A method for detecting matrine on quinoa

Abstract

The invention discloses a method for detecting matrine on quinoa, and belongs to the technical field of pesticide detection. The method for detecting matrine on quinoa comprises the following steps: (1) preparing a standard working solution of matrine, and then using a liquid chromatography tandem mass spectrometer (LC-MS / MS) to detect and draw a standard curve; (2) weighing a sample to be tested, adding ammonia water and letting it stand, then adding an organic solvent and fully mixing, adding salt and anhydrous magnesium sulfate, centrifuging after mixing, taking the supernatant to purify, and obtaining a liquid to be tested; (3) using a liquid chromatography-tandem mass spectrometer to detect the liquid to be tested, and calculating the matrine content in the liquid to be tested according to the standard curve. The method of the present invention has high reliability, is fast and accurate, is suitable for the rapid determination of matrine in quinoa plants, provides technical support for the safety of quinoa, and is suitable for batch detection of quinoa plants.

Description

Technical Field

[0001] The invention relates to the technical field of pesticide detection, and in particular to a method for detecting matrine on quinoa. Background Art

[0002] Quinoa (Chenopodium quinoa willd), a plant of the genus Chenopodium in the Amaranthaceae family, is also known as quinoa, southern quinoa, quinoa, etc. It originated in the high altitude areas of the Andes Mountains in South America and has a cultivation history of nearly 7,000 years. It is mainly planted experimentally in Africa, Europe, Asia and other regions. Quinoa prefers plateaus and mountainous areas with good drainage, cold and dry, mild but high relative humidity. In order to meet people's continuous demand for quinoa quality and yield, producers are forced to use a large amount of pesticides (unscientific, blind, and large-scale use of pesticides), causing pests and diseases to develop resistance and tolerance, and gradually reducing or even eliminating the efficacy of pesticides. At the same time, long-term reliance on chemical pesticides for prevention and control has led to increasing problems such as non-point source pollution and water source pollution.

[0003] Matrine is a quinolizidine alkaloid isolated from Sophora japonica plants. Its molecular formula is C 15 H 24 N 2 O, with a relative molecular mass of 248.37. Matrine preparations include 0.6% matrine aqueous solution, 0.8% matrine lactone aqueous solution, 1% matrine solution, 1.1% matrine solution, 1.1% matrine powder, etc. Pesticide products with it as the active ingredient have been widely used on a variety of crops such as fruits, vegetables, tea and tobacco. "National Food Safety Standard (GB2763-2022): Maximum Residue Limits of Pesticides in Food" stipulates that the maximum residue of matrine in cabbage, cucumber and pear is 5 mg / kg, and the maximum residue in tangerine, orange and mandarin is 1 mg / kg, but in these matrices, no national inspection standard detection method for matrine residues is given; there are few reports on residue detection in soil, and the detection of residues in quinoa has not yet been reported. Summary of the invention

[0004] The purpose of the present invention is to provide a method for detecting matrine on quinoa to solve the problems existing in the prior art. The present invention establishes a method for quickly determining the residues of matrine in quinoa plants by liquid chromatography-tandem mass spectrometry (HPLC-MS / MS), so as to provide technical support for the safety of quinoa. The detection method of the present invention has the advantages of high reliability, rapidity and accuracy.

[0005] To achieve the above object, the present invention provides the following scheme: a method for detecting matrine on quinoa, comprising the following steps:

[0006] (1) preparing a standard working solution of matrine, and then detecting it by liquid chromatography-tandem mass spectrometry and drawing a standard curve;

[0007] (2) Weigh the sample to be tested, add ammonia water and let it stand, then add an organic solvent and mix thoroughly, then add salt and anhydrous magnesium sulfate, mix well and centrifuge, take the supernatant and purify it to obtain a test solution;

[0008] (3) The test solution is detected by liquid chromatography-tandem mass spectrometry, and the matrine content in the test solution is calculated according to a standard curve.

[0009] Furthermore, the structural formula of matrine is shown in formula (1):

[0010]

[0011] Furthermore, the concentration series of the matrine standard working solution are 0.005 mg / L, 0.01 mg / L, 0.05 mg / L, 0.1 mg / L, 0.5 mg / L and 1.0 mg / L, respectively.

[0012] Furthermore, the sample to be tested is one or more of quinoa roots, quinoa stems, quinoa seeds and quinoa leaves.

[0013] Furthermore, the organic solvent includes methanol or acetonitrile.

[0014] Furthermore, the purifiers used in the purification include PSA and GCB.

[0015] Furthermore, when the sample to be tested is quinoa root, the preparation of the test solution specifically includes:

[0016] Weigh 2.00g of quinoa root sample, add 3mL of ammonia water (concentration of 25%), vortex evenly, let stand for 10min, then add 20mL of acetonitrile, vortex and oscillate for 3min to fully mix, add 1g of sodium chloride and 4g of anhydrous magnesium sulfate, vortex and oscillate for 1min, and centrifuge at 5000r / min for 5min; take 1.5mL of supernatant, place it in a 2mL centrifuge tube pre-added with 100mgPSA, 20mgGCB and 100mg anhydrous magnesium sulfate, vortex for 1min, centrifuge at 12000r / min for 2min, take the supernatant and filter it through a 0.22μm filter membrane to obtain the test solution.

[0017] Furthermore, when the sample to be tested is quinoa stem, the preparation of the test solution specifically includes:

[0018] Weigh 2.00g of quinoa stem sample, add 3mL of ammonia water (concentration of 25%), vortex evenly, let stand for 10min, then add 20mL of acetonitrile, vortex and oscillate for 3min to fully mix, add 1g of sodium chloride and 4g of anhydrous magnesium sulfate, vortex and oscillate for 1min, and centrifuge at 5000r / min for 5min; take 1.5mL of supernatant, place it in a 2mL centrifuge tube pre-added with 100mgPSA, 20mgGCB and 100mg anhydrous magnesium sulfate, vortex for 1min, centrifuge at 12000r / min for 2min, take the supernatant and filter it through a 0.22μm filter membrane to obtain the test solution.

[0019] Furthermore, when the sample to be tested is quinoa grains, the preparation of the test solution specifically includes:

[0020] Weigh 2.00g quinoa seed sample, add 3mL ammonia water (concentration 25vol.%), vortex evenly, let stand for 10min, then add 20mL acetonitrile, vortex and oscillate for 3min to mix thoroughly, add 1g sodium chloride and 4g anhydrous magnesium sulfate, vortex and oscillate for 1min, and centrifuge at 5000r / min for 5min; take 1.5mL supernatant, place it in a 2mL centrifuge tube pre-added with 70mgPSA, 20mgGCB and 100mg anhydrous magnesium sulfate, vortex for 1min, centrifuge at 12000r / min for 2min, take the supernatant and filter it through a 0.22μm filter membrane to obtain the test solution.

[0021] Furthermore, when the sample to be tested is quinoa leaves, the preparation of the test solution specifically includes:

[0022] Weigh 2.00g of quinoa leaf sample, add 1mL of ammonia water (concentration of 25%), vortex evenly, let stand for 10min, then add 20mL of methanol and vortex for 3min to mix thoroughly, add 1g of sodium chloride and 4g of anhydrous magnesium sulfate, vortex for 1min, and centrifuge at 5000r / min for 5min; take 1.5mL of supernatant, place it in a 2mL centrifuge tube pre-added with 150mgPSA, 20mgGCB and 100mg anhydrous magnesium sulfate, vortex for 1min, centrifuge at 12000r / min for 2min, take the supernatant and filter it through a 0.22μm filter membrane to obtain the test solution.

[0023] Furthermore, the mass spectrometry detection conditions of the liquid chromatography-tandem mass spectrometer detection are:

[0024] The ESI positive ion mode (with strong ionization efficiency) was used; the nebulizer gas flow rate was 3.0 L / min; the drying gas flow rate was 15 L / min; the DL temperature was 250°C; and the heating block temperature was 450°C.

[0025] Furthermore, the parent ion used in the mass spectrometry detection is m / z=249, and the daughter ions are m / z=148, 97.95 and 55.

[0026] Furthermore, the chromatographic detection conditions of the liquid chromatography-tandem mass spectrometer detection are:

[0027] Chromatographic column: Shim-pack XR-ODSⅡ (2.0mmi.d.×75mm, 1μL) chromatographic column; flow rate: 0.3mL / min; injection volume: 1μL; column temperature: 40℃; mobile phase: A is methanol, B is 5mmol / L ammonium formate aqueous solution.

[0028] Furthermore, the elution procedure of the chromatographic detection is: 0-1.5 min, 10% A; 1.5-2 min, 10-90% A; 2-6.5 min, 90% A; 6.5-7.5 min, 90-10% A; 7.5-8 min, 10% A.

[0029] The present invention discloses the following technical effects:

[0030] The present invention establishes an analytical method for detecting matrine in quinoa plants by combining QuEChERS with LC-MS / MS. The detection method of the present invention has simple pretreatment, high sensitivity, and stable recovery rate. The method is used for the determination of quinoa to successfully detect the content of matrine in quinoa. The method has high reliability, is fast and accurate, is suitable for batch detection of quinoa samples, and can become a conventional detection technology for matrine residues in quinoa. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 The chromatograms of 1.0 mg / L matrine standard working solution under different mobile phases;

[0033] Figure 2 The chromatogram is of the standard working solution of matrine with a concentration of 0.5 mg / L in Example 1 of the present invention;

[0034] Figure 3The chromatograms are matrix-labeled and added and recovered under different matrices in Example 1 of the present invention, wherein A is a quinoa root matrix-labeled chromatogram, B is a quinoa root added and recovered chromatogram, C is a quinoa stem matrix-labeled chromatogram, D is a quinoa stem added and recovered chromatogram, E is a quinoa leaf matrix-labeled chromatogram, F is a quinoa leaf added and recovered mass spectrum, G is a quinoa seed matrix-labeled chromatogram, and H is a quinoa seed added and recovered chromatogram. DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0036] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0037] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0038] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0039] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0040] Selection of mobile phase in the following embodiments of the present invention: Methanol or acetonitrile is used as the mobile phase, and the relative abundance of matrine ions in methanol or acetonitrile is determined. The results show that the response intensity and peak area of ​​matrine in methanol are better than those in acetonitrile. In order to obtain a good chromatographic peak shape, response value and a high signal-to-noise ratio, the effects of using 0.1% formic acid and acetic acid aqueous solutions, 5mmol ammonium formate (5mmol / L ammonium formate aqueous solution), ammonium acetate aqueous solution, 0.1% formic acid-5mmol ammonium formate, and 0.1% acetic acid-5mmol ammonium acetate aqueous solution as the aqueous phase were determined respectively. It was found that using 5mmol ammonium formate as the aqueous phase had a better effect. The chromatograms of 1.0mg / L matrine standard working solution under different mobile phases are shown in FIG. Figure 1 .

[0041] Selection of mass spectrometry conditions in the following embodiments of the present invention: According to the molecular structure characteristics and chemical ionization properties of the compounds, the signal differences of the compounds in the positive and negative ion modes of the ESI source were investigated respectively. Since matrine is a weakly alkaline compound containing nitrogen in its chemical structure, it is easy to add protons with positive charges. Therefore, it is suitable to use ESI+ mode (ESI positive ion mode) for detection.

[0042] The following examples of the present invention are about the selection of pretreatment extraction solvents: the effects of two hydrophilic extraction solvents, methanol and acetonitrile, on the recovery rate of matrine in different samples (matrices) were screened. The results showed that methanol was the best extractant for matrine in leaves, and acetonitrile was the best extractant for matrine in roots, stems and seeds.

[0043] The following examples of the present invention optimize the amount of extraction solvent used in the pretreatment: 20 mL of acetonitrile is selected as the extraction solvent for roots, stems and seeds, and 20 mL of methanol is selected as the extraction solvent for leaves.

[0044] The following examples of the present invention optimize the amount of ammonia used in pretreatment: The chemical structure of matrine contains amino groups (-NH 2 ), weak alkaline, matrine extraction effect is better under weak alkaline conditions. 20mL acetonitrile + 3mL ammonia water was selected as the best extraction solvent for quinoa roots, stems and seeds, and 20mL methanol + 1mL ammonia water was selected as the best extraction solvent for quinoa leaves.

[0045] Optimization of the pre-treatment purifier in the following examples of the present invention: Quinoa is rich in vitamins, polyphenols, flavonoids, saponins and phytosterols, and has high protein. Unsaturated fatty acids account for 83% of the fat it contains, and its pigment content is high. Therefore, the effects of different doses (30mg, 50mg, 70mg, 100mg, 150mg) of PSA, C18, Florisil and (20mg, 40mg, 60mg, 80mg, 100mg) of GCB on the recovery rate of matrine in quinoa plants were investigated. The results showed that the root and stem had the best purification effect using 100mg PSA + 20mg GCB, the grain had the best purification effect using 70mg PSA + 20mg GCB, and the leaf had the best purification effect using 150mg PSA + 20mg GCB.

[0046] Example 1

[0047] A method for detecting matrine on quinoa:

[0048] (1) Preparation of matrine standard working solution

[0049] Weigh matrine standard, dissolve it with methanol and make up to volume in a brown volumetric flask, dissolve it with ultrasonic, prepare a standard stock solution with a concentration of 100 mg / L, store it in a -18℃ refrigerator away from light, and then dilute it with methanol (chromatographic grade) to concentrations of 0.005 mg / L, 0.01 mg / L, 0.05 mg / L, 0.1 mg / L, 0.5 mg / L (see chromatogram for details) Figure 2 ) and a series of standard working solutions of 1.0 mg / L.

[0050] (2) Pretreatment of samples to be tested

[0051] A. Pretreatment of quinoa root: Weigh 2.00 g of quinoa root sample, add 3 mL of ammonia water (concentration of 25%), vortex evenly, let stand for 10 min, then add 20 mL of acetonitrile, vortex and oscillate for 3 min to fully mix, add 1 g of sodium chloride and 4 g of anhydrous magnesium sulfate, vortex and oscillate for 1 min, and centrifuge at 5000 r / min for 5 min; take 1.5 mL of supernatant, place it in a 2 mL centrifuge tube pre-added with 100 mg PSA, 20 mg GCB and 100 mg anhydrous magnesium sulfate, vortex for 1 min, centrifuge at 12000 r / min for 2 min, take the supernatant and filter it through a 0.22 μm filter membrane to obtain the quinoa root test solution.

[0052] B. Pretreatment of quinoa stem: Weigh 2.00 g of quinoa stem sample, add 3 mL of ammonia water (concentration of 25%), vortex evenly, let stand for 10 min, then add 20 mL of acetonitrile, vortex and oscillate for 3 min to fully mix, add 1 g of sodium chloride and 4 g of anhydrous magnesium sulfate, vortex and oscillate for 1 min, and centrifuge at 5000 r / min for 5 min; take 1.5 mL of supernatant, place it in a 2 mL centrifuge tube pre-added with 100 mg PSA, 20 mg GCB and 100 mg anhydrous magnesium sulfate, vortex for 1 min, centrifuge at 12000 r / min for 2 min, take the supernatant and filter it through a 0.22 μm filter membrane to obtain the quinoa stem test solution.

[0053] C. Pretreatment of quinoa seeds: Weigh 2.00 g of quinoa seed sample, add 3 mL of ammonia water (concentration of 25%), vortex evenly, let stand for 10 min, then add 20 mL of acetonitrile, vortex and oscillate for 3 min to fully mix, add 1 g of sodium chloride and 4 g of anhydrous magnesium sulfate, vortex and oscillate for 1 min, and centrifuge at 5000 r / min for 5 min; take 1.5 mL of supernatant, place it in a 2 mL centrifuge tube pre-added with 70 mg PSA, 20 mg GCB and 100 mg anhydrous magnesium sulfate, vortex for 1 min, centrifuge at 12000 r / min for 2 min, take the supernatant and filter it through a 0.22 μm filter membrane to obtain the quinoa seed test solution.

[0054] D. Pretreatment of quinoa leaves: Weigh 2.00 g of quinoa leaf sample, add 1 mL of ammonia water (concentration of 25%), vortex evenly, let stand for 10 min, then add 20 mL of methanol and vortex for 3 min to mix thoroughly, add 1 g of sodium chloride and 4 g of anhydrous magnesium sulfate, vortex for 1 min, and centrifuge at 5000 r / min for 5 min; take 1.5 mL of supernatant, place it in a 2 mL centrifuge tube pre-added with 150 mg PSA, 20 mg GCB and 100 mg anhydrous magnesium sulfate, vortex for 1 min, centrifuge at 12000 r / min for 2 min, take the supernatant and filter it through a 0.22 μm filter membrane to obtain the quinoa leaf test solution.

[0055] (3) Mass spectrometry conditions

[0056] The molecular mass of matrine is 249, and it has a strong ionization efficiency in ESI positive ion mode; nebulizing gas flow rate: 3.0 L / min; drying gas flow rate: 15 L / min; DL temperature: 250°C; heating block temperature: 450°C.

[0057] According to the parent ion scanning and daughter ion scanning results of matrine, the parent ion m / z = 249, daughter ions m / z = 148, 97.95 and 55 were monitored, and the quantitative ion was m / z = 148, and the qualitative and quantitative analysis of matrine was performed. Other mass spectrometry parameters are shown in Table 1.

[0058] Table 1 Mass spectrometry parameters

[0059]

[0060] (4) Chromatographic conditions

[0061] Analytical chromatographic column: Shim-pack XR-ODSⅡ (2.0mmi.d.×75mm, 1μL); flow rate: 0.3mL / min; injection volume: 1μL; column temperature: 40℃; mobile phase: A is methanol, B is 5mmol / L ammonium formate aqueous solution, mobile phase gradient elution is shown in Table 2.

[0062] Table 2 Mobile phase gradient

[0063] Time / min A / ％ B / ％ 0～1.5 10 90 1.5～2 10～90 90～10 2～6.5 90 10 6.5～7.5 90～10 10～90 7.5～8 10 90

[0064] (5) The prepared series of standard working solutions were tested according to the above method, and the standard curve was drawn with the injection mass concentration (x) as the horizontal axis and the peak area (y) as the vertical axis. The detection limit and quantification limit of this method were calculated using a 3-fold signal-to-noise ratio (S / N). The results are shown in Table 3.

[0065] Table 3 Standard curve equation, correlation coefficient, detection limit, quantification limit and matrix effect

[0066]

[0067] When the matrix effect |ME| is less than 20%, the matrix effect can be ignored and the solvent standard curve can be used for quantitative analysis; when 20% < |ME| < 50%, the matrix effect is considered to be strong and the blank matrix standard curve needs to be used for quantitative analysis; when |ME| > 50%, it is necessary to re-establish a pretreatment method suitable for the sample matrix. As can be seen from Table 3, the matrix effect |ME| is less than 20%, the matrix effect can be ignored, and the solvent standard curve can be used for quantitative analysis.

[0068] It can be seen from Table 3 that in the range of 0.005 to 1 mg / L, R 2 The values ​​of the concentration of matrine and the peak area were all greater than 0.999, and the mass concentration of matrine and the peak area showed a good linear relationship. The detection limits (LOD) of matrine in quinoa roots, stems, leaves and seeds were 0.001, 0.003, 0.003 and 0.001 mg / kg, respectively, and the quantification limits (LOQ) were 0.005, 0.01, 0.01 and 0.005 mg / kg, respectively. The linear equation, quantification limit and detection limit all met the requirements for pesticide residue detection (NY / T788-2018).

[0069] (6) Accuracy and precision of the test method (addition recovery test)

[0070] A. Quinoa root addition recovery test: Weigh 2.00 g of blank quinoa root sample (quinoa root without matrine), add matrine standard sample to the final concentration of 0.1 mg / kg, 1.0 mg / kg and 10 mg / kg, then perform pretreatment according to the method of step (2), and then perform detection according to the method of steps (3) to (4), and perform 5 parallel injections at each concentration level.

[0071] B. Quinoa stem addition recovery test: Weigh 2.00 g of blank quinoa stem sample (quinoa stem sample without matrine), add matrine standard sample to the final concentration of 0.1 mg / kg, 1.0 mg / kg and 10 mg / kg, then perform pretreatment according to the method of step (2), and then perform detection according to the method of steps (3) to (4), and perform 5 parallel injections at each concentration level.

[0072] C. Quinoa seed addition recovery test: Weigh 2.00 g of blank quinoa seed sample (quinoa seed sample without matrine), add matrine standard sample to the final concentration of 0.1 mg / kg, 1.0 mg / kg and 10 mg / kg, then perform pretreatment according to the method of step (2), and then perform detection according to the method of steps (3) to (4), and perform 5 parallel injections at each concentration level.

[0073] D. Quinoa leaf addition recovery test: Weigh 2.00 g of blank quinoa leaf sample (quinoa leaf sample without matrine), add matrine standard sample to the final concentration of 0.1 mg / kg, 1.0 mg / kg and 10 mg / kg, then perform pretreatment according to the method of step (2), and then perform detection according to the method of steps (3) to (4), and perform 5 parallel injections at each concentration level.

[0074] The average recovery and relative standard deviation were calculated. The intra-day precision was determined by analyzing each spike level 6 times in parallel within 1 day, while the inter-day precision was calculated and analyzed by continuous measurement for three days, with three replicates per day. The intra-day and inter-day precision of this method were expressed as relative standard deviations (RSDs). The results are shown in Table 4. The chromatograms of matrix-spiked and spiked recovery under different matrices are shown in Table 4. Figure 3 , Figure 3 Among them, A is the matrix-standard chromatogram of quinoa root, B is the added recovery chromatogram of quinoa root, C is the matrix-standard chromatogram of quinoa stem, D is the added recovery chromatogram of quinoa stem, E is the matrix-standard chromatogram of quinoa leaf, F is the added recovery mass spectrum of quinoa leaf, G is the matrix-standard chromatogram of quinoa seed, and H is the added recovery chromatogram of quinoa seed; Figure 3 The matrix standard for quinoa roots and seeds is 0.5 mg / L, and the addition level is 10 mg / L. The matrix standard for quinoa stems and leaves is 1 mg / L, and the addition level is 10 mg / L.

[0075] Table 4. Validation data of matrine in quinoa plants

[0076]

[0077] As can be seen from Table 4, the average recoveries (Rec) of matrine in quinoa roots, stems, leaves and seeds were 80.59-98.37%, 72.42-87.03%, 74.62-89.72% and 88.93-94.42%, respectively, and the relative standard deviations (RSD) were 2.63-6.84%, 2.22-6.45%, 1.25-4.64% and 2.02-4.12%, respectively. The intra-day and inter-day precisions of the four matrices (quinoa plants) met the requirements for pesticide residue analysis, and the RSDs were less than 8.72% and 7.32%, respectively.

[0078] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for detecting matrine on quinoa, characterized in that: The following steps are involved: (1) preparing a standard working solution of matrine, and then detecting it by liquid chromatography-tandem mass spectrometry and drawing a standard curve; (2) Weigh the sample to be tested, add ammonia water and let it stand, then add an organic solvent and mix thoroughly, then add salt and anhydrous magnesium sulfate, mix well and centrifuge, take the supernatant and purify it to obtain a test solution; (3) using a liquid chromatography-tandem mass spectrometer to detect the test solution, and calculating the matrine content in the test solution according to a standard curve; The sample to be tested is one or more of quinoa roots, quinoa stems, quinoa seeds and quinoa leaves; The organic solvent includes methanol or acetonitrile; The purifiers used in the purification include PSA and GCB; The chromatographic detection conditions of the liquid chromatography-tandem mass spectrometer detection are: Chromatographic column: Shim-pack XR-ODSⅡ chromatographic column, 2.0mmi.d.×75mm, 1μL; flow rate: 0.3mL / min; injection volume: 1μL; column temperature: 40℃; mobile phase: A is methanol, B is 5mmol / L ammonium formate aqueous solution; The elution procedure of the chromatographic detection is: 0-1.5 min, 10% A; 1.5-2 min, 10-90% A; 2-6.5 min, 90% A; 6.5-7.5 min, 90-10% A; 7.5-8 min, 10% A.

2. The method for detecting matrine on quinoa according to claim 1, characterized in that: The concentration series of the matrine standard working solution are 0.005 mg / L, 0.01 mg / L, 0.05 mg / L, 0.1 mg / L, 0.5 mg / L and 1.0 mg / L respectively.

3. The method for detecting matrine on quinoa according to claim 1, characterized in that: The mass spectrometry detection conditions of the liquid chromatography-tandem mass spectrometer detection are: ESI positive ion mode was used; nebulizer gas flow rate: 3.0 L / min; drying gas flow rate: 15 L / min; DL temperature: 250°C; heating block temperature: 450°C.

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