A HPLC-MS / MS detection method for 4-fluoro-N-isopropylaniline in soil and water

Abstract

The invention discloses a HPLC-MS / MS detection method for 4-fluoro-N-isopropylaniline in soil and water. The injection concentration of 4-fluoro-N-isopropylaniline in the invention shows a good linear relationship in the range of 0.50 μg / L to 20.0 μg / L, the linear equation is y=55256.42x-299.60, and the linear correlation coefficient R 2 =0.9996; precision RSD% is 0.3645%, RSD of target peak R.T. 0.65%, RSD Area The detection limit of the present invention is 4.08 ng / L, the quantitative limit is 10.89 ng / L, and the detection sensitivity is high; the target peak is 0.5 min, the detection efficiency is high, the instrument operation time is short, and the detection cost is low; the method can well detect the content of 4-fluoro-N-isopropylaniline in environmental soil and water, which is of great significance to the protection of soil and water environment. The present invention has the advantages of simple operation, good repeatability, good separation effect, high accuracy and precision, etc.

Description

Technical Field

[0001] The invention belongs to the field of environmental detection, and in particular relates to a HPLC-MS / MS detection method for 4-fluoro-N-(1-methylethyl)aniline in soil and water. Background Art

[0002] 4-Fluoro-N-isopropylaniline, also known as 4-fluoro-N-(1-methylethyl)aniline, has a molecular formula of C9H 12 FN, molecular weight 153.2, CAS number 70441-63-3. 4-Fluoro-N-isopropylaniline is an important organic synthesis intermediate and pesticide intermediate, which can usually be used to synthesize flufenacet, which is an aromatic oxygen amide herbicide that mainly works by inhibiting cell division and growth. It has the advantages of high herbicidal activity, broad weed control spectrum, wide application of crops, and high safety. It can effectively control annual grass weeds and broad-leaved weeds before and after germination. The structural formula of 4-Fluoro-N-isopropylaniline is shown below:

[0003]

[0004] Due to the adsorption and physical and chemical absorption of soil matrix and water environment, aniline substances are easily accumulated in soil after entering soil or water environment, causing lasting harm to the environment. The polluted soil matrix and water environment are complex, with many types of interfering substances and low content of target substances, which requires extremely high analytical detection methods. At present, the public method for determining the content of 4-fluoro-N-isopropylaniline is gas chromatography, and the detection method of high-performance liquid chromatography tandem mass spectrometry has not been reported in the literature.

[0005] The enterprise standard "Q / FRG 067-20214-Fluoro-N-isopropylaniline" discloses the gas chromatography detection method of 4-fluoro-N-isopropylaniline, and specifically discloses "using Agilent6890 or 7890A gas chromatograph or equivalent chromatograph; FID detector, chromatographic column: DB-624 (30×0.32m×1.80um) or similar chromatographic column; carrier gas: high-purity nitrogen; constant flow: 1.0ml / min; hydrogen flow: 50ml / min; air flow: 300ml / min; split ratio: 100:1; chemical chamber temperature: 260℃; detection chamber temperature: 300℃; column temperature: 50℃ for 1min and then increase the temperature to 260℃ at a rate of 12℃ / min, and keep warm for 10min. Directly inject 10uL for analysis, and calculate the content by area normalization method." This method is used for the detection of pure 4-fluoro-N-isopropylaniline. However, the detection of 4-fluoro-N-isopropylaniline in environmental soil or water has the problems of insufficient sensitivity, poor anti-interference ability and unguaranteed stability.

[0006] Therefore, establishing an accurate, efficient and environmentally friendly method for detecting 4-fluoro-N-isopropylaniline in soil and water is of great significance for environmental monitoring and subsequent governance in areas where 4-fluoro-N-isopropylaniline is produced and used. Summary of the invention

[0007] The invention aims to overcome the problems that the detection method of 4-fluoro-N-isopropylaniline in the prior art has low sensitivity and poor stability and cannot detect 4-fluoro-N-isopropylaniline in environmental soil and water, and to provide an HPLC-MS / MS detection method for 4-fluoro-N-isopropylaniline in soil and water with high sensitivity, strong specificity and a detection limit of ng / L level.

[0008] The purpose of the present invention is achieved by the following technical solutions:

[0009] A HPLC-MS / MS detection method for 4-fluoro-N-isopropylaniline in soil and water, the detection steps are as follows:

[0010] 1. A HPLC-MS / MS method for detecting 4-fluoro-N-isopropylaniline in soil and water, characterized in that the detection steps are as follows:

[0011] (1) Preparation of standard working solution: Accurately weigh 0.10225 g of 4-fluoro-N-isopropylaniline standard sample into a 100 mL volumetric flask, dissolve it in acetonitrile and make up to volume, shake well, and prepare a standard stock solution with a concentration of 1000.00 mg / L; take an appropriate amount of the standard stock solution and dilute it step by step with acetonitrile to prepare a series of standard working solutions with concentrations of 0.50 to 20.0 μg / L.

[0012] (2) Drawing of standard curve: Set the operating conditions of the HPLC-MS / MS instrument, aspirate 5 μL of the series of standard working solutions in step (1) and inject them into the HPLC-MS / MS instrument for measurement, and draw a calibration curve and a linear regression equation with the concentration of 4-fluoro-N-isopropylaniline as the horizontal axis and the peak area as the vertical axis.

[0013] (3) Preparation of soil sample solution: Collect the soil sample to be tested, air-dry, grind and sieve it in sequence, weigh 10.0 g of the processed soil sample to be tested into a 250 mL conical flask, add 50 mL of acetonitrile, shake and let stand, take the supernatant and filter it with a 0.22 μm filter membrane;

[0014] (4) Preparation of water sample solution: Take 10 mL of the water sample to be tested and filter it through a 0.22 μm filter membrane.

[0015] (5) Determination and calculation of samples: Set the operating conditions of the HPLC-MS / MS instrument, take 5 μL of the soil sample solution and the water sample solution to be tested for determination, record the chromatograms, and calculate the content of 4-fluoro-N-isopropylaniline in the samples by the external standard method.

[0016] Preferably, the concentrations of the series of standard working solutions are 0.50, 1.00, 2.00, 4.00, 8.00, 10.0, and 20.0 μg / L.

[0017] In the HPLC-MS / MS instrument operating conditions, the HPLC uses Eclipse Plus C18 RRHD as the chromatographic column, with specifications of 50×2.1 mm, 1.8 μm. The analysis conditions of the HPLC are: flow rate of 0.3 mL / min; mobile phase composed of acetonitrile and 0.1% formic acid water, the volume ratio of acetonitrile and 0.1% formic acid water is 80:20; column temperature is 30°C.

[0018] In the HPLC-MS / MS instrument operating conditions, the ion source of the mass spectrometer was AJS ESI source, in positive ion mode.

[0019] The ion source parameters of the mass spectrometer are: drying gas: N2; drying gas temperature: 300℃; drying gas flow rate: 5L / min; sheath gas: N2; sheath gas temperature: 250℃; sheath gas flow rate: 11L / min; nebulizer pressure (Nebulizer): 45psi; nozzle voltage: +500 / -500V; capillary voltage (Capillary): +3500 / -3500V.

[0020] The mass spectrometer was monitored in MRM mode.

[0021] The MRM ion acquisition parameters are as follows:

[0022]

[0023] * is the quantitative ion.

[0024] When the concentration of 4-fluoro-N-isopropylaniline in this method is in the range of 0.50 μg / L to 20 μg / L, there is a linear relationship between the peak area y and the concentration x, and the linear regression equation is y=55256.42x-299.60, and the linear correlation coefficient R 2 =0.9996.

[0025] The detection limit of this method for 4-fluoro-N-isopropylaniline is 4.08 ng / L, and the quantification limit is 10.89 ng / L.

[0026] The soil samples of the present invention are collected with reference to the provisions of HJ / T166-2004 "Technical Specifications for Soil Environmental Monitoring". In general, mixed samples are collected, and according to the actual pollution situation (accidents discovered in time: 0-5cm for spillage, 0-20cm for explosion; long-term leakage not discovered in time: urban or factory soil 0-30 and 30-60cm two-layer sampling, farmland soil 0-20cm, orchard soil 0-60cm), the appropriate depth is selected to collect soil. There are 5 to 20 collection points in the area. The soil collected at each point is evenly mixed and discarded by quartering, and 1 to 2kg of soil samples are retained.

[0027] The water samples of the present invention are collected according to the provisions of HJ494-2009 "Technical Guide for Water Quality Sampling" for different sampling types, such as sampling of open rivers, sampling of reservoirs and lakes, sampling of groundwater, sampling of sewage, etc.

[0028] The beneficial effects of the present invention are:

[0029] 1. The results of the validation test of the analytical method of the present invention show that the injection concentration of 4-fluoro-N-isopropylaniline is in the range of 0.50 μg / L to 20.0 μg / L and the linear equation is:

[0030] y=55256.42x-299.60, linear correlation coefficient R 2 =0.9996; the average recovery rate of addition in soil ranged from 82.4% to 83.2%, and the average recovery rate of addition in water ranged from 86.1% to 97.0%; the precision RSD% was 0.3645%, and the RSD of the target peak was R.T. 0.65%, RSD Area The invention has the advantages of simple operation, good repeatability, good separation effect, high accuracy and precision, etc.

[0031] 2. The present invention overcomes the problems of low sensitivity, poor anti-interference ability and unguaranteed stability of gas chromatography in the past. The detection limit of the present invention is 4.08 ng / L, the quantitative limit is 10.89 ng / L, the detection sensitivity is high, and the detection purpose can still be achieved when the content of 4-fluoro-N-isopropylaniline is low in soil or water environment; the target peak emerges at 0.5 min, the detection efficiency is high, the instrument running time is short, and the detection cost is low. The method is suitable for qualitative and quantitative detection of chlorohydrin imines in soil and water environment during the production process, and is also suitable for laboratory detection and analysis.

[0032] 3. The present invention provides a HPLC-MS / MS detection method for 4-fluoro-N-isopropylaniline in soil and water. The method can well detect the content of 4-fluoro-N-isopropylaniline in environmental soil and water, which is of great significance to soil and water environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a calibration curve diagram of 4-fluoro-N-isopropylaniline;

[0034] Figure 2 This is a typical spectrum of 4-fluoro-N-isopropylaniline (8.00 μg / L);

[0035] Figure 3 This is a typical reproducible spectrum of 4-fluoro-N-isopropylaniline (4.00 μg / L);

[0036] Figure 4 This is a typical spectrum of the detection limit of 4-fluoro-N-isopropylaniline (0.01μg / L);

[0037] Figure 5 This is a typical spectrum of the quantification limit of 4-fluoro-N-isopropylaniline (1.00 μg / L);

[0038] Figure 6 This is a typical graph of the recovery rate of 4-fluoro-N-isopropylaniline in soil (blank control);

[0039] Figure 7 This is a typical graph of the recovery rate of 4-fluoro-N-isopropylaniline in soil (0.1 mg / L);

[0040] Figure 8 This is a typical graph of the recovery rate of 4-fluoro-N-isopropylaniline added to soil (10.0 mg / L);

[0041] Fig. 9 This is a typical graph of the recovery rate of 4-fluoro-N-isopropylaniline added to water (blank control);

[0042] Fig.10 This is a typical graph of the recovery rate of 4-fluoro-N-isopropylaniline in water (0.1 mg / L);

[0043] Fig.11 This is a typical graph of the recovery rate of 4-fluoro-N-isopropylaniline in water (10.0 mg / L). DETAILED DESCRIPTION

[0044] The present invention is further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any form.

[0045] The main instruments and reagents used in this experiment include but are not limited to:

[0046] 1. Main instruments and equipment

[0047] (1) LC-MS / MS: Agilent 1260-6470A;

[0048] (2) Electronic balance: Mettler-Toledo (China) Co., Ltd., XSE205DU;

[0049] (3) Electronic balance: Mettler-Toledo (China) Co., Ltd., MS1602S / 01;

[0050] (4) Constant temperature culture oscillator: Shanghai Zhicheng Analytical Instrument Manufacturing Co., Ltd., ZWY-240;

[0051] (5) Commonly used glass instruments such as volumetric flasks and pipettes.

[0052] 2. Main reagents

[0053] (1) Fi-Aniline, provided by the customer, purity 97.8%;

[0054] (2) Acetonitrile: chromatographic grade, ANPEL Inc.;

[0055] (3) Formic acid: analytical grade, Tianjin Fuyu Fine Chemical Co., Ltd.

[0056] 3. Test samples

[0057] 3.1 Soil samples to be tested

[0058] The soil used in this experiment was purchased from the Institute of Pesticide Control of the Ministry of Agriculture and Rural Affairs, Jilin Province Gongzhuling Black Soil T2020005. The soil was air-dried and passed through a 1.0 mm sieve and stored at room temperature away from light.

[0059] The preparation steps of the soil sample to be tested are as follows: weigh 10 g of the above black soil into a 250 mL conical flask, add 0.1 mL of a 4-fluoro-N-isopropylaniline standard working solution diluted with acetonitrile to a concentration of 100 μg / L, and vortex mix to obtain a soil sample to be tested with a theoretical concentration of 4-fluoro-N-isopropylaniline of 10 μg / kg.

[0060] 3.2 Water samples to be tested

[0061] This experiment uses UP water as a representative of environmental water bodies. UP water comes from the tap water of this laboratory and is prepared by an ultrapure water machine. The resistivity of UP water is 18.2 MΩ×cm.

[0062] The preparation steps of the water sample to be tested are as follows: aspirate 1.0 mL of the 4-fluoro-N-isopropylaniline standard working solution diluted with acetonitrile to a concentration of 100 μg / L into a 100 mL volumetric flask, and dilute to volume with UP water to obtain the water sample to be tested with a theoretical concentration of 4-fluoro-N-isopropylaniline of 1.0 μg / L.

[0063] Example 1

[0064] (1) Preparation of standard working solution: Accurately weigh 0.10225 g of 4-fluoro-N-isopropylaniline standard into a 100 mL volumetric flask, dissolve it in acetonitrile and make up to volume, shake well, and prepare a standard stock solution with a concentration of 1000.00 mg / L; take an appropriate amount of the standard stock solution and dilute it step by step with acetonitrile to prepare a series of standard working solutions with concentrations of 0.50, 1.00, 2.00, 4.00, 8.00, 10.0, and 20.0 μg / L.

[0065] (2) Drawing of standard curve: Set the operating conditions of the HPLC-MS / MS instrument, draw 5 μL of the series of standard working solutions in step (1) and inject them into the HPLC-MS / MS instrument for measurement. The measurement results are shown in Table 1. The concentration of 4-fluoro-N-isopropylaniline is used as the horizontal axis and the peak area is used as the vertical axis to draw the calibration curve and linear regression equation. When the concentration of 4-fluoro-N-isopropylaniline is in the range of 0.50 μg / L to 20 μg / L, there is a linear relationship between the peak area y and the concentration x. The linear regression equation is y=55256.42x-299.60, and the linear correlation coefficient R 2 =0.9996.

[0066] Table 1: Analysis results of 4-fluoro-N-isopropylaniline series standard working solutions

[0067]

[0068]

[0069] (3) Preparation of soil sample solution: Weigh 10.0 g of the soil sample to be tested into a 250 mL conical flask, add 50 mL of acetonitrile, shake, and let stand. Take the supernatant and filter it with a 0.22 μm filter membrane;

[0070] (4) Preparation of water sample solution: Take 10 mL of the water sample to be tested and filter it through a 0.22 μm filter membrane.

[0071] (5) Determination and calculation of samples: Set the operating conditions of the HPLC-MS / MS instrument, take 5 μL of the soil sample solution and the water sample solution to be tested for determination, record the chromatogram, and calculate the content of 4-fluoro-N-isopropylaniline in the soil sample and the water sample by the external standard method. The working curve formula is: y=ax+b. Where y represents the peak area of ​​the chromatographic peak response of 4-fluoro-N-isopropylaniline, x represents the concentration of 4-fluoro-N-isopropylaniline, a is the slope of the standard working curve, and b is the intercept of the standard working curve.

[0072] The operating conditions of HPLC-MS / MS instrument were:

[0073] HPLC operating conditions:

[0074] Column: Eclipse Plus C18 RRHD, 50×2.1 mm, 1.8 μm;

[0075] Flow rate: 0.3 mL / min;

[0076] Mobile phase: acetonitrile and 0.1% formic acid water, the volume ratio of acetonitrile and 0.1% formic acid water is 80:20;

[0077] Column temperature: 30℃.

[0078] Mass spectrometry operating conditions:

[0079] Ion source: AJS ESI source, positive ion mode;

[0080] Ion source parameters: Drying gas: N2; Drying gas temperature: 300°C; Drying gas flow rate: 5L / min; Sheath gas: N2; Sheath gas temperature: 250°C; Sheath gas flow rate: 11L / min; Nebulizer pressure: 45psi; Nozzle voltage: +500 / -500V; Capillary voltage: +3500 / -3500V;

[0081] Monitoring mode: MRM;

[0082] The MRM ion acquisition parameters are as follows:

[0083]

[0084]

[0085] * is the quantitative ion.

[0086] Comparative Example 1:

[0087] Source of method: The method in the reference document is adopted, namely "Q / FRG 067-20214-Fluoro-N-isopropylaniline".

[0088] Test conclusion: When this method detects soil and water samples, the sensitivity is low, and the detection limit is at the mg / kg level. When the concentration of 4-fluoro-N-isopropylaniline in soil and water samples is low, the purpose of detection cannot be achieved; the target separation effect is not good, the peak shape is poor, and the anti-interference ability is poor; the detection efficiency is low, the instrument running time is long, the solvent consumption is large, and the detection cost is high, so this method is not used.

[0089] The following is the methodology verification test of the present invention:

[0090] 1. Exclusivity

[0091] The HPLC-MS / MS analysis method established by the present invention was used to measure water blank samples, water added recovery rate samples, soil blank samples, and soil added recovery rate samples, and the spectra of the water and soil blank samples and the added recovery rate samples were compared. 4-fluoro-N-isopropylaniline peaked at 0.5 min, and the blank sample had no interference peak at this time point. The results showed that the method had good specificity for 4-fluoro-N-isopropylaniline.

[0092] 2. Repeatability

[0093] The standard working solution of 4-fluoro-N-isopropylaniline with a concentration of 4.00 μg / L was selected for the method repeatability test. The injection was repeated 6 times according to the instrument operation conditions of the present invention. The analysis results are shown in Table 2. The RSD of the target peak R.T. 0.65%, RSD Area is 3.19%, which is less than 5.00%. The results show that the present invention can be used for the qualitative and quantitative analysis of 4-fluoro-N-isopropylaniline. Figure 3 .

[0094] Table 2: Repeatability test results

[0095] frequency Retention time (min) Peak area( / ) 1 0.558 195090 2 0.558 195359 3 0.551 197531 4 0.551 205782 5 0.551 205885 6 0.551 210147 average value 0.553 201632 RSD(%) 0.65 3.19

[0096] 3. Limit of detection and limit of quantification

[0097] A 0.10 μg / L 4-fluoro-N-isopropylaniline standard working solution was prepared for the detection limit test, and a 1.00 μg / L 4-fluoro-N-isopropylaniline standard working solution was prepared for the quantification limit test. The injections were repeated 3 times according to the instrument operation conditions of the present invention, and the LOD and LOQ were calculated by S / N. The average results of the 3 analyses showed that the LOD of the present invention for 4-fluoro-N-isopropylaniline was 4.08 ng / L and the LOQ was 10.89 ng / L. The detailed results are shown in Table 3. Figure 4 , Figure 5 .

[0098] Table 3: Limits of detection and quantification

[0099] Number of measurements Analytical concentration (μg / L) S / N LOD(ng / L) LOQ(ng / L) 1 0.10 74.1 4.05 - 2 0.10 74.3 4.04 - 3 0.10 72.2 4.16 - 1 1.00 931.4 - 10.74 2 1.00 904.0 - 11.06 3 1.00 919.3 - 10.88 average value - - 4.08 10.89

[0100] 4. Recovery rate of soil and water samples

[0101] 4.1 Recovery rate of soil sample addition

[0102] An appropriate amount of the 1000.00 mg / L 4-fluoro-N-isopropylaniline standard stock solution in Example 1 was taken and diluted with acetonitrile to prepare a standard working solution with concentrations of 100 μg / L and 10.0 mg / L.

[0103] About 10.0 g of black soil was weighed into a 250 mL conical flask, and 1 mL of 4-fluoro-N-isopropylaniline standard working solution with concentrations of 100 μg / L and 10.0 mg / L was added thereto, and vortexed to mix well to prepare two soil recovery rate samples with concentrations of 10 μg / kg and 1.0 mg / kg. 50 mL of acetonitrile was added to the conical flask, and after oscillation and standing, the supernatant was filtered with a 0.22 μm filter membrane (high concentration acetonitrile was diluted 25 times), and the concentration of 4-fluoro-N-isopropylaniline in the soil recovery rate sample was determined according to the instrument operation conditions of the present invention. Five samples of each concentration were prepared in parallel, and a soil blank test was performed at the same time.

[0104] The analysis results are shown in Table 4. Figure 6 , Figure 7 , Figure 8 The average recovery rates of 4-fluoro-N-isopropylaniline at two different concentrations in soil were 82.4% and 83.2%, and the standard deviations of the recovery rates were 0.8% and 3.1%, respectively.

[0105] Table 4: Recovery results of soil addition

[0106]

[0107]

[0108] 4.2 Recovery rate of water sample addition

[0109] Take 1mL of 100μg / L and 10mg / L 4-fluoro-N-isopropylaniline standard working solution in a 100mL volumetric flask, dilute with UP water, and obtain 1.0μg / L and 100μg / L water recovery samples, respectively. Take the water recovery sample and filter it with a 0.22μm filter membrane (high concentration acetonitrile is diluted 10 times), and measure the 4-fluoro-N-isopropylaniline concentration in the water recovery sample according to the instrument operation conditions of the present invention. Each concentration sample is made in parallel for 5 copies, and a water blank test is performed at the same time.

[0110] The analysis results are shown in Table 5. Fig. 9 , Fig.10 , Fig.11 The average recovery rates of 4-fluoro-N-isopropylaniline at two different concentrations in water were 97.0% and 86.1%, and the standard deviations of the recovery rates were 4.2% and 2.7%, respectively.

[0111] Table 5: Recovery results of water addition

[0112]

[0113] Although the present invention has been described in detail above by means of general description, specific implementation methods and experiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A HPLC-MS / MS method for detecting 4-fluoro-N-isopropylaniline in soil and water, characterized in that: The detection steps are as follows: (1) Preparation of standard working solution: accurately weigh 0.10225 g of 4-fluoro-N-isopropylaniline standard sample into a 100 mL volumetric flask, dissolve it in acetonitrile and make up to volume, shake well, and prepare a standard stock solution with a concentration of 1000.00 mg / L; take an appropriate amount of the standard stock solution and dilute it step by step with acetonitrile to prepare a series of standard working solutions with concentrations of 0.50 to 20.0 μg / L; (2) Drawing of standard curve: Set the operating conditions of the HPLC-MS / MS instrument, draw 5 μL of the series of standard working solutions in step (1) and inject them into the HPLC-MS / MS instrument for measurement, and draw a calibration curve and a linear regression equation with the concentration of 4-fluoro-N-isopropylaniline as the abscissa and the peak area as the ordinate; (3) Preparation of soil sample solution: Collect the soil sample to be tested, air-dry, grind and sieve it in sequence, weigh 10.0 g of the processed soil sample to be tested into a 250 mL conical flask, add 50 mL of acetonitrile, shake and let stand, take the supernatant and filter it with a 0.22 μm filter membrane; (4) Preparation of water sample solution: Take 10 mL of the water sample to be tested and filter it through a 0.22 μm filter membrane; (5) Determination and calculation of samples: Set the operating conditions of the HPLC-MS / MS instrument, take 5 μL of the soil sample solution and the water sample solution to be tested for determination, record the chromatogram, and calculate the content of 4-fluoro-N-isopropylaniline in the sample by the external standard method; In the operating conditions of the HPLC-MS / MS instrument, the high performance liquid chromatography uses Eclipse Plus C18 RRHD as a chromatographic column with a specification of 50×2.1 mm and 1.8 μm; the flow rate is 0.3 mL / min; the mobile phase consists of acetonitrile and 0.1% formic acid water; the column temperature is 30° C.; the volume ratio of the mobile phase acetonitrile and 0.1% formic acid water is 80:20; In the operating conditions of the HPLC-MS / MS instrument, the ion source of the mass spectrometer is AJSESI source, positive ion mode; the ion source parameters of the mass spectrometer are: drying gas: N 2 ; Drying gas temperature: 300℃; Drying gas flow rate: 5L / min; Sheath gas: N 2 ; Sheath gas temperature: 250℃; Sheath gas flow rate: 11L / min; Nebulizer pressure: 45psi; Nozzle voltage: +500 / -500V; Capillary voltage: +3500 / -3500V; The monitoring mode of mass spectrometry is MRM, and the MRM ion acquisition parameters are: Compound name 4-fluoro-N-isopropylaniline, parent ion 154, daughter ion quantification ion 112, fragmentation voltage 65V, acceleration voltage 5V, polarity is positive; parent ion 154, daughter ion 92, fragmentation voltage 65V, acceleration voltage 5V, polarity is positive.

2. The HPLC-MS / MS detection method for 4-fluoro-N-isopropylaniline in soil and water according to claim 1, wherein in step (1), the concentrations of the series of standard working solutions are 0.50, 1.00, 2.00, 4.00, 8.00, 10.0, and 20.0 μg / L.

3. The HPLC-MS / MS detection method for 4-fluoro-N-isopropylaniline in soil and water according to claim 1, characterized in that: In step (2), the linear regression equation is y=55256.42x-299.60, and the linear correlation coefficient R 2 =0.9996.

4. The HPLC-MS / MS detection method for 4-fluoro-N-isopropylaniline in soil and water according to claim 1, characterized in that: The detection limit of the method for 4-fluoro-N-isopropylaniline is 4.08 ng / L, and the quantification limit is 10.89 ng / L.

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