A method for simultaneously detecting multiple organophosphorus pesticide residues in prepared dishes

Abstract

The present invention relates to the field of food detection technology, and in particular to a method for simultaneously detecting multiple organophosphorus pesticide residues in pre-prepared dishes. The method comprises the following steps: (1) crushing the pre-prepared dish sample to obtain the pre-prepared dish sample; (2) mixing the pre-prepared dish sample with water, acetonitrile, anhydrous magnesium sulfate, and sodium chloride, shaking for 10 to 20 minutes, centrifuging, taking the supernatant, purifying the supernatant, and filtering with a microporous filter membrane to obtain a sample to be tested; (3) detecting the peak area of ​​the organophosphorus in the sample to be tested by high performance liquid chromatography-mass spectrometry, substituting the obtained peak area into a standard curve to obtain the content of the organophosphorus; according to the method of the present invention, 10 organophosphorus pesticide residues can be simultaneously detected in pre-prepared dishes, namely, dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malathion, fenthion sulfone, malathion, and omethoate, with a recovery rate of more than 90%. The method provides a basis for the detection of pesticide residues in pre-prepared dishes.

Description

Technical Field

[0001] The present invention relates to the technical field of food detection, and in particular to a method for simultaneously detecting multiple organophosphorus pesticide residues in prepared dishes. Background Art

[0002] Pre-prepared meals refer to convenient dishes that use modern standardized assembly line processes to pre-process the ingredients to simplify the preparation steps. With the rapid development of the pre-prepared meal market, more and more pre-prepared meals have entered people's lives.

[0003] Organophosphates are commonly used pesticides in vegetable cultivation. They are neurotoxins that are difficult to decompose in the environment and can even transform into more toxic substances, posing a serious threat. Eating vegetables containing organophosphate residues can cause symptoms such as muscle tremors, cramps, and elevated blood pressure.

[0004] When preparing pre-prepared meals, the safety of the resulting dishes remains a matter of concern due to the unclear origin of the vegetable raw materials. To ensure the safety of pre-prepared meals and public health, methods for detecting organophosphorus pesticide residues in pre-prepared meals are urgently needed. However, existing methods have not yet been found to detect organophosphorus pesticide residues in pre-prepared meals.

[0005] Based on this, the present invention is proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for simultaneously detecting multiple organophosphorus pesticide residues in prepared dishes.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a method for simultaneously detecting multiple organophosphorus pesticide residues in prepared dishes, comprising the following steps:

[0009] (1) crushing the prepared food to obtain a prepared food sample;

[0010] (2) Mixing the prepared food sample with water, acetonitrile, anhydrous magnesium sulfate, and sodium chloride, shaking for 10 to 20 minutes, centrifuging, collecting the supernatant, purifying the supernatant, and filtering with a microporous filter membrane to obtain the sample to be tested;

[0011] (3) detecting the peak area of ​​the organophosphorus in the sample by high performance liquid chromatography-mass spectrometry, substituting the obtained peak area into the standard curve to obtain the organophosphorus content;

[0012] The chromatographic conditions for HPLC-MS detection are as follows: Column: ACQUITY UPLC HSS T3 (2.1×100 mm, 1.8 μm), column temperature: 34-36°C, injection volume: 0.8-1.2 μL, mobile phase A: 2% methanol solution, mobile phase B: 98% methanol solution, flow rate: 0.2-0.4 mL / min; gradient elution program: 0-4 min, 100-80% mobile phase A, 0-20% mobile phase B; 4-5.5 min, 80-60% mobile phase A, 20-40% mobile phase B; 5.5-10.5 min, 60-0% mobile phase A, 40-100% mobile phase B; 10.5-12.9 min, 100% mobile phase B; 12.9-15 min, 0-100% mobile phase A, 100-0% mobile phase B; 15-20 min, 100% mobile phase A;

[0013] The mass spectrometry conditions for high performance liquid chromatography-mass spectrometry detection were as follows: detection mode: multiple ion reaction monitoring (MRM); capillary voltage: positive source 3.0 kV, negative source 2.0 kV; ion source temperature 150°C; cone gas flow rate: 150 L / h; desolvation gas temperature: 550°C; desolvation gas flow rate: 900 L / h.

[0014] Preferably, the mass volume ratio of the pre-prepared dish sample and water in step (2) is 1 g: 0.5-0.7 mL;

[0015] The mass volume ratio of the pre-prepared dish sample and acetonitrile in step (2) is 1 g: 1-2 mL;

[0016] The mass ratio of the pre-prepared dish sample and anhydrous magnesium sulfate in step (2) is 1:1 to 1.5;

[0017] The mass ratio of the pre-prepared dish sample and sodium chloride in step (2) is 1:0.6-0.8.

[0018] Preferably, the oscillation speed in step (2) is 2000-3000 rpm.

[0019] Preferably, the centrifugal speed in step (2) is 5500-6000 rpm, and the centrifugal time is 3-4 min.

[0020] Preferably, the method for purifying the supernatant in step (2) is to use a purifying agent for purification;

[0021] The purifier comprises anhydrous magnesium sulfate, N-propylethylenediamine and octadecylsilane in a mass ratio of 10-20:2-3:1;

[0022] During purification, the mass volume ratio of the purifying agent to the supernatant is 100-120 mg:1 mL.

[0023] Preferably, the pore size of the microporous filter membrane in step (2) is 0.2 to 0.3 μm.

[0024] Preferably, the organophosphorus includes dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malathion, fenthion sulfone, malathion and omethoate.

[0025] The present invention provides a method for simultaneously detecting multiple organophosphorus pesticide residues in pre-prepared dishes. The method comprises the following steps: (1) crushing the pre-prepared dishes to obtain a pre-prepared dish sample; (2) mixing the pre-prepared dish sample with water, acetonitrile, anhydrous magnesium sulfate, and sodium chloride, shaking for 10 to 20 minutes, centrifuging, collecting the supernatant, purifying the supernatant, and filtering with a microporous filter membrane to obtain a test sample; (3) detecting the peak area of ​​the organophosphorus in the test sample by high performance liquid chromatography-mass spectrometry, substituting the obtained peak area into a standard curve to obtain the organophosphorus content. According to the method of the present invention, 10 organophosphorus pesticide residues can be simultaneously detected in pre-prepared dishes, namely, dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malaxon, fenthion sulfone, malathion, and omethoate, with a recovery rate of over 90%. This method provides a basis for the detection of pesticide residues in pre-prepared dishes. DETAILED DESCRIPTION

[0026] In an embodiment of the present invention, during the high performance liquid chromatography detection process, mobile phase A is a 2vt% methanol solution containing 5mmol of ammonium formate and 0.1% of formic acid; mobile phase B is a 98% methanol solution; the 98% methanol solution contains 5mmol of ammonium formate and 0.1% of formic acid.

[0027] The technical effects provided by the present invention are described in detail below with reference to the embodiments, but they should not be understood as limiting the scope of protection of the present invention.

[0028] The standard products of dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malaxon, fenthion sulfone, malathion and omethoate described in the examples of the present invention are commercially available.

[0029] Example 1

[0030] Dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malaxon, fenthion sulfone, malathion and oxymethoate standards were prepared into 1 mg / L standard solutions using acetonitrile, and 1 mL of each solution was mixed to obtain a mixed standard solution.

[0031] The mixed standard solution was prepared into standard solutions at 1 μg / L, 5 μg / L, 10 μg / L, 25 μg / L, 50 μg / L, and 100 μg / L. A blank sample matrix was added to the standard solutions to obtain matrix-standard solutions. The matrix-standard solutions were subjected to HPLC-MS / MS analysis, with the concentration of the matrix-standard solution as the abscissa and the peak area as the ordinate, to obtain linear equations for each organophosphorus. The results are shown in Table 3.

[0032] The blank sample matrix was prepared by crushing seasonal snap beans produced by Shandong Changqingyuan Food Co., Ltd. to obtain a pre-prepared meal sample. After mixing 10 g of the pre-prepared meal sample with 6 mL of water, 10 mL of acetonitrile, 10 g of anhydrous magnesium sulfate, and 8 g of sodium chloride were added. The mixture was shaken at 2500 rpm for 15 minutes, centrifuged at 6000 rpm for 3 minutes, and the supernatant was collected. 6 mL of the supernatant was transferred to a centrifuge tube containing 600 mg of anhydrous magnesium sulfate, 80 mg of N-propylethylenediamine, and 40 mg of octadecylsilane. The mixture was centrifuged at 6000 rpm for 3 minutes, and the supernatant was collected to obtain a purified solution. The purified solution was filtered through a 0.25 μm microporous filter to obtain the blank sample matrix.

[0033] The chromatographic conditions were as follows: chromatographic column: ACQUITY UPLC HSS T3 (2.1×100 mm, 1.8 μm), column temperature: 34–36°C, injection volume: 0.8–1.2 μL, mobile phase A: 2% methanol solution (5 mmol ammonium formate and 0.1% formic acid), mobile phase B: 98% methanol solution (5 mmol ammonium formate and 0.1% formic acid), flow rate: 0.3 mL / min; the gradient elution program is shown in Table 1.

[0034] Table 1 Gradient elution program

[0035] Time min Mobile phase A Mobile phase B 0 100 0 4 80 20 5.5 60 40 10.5 0 100 12.9 0 100 15 100 0 20 100 0

[0036] The mass spectrometry conditions were as follows: detection mode: multiple ion reaction monitoring (MRM); capillary voltage: positive source 3.0 kV, negative source 2.0 kV; ion source temperature 150 °C; cone gas flow rate: 150 L / h; desolvation gas temperature: 550 °C; desolvation gas flow rate: 900 L / h. The detailed mass spectrometry parameters are shown in Table 2.

[0037] Table 2 Mass spectrometry parameters of different organophosphorus

[0038]

[0039] Table 3 Linear equations for different organophosphorus

[0040]

[0041]

[0042] Table 3 shows that the correlation coefficients of the 10 organophosphorus compounds were all greater than 0.9995, indicating a good linear relationship within the concentration range of 1 to 100 μg / L.

[0043] Example 2

[0044] The blank matrix sample obtained in Example 1 was spiked with 1 μg / L, 25 μg / L, and 100 μg / L of the standard solution prepared in Example 1. The peak areas of the standard solutions at different concentrations were measured using the chromatographic and mass spectrometric conditions of Example 1, and the recoveries were calculated. The results are shown in Table 4.

[0045] Table 4 Recovery rates of different spiked amounts

[0046]

[0047]

[0048] As shown in Table 4, the recovery rate of the present invention is 92.49-106.5%, indicating that the method of the present invention has high accuracy and can meet the requirements of simultaneously detecting 10 organophosphorus pesticide residues in prepared dishes.

[0049] Example 3

[0050] The method of Example 1 was used to detect the contents of 10 organophosphorus species in frozen green wheat kernels produced by Shandong Changqingyuan Food Co., Ltd.

[0051] The treatment method of the frozen green wheat kernels before high performance liquid chromatography detection was carried out according to the preparation method of the blank sample matrix in Example 1.

[0052] The test results are shown in Table 5.

[0053] Table 5 Organic phosphorus content in frozen green wheat kernels detected by the method of the present invention

[0054]

[0055] “-” means not detected.

[0056] As shown in Table 5, the frozen green wheat kernels produced by Shandong Changqingyuan Food Co., Ltd. contain a small amount of bisulphide.

[0057] Example 4

[0058] The method of Example 1 was used to detect the contents of 10 organophosphorus species in the pre-cooked minced meat eggplant produced by Anhui Qiaolemi Food Technology Co., Ltd.

[0059] The minced meat eggplant was treated before high performance liquid chromatography detection according to the preparation method of the blank sample matrix in Example 1.

[0060] The test results are shown in Table 6.

[0061] Table 6 Organic phosphorus content in frozen green wheat kernels detected by the method of the present invention

[0062]

[0063] “-” means not detected.

[0064] Table 6 shows that the pre-prepared dishes produced by Anhui Qiaolemi Food Technology Co., Ltd. contain small amounts of carbofuran and fenthion.

[0065] In summary, the present invention provides a method for simultaneously detecting multiple organophosphorus pesticide residues in pre-prepared dishes. The method comprises the following steps: (1) crushing the pre-prepared dishes to obtain a pre-prepared dish sample; (2) mixing the pre-prepared dish sample with water, acetonitrile, anhydrous magnesium sulfate, and sodium chloride, shaking for 10 to 20 minutes, centrifuging, collecting the supernatant, purifying the supernatant, and filtering with a microporous filter membrane to obtain a sample to be tested; (3) detecting the peak area of ​​the organophosphorus in the sample to be tested by high performance liquid chromatography-mass spectrometry, substituting the obtained peak area into the standard curve to obtain the organophosphorus content. According to the method of the present invention, 10 organophosphorus pesticide residues can be simultaneously detected in pre-prepared dishes, namely, dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malathion, fenthion sulfone, malathion, and omethoate, with a recovery rate of more than 90%. This provides a basis for the detection of pesticide residues in pre-prepared dishes.

[0066] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for simultaneously detecting multiple organophosphorus pesticide residues in prepared dishes, characterized in that: The steps include: (1) crushing the prepared food to obtain a prepared food sample; (2) Mix the prepared food sample with water, acetonitrile, anhydrous magnesium sulfate, and sodium chloride, shake for 10 to 20 minutes, centrifuge, and collect the supernatant. After purifying the supernatant, filter it with a microporous filter membrane to obtain the sample to be tested; (3) Detect the peak area of ​​organophosphorus in the sample by high performance liquid chromatography-mass spectrometry, substitute the obtained peak area into the standard curve to obtain the content of organophosphorus; The method for purifying the supernatant in step (2) is to use a purifying agent for purification; The purifier comprises anhydrous magnesium sulfate, N-propylethylenediamine and octadecylsilane in a mass ratio of 10-20:2-3:1; The chromatographic conditions for HPLC-MS detection were as follows: chromatographic column: ACQUITY UPLC HSS T3, 2.1×100 mm, 1.8 μm, column temperature: 34–36°C, injection volume: 0.8–1.2 μL, mobile phase A: 2% methanol solution containing 5 mmol ammonium formate and 0.1% formic acid, mobile phase B: 98% methanol solution containing 5 mmol ammonium formate and 0.1% formic acid, flow rate: 0.2–0.4 mL / min; gradient elution program: 0–4 min, 100–80% mobile phase A, 0–20% mobile phase B; 4–5.5 min, 80–60% mobile phase A, 20–40% mobile phase B; 5.5–10.5 min, 60–0% mobile phase A, 40–100% mobile phase B; 10.5–12.9 min, 100% mobile phase B. 12.9-15 min, 0-100% mobile phase A, 100-0% mobile phase B; 15-20 min, 100% mobile phase A; The mass spectrometry conditions for high performance liquid chromatography-mass spectrometry detection were as follows: detection mode: multiple ion reaction monitoring (MRM); capillary voltage: positive source 3.0 kV, negative source 2.0 kV; ion source temperature: 150°C; cone gas flow rate: 150 L / h; desolvation gas temperature: 550°C; desolvation gas flow rate: 900 L / h; The organophosphorus includes dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malathion, fenthion sulfone, malathion and omethoate.

2. The method according to claim 1, characterized in that The mass volume ratio of the pre-prepared dish sample and water in step (2) is 1 g: 0.5-0.7 mL; The mass volume ratio of the mixture of the prepared dish sample and acetonitrile in step (2) is 1 g: 1-2 mL; The mass ratio of the pre-prepared dish sample and anhydrous magnesium sulfate in step (2) is 1:1-1.5; The mass ratio of the pre-prepared dish sample and sodium chloride in step (2) is 1:0.6~0.

8.

3. The method according to claim 2, characterized in that The oscillation speed in step (2) is 2000-3000 rpm.

4. The method according to claim 3, characterized in that The centrifugal speed in step (2) is 5500-6000 rpm, and the centrifugal time is 3-4 min.

5. The method according to claim 4, characterized in that During purification, the mass volume ratio of the purifying agent to the supernatant is 100~120mg:1mL.

6. The method according to claim 5, characterized in that The pore size of the microporous filter membrane in step (2) is 0.2-0.3 μm.

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