Method for rapidly detecting pesticide residues in blueberries

Abstract

The invention discloses a method for rapidly detecting pesticide residues in blueberries, and relates to the technical field of blueberry pesticide detection.The method comprises the steps that 10 g of a fully-ground blueberry sample is placed in a 100 ml centrifuge tube with a plug, 10 ml of a 0.1 mol / L hydrochloric acid aqueous solution and 10 ml of dichloromethane are added, 100 microliters of a mixed internal standard solution is added, after vortex oscillation is conducted for about 30 min, centrifugation is conducted for 5 min at the speed of 5000 r / min, 2 ml of a lower layer organic phase is taken, and the concentration of the lower layer organic phase is 10 ml; and after blow-drying by a nitrogen blowing instrument, adding 2ml of methanol for redissolving, and then adding an LCMS instrument for detection. The detection method disclosed by the invention can be used for simultaneously detecting 11 types of blueberry bactericides in national food standards and three types of bactericides such as mancozeb, metalaxyl and procymidone which are widely used in blueberry production at present. The result of the analysis method shows that the linearity of most components is good in the range of 5-100 g / L, the recovery rate of 14 pesticides is 94.9%-101.3% in the range of 5-50 [mu] g / kg, and the detection limit and the quantification limit of the method are 0.001 [mu] g / g-0. 03 [mu] g / g and 0.005 [mu] g / g-0. 010 [mu] g / g respectively. The method is simple, convenient and rapid to operate, and the sensitivity, accuracy and precision can meet the technical requirements of detection of various pesticide residues.

Description

Technical Field

[0001] The present invention relates to the technical field of blueberry pesticide detection, and specifically provides a rapid detection method for pesticide residues in blueberries. Background Technique

[0002] Blueberries belong to the genus Vaccinium of the Ericaceae family.

[0003] For blueberry diseases, in addition to conventional measures such as selecting disease-resistant varieties, crop rotation, and rain-sheltered cultivation, chemical control is still the main measure at present. Since the 1980s in China, especially since the implementation of the newly revised "Regulations on Pesticide Management" in 2017, a strict pesticide registration system has been implemented. Pesticides that have not been registered are not allowed to be produced, sold, or used, and registered pesticides are not allowed to be used beyond the registered crop scope / location. The "Regulations on the Prevention and Control of Crop Diseases and Pests" implemented since May 1, 2020 also clearly stipulates that when relevant units and individuals carry out crop disease and pest control using pesticides, they should abide by the pesticide safety and rational use system and strictly use pesticides in accordance with the pesticide label or instructions.

[0004] As of now, in China's GB2763-2021 "National Food Safety Standard Maximum Residue Limits of Pesticides in Foods", the maximum residue limits of 11 types of blueberry fungicides are mainly clearly specified, and the specific data are shown in Table 1.

[0005] Table 1 Maximum Residue Limits of Fungicides in Blueberries Specified in GB2763-2021 in China Pesticide Name Residue Acceptable Daily Intake (mg / kg bw) Maximum Residue Limit (mg / kg bw) Pyraclostrobin Pyraclostrobin 0.03 4 Fludioxonil Fludioxonil 0.4 2 Cyclanilide Cyclanilide 0.2 5 Fenbuconazole Fenbuconazole 0.03 0.5 Captan Captan 0.1 20 Triforine Sum of triforine and trichloroacetaldehyde (expressed as triforine) 0.03 1 Carbendazim Carbendazim 0.03 1 Pyrimethanil Pyrimethanil 0.2 3 Boscalid Boscalid 0.04 10 Azoxystrobin Azoxystrobin 0.2 5 Cyprodinil Cyprodinil 0.03 10 In addition to the above 11 types of fungicides, there are no corresponding standards for fungicides such as mancozeb, metalaxyl, and procymidone widely used in current blueberry production because there is no suitable method for accurate detection and control.

[0006] Currently, the main detection method for the above fungicides is gas chromatography. It is found in the experiment that when gas chromatography is used to detect 14 types of pesticide residues in blueberries, due to the relatively close boiling points of some of the residual solvents, the resolution in the gas detection results is significantly lower (<1.5), resulting in poor accuracy of the detection results. By querying relevant information, it can be seen that there is currently no liquid chromatography-mass spectrometry method that can simultaneously detect the above pesticide residues. Moreover, the blueberry matrix is relatively complex, and the extraction recovery rate of pesticide residues in blueberries by conventional methods significantly does not meet the requirements. The pesticide residues in the sample cannot be completely extracted, and there are many impurities in the extraction solution, which will interfere with the subsequent detection results, resulting in the detection results being unable to reflect the actual results. Therefore, we propose a rapid detection method for pesticide residues in blueberries. Summary of the Invention

[0007] The purpose of the present invention is to provide a rapid detection method for pesticide residues in blueberries to solve the problems raised in the above background technique.

[0008] To achieve the above object, the present invention provides the following technical solution: A rapid detection method for pesticide residues in blueberries, including the first step: Generation of a standard curve: Prepare standard stock solutions by mixing internal standard substances and 14 types of pesticide samples such as pyraclostrobin, fludioxonil, cyprodinil, fenbuconazole, captan, triforine, carbendazim, pyrimethanil, boscalid, azoxystrobin, cyprodinil, mancozeb, metalaxyl, procymidone, etc.; Prepare a mixed standard working solution using the standard stock solution; Set the working parameters of the gas chromatograph triple quadrupole mass spectrometer. The chromatographic conditions are as follows: Liquid chromatography conditions: Chromatographic column: Agilent, InfinityLab, Poroshell, 120, EC-C18 (4.6*150mm, 2.7µm); Column temperature: 30°C; Flow rate: 0.8ml / min; Injection volume: 5µl; Mobile phase A: 0.01M ammonium acetate aqueous solution (adjusted to pH 4.5 with acetic acid); Mobile phase B: methanol:acetonitrile = 70:30, gradient elution program: 0min, 80%A, 3min, 80%A, 8min, 65%A, 12min, 20%A, 15min, 20%A, 20min, 80%A, 25min, 80%A; Mass spectrometry conditions: Ion source type: ESI Scan type: Positive ion mode scan Mass-to-charge ratio acquisition range: 100 - 2000 Dwell time: 500ms Gain factor: 1 Dry gas temperature: 350°C Dry gas flow rate: 11.0L / min Nebulizer pressure: 55psi Generate a standard curve model of internal standard substances and various pesticides in blueberries in the liquid chromatography triple quadrupole mass spectrometer The second step: Accurately weigh 10g of well-ground blueberry samples into a 100ml stoppered centrifuge tube; The third step: Add 50ml of a mixed solution of ethyl acetate and ethanol containing 0.2% formic acid and 100µl of a mixed internal standard solution to the centrifuge tube, and then mix and shake well; The fourth step: Add ProElut, QuECHERS, EN, extraction salt (4g MgSO4 + 1g NaCl + 1g sodium citrate + 0.5g sodium hydrogen citrate); The fifth step: After shaking for 3min, centrifuge at 5000r / min for 5min using a centrifuge; Step 6: Take 1 ml of the upper clear liquid and add it to a ProElut, QuECHERS, EN purification tube (containing 25 mg PSA + 150 mg MgSO4). Step 7: After shaking for 3 min, centrifuge at 5000 r / min for 5 min using a centrifuge. Step 8: Take the upper clear liquid into a sample vial and then perform LCMS detection.

[0009] Preferably, take an appropriate amount of blueberry samples, after crushing, homogenizing and other treatments, add an appropriate amount of extraction solvent for extraction to obtain blueberry extract.

[0010] Preferably, the purification treatment step uses an improved QuEChERS method to purify the blueberry extract, in which the extracted organic solvent is changed from acetonitrile to a mixed solution of ethyl acetate and ethanol with 0.25% formic acid (v:v = 1:1).

[0011] Preferably, the liquid chromatography separation step uses a high-performance liquid chromatography system, the chromatographic column is an Agilent, InfinityLab, Poroshell, 120, EC-C18 (4.6 * 150 mm, 2.7 µm) column, and the mobile phase is gradient elution with an ammonium acetate and methanol / acetonitrile mixed solution.

[0012] Preferably, the mass spectrometry detection step uses a triple quadrupole mass spectrometry system, the ionization mode is electrospray positive ion ionization mode, and multi-reaction monitoring scanning mode (MRM) detection is performed, and the fragmentation voltage is set at 135 V.

[0013] Compared with the prior art, the beneficial effects of the present invention are: The present invention herein uses a simple pretreatment method to determine pesticide residues in blueberries by high-performance liquid chromatography triple quadrupole mass spectrometry tandem method. In the range of 5 - 50 µg / kg, the recoveries of 14 pesticides are between 94.9% and 101.3%. The detection limits and quantification limits of the method are in the ranges of 0.001 μg / g - 0.03 μg / g and 0.005 μg / g - 0.010 μg / g respectively. The sensitivity, accuracy and repeatability of the method all meet the requirements of pesticide residue analysis and detection. The sample pretreatment process is simple, the method is accurate and reliable, and the resolution of each pesticide meets the requirements, which is applicable to the actual detection of blueberry pesticides. Description of the Drawings

[0014] Figure 1 It is a flow chart of sample pretreatment and inspection; Figure 2 It is a typical chromatogram of a mixed standard sample; Detailed Embodiments

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0016] Please refer to Figure 1 - 2 , the present invention provides a technical solution: a rapid detection method for pesticide residues in blueberries, including the first step: generation of a standard curve: Prepare standard stock solutions by mixing internal standard substances and 14 types of pesticide samples such as pyraclostrobin, fludioxonil, boscalid, fenbuconazole, captan, tridemorph, carbendazim, pyrimethanil, boscalid, azoxystrobin, cyprodinil, mancozeb, metalaxyl, procymidone, etc. Prepare a mixed standard working solution using the standard stock solution. Set the working parameters of the gas chromatograph triple quadrupole mass spectrometer. The chromatographic conditions are as follows: Liquid chromatography conditions: Chromatographic column: Agilent, InfinityLab, Poroshell, 120, EC-C18 (4.6*150mm, 2.7µm); column temperature: 30°C; flow rate: 0.8ml / min; injection volume: 5µl; mobile phase A: 0.01M ammonium acetate aqueous solution (adjust the pH to 4.5 with acetic acid); mobile phase B: methanol: acetonitrile = 70:30, gradient elution program: 0min, 80%A, 3min, 80%A, 8min, 65%A, 12min, 20%A, 15min, 20%A, 20min, 80%A, 25min, 80%A; Mass spectrometry conditions: Ion source type: ESI Scan type: positive ion mode scan Mass-to-charge ratio acquisition range: 100 - 2000 Dwell time: 500ms Gain factor: 1 Dry gas temperature: 350°C Dry gas flow rate: 11.0L / min Nebulizer pressure: 55psi Generate a standard curve model of the internal standard substance and various blueberry pesticides in the liquid chromatography triple quadrupole mass spectrometer. The second step: accurately weigh 10g of well-ground blueberry samples into a 100ml stoppered centrifuge tube; Step 3: Add 50 ml of a mixed solution of ethyl acetate and ethanol containing 0.2% formic acid and 100 µl of a mixed internal standard solution to a centrifuge tube, mix well and shake; Step 4: Add ProElut, QuECHERS, EN, extraction salts (4 g MgSO4 + 1 g NaCl + 1 g sodium citrate + 0.5 g disodium hydrogen citrate); Step 5: After shaking for 3 min, centrifuge at 5000 r / min for 5 min using a centrifuge; Step 6: Take 1 ml of the supernatant and add it to a ProElut, QuECHERS, EN purification tube (containing 25 mg PSA + 150 mg MgSO4); Step 7: After shaking for 3 min, centrifuge at 5000 r / min for 5 min using a centrifuge; Step 8: Take the supernatant and transfer it to an injection vial, then perform LCMS detection.

[0017] Take an appropriate amount of blueberry samples, after crushing, homogenizing and other treatments, add an appropriate amount of extraction solvent for extraction to obtain blueberry extract; Add ProElut, QuECHERS, EN, extraction salts (4 g MgSO4 + 1 g NaCl + 1 g sodium citrate + 0.5 g disodium hydrogen citrate) to the blueberry extract.

[0018] Place the extract added with extraction salts on a vortex mixer and shake for 3 min, then centrifuge at 5000 r / min for 5 min using a centrifuge.

[0019] After the operation is completed, take 1 ml of the supernatant and add it to a ProElut, QuECHERS, EN purification tube (containing 25 mg PSA + 150 mg MgSO4).

[0020] Subsequently, transfer the above purification tube to a vortex mixer and shake for 3 min, then centrifuge at 5000 r / min for 5 min using a centrifuge.

[0021] Take the centrifuged supernatant and perform LCMS detection.

[0022] 1.1 Main instruments and reagents: High-performance liquid chromatography-triple quadrupole tandem mass spectrometer: Agilent, 1260II-6495D type; ten-thousandth electronic balance: ME204 type; high-speed centrifuge: KH19A type; nitrogen evaporator: HGC-24 type; vortex mixer: MS200 type; ultrasonic cleaner: 2500TH type; shaker: Herocell, C1 type; ultrapure water purifier: Merck, Mill-Q, reference type.

[0023] Reagents: Methanol, Ethyl acetate, Acetonitrile, Ethanol, Acetic acid.

[0024] Experimental procedure: Preparation and extraction of samples: Accurately weigh 10 g of well-ground blueberry samples into a 100-ml stoppered centrifuge tube, add 25 ml of a mixed solution containing 0.25% ethyl acetate and ethanol and 100 μl of a mixed internal standard solution. After shaking well, add ProElut, QuECHERS, EN, extraction salts (4 g MgSO4 + 1 g NaCl + 1 g sodium citrate + 0.5 g disodium hydrogen citrate), and mix well by shaking for 3 min. Then transfer to a centrifuge and centrifuge at 5000 r / min for 5 min. Take 1 ml of the upper clear liquid and add it to a ProElut, QuECHERS, EN purification tube (containing 25 mg PSA + 150 mg MgSO4), shake well for 3 min, centrifuge at 5000 r / min for 5 min, and transfer the upper clear liquid to a liquid phase injection vial for use as a test sample solution. Mixed standard solution: Weigh 50 mg of each of the above 14 standards into the same 50-ml volumetric flask, add methanol for dilution and volume fixation to obtain a mixed reference solution with a concentration of 1.0 mg / ml.

[0025] Detection conditions: Chromatographic column: Agilent, InfinityLab, Poroshell, 120, EC-C18 (4.6 * 150 mm, 2.7 μm) Mobile phase A: 0.01 M sodium acetate aqueous solution (adjusted to pH 4.5 with acetic acid) Mobile phase B: Methanol: Acetonitrile = 70:30 Diluent: Methanol: Acetonitrile = 70:30 Column temperature: 30 °C Flow rate: 0.8 ml / min Injection volume: 5 μl Detection wavelength: 254 nm The gradient elution program is shown in the following table: Time (min) Flow Rate (ml / min) Mobile Phase A (%) Mobile Phase B (%) 0 0.8 80 20 3 0.8 80 20 8 0.8 65 35 12 0.8 20 80 15 0.8 20 80 20 0.8 80 20 25 0.8 80 20 Mass spectrometry detection parameters: Ion source type: ESI Scan type: Positive ion mode scan Mass-to-charge ratio acquisition range: 100 - 2000 Dwell time: 500 ms Gain factor: 1 Dry gas temperature: 350 °C Dry gas flow rate: 11.0 L / min Nebulizer pressure: 55 psi See the detection spectrum in Figure 2 ; Calculation of the determination results of pesticide residues: Quantitative analysis of pesticide residues is carried out by the internal standard method, that is, the quantitative ion pair peak areas of the target substance and its corresponding isotope internal standard are regressed against their corresponding concentrations to obtain a standard curve, with the correlation coefficient greater than or equal to 0.995. The extracted samples are measured, and the chromatographic peak areas of the quantitative ion pairs of the detected analytes and internal standards are measured and substituted into the standard curve to obtain the residue amounts of each pesticide.

[0026] Quantitation limit and detection limit of the present invention: Inject standard working solutions of each pesticide at different concentrations into LC-MS, and calculate the detection limit (LOD) at 3 times the signal-to-noise ratio (S / N = 3). The detection limit is between 0.001 μg / g and 0.03 μg / g. Calculate the quantitation limit (LOQ) at 10 times the signal-to-noise ratio (S / N = 10). The detection limit is between 0.005 μg / g and 0.010 μg / g.

[0027] Repeatability and spiked recovery rate of the method of the present invention: Add standard solutions of mixed standard pesticides to blueberry samples, then perform pretreatment and LC-MS analysis, and calculate the recovery rate according to the spiked amount and measured value. The results are shown in Table 2. It can be seen from Table 2 that the recovery rates of 14 pesticides are all between 94.5% and 101.5%, and the average relative standard deviation (RSD) is less than 5%, indicating that the method of the present invention has a high recovery rate and good repeatability.

[0028] Linearity of the method of the present invention Prepare a series of standard solutions of different concentrations from the mixed standard solution of pesticides, perform HPLC-MS detection, make a standard regression curve with the peak area Y against the mass concentration X, obtain the linear regression equation of each pesticide component, and each component has good linearity in the range of 0.5 - 100 g / L.

[0029] Table 2: Linear equations and correlation coefficients of 14 pesticide residues in blueberries Pesticide Type Linear Equation Correlation Coefficient Pyraclostrobin Y = 63.72X + 15.73 <![CDATA[R 2 =0.9986]]> Fludioxonil Y = 143.57X + 3.72 <![CDATA[R 2 =0.9993]]> Cyclanilide Y = 113.43X + 6.94 <![CDATA[R 2 =0.9988]]> Fenbuconazole Y = 97.66X + 23.48 <![CDATA[R 2 =0.9997]]> Captan Y = 59.45X + 13.93 <![CDATA[R 2 =0.9986]]> Triforine Y = 57.66X + 19.73 <![CDATA[R 2 =0.9992]]> Carbendazim Y = 149.62X + 9.71 <![CDATA[R 2 =0.9979]]> Pyrimethanil Y = 183.94X + 25.31 <![CDATA[R 2 =0.9983]]> Boscalid Y = 139.32X + 15.29 <![CDATA[R 2 =0.9997]]> Azoxystrobin Y = 107.62X + 14.98 <![CDATA[R 2 =0.9978]]> Cyprodinil Y = 37.26X + 15.03 <![CDATA[R 2 =0.9990]]> Mancozeb Y = 168.86X + 40.81 <![CDATA[R 2 =0.9987]]> Metalaxyl Y = 137.36X + 7.51 <![CDATA[R 2 =0.9989]]> Procymidone Y = 207.76X + 13.38 <![CDATA[R 2 =0.9991]]> Table 3: Recovery rates and repeatability of 14 pesticide residues in blueberries (n = 6) Serial Number Pesticide Retention Time (min) Correlation Coefficient Recovery Rate (%) RSD (%) 1 Pyraclostrobin 6.653 0.9997 97.3 1.17 2 Fludioxonil 11.081 0.9993 98.2 2.86 3 Cyclanilide 8.560 0.9998 95.7 0.59 4 Fenbuconazole 4.323 0.9995 96.4 1.83 5 Captan 9.125 0.9997 99.3 1.26 6 Triforine 15.743 0.9995 100.8 0.97 7 Carbendazim 3.196 0.9999 96.9 2.95 8 Pyrimethanil 13.898 0.9992 95.8 3.42 9 Boscalid 18.865 0.9993 99.2 0.98 10 Azoxystrobin 4.979 0.9998 94.9 2.67 11 Cyprodinil 7.896 0.9994 101.3 1.69 12 Mancozeb 18.416 0.9998 98.3 0.88 13 Metalaxyl 9.554 0.9995 99.6 1.96 14 Procymidone 4.917 0.9992 100.7 1.83 In this paper, an optimized QuECHERS pretreatment method is adopted. Compared with the original method, the organic reagents used are safer. At the same time, the ethyl acetate and ethanol mixed solution (v:v = 2:5) with 0.25% formic acid has significantly higher recovery rates for various pesticides in blueberries than conventional solvents such as acetonitrile. The residues of pesticides in blueberries are determined by high performance liquid chromatography triple quadrupole mass spectrometry using Agilent, InfinityLab, Poroshell, 120, EC-C18 (4.6*150mm, 2.7µm). The single needle detection time of the short column is significantly shorter than that of the long column, and the packing inner diameter of 2.7µm can significantly improve the separation degree of various pesticide residues. In the range of 5 - 50µg / kg, the recovery rates of 14 pesticides in this method are between 94.9% and 101.3%. The detection limits and quantification limits of the method are in the ranges of 0.001μg / g - 0.03μg / g and 0.005μg / g - 0.010μg / g respectively. The sensitivity, accuracy and repeatability of the method all meet the requirements of pesticide residue analysis and detection. The sample pretreatment process is simple, the method is accurate and reliable, and the separation degree of each pesticide meets the requirements, which is applicable to the actual detection of pesticides in blueberries.

[0030] It should be noted that in this paper, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0031] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A rapid detection method for pesticide residues in blueberries, characterized in that, It includes the following steps: The first step: Generation of the standard curve: Prepare standard stock solutions of the internal standard and 14 types of pesticide samples including pyraclostrobin, fludioxonil, cyprodinil, fenbuconazole, captan, tridemorph, carbendazim, pyrimethanil, boscalid, azoxystrobin, cyprodinil, mancozeb, metalaxyl, procymidone; Prepare a mixed standard working solution using the standard stock solutions; Set the working parameters of the gas chromatograph triple quadrupole mass spectrometer. The chromatographic conditions are as follows: Liquid chromatography conditions: Chromatographic column: Agilent, InfinityLab, Poroshell, 120, EC-C18 (4.6*150mm, 2.7μm); Column temperature: 30°C; Flow rate: 0.8 ml / min; Injection volume: 5 μl; Mobile phase A: 0.01M ammonium acetate aqueous solution (adjusted to pH 4.5 with acetic acid); Mobile phase B: methanol: acetonitrile = 70:30, gradient elution program: 0 min, 80% A, 3 min, 80% A, 8 min, 65% A, 12 min, 20% A, 15 min, 20% A, 20 min, 80% A, 25 min, 80% A; Mass spectrometry conditions: Ion source type: ESI; Scan type: Positive ion mode scan; Mass-to-charge ratio acquisition range: 100 - 2000; Dwell time: 500 ms; Gain factor: 1; Dry gas temperature: 350°C; Dry gas flow rate: 11.0 L / min; Nebulizer pressure: 55 psi; Generate a standard curve model of the internal standard and various pesticides in blueberries in the liquid chromatography triple quadrupole mass spectrometer; The second step: Accurately weigh 10 g of well-ground blueberry samples into a 100 ml stoppered centrifuge tube; The third step: Add 50 ml of a mixed solution of ethyl acetate and ethanol containing 0.2% formic acid and 100 μl of the mixed internal standard solution to the centrifuge tube, then mix and shake well; The fourth step: Add ProElut, QuECHERS, EN, extraction salts (4 g MgSO4 + 1 g NaCl + 1 g sodium citrate + 0.5 g disodium hydrogen citrate); The fifth step: After shaking for 3 min, centrifuge at 5000 r / min for 5 min using a centrifuge; The sixth step: Take 1 ml of the upper clear liquid and add it to a ProElut, QuECHERS, EN purification tube (containing 25 mg PSA + 150 mg MgSO4); The seventh step: After shaking for 3 min, centrifuge at 5000 r / min for 5 min using a centrifuge; The eighth step: Take the upper clear liquid into an injection vial and then perform LCMS detection.

2. The rapid detection method for pesticide residues in blueberries according to claim 1, wherein: The sample preparation steps include taking an appropriate amount of blueberry samples, subjecting them to treatments such as crushing and homogenization, and then adding an appropriate amount of extraction solvent for extraction to obtain a blueberry extract.

3. A rapid detection method for pesticide residues in blueberries according to claim 1, characterized in that: The purification treatment step uses an improved QuEChERS method to purify the blueberry extract, where the extracted organic solvent is replaced with a mixed solution of ethyl acetate and ethanol containing 0.25% formic acid (v:v = 1:1).

4. The rapid detection method for pesticide residues in blueberries according to claim 1 is characterized in that: The liquid chromatography separation step uses a high performance liquid chromatography system. The chromatographic column is an Agilent, InfinityLab, Poroshell, 120, EC-C18 (4.6*150 mm, 2.7 μm) column, and the mobile phase is gradient elution with an ammonium acetate and methanol / acetonitrile mixed solution.

5. A rapid detection method for pesticide residues in blueberries according to claim 1, characterized in that: The mass spectrometry detection step uses a triple quadrupole mass spectrometry system. The ionization mode is the electrospray positive ion ionization mode, and multi-reaction monitoring scanning mode (MRM) detection is carried out. The fragmentation voltage is set at 135 V.

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