single isomer products, product quality control by manufacturers, and control of the residues of cis and trans isomers of chlorfenvinphos and methyl chlorfenvinphos in agricultural products. Summary of the invention

[0006] The object of the present invention is to provide a method for separating and determining isomers of chlorfenvinphos and methyl chlorfenvinphos by reversed phase liquid chromatography tandem mass spectrometry, which can realize quantitative analysis of isomers of chlorfenvinphos and methyl chlorfenvinphos in a sample to be tested.

[0007] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A method for separating and detecting isomers of chlorfenvinphos and methylchlorfenvinphos, comprising the following steps:

[0009] 1) Pre-treating the sample to be tested to obtain a solution to be tested;

[0010] 2) Reverse phase liquid chromatography tandem mass spectrometry is used to detect the test solution;

[0011] 3) Calculate the contents of different isomers of chlorfenvinphos and methylchlorfenvinphos in the sample to be tested according to the standard working curve;

[0012] In step 2), the chromatographic column used for reversed phase liquid chromatography detection is filled with silica gel coated with amylose-tris (3,5-dimethylphenylcarbamate) on the surface, and the mobile phase used is acetonitrile and formic acid aqueous solution (0.1% volume fraction). Tris (3,5-dichlorophenylcarbamate located outside the amylose cavity in the chromatographic column can identify isomers containing specific functional groups (benzene ring and phosphate group structure) through dipole-dipole or π-π interactions under the action of acetonitrile and formic acid aqueous solution, thereby achieving better separation of compounds containing both benzene ring and phosphate group.

[0013] Preferably, the chromatographic column is Lux ® Amylose-1 column. The Lux ® The Amylose-1 column has a length of 150 mm, an inner diameter of 4.6 mm, and a filler particle size of 3 μm.

[0014] Preferably, the column temperature of the chromatographic column used in the reverse phase liquid chromatography detection is 35-45°C.

[0015] Preferably, the mobile phase is acetonitrile and formic acid aqueous solution (0.1% volume fraction); the liquid chromatography detection adopts isocratic elution mode, and the ratio of acetonitrile and formic acid aqueous solution (0.1% volume fraction) is 80%:20%; the mobile phase flow rate is 0.25-0.35mL / min.

[0016] Depending on the sample to be tested, the pre-treatment method is also different, but all can be treated according to the pre-treatment method used in the prior art for detecting organic matter in the sample to be tested. The sample to be tested is a product of chlorpyrifos and methyl chlorpyrifos or an agricultural product. The pre-treatment required when the sample to be tested is a product of chlorpyrifos and methyl chlorpyrifos includes the steps of diluting and filtering the chlorpyrifos and methyl chlorpyrifos products. When the sample to be tested is an agricultural product, the pre-treatment includes the steps of extracting the sample to be tested and purifying the extract. For example, the improved QuEChERS method can be used to pre-treat agricultural products to extract chlorpyrifos and methyl chlorpyrifos in agricultural products to reduce matrix interference.

[0017] The agricultural product is tobacco or grain.

[0018] The pretreatment comprises the following steps: crushing the sample to be tested, extracting it with an organic solvent, adding an extraction salt, mixing it, and centrifuging it, taking the supernatant, purifying it with an adsorbent containing spherical carbon, and centrifuging it again to obtain the supernatant to obtain the solution to be tested. Spherical carbon has excellent carbon content and pore structure, and also has a large surface area. Compared with other purifiers, it can better remove pigments and purify the matrix.

[0019] In mass spectrometry, the quantitative ion pairs of chlorfenvinphos and methylchlorfenvinphos were 358.9 / 155.0 and 331.1 / 127.1 respectively; the qualitative ion pairs were 358.9 / 205.1 and 331.1 / 205.1 respectively. The declustering voltage of the quantitative ion pair and the qualitative ion pair of chlorfenvinphos were both 28V, and the collision energy was 12V and 30V respectively; the declustering voltage of the quantitative ion pair and the qualitative ion pair of methylchlorfenvinphos were both 28V, and the collision energy was 20V and 16V respectively.

[0020] Preferably, the mass spectrometry detection conditions are: the ion source is an electrospray ion source (ESI); the scanning mode is positive ion scanning; the capillary voltage is 2.6-2.8 KV; the ion source temperature is 140-150°C; the desolvation gas temperature is 320-340°C; the desolvation gas flow rate is 580-620 L / h; and the cone gas flow rate is 40-50 L / h.

[0021] The method for separating and detecting isomers of chlorfenvinphos and methyl chlorfenvinphos uses reverse phase liquid chromatography tandem mass spectrometry, selects a chromatographic column with silica gel coated with amylose-tris (3,5-dimethylphenylcarbamate) on the surface as filler, uses acetonitrile and formic acid aqueous solution (0.1% volume fraction) as mobile phase, and quantifies the cis and trans isomers of chlorfenvinphos and methyl chlorfenvinphos by tandem mass spectrometry, thereby realizing rapid separation and detection of the cis and trans isomers of chlorfenvinphos and methyl chlorfenvinphos, and reducing false positive results.

[0022] The method for separating and detecting isomers of chlorfenvinphos and methyl chlorfenvinphos has a fast quantitative analysis speed for cis-trans isomers of chlorfenvinphos and methyl chlorfenvinphos, and the time consumption can be shortened to less than 11 minutes. The filler of the chromatographic column used is sub-2 μm particles. Compared with the chromatographic column using sub-5 μm particles, the chromatographic column has a faster separation speed. The minimum detection limit of cis-trans isomers of chlorfenvinphos and methyl chlorfenvinphos is 0.007 mg / kg, the sensitivity and accuracy are high, and the separation degree of isomers is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the selected ion chromatogram of the matrix mixed standard working solution in Example 1.

[0024] Figure 2 This is the LC-MS / MS selected ion chromatogram of the matrix mixed standard working solution in Comparative Example 1.

[0025] Figure 3 This is the LC-MS / MS selected ion chromatogram of the matrix mixed standard working solution in Comparative Example 2. DETAILED DESCRIPTION

[0026] The method for separating and detecting isomers of chlorfenvinphos and methylchlorfenvinphos provided by the present invention comprises the following steps:

[0027] 1) Pre-treating the sample to be tested to obtain a solution to be tested;

[0028] 2) Reverse phase liquid chromatography tandem mass spectrometry is used to detect the test solution;

[0029] 3) Calculating the content of cis-isomers of chlorfenvinphos and methyl chlorfenvinphos and / or trans-isomers of chlorfenvinphos and methyl chlorfenvinphos in the sample to be tested according to the standard working curve;

[0030] In step 2), the chromatographic column used in the reversed phase liquid chromatography tandem mass spectrometry is filled with silica gel coated with amylose-tris(3,5-dimethylphenylcarbamate) on the surface, and the mobile phase used is acetonitrile and formic acid aqueous solution (0.1% volume fraction).

[0031] In a specific embodiment of the present invention, when the sample to be tested is an agricultural product, the pretreatment method is an improved QuEChERS method, comprising the following steps: crushing the sample to be tested and extracting it with an organic solvent, then adding an extraction salt and mixing it, and then centrifuging it, taking the supernatant and purifying it with an adsorbent, and centrifuging it again to obtain the supernatant to obtain the test solution.

[0032] The organic solvent is acetonitrile. The extraction salt is composed of the following components in parts by weight: 5 parts of anhydrous magnesium sulfate, 1 part of sodium chloride, 1 part of sodium citrate and 0.5 parts of disodium hydrogen citrate. The mass ratio of the sample to be tested to the extraction salt is 2:7.5. The adsorbent is composed of the following components: 150 mg of anhydrous magnesium sulfate, 25 mg of PSA and 2.5 mg of spherical carbon.

[0033] In a specific embodiment of the present invention, the flow rate of the mobile phase during reverse phase liquid chromatography detection is 0.3 mL / min.

[0034] In a specific embodiment of the present invention, the injection volume during reverse phase liquid chromatography detection is 5 μL.

[0035] In a specific embodiment of the present invention, the mobile phase is acetonitrile and formic acid aqueous solution (0.1% volume fraction) 。Acetonitrile is a non-protonated solvent with high polarity, and it can easily react with the benzene ring and phosphate group in the analyte to perform selective elution. Methanol, on the other hand, has a weaker polarity and relatively weaker selectivity with the analyte.

[0036] In a specific embodiment of the present invention, the elution is isocratic elution, and the ratio of acetonitrile to formic acid aqueous solution (0.1% volume fraction) is 80%:20%.

[0037] In a specific embodiment of the present invention, the detection result is analyzed by an external standard method to calculate the contents of chlorfenvinphos and methylchlorfenvinphos isomers in the sample to be tested.

[0038] In a specific embodiment of the present invention, in step 3), the standard working curve is determined by the method of the prior art. And according to the different isomers of chlorpyrifos and methyl chlorpyrifos to be detected, a standard working curve of cis-isomers of chlorpyrifos and methyl chlorpyrifos or a standard working curve of trans-isomers of chlorpyrifos and methyl chlorpyrifos can be established; if the contents of cis-isomers of chlorpyrifos and methyl chlorpyrifos and trans-isomers of chlorpyrifos and methyl chlorpyrifos are determined at the same time, standard working curves of the two need to be established respectively. The standard working solution used to determine the standard working curve is prepared according to the method in the prior art. In order to eliminate the influence of the matrix of the sample to be tested, the standard solutions used when determining the standard working curve are all matrix mixed standard working solutions.

[0039] The technical solution of the present invention is further described below in conjunction with specific implementation methods.

[0040] The acetonitrile used in Example 1 and Example 2 is a chromatographic grade reagent, sodium citrate and sodium chloride are both analytical grade reagents, and distilled water meets the requirements of first-class water in GB / T 6682; E-chlorfenapyr, Z-chlorfenapyr, E-methylchlorfenapyr and Z-methylchlorfenapyr standard solutions (100 μg / mL) were purchased from Tianjin Alta Co., Ltd.; the mass spectrometer used was a Waters TQS quadrupole tandem mass spectrometer; and the weighing was done using a Swiss Mettler AE 163 electronic balance (sensitivity: 0.0001 g).

[0041] Example 1

[0042] The method for separating and detecting isomers of chlorfenvinphos and methylchlorfenvinphos in this embodiment comprises the following steps:

[0043] 1) Prepare the blank sample matrix solution as follows: accurately weigh 2 g of the ground grain blank sample into a 50 mL centrifuge tube with a lid, add 10 mL of water, add 10 mL of acetonitrile after soaking, and then place the centrifuge tube on a vortex mixer and shake at 2000 rpm for 5 min. Then add 5 g of anhydrous magnesium sulfate, 1 g of sodium chloride, 1 g of sodium citrate and 0.5 g of disodium hydrogen citrate to the centrifuge tube, immediately shake at 2000 rpm for 5 min on a vortex mixer, and then centrifuge at 6000 rpm for 3 min; transfer 1.0 mL of the supernatant into a 1.5 mL centrifuge tube, add 150 mg of anhydrous magnesium sulfate, 25 mg of PSA and 2.5 mg of spherical carbon, shake at 2000 rpm for 2 min on a vortex mixer, and centrifuge at 6000 rpm for 3 min; aspirate the supernatant and filter it through a 0.45 μm organic phase filter membrane. The filtrate obtained is the blank sample matrix solution and is set aside.

[0044] 2) Prepare the matrix mixed standard working solution as follows: pipette 0.1 mL of E-chlorfenapyr, Z-chlorfenapyr, E-methylchlorfenapyr and Z-methylchlorfenapyr standard solutions (100 μg / mL) into 10 mL volumetric flasks, dissolve and dilute to the mark with acetonitrile to prepare standard stock solutions (1.0 μg / mL); pipette 50 μL, 100 μL, 200 μL, 500 μL, 1000 μL and 2000 μL of the secondary standard stock solutions into 6 10 mL volumetric flasks, dilute to the mark with acetonitrile to prepare standard working solutions; then pipette 500 μL of the above standard working solutions and mix with 500 μL of blank sample matrix solution to prepare matrix mixed standard working solutions.

[0045] 3) The matrix mixed standard working solutions of various concentrations prepared in step 2) are subjected to reverse phase liquid chromatography tandem mass spectrometry detection, and the selected ion peak areas of cis-isomers of chlorfenapyr and methyl chlorfenapyr (Z-chlorfenapyr and Z-methyl chlorfenapyr) and trans-isomers of chlorfenapyr and methyl chlorfenapyr (E-chlorfenapyr and E-methyl chlorfenapyr) are recorded. The selected ion chromatogram obtained by detection is shown in Figure 1 ; Then, the concentration value of each isomer was used as the independent variable and the corresponding selected ion peak area was used as the dependent variable to calculate the univariate linear regression equation as the standard working curve. The specific detection results are shown in Table 1.

[0046] Table 1 Test results of matrix mixed standard working solution

[0047] Isomers Retention time (min) Linear regression equation Linear correlation coefficient Linear range (ng / mL) Detection limit (mg / kg) E-Insecticide 9.09 Y=3200X+1044 0.9998 5~200 0.009 Z-Insecticide 8.68 Y=5565X+2421 0.9998 5~200 0.007 E-Methylchlorfenapyr 8.36 Y=721X+1026 0.9996 5~200 0.015 Z-Methylchlorfenapyr 7.91 Y=1797X+429 0.9996 5~200 0.012

[0048] Reversed-phase liquid chromatography tandem mass spectrometry detection conditions:

[0049] Chromatographic conditions: Chromatographic column: size 150 mm × 4.6 mm, 3.0µm Lux ® Amylose-1 column; mobile phase: acetonitrile and formic acid aqueous solution (0.1% volume fraction), flow rate: 0.3 mL / min; isocratic elution; column temperature: 40℃; injection volume: 5µL; the ratio of acetonitrile and formic acid aqueous solution (0.1% volume fraction) is 80%:20%.

[0050] Mass spectrometry conditions: ion source is electrospray ion source (ESI); scanning mode is positive ion scanning; capillary voltage is 2.6 KV; ion source temperature is 140℃; desolvation gas temperature is 320℃; desolvation gas flow rate is 580 L / h; cone gas flow rate is 40L / h; the quantitative ion pairs of chlorfenapyr and methyl chlorfenapyr are 358.9 / 155.0 and 331.1 / 127.1 respectively; the qualitative ion pairs are 358.9 / 205.1 and 331.1 / 205.1 respectively. The declustering voltage of the quantitative ion pair and the qualitative ion pair of chlorfenapyr are both 28V, and the collision energy is 12V and 30V respectively; the declustering voltage of the quantitative ion pair and the qualitative ion pair of methyl chlorfenapyr are both 28V, and the collision energy is 20V and 16V respectively.

[0051] 4) Pretreatment of the sample to be tested: Accurately weigh 2 g of the ground grain sample to be tested into a 50 mL centrifuge tube with a lid, add 10 mL of distilled water, add 10 mL of acetonitrile after soaking, and then place the centrifuge tube on a vortex mixer and shake at 2000 rpm for 5 min. Then add 5 g of anhydrous magnesium sulfate, 1 g of sodium chloride, 1 g of sodium citrate and 0.5 g of disodium hydrogen citrate to the centrifuge tube, immediately shake at 2000 rpm for 5 min on a vortex mixer, and then centrifuge at 6000 rpm for 3 min; transfer 1.0 mL of the supernatant to a 1.5 mL centrifuge tube, add 150 mg of anhydrous magnesium sulfate, 25 mg of PSA and 2.5 mg of spherical carbon, shake at 2000 rpm for 2 min on a vortex mixer, and centrifuge at 6000 rpm for 3 min. Pipette the supernatant and filter it through a 0.45 μm organic phase filter membrane, and dilute it twice with acetonitrile to obtain the test solution;

[0052] 5) The test solution obtained in step 4) is subjected to reverse phase liquid chromatography tandem mass spectrometry (LC-MS / MS) according to the chromatographic conditions and mass spectrometry conditions in step 3), and each elution peak is separated according to the quantitative ion pair, qualitative ion pair and elution peak retention time of each isomer in Table 1.

[0053] The selected ion peak areas corresponding to the cis-isomers of chlorfenvinphos and methyl chlorfenvinphos and the trans-isomers of chlorfenvinphos and methyl chlorfenvinphos were recorded respectively, and the selected ion peak area corresponding to each isomer was substituted into the univariate linear regression equation obtained in step 3), and the concentrations of E-chlorfenvinphos and Z-chlorfenvinphos in the test solution were obtained to be 6.0 ng / mL and 6.0 ng / mL, respectively. The contents of Z-chlorfenvinphos and E-chlorfenvinphos in the grain sample to be tested were calculated to be 0.03 mg / kg.

[0054] In order to determine the accuracy of the method of this embodiment, 2 g of grain sample was added with 0.1 mL of standard stock solution so that the amount of E-chlorfenapyr, Z-chlorfenapyr, E-methylchlorfenapyr and Z-methylchlorfenapyr added to the sample was 0.05 mg / kg. The sample was pretreated according to step 4) and analyzed according to the chromatographic conditions and mass spectrometry conditions of step 3). The selected ion peak area of ​​each isomer was measured and substituted into the standard curve obtained in step 3). The contents of E-chlorfenapyr, Z-chlorfenapyr, E-methylchlorfenapyr and Z-methylchlorfenapyr in the sample were 0.070, 0.075, 0.044 and 0.042 mg / kg, respectively, that is, the spiked recoveries of the target substances were 87.5%, 93.8%, 88.0% and 84.0%, respectively, indicating that the method of this embodiment is accurate.

[0055] Example 2

[0056] The method for separating and detecting isomers of chlorfenvinphos and methylchlorfenvinphos in this embodiment is completely the same as that in Example 1, except that the sample to be tested is another tobacco sample.

[0057] In the tobacco samples in Example 2, E-fenpyrot, methylfenpyrot, Z-fenpyrot, and methylfenpyrot were not detected.

[0058] Comparative Example 1

[0059] The method for separating and detecting the isomers of chlorfenvinphos and methyl chlorfenvinphos in this embodiment is completely the same as that in Example 1, except that the chromatographic column used is CHIRALPAK® OD-3R. The isomers of chlorfenvinphos and methyl chlorfenvinphos cannot be separated. Figure 2 .

[0060] Comparative Example 2

[0061] The method for separating and detecting the isomers of chlorfenvinphos and methyl chlorfenvinphos in this example is exactly the same as that in Example 1, except that the chromatographic column used is CHIRALPAK® AD-3R. The isomers of chlorfenvinphos and methyl chlorfenvinphos cannot be baseline separated. Figure 3 .

Claims

1. A method for separating and determining isomers of chlorfenvinphos and methyl chlorfenvinphos by reverse phase liquid chromatography tandem mass spectrometry, characterized in that: The following steps are involved: 1) Pre-treating the sample to be tested to obtain a solution to be tested; 2) The solution to be tested was detected by reverse phase liquid chromatography tandem mass spectrometry, and the chromatographic column used was filled with silica gel coated with amylose-tris (3,5-dimethylphenylcarbamate) on the surface. The chromatographic column was Lux ® The mobile phase of Amylose-1 column was acetonitrile and 0.1% formic acid in water; 3) Calculate the contents of chlorfenvinphos and methylchlorfenvinphos isomers in the sample to be tested according to the standard working curve.

2. The method for separating and determining isomers of chlorfenvinphos and methylchlorfenvinphos according to claim 1, characterized in that: Lux ® The Amylose-1 column has a length of 150 mm, an inner diameter of 4.6 mm, and a filler particle size of 3 μm.

3. The method for separating and determining isomers of chlorfenvinphos and methylchlorfenvinphos according to claim 1 or 2, characterized in that: The column temperature of the chromatographic column used in reversed-phase liquid chromatography detection is 35~45℃.

4. The method for separating and determining isomers of chlorfenvinphos and methylchlorfenvinphos according to claim 1, characterized in that: Liquid chromatography detection adopts isocratic elution mode, the volume ratio of acetonitrile and 0.1% volume fraction formic acid aqueous solution is 80%:20%; the flow rate of mobile phase is 0.25-0.35mL / min.

5. The method for separating and determining isomers of chlorfenvinphos and methylchlorfenvinphos according to claim 1, characterized in that: The samples to be tested are chlorfenapyr and methylchlorfenapyr products or agricultural products.

6. The method for separating and determining isomers of chlorfenvinphos and methylchlorfenvinphos according to claim 5, characterized in that: The agricultural product is tobacco or grain.

7. The method for separating and determining isomers of chlorfenvinphos and methylchlorfenvinphos according to claim 1, characterized in that: The pretreatment comprises the following steps: crushing the sample to be tested, extracting it with an organic solvent, adding extraction salt, mixing it and centrifuging it, taking the supernatant and purifying it with an adsorbent containing spherical carbon, centrifuging it again and taking the supernatant to obtain the solution to be tested.

8. The method for separating and determining isomers of chlorfenvinphos and methylchlorfenvinphos according to claim 1, characterized in that: In mass spectrometry detection, the quantitative ion pairs of chlorfenvinphos and methylchlorfenvinphos were 358.9 / 155.0 and 331.1 / 127.1 respectively; the qualitative ion pairs were 358.9 / 205.1 and 331.1 / 205.1 respectively; the declustering voltages of the quantitative ion pair and the qualitative ion pair of chlorfenvinphos were both 28 V, and the collision energies were 12 V and 30 V respectively; the declustering voltages of the quantitative ion pair and the qualitative ion pair of methylchlorfenvinphos were both 28 V, and the collision energies were 20 V and 16 V respectively.

9. The method for separating and determining isomers of chlorfenvinphos and methylchlorfenvinphos according to claim 1, characterized in that: The mass spectrometry detection conditions are as follows: the ion source is an electrospray ion source (ESI); the scanning mode is a positive ion scan; the capillary voltage is 2.6-2.8 KV; the ion source temperature is 140-150°C; the desolvation gas temperature is 320-340°C; the desolvation gas flow rate is 580-620 L / h; and the cone gas flow rate is 40-50 L / h.

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