Method for simultaneously detecting multiple organophosphorus pesticide residues in prefabricated vegetable

Abstract

The invention relates to the technical field of food detection, in particular to a method for simultaneously detecting various organophosphorus pesticide residues in prefabricated vegetables. Comprising the following steps: (1) crushing a pre-prepared vegetable sample to obtain a pre-prepared vegetable sample; (2) mixing the pre-prepared vegetable sample with water, acetonitrile, anhydrous magnesium sulfate and sodium chloride, oscillating for 10-20 minutes, centrifuging, taking supernatant, purifying the supernatant, and filtering with a microfiltration membrane to obtain a sample to be detected; and (3) detecting the peak area of the organophosphorus in the sample to be detected by high performance liquid chromatography-mass spectrometry, and substituting the obtained peak area into the standard curve to obtain the content of the organophosphorus, according to the method disclosed by the invention, the 10 kinds of organophosphorus pesticide residues, namely dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malasofos, fenthion sulfone, malathion and omethoate, in the prefabricated vegetable can be detected at the same time, and the recovery rate is 90% or above. And a basis is provided for detection of pesticide residues in the prefabricated vegetables.

Description

Technical Field

[0001] The 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 food refers to convenient food that uses modern standardized assembly line operations to pre-process food ingredients to simplify the steps of making food. With the rapid development of the pre-prepared food market, more and more pre-prepared food has entered people's lives.

[0003] Organophosphates are commonly used pesticides in vegetable cultivation. Organophosphates are neurotoxins that are not easily decomposed in the environment and may be transformed into more toxic substances, which are very harmful. People who eat vegetables containing organophosphate residues will experience symptoms such as muscle tremors, cramps, and increased blood pressure.

[0004] When preparing pre-prepared dishes, the safety of the prepared pre-prepared dishes needs to be studied because the source of the vegetable raw materials is unclear. In order to ensure the safety of pre-prepared dishes and people's health, a method for detecting organophosphorus pesticide residues in pre-prepared dishes is urgently needed, but the prior art has not found a method for detecting organophosphorus pesticide residues in pre-prepared dishes.

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

[0006] The object 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, taking the supernatant, purifying the supernatant, and filtering with a microporous filter membrane to obtain a sample to be tested;

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

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

[0013] The mass spectrometry conditions for HPLC-MS / MS 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 food 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 to 20:2 to 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 of the present invention 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, taking the supernatant, purifying the supernatant, filtering with a microporous filter membrane, and obtaining 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, and obtaining the content of the organophosphorus. According to the method of the present invention, 10 organophosphorus pesticide residues in pre-prepared dishes can be detected simultaneously, namely, dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malathion, fenthion sulfone, malathion, and omethoate, and the recovery rate is above 90%. It 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, and the 2vt% methanol solution contains 5mmol ammonium formate and 0.1% formic acid; mobile phase B is a 98% methanol solution; the 98% methanol solution contains 5mmol ammonium formate and 0.1% formic acid.

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

[0028] The standard products of dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malathion, 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 omethoate standards were respectively prepared into 1 mg / L standard solutions using acetonitrile, and 1 mL of each was mixed to obtain a mixed standard solution.

[0031] Take the mixed standard solution and prepare it into 1μg / L, 5μg / L, 10μg / L, 25μg / L, 50μg / L, and 100μg / L standard solutions. Add the blank sample matrix to the standard solution to obtain the matrix-standard solution. The matrix-standard solution is subjected to high performance liquid chromatography-mass spectrometry detection, and the concentration of the matrix-standard solution is used as the horizontal coordinate and the peak area is used as the vertical coordinate to obtain the linear equation of each organic phosphorus. The results are shown in Table 3.

[0032] The preparation method of the blank sample matrix is ​​as follows: crush the seasonal oil beans produced by Shandong Changqingyuan Food Co., Ltd. to obtain the pre-prepared food sample. After mixing and soaking 10g of the pre-prepared food sample with 6mL of water, add 10mL of acetonitrile, 10g of anhydrous magnesium sulfate, and 8g of sodium chloride, shake at 2500rpm for 15min, centrifuge at 6000rpm for 3min, and take the supernatant. Take 6mL of the supernatant and put it into a centrifuge tube containing 600mg of anhydrous magnesium sulfate, 80mg of N-propylethylenediamine and 40mg of octadecylsilane, centrifuge at 6000rpm for 3min, take the supernatant, and obtain the purified liquid. After passing the purified liquid through a 0.25μm microporous filter membrane, a blank sample matrix is ​​obtained.

[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 was 2 vt% methanol solution (5 mmol ammonium formate and 0.1% formic acid), mobile phase B was 98 vt% methanol solution (5 mmol ammonium formate and 0.1% formic acid), flow rate was 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 organic phosphorus

[0040]

[0041]

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

[0043] Example 2

[0044] 1 μg / L, 25 μg / L and 100 μg / L of the standard solution prepared in Example 1 were added to the blank matrix sample obtained in Example 1, and the peak areas of the standard solutions of different concentrations were detected according to the chromatographic and mass spectrometric conditions of Example 1, and the recovery was 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%, which shows that the method of the present invention has high accuracy and can meet the requirements of simultaneously detecting 10 organophosphorus pesticide residues in pre-prepared dishes.

[0049] Example 3

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

[0051] The method for treating frozen green wheat kernels before high performance liquid chromatography detection is carried out according to the method for preparing 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 thiosulfate.

[0057] Example 4

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

[0059] The method for treating the minced meat eggplant before high performance liquid chromatography detection is carried out according to the method for preparing 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, it can be seen that the present invention provides a method for simultaneously detecting multiple organophosphorus pesticide residues in pre-prepared dishes. The method of the present invention 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, taking the supernatant, purifying the supernatant, filtering with a microporous filter membrane, and obtaining 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, and obtaining 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, and the recovery rate is above 90%. It 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 principle of the present invention. These improvements and modifications should also be regarded as 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) Mixing the prepared food 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 organic phosphorus in the sample by high performance liquid chromatography-mass spectrometry, substituting the obtained peak area into the standard curve to obtain the content of the organic phosphorus; The chromatographic conditions for HPLC-MS detection are as follows: Chromatographic column: ACQUITYUPLC HSS T3 (2.1×100mm, 1.8μm), column temperature: 34~36℃, injection volume: 0.8~1.2μL, mobile phase A is 2vt% methanol solution, mobile phase B is 98vt% methanol solution, flow rate is 0.2~0.4mL / min; gradient elution program is: 0~4min, 100~80% mobile phase A, 0~20% mobile phase B; 4~5.5min, 80~60% mobile phase A, 20~40% mobile phase B; 5.5~10.5min, 60~0% mobile phase A, 40~100% mobile phase B; 10.5~12.9min, 100% mobile phase B; 12.9~15min, 0~100% mobile phase A, 100~0% mobile phase B; 15~20min, 100% mobile phase A; The mass spectrometry conditions for HPLC-MS / MS 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.

2. The method according to claim 1, characterized in that The mass volume ratio of the pre-prepared food sample and water in step (2) is 1 g: 0.5-0.7 mL; The mass volume ratio of the pre-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 to 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 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 to 20:2 to 3:1; During purification, the mass volume ratio of the purifying agent to the supernatant is 100-120 mg:1 mL.

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

7. The method according to any one of claims 1 to 6, characterized in that: The organophosphates include dimethoate, dichlorvos, phorate, isocarbophos, chlorpyrifos, fenthion, malaoxon, fenthion sulfone, malathion and omethoate.

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