Rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed

Abstract

The invention belongs to the technical field of feed detection, and specifically relates to a rapid detection method for pesticide, veterinary drug and fungal toxin residues in feed, comprising the following steps: using a mixed extract of methanol, acetonitrile and isopropanol to extract a sample under alkaline conditions and acidic conditions in turn, mixing, solid phase extraction adsorbent (including N-vinylbenzene modified ferroferric oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C 18 After purification by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS) in multiple reaction monitoring scanning mode, quantification is performed by external standard method or internal standard method. It can quickly and accurately detect 420 pesticides, 163 veterinary drugs and their metabolites and 13 mycotoxins in feed at the same time, with a quantitative limit of 0.01 μg / kg to 50 μg / kg, which is of great significance for ensuring food safety, public health and the sustainable development of animal husbandry.

Description

Technical Field

[0001] The invention belongs to the technical field of feed detection, and in particular relates to a rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed. Background Art

[0002] With the rapid development of animal husbandry, the feed industry has also been driven to develop. During the processing, storage and transportation of feed, it is also very susceptible to various fungal contamination, thus producing various mycotoxins. The raw materials such as crops used in its production are also contaminated by pesticide residues. These residues of pesticides, veterinary drugs and mycotoxins not only affect animal health, but also pose a threat to human health. Through testing, it helps to ensure that feed products meet regulatory requirements and prevent feed containing banned drugs from entering the breeding process, thereby improving the quality of livestock and poultry products, helping to control the development of drug resistance, protecting consumer health, promoting the healthy development of animal husbandry, and helping to improve the international competitiveness of my country's livestock and poultry products.

[0003] There are few standard methods for testing raw materials and pesticide residues in feed. Basically, they refer to the detection methods for pesticide residues in food or are optimized and improved separately for special types of feed. Due to the wide variety of veterinary drugs, the detection methods may not cover all possible residues, resulting in the neglect of the detection of some veterinary drug residues. Although rapid detection methods are easy to operate, they are insufficient in accuracy and sensitivity. The detection methods of mycotoxins face the problems of complex sample pretreatment, insufficient detection sensitivity and specificity. In recent years, the use of high-resolution mass spectrometry technology for feed residue analysis has become increasingly popular. This technology can monitor a variety of potential contaminants and residues, including pesticides, veterinary drugs and natural toxins. Full scan analysis can theoretically screen an unlimited number of compounds in a single analysis. The wide scanning range will inevitably lose sensitivity, especially for most low-limit drugs, which are not sensitive enough and the detection limit cannot meet the limit requirements. Summary of the invention

[0004] In view of the deficiencies in the above-mentioned prior art, the present invention provides a rapid detection method for pesticide, veterinary drug and fungal toxin residues in feed. The rapid detection method optimizes sample extraction technology and combines nanomaterial-assisted detection technology to achieve simultaneous detection of 420 pesticides, 163 veterinary drugs and their metabolites and 13 fungal toxins in livestock feed, thereby improving the sensitivity, accuracy and speed of detection, while reducing costs and operational complexity, greatly reducing the intensity of detection work, reducing detection costs, using a small amount of reagents, and being friendly to humans and the environment.

[0005] The specific technical solutions are as follows:

[0006] A rapid detection method for pesticide, veterinary drug and fungal toxin residues in feed, comprising the following steps: using a mixed extract of methanol, acetonitrile and isopropanol to extract a sample under alkaline conditions and acidic conditions in turn, after mixing and solid phase extraction adsorbent purification, using ultra-high performance liquid chromatography-tandem mass spectrometry to detect in a multiple reaction monitoring scanning mode, and quantitatively using an external standard method or an internal standard method, which can quickly and accurately perform qualitative and quantitative analysis on 420 pesticides, 163 veterinary drugs and their metabolites and 13 fungal toxins in feed at the same time;

[0007] The solid phase extraction adsorbent comprises an N-vinylbenzene modified ferroferric oxide functionalized magnetic nano-adsorbent material and an octadecyl silica gel C 18 Adsorbent.

[0008] By adopting the above technical scheme, the present invention uses methanol and acetonitrile as conventional extraction solvents, adds isopropanol to increase the compatibility of the solvent and the sample, and cooperates with the acidic mixed solution and the alkaline mixed solution to extract more types and kinds of residual compounds with different acidity and alkalinity and different polarity in the feed, and the ferrous oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C modified by N-vinylbenzene are used. 18 The adsorbent is effectively purified and detected by ultra-high performance liquid chromatography-tandem mass spectrometry to achieve the goals of sufficient extraction, thorough purification, effective separation and high-sensitivity detection. It has achieved the simultaneous detection of 420 pesticides, 163 veterinary drugs and their metabolites and 13 fungal toxins in feed within 10 minutes.

[0009] Furthermore, the mixed extract is a uniform mixture of equal volumes of methanol, acetonitrile and isopropanol, and an alkaline regulator and an acidic regulator are added to the mixed extract respectively, and the sample is extracted in sequence.

[0010] Furthermore, the alkaline regulator includes ammonia water, and the amount of ammonia water added accounts for 1.0% to 4.0% of the mixed extraction liquid volume fraction; the acidic regulator includes formic acid, and the amount of formic acid added accounts for 0.2% to 2.0% of the mixed extraction liquid volume fraction.

[0011] Furthermore, the extraction method is a joint extraction with acid and alkali solutions. The sample is first extracted by vortexing with an ammonium mixed extract containing an alkaline regulator, and then extracted by vortexing with an acidified mixed extract containing an acidic regulator for a second time. The two extracts are combined and mixed evenly to obtain the extract to be purified.

[0012] Furthermore, the amount of the mixed extract used in each extraction is equal, the amount of the mixed extract used is 10.0 ml, and the extraction time of vortex oscillation is 5 minutes to 10 minutes.

[0013] Further, the purification comprises the following steps: firstly, N-vinylbenzene modified ferroferric oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C 18 After the adsorbents are mixed, they are filled into a syringe-type solid phase extraction column and compacted. Before use, they are rinsed with acetonitrile, methanol and the extract to be purified, air is injected, the liquid is emptied, and then the extract to be purified is absorbed and passed through the extraction column. The purified liquid is collected and passed through an organic filter membrane.

[0014] Furthermore, the N-vinylbenzene modified ferroferric oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C 18 The mass ratio of adsorbent is 1:1~2.

[0015] Furthermore, the amount of solid phase extraction adsorbent used per milliliter of the extract to be purified is 30 mg to 50 mg.

[0016] Furthermore, when using ultra performance liquid chromatography-tandem mass spectrometry for detection, a core-shell chromatographic column was used, mobile phase A was an aqueous solution of 2 mM ammonium formate (containing 0.1% formic acid by volume), mobile phase B was a methanol solution of 2 mM ammonium formate, and gradient elution was adopted with a flow rate of 0.5 mL / min, an injection volume of 2 μL, and an injection time of 10 min.

[0017] Furthermore, when using ultra-high performance liquid chromatography-tandem mass spectrometry for detection, the ion source is an electrospray ionization source ESI, and detection is performed using a polarity-switching positive and negative ion simultaneous scanning method.

[0018] Furthermore, a rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed comprises the following steps:

[0019] (1) Sample weighing: Accurately weigh the evenly crushed sample. If the moisture content of the sample is less than 50%, weigh 2.0 g and then add 3.0 mL of water; if the moisture content of the sample is greater than 50%, weigh 5.0 g;

[0020] (2) Preparation of mixed extract:

[0021] Preparation of mixed extract solution 1: firstly mix equal volumes of methanol, acetonitrile and isopropanol, add 1.0% to 4.0% ammonia water and mix evenly to obtain mixed extract solution 1;

[0022] Preparation of mixed extract solution 2: firstly mix equal volumes of methanol, acetonitrile and isopropanol, add 0.2% to 2.0% formic acid by volume and mix evenly to obtain mixed extract solution 2;

[0023] (3) Sample extraction: Add 10 ml of mixed extract solution 1 to the weighed sample, vortex and extract at 2000-2500 rpm for 5-10 minutes, centrifuge at 8000 rpm for 5-10 minutes, transfer the supernatant to a graduated colorimetric tube, add 10 ml of mixed extract solution 2 to the remaining residue and repeat the extraction, combine the two extracts, and dilute to 25 ml with acetonitrile to obtain the extract to be purified;

[0024] (4) Purification of the extract: First, N-vinylbenzene-modified ferroferric oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C 18 The adsorbents are mixed in a mass ratio of 1:1-2 to obtain a solid phase extraction adsorbent, and then 30 mg-50 mg of the solid phase extraction adsorbent is accurately weighed and filled into a 1 ml syringe-type solid phase extraction column and compacted for standby use. Before use, 1.0 ml of acetonitrile, 1.0 ml of methanol and 1.0 ml of the extract to be purified are used to rinse, inject air, drain the liquid, and then absorb 1.0 ml of the extract to be purified, pass through the extraction column, collect the purified liquid, and pass through a 0.22 μm polytetrafluoroethylene organic filter membrane;

[0025] (5) Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS) analysis: The separation column used was CORTECS Premier The T3 core-shell chromatographic column has an inner diameter of 2.1 mm, a particle size of 2.7 μm, and a column length of 100 mm. The mobile phase A is an aqueous solution of 2 mM ammonium formate (containing 0.1% formic acid by volume), and the mobile phase B is a methanol solution of 2 mM ammonium formate. Gradient elution is adopted with a flow rate of 0.5 mL / min, an injection volume of 2 μL, and an injection time of 10 min. The ion source is an electrospray ionization source ESI, and polarity switching positive and negative ions are scanned simultaneously. The ion source temperature is 150°C, the capillary voltage is 0.5~1.5 kV, the desolvation gas temperature is 400~450°C, the desolvation gas flow rate is 900~1100 liters per hour, the spray gas flow rate is 300 liters per hour, and the cone backflush gas flow rate is 150~300 liters per hour. The detection is carried out in the multiple reaction monitoring scanning mode, and the quantification is carried out by the external standard method or the internal standard method, so as to simultaneously carry out qualitative and quantitative analysis of pesticides, veterinary drugs and mycotoxins in feed.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The present invention uses methanol and acetonitrile as conventional extraction solvents, and adds isopropanol to increase the compatibility of the solvent and the sample, and cooperates with an acidic organic mixed solution (acidic regulator) and an alkaline organic mixed solution (alkaline regulator) to extract more types and kinds of residual compounds with different acidity and alkalinity and different polarity in the feed. The N-vinylbenzene-modified ferroferric oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C 18Effective purification by adsorbent, effective separation by core-shell chromatographic column, and simultaneous scanning of positive and negative ions with high-sensitivity polarity switching achieve the goals of full extraction, thorough purification, effective separation, and high-sensitivity detection, and achieve simultaneous detection of 420 pesticides, 163 veterinary drugs and their metabolites, and 13 mycotoxins in feed within 10 minutes;

[0028] (2) The rapid detection method provided by the present invention has a quantitative limit of 0.01 μg / kg to 50 μg / kg, a simulated addition recovery rate of 76.3% to 99.9%, and a relative standard deviation of less than 9.7%. The method is highly robust, versatile, simple, convenient, and fast, low in cost, uses less reagents, is friendly to humans and the environment, and is an environmentally friendly green chemical analysis method;

[0029] (3) Methanol and acetonitrile are conventional extraction solvents and are often used for the extraction of pesticides and mycotoxins. In the present invention, the addition of isopropanol increases the compatibility of the solvent and the sample; the addition of formic acid or ammonia water as an additive in the mixed extract changes the pH value of the mixed extract, which can stabilize the target and increase the solubility of the target. The alkaline and acidic extractions are performed in two steps, which can extract more residual pesticides and mycotoxins in the sample.

[0030] (4) Typical solid phase extraction materials include C 18 Bonded silica gel, graphitized carbon black, N-propylethylenediamine (PSA), alumina, high molecular polymers, multi-walled carbon nanotubes, etc. are used in pesticide residue detection and veterinary drug residue detection to adsorb various impurities and matrix interferences. There are also anionic and cationic adsorbents that use ion exchange technology to adsorb specific types of compounds, and then use the changes in ion strength to enrich and elute the target. Some special materials such as molecular imprinting technology materials use a receptor-antibody mechanism to capture a certain compound or a certain type of compound in the extract. They are more specific, but are not suitable for the analysis of multiple types of targets.

[0031] The matrix in feed is more complex, including various metal ions, organic small molecule polymers, proteins and lipids. These complex components may cause a series of problems such as instrument contamination, signal interference and matrix effect. Nano characterization technology is a technology that crosses the basic theoretical research and practical application of high-tech materials. Under the nano characterization technology, the application of magnetic nano materials is becoming more and more vigorous.

[0032] The rapid detection method of the present invention is compared with the above adsorption materials. It is found that the use of ferroferric oxide functionalized magnetic nano-adsorption materials modified with N-vinylbenzene can effectively adsorb metal ions, organic small molecule polymers and proteins in feed. Octadecyl silica gel C 18It has a strong adsorption capacity for lipids in various feeds. It has been confirmed by adding and recycling that the mass ratio of the mixture is 1:1~2. As a solid phase extraction adsorbent, the usage is 30 mg~50 mg per ml of the extract to be purified. It will not produce excessive adsorption and interference to pesticides, veterinary drugs and fungal toxins during purification. At the same time, the signal interference and matrix effect of the instrument can reach the lowest level, meeting the requirements of method accuracy.

[0033] (5) The separation chromatographic column used in the UPLC-MS / MS analysis of the present invention is a CORTECS Premier T3 core-shell chromatographic column, which is a combination of solid core particles and MaxPeak high performance surface (HPS) technology. Compared with fully porous particles of the same size, solid core particles can achieve higher column efficiency at low column pressures, while MaxPeak HPS technology can reduce unnecessary interactions between analytes and metal ions in typical stainless steel chromatographic columns. By combining these two technologies in a chromatographic column series in a convenient and efficient manner, reliable data for all analytes can be obtained at a higher throughput, which is very suitable for the simultaneous analysis of multiple pesticides, veterinary drugs and mycotoxins. DETAILED DESCRIPTION

[0034] The principles and features of the present invention are described below in conjunction with examples. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0035] The following examples further illustrate the method of simulated sample addition.

[0036] Sample preparation: 1 kg of each of silage, pig feed and dog food samples were homogenized and crushed evenly. Three different concentrations of mixed standards of pesticides, veterinary drugs and mycotoxins were added to the prepared samples, with the added concentrations of 1.0 μg / kg, 2.0 μg / kg and 10.0 μg / kg, respectively. The samples were frozen in a -18°C refrigerator for later use.

[0037] The N-vinylbenzene-modified ferroferric oxide functionalized magnetic nano-adsorbent materials used in the following examples were purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., with a particle size of 10-30 nanometers, and octadecyl silica gel C 18 The adsorbent was purchased from Shenzhen Comma Biotechnology Co., Ltd. with a particle size of 40-60 μm.

[0038] Example 1

[0039] The simulated spiked silage is taken as a sample. The rapid detection method for pesticide, veterinary drug and mycotoxin residues in the sample comprises the following steps:

[0040] (1) Preparation of mixed extract:

[0041] Preparation of mixed extract solution 1: firstly mix equal volumes of methanol, acetonitrile and isopropanol, add 4.0% by volume of ammonia water and mix evenly to obtain mixed extract solution 1;

[0042] Preparation of mixed extract solution 2: firstly mix equal volumes of methanol, acetonitrile and isopropanol, add 2.0% by volume of formic acid and mix evenly to obtain mixed extract solution 2;

[0043] (2) Sample extraction: Weigh 5.0 g of the above silage sample, weigh 8 replicates for each added concentration, add 10.0 ml of mixed extract solution 1 to each sample, vortex at 2500 rpm for 5 minutes, centrifuge at 8000 rpm for 5 minutes, transfer the supernatant to a colorimetric tube, add 10.0 ml of mixed extract solution 2 to the remaining residue, repeat the above oscillation and centrifugation operation, combine the extracts, and dilute to 25 ml with acetonitrile to obtain the extract to be purified;

[0044] (3) Purification of the extract: First, N-vinylbenzene-modified ferroferric oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C 18 The adsorbents were mixed in a mass ratio of 1:1 to obtain a solid phase extraction adsorbent, and then 30 mg of the solid phase extraction adsorbent was accurately weighed and filled into a 1 ml syringe-type solid phase extraction column and compacted for standby use. Before use, 1.0 ml of acetonitrile, 1.0 ml of methanol and 1.0 ml of the extract to be purified were used to rinse, air was injected, the liquid was emptied, and then 1.0 ml of the extract to be purified was sucked and passed through the extraction column, and the purified liquid was collected and passed through a 0.22 μm polytetrafluoroethylene organic filter membrane;

[0045] (4) UPLC-MS / MS analysis: The separation column used was a CORTECS Premier T3 core-shell column with an inner diameter of 2.1 mm, a particle size of 2.7 μm, and a column length of 100 mm. Mobile phase A was an aqueous solution of 2 mM ammonium formate (containing 0.1% by volume formic acid), and mobile phase B was a methanol solution of 2 mM ammonium formate. Gradient elution was used with a flow rate of 0.5 mL / min. The initial proportion of mobile phase A was 95%, which was maintained for 0.5 min, then linearly changed to 5% within 9.5 min, maintained for 2.5 min, and restored to 95% within 9.1 min, and maintained for 10 min. The total injection time was 10 min; the injection volume was 2 μL; the ion source was ESI (polarity switching, positive and negative ions scanned simultaneously), the ion source temperature was 150 °C, the capillary voltage was 1.5 kV, the desolvation gas temperature was 400 °C, the desolvation gas flow rate was 1000 liters per hour, the spray gas flow rate was 300 liters per hour, the cone backflush gas flow rate was 300 liters per hour, the scanning mode was multiple reaction monitoring, and the internal standard method or external standard method was used for quantitative analysis. The pesticides, veterinary drugs and mycotoxins in the samples were qualitatively and quantitatively analyzed simultaneously.

[0046] (5) Statistics of quantitative test results: The average recovery rates of various pesticides, veterinary drugs and mycotoxins added to silage were 76.3% to 99.9%, and the relative standard deviation of parallel samples was less than 9.7%. For details, see Table 1 Simulated recovery rates and relative standard deviations of pesticides, veterinary drugs and their metabolites and mycotoxins (n=8).

[0047] Example 2

[0048] The simulated spiked pig feed is taken as a sample. The rapid detection method of pesticide, veterinary drug and mycotoxin residues in the sample comprises the following steps:

[0049] (1) Preparation of mixed extract:

[0050] Preparation of mixed extract solution 1: firstly mix equal volumes of methanol, acetonitrile and isopropanol, add 2.0% by volume of ammonia water and mix evenly to obtain mixed extract solution 1;

[0051] Preparation of mixed extract solution 2: firstly mix equal volumes of methanol, acetonitrile and isopropanol, add 1.0% by volume of formic acid and mix evenly to obtain mixed extract solution 2;

[0052] (2) Sample extraction: Weigh 2.0 g of the above pig feed sample, add 3.0 g of pure water to soak, weigh 8 parallels for each added concentration, add 10.0 ml of mixed extract solution 1 to each sample, vortex at 2200 rpm for 8 minutes, centrifuge at 8000 rpm for 5 minutes, transfer the supernatant to a colorimetric tube, add 10.0 ml of mixed extract solution 2 to the remaining residue, repeat the above oscillation and centrifugation operation, combine the extracts, and dilute to 25 ml with acetonitrile to obtain the extract to be purified;

[0053] (3) Purification of the extract: First, N-vinylbenzene-modified ferroferric oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C 18 The adsorbents were mixed at a mass ratio of 1:1.5 to obtain a solid phase extraction adsorbent, and then 40 mg of the solid phase extraction adsorbent was accurately weighed and filled into a 1 ml syringe-type solid phase extraction column and compacted for standby use. Before use, 1.0 ml of acetonitrile, 1.0 ml of methanol and 1.0 ml of the extract to be purified were used to rinse, air was injected, the liquid was emptied, and then 1.0 ml of the extract to be purified was sucked and passed through the extraction column, and the purified liquid was collected and passed through a 0.22 μm polytetrafluoroethylene organic filter membrane;

[0054] (4) UPLC-MS / MS analysis: The separation column used was a CORTECS Premier T3 core-shell column with an inner diameter of 2.1 mm, a particle size of 2.7 μm, and a column length of 100 mm. Mobile phase A was an aqueous solution of 2 mM ammonium formate (containing 0.1% by volume formic acid), and mobile phase B was a methanol solution of 2 mM ammonium formate. Gradient elution was used with a flow rate of 0.5 mL / min. The initial proportion of mobile phase A was 95%, which was maintained for 0.5 min, then linearly changed to 5% within 9.5 min, maintained for 2.5 min, and restored to 95% within 9.1 min, and maintained for 10 min. The total injection time was 10 min; the injection volume was 2 μL; the ion source was ESI (polarity switching, positive and negative ions scanned simultaneously), the ion source temperature was 150 °C, the capillary voltage was 1.0 kV, the desolvation gas temperature was 450 °C, the desolvation gas flow rate was 900 liters per hour, the spray gas flow rate was 300 liters per hour, the cone backflush gas flow rate was 150 liters per hour, the scanning mode was multiple reaction monitoring, and the internal standard method or external standard method was used for quantitative analysis. The pesticides, veterinary drugs and mycotoxins in the samples were qualitatively and quantitatively analyzed simultaneously.

[0055] (5) Statistics of quantitative test results: The average recovery rates of various pesticides, veterinary drugs and mycotoxins added to pig feed ranged from 76.3% to 99.9%, and the relative standard deviation of parallel samples was less than 9.7%. For details, see Table 1 for simulated addition recovery rates and relative standard deviations of pesticides, veterinary drugs and their metabolites and mycotoxins (n=8).

[0056] Example 3

[0057] The simulated spiked dog food is taken as a sample, and the rapid detection method of pesticide, veterinary drug and mycotoxin residues in the sample comprises the following steps:

[0058] (1) Preparation of mixed extract:

[0059] Preparation of mixed extract solution 1: firstly mix equal volumes of methanol, acetonitrile and isopropanol, add 1.0% by volume of ammonia water and mix evenly to obtain mixed extract solution 1;

[0060] Preparation of mixed extract solution 2: firstly mix equal volumes of methanol, acetonitrile and isopropanol, add 0.2% by volume of formic acid and mix evenly to obtain mixed extract solution 2;

[0061] (2) Sample extraction: Weigh 2.0 g of the above dog food sample, add 3.0 g of pure water to soak, weigh 8 parallel samples for each concentration, add 10.0 ml of mixed extract solution 1 to each sample, vortex at 2000 rpm for 10 minutes, centrifuge at 8000 rpm for 5 minutes, transfer the supernatant to a colorimetric tube, add 10.0 ml of mixed extract solution 2 to the remaining residue, repeat the above oscillation and centrifugation operation, combine the extracts, and dilute to 25 ml with acetonitrile to obtain the extract to be purified;

[0062] (3) Purification of the extract: First, N-vinylbenzene-modified ferroferric oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C 18 The adsorbents were mixed in a mass ratio of 1:2 to obtain a solid phase extraction adsorbent, and then 50 mg of the solid phase extraction adsorbent was accurately weighed and filled into a 1 ml syringe-type solid phase extraction column and compacted for standby use. Before use, 1.0 ml of acetonitrile, 1.0 ml of methanol and 1.0 ml of the extract to be purified were used to rinse, air was injected, the liquid was emptied, and then 1.0 ml of the extract to be purified was sucked and passed through the extraction column, and the purified liquid was collected and passed through a 0.22 μm polytetrafluoroethylene organic filter membrane;

[0063] (4) UPLC-MS / MS analysis: The separation column used was a CORTECS Premier T3 core-shell column with an inner diameter of 2.1 mm, a particle size of 2.7 μm, and a column length of 100 mm. Mobile phase A was an aqueous solution of 2 mM ammonium formate (containing 0.1% by volume formic acid), and mobile phase B was a methanol solution of 2 mM ammonium formate. Gradient elution was used with a flow rate of 0.5 mL / min. The initial proportion of mobile phase A was 95%, which was maintained for 0.5 min, then linearly changed to 5% within 9.5 min, maintained for 2.5 min, and restored to 95% within 9.1 min, and maintained for 10 min. The total injection time was 10 min; the injection volume was 2 μL; the ion source was ESI (polarity switching, positive and negative ions scanned simultaneously), the ion source temperature was 150 ° C, the capillary voltage was 0.5 kV, the desolvation gas temperature was 420 ° C, the desolvation gas flow rate was 1100 liters per hour, the spray gas flow rate was 300 liters per hour, the cone backflush gas flow rate was 150 liters per hour, the scanning mode was multiple reaction monitoring, and the internal standard method or external standard method was used for quantitative analysis. The pesticides, veterinary drugs and mycotoxins in the samples were qualitatively and quantitatively analyzed simultaneously;

[0064] (5) Statistics of quantitative test results: The average recovery rates of various pesticides, veterinary drugs and mycotoxins added to dog food ranged from 76.3% to 99.9%, and the relative standard deviations of parallel samples were less than 9.7%. For details, see Table 1 for the quantification limits LOQ, simulated addition recovery rates REC and relative standard deviations RSD (n=8) of pesticides, veterinary drugs and their metabolites and mycotoxins.

[0065] Table 1 LOQ, simulated spiked recoveries REC and relative standard deviations RSD of pesticides, veterinary drugs, their metabolites and mycotoxins (n=8, 3 matrices, 3 spiked concentrations)

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077] In summary, the present invention provides a rapid detection method for pesticide, veterinary drug and fungal toxin residues in feed, which has high sensitivity, precise quantitative analysis, durability and robustness. By optimizing the sample extraction technology and combining the nanomaterial-assisted detection technology, it realizes the simultaneous detection of 420 pesticides, 163 veterinary drugs and their metabolites and 13 fungal toxins in poultry and livestock feed, improves the sensitivity, accuracy and speed of detection, reduces the cost and operation complexity, greatly reduces the intensity of detection work, reduces the detection cost, uses a small amount of reagents, is friendly to humans and the environment, and belongs to an environmentally friendly green chemical analysis method.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed, characterized in that: The method comprises the following steps: using a mixed extract of methanol, acetonitrile and isopropanol to extract a sample under alkaline conditions and acidic conditions in turn, after mixing and solid phase extraction adsorbent purification, using ultra-high performance liquid chromatography-tandem mass spectrometry to detect in a multiple reaction monitoring scanning mode, and quantitatively analyzing pesticides, veterinary drugs and fungal toxins in feed by external standard method or internal standard method; The solid phase extraction adsorbent comprises an N-vinylbenzene modified ferroferric oxide functionalized magnetic nano-adsorbent material and an octadecyl silica gel C 18 Adsorbent; The mixed extract is a uniform mixture of equal volumes of methanol, acetonitrile and isopropanol. An alkaline regulator and an acidic regulator are added to the mixed extract respectively, and the sample is extracted in sequence.

2. The rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed according to claim 1, characterized in that: The N-vinylbenzene modified ferroferric oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C 18 The mass ratio of adsorbent is 1:1~2.

3. The rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed according to claim 1 or 2, characterized in that: The alkaline regulator includes ammonia water, and the amount of ammonia water added accounts for 1.0% to 4.0% of the mixed extraction liquid volume fraction; the acidic regulator includes formic acid, and the amount of formic acid added accounts for 0.2% to 2.0% of the mixed extraction liquid volume fraction.

4. The rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed according to claim 3, characterized in that: The extraction method is a joint extraction of acid and alkali solutions. The sample is first extracted by vortexing with an ammonium mixed extract containing an alkaline regulator, and then extracted by vortexing with an acidified mixed extract containing an acidic regulator for a second time. The two extracts are combined and mixed evenly to obtain the extract to be purified.

5. The rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed according to claim 4, characterized in that: The amount of mixed extract used in each extraction is equal, and the extraction time of vortex oscillation is 5 minutes to 10 minutes.

6. The rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed according to claim 1 or 2, characterized in that: The purification comprises the following steps: firstly, N-vinylbenzene modified ferroferric oxide functionalized magnetic nano-adsorbent material and octadecyl silica gel C 18 After the adsorbents are mixed, they are filled into a syringe-type solid phase extraction column and compacted. Before use, they are rinsed with acetonitrile, methanol and the extract to be purified, air is injected, the liquid is emptied, and then the extract to be purified is absorbed and passed through the extraction column. The purified liquid is collected and passed through an organic filter membrane.

7. The rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed according to claim 6, characterized in that: The amount of solid phase extraction adsorbent used per milliliter of the extract to be purified is 30 mg to 50 mg.

8. The rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed according to claim 1, characterized in that: When using ultra performance liquid chromatography-tandem mass spectrometry for detection, a core-shell chromatographic column was used, mobile phase A was an aqueous solution containing 0.1% formic acid-2 mM ammonium formate with a volume fraction, mobile phase B was a methanol solution of 2 mM ammonium formate, gradient elution was adopted, the flow rate was 0.5 mL / min, the injection volume was 2 μL, and the injection time was 10 min.

9. The rapid detection method for pesticide, veterinary drug and mycotoxin residues in feed according to claim 1, characterized in that: When using ultra-high performance liquid chromatography-tandem mass spectrometry for detection, the ion source is an electrospray ionization source ESI, and detection is performed using a polarity-switching positive and negative ion simultaneous scanning method.

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