A method for detecting quinclorac residues in plant-derived foods with low matrix effect

Abstract

The present invention relates to a method for detecting quinclorac residues in plant-derived foods with low matrix effects. The method comprises the following specific steps: (1) drawing a standard curve; (2) extracting samples; (3) purifying; (4) determining the recovery rate; and (5) determining the quinclorac content in samples. The method for detecting quinclorac residues in plant-derived foods with low matrix effects utilizes acetonitrile extraction, and the extract is purified by a solid phase extraction column and then measured on a machine. The method adopts a liquid chromatography-tandem mass spectrometry atmospheric pressure chemical ionization source, has high selectivity and sensitivity, effectively reduces matrix effects, can directly use a solvent standard curve for quantification, has high accuracy and precision, and provides technical support for the next step of improving and supplementing residents' dietary intake and risk data of quinclorac and formulating maximum residue limits.

Description

Technical Field

[0001] The invention belongs to the field of modern food, and in particular relates to a method for detecting quinclorac residues in plant-derived foods with low matrix effect. Background Art

[0002] Quinclorac is a herbicide with a new molecular skeleton independently developed by my country. It can be used to control weeds in sorghum, corn, sugarcane, wheat and cotton fields, and shows high herbicidal activity against a variety of broadleaf weeds and grass weeds. With the promotion and application of quinclorac, it is increasingly urgent to formulate its residue limit standards in plant-derived foods, and the development of quinclorac residue detection methods is the premise and basis for formulating limit standards. Feng Yizhi et al. established a high-performance liquid chromatography-tandem mass spectrometry method to detect quinclorac residues in sorghum. This method uses an electrospray ion source, and the matrix effect is obvious. It is necessary to use a blank matrix matching standard solution to overcome the matrix effect in order to accurately quantify. In actual detection, especially in the detection of samples involving multiple matrices, it is necessary to prepare different matrix standard curves for quantification, which is cumbersome to operate and has low detection efficiency. Summary of the invention

[0003] The purpose of the present invention is to use liquid chromatography tandem mass spectrometry technology with an atmospheric pressure chemical ionization source combined with a solid phase extraction pretreatment method to solve the problems in the prior art that quinclorac has obvious matrix effect under an electrospray ion source, the quantitative operation is cumbersome, and the detection efficiency is low.

[0004] The present invention is achieved through the following technical scheme: a method for detecting quinclorac residues in plant-derived foods with low matrix effect, which is special in that it includes the following specific steps:

[0005] (1) Drawing of standard curve

[0006] Weigh the quinoline standard and dilute it with methanol to obtain a 10 mg / L quinoline solution, dilute the 10 mg / L quinoline solution with methanol to obtain a 0.01 mg / L to 0.2 mg / L quinoline standard solution, perform liquid chromatography tandem mass spectrometry analysis and detection, and the linear correlation is good; perform regression with concentration as the abscissa and peak area as the ordinate to obtain a quinoline standard curve;

[0007] (2) Sample extraction

[0008] Weigh the crushed sample to be tested, add water and acetonitrile, vortex for 2 minutes, add sodium chloride, continue vortexing for 1 minute, and finally centrifuge at room temperature for 3 minutes to separate the acetonitrile phase and the aqueous phase;

[0009] (3) Purification

[0010] The acetonitrile solution to be purified is directly drawn through a solid phase extraction column, and the filtrate is collected for testing;

[0011] (4) Recovery rate determination

[0012] Weigh the blank sample after crushing, add quinclorac standard solution at the addition amount of 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg respectively, repeat steps (2) and (3), perform liquid chromatography tandem mass spectrometry analysis, compare with the quinclorac standard curve in step (1), calculate, obtain the quinclorac determination value, and calculate the recovery rate;

[0013] (5) Determination of quinclorac content in samples

[0014] The quinclorac content detected in step (3) is compared with the quinclorac standard curve in step (1) and calculated to obtain the actual quinclorac content in the sample to be tested.

[0015] Preferably, in step (1), the specific concentration range of quinclorac with good linear correlation is: good linearity between 0.01 mg / L and 0.2 mg / L.

[0016] Furthermore, in the step (1), the standard curve of quinclorac is: Y=657938X-44, and the correlation coefficient r=0.9999.

[0017] Preferably, in step (2), 2.0 to 10.0 g of the sample to be tested is weighed, 5 to 10 mL of water is added, 10 to 20 mL of acetonitrile is added, and 5 to 8 g of sodium chloride is added.

[0018] Preferably, in step (3), 3 to 5 mL of the purified acetonitrile solution is drawn, and the solid phase extraction column used is a polystyrene-divinylbenzene solid phase extraction column or an amino solid phase extraction column.

[0019] Preferably, in the steps (1) and (4), the liquid chromatography conditions are as follows: chromatographic column: ZORBAX SB C18 2.1×50mm×3.5 μm; column temperature 40°C; mobile phase A: 0.1% formic acid in water, mobile phase B: 0.1% formic acid in methanol; mobile phase gradient 0-1.0 min 10% B, 1.0-5.0 min 10% B-95% B, 5.0-8.0 min 95% B, 8.1 min 10% B; flow rate 0.8 mL / min; injection volume 1 μL; mass spectrometry conditions are atmospheric pressure chemical ionization positive ion mode; desolvation tube temperature 200°C; heating module temperature 200°C; ion source temperature 350°C; drying gas flow rate 5 L / min, nebulizing gas flow rate 3 L / min, collision gas pressure 230 kPa; scanning mode was multiple reaction monitoring; quinclorac quantitative ion pair: 419 / 281; qualitative ion pairs: 419 / 69 and 419 / 111.

[0020] This low-matrix effect method for detecting quinclorac residues in plant-derived foods uses acetonitrile extraction, and the extract is purified by a solid phase extraction column before being measured on a machine. It uses a liquid chromatography-tandem mass spectrometry atmospheric pressure chemical ionization source, has high selectivity and sensitivity, and effectively reduces the matrix effect. It can directly use a solvent standard curve for quantification, and has high accuracy and precision. It provides technical support for the next step of improving and supplementing residents' quinclorac dietary intake and risk data and formulating maximum residue limits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 : High performance liquid chromatography tandem mass spectrometry (MRM) chromatogram of the sample added with 0.01 mg / kg quinclorac standard solution in the embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following is a specific implementation of the present invention with reference to the accompanying drawings to further illustrate the detection method of the present invention.

[0023] Example 1

[0024] 1. Main instruments, equipment and materials

[0025] Shimadzu LC / MS 8040; multi-tube vortexer (Detelogy); Lu Xiangyi centrifuge TG 16; Sartorius BL610 electronic analytical balance; Merck Milli-Q ultrapure water system; amino solid phase extraction column (Agilent); polystyrene-divinylbenzene solid phase extraction column (Waters); methanol, acetonitrile, and formic acid were all chromatographic grade.

[0026] 2. Determination method

[0027] (1) Drawing of standard curve

[0028] Weigh the quintrione standard and dilute it with methanol to obtain a 10 mg / L quintrione solution, dilute the 10 mg / L quintrione solution with methanol to obtain 0.01 mg / L, 0.04 mg / L, 0.08 mg / L, 0.1 mg / L, and 0.2 mg / L quintrione series standard solutions, and perform liquid chromatography tandem mass spectrometry analysis and detection; perform regression with concentration as the abscissa and peak area as the ordinate to obtain a quintrione standard curve: Y=657938X-44, with a correlation coefficient r=0.9999;

[0029] (2) Sample extraction

[0030] Weigh 2.0 g of crushed wheat, add 10 mL of water and 20 ml of acetonitrile, vortex for 2 min, then add 8 g of sodium chloride, vortex for 1 min, centrifuge for 3 min, and separate the acetonitrile phase and the aqueous phase;

[0031] (3) Purification

[0032] 3 mL of the acetonitrile solution to be purified was directly passed through a polystyrene-divinylbenzene solid phase extraction column, and the filtrate was collected for testing;

[0033] (4) Recovery rate determination

[0034] Weigh 15 portions of 2.0 g of cracked wheat blank samples and add three levels of 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg, respectively. Repeat steps (2) and (3). Repeat each addition concentration 5 times. Perform liquid chromatography tandem mass spectrometry analysis to obtain the quinclorac determination value and calculate the recovery rate. The data are shown in Table 1.

[0035] (5) Determination of quinclorac content in samples

[0036] The quinclorac content detected in step (3) is compared with the quinclorac standard curve in step (1) and calculated to obtain the actual residual quinclorac content in the sample to be tested.

[0037] Among them, the liquid chromatography tandem mass spectrometry instrument conditions were set as follows:

[0038] Liquid chromatography conditions: chromatographic column: ZORBAX SB C18 2.1×50 mm×3.5 μm; column temperature 40℃; mobile phase A: 0.1% formic acid in water, mobile phase B: 0.1% formic acid in methanol; mobile phase gradient: 0-1.0 min 10%B, 1.0-5.0 min 10%B-95%B, 5.0-8.0min 95%B, 8.1min 10%B; flow rate 0.8 mL / min; injection volume 1 μL; mass spectrometry conditions: atmospheric pressure chemical ionization positive ion mode; desolvation tube temperature 200℃; heating module temperature 200℃; ion source temperature 350℃; drying gas flow rate 5 L / min, nebulizer gas flow rate 3 L / min, collision gas pressure 230 kPa; scanning mode: multiple reaction monitoring; quinclorac quantitative ion pair: 419 / 281 qualitative ion pair: 419 / 69 and 419 / 111.

[0039] Table 1 Recovery and precision of quinclorac

[0040]

[0041] According to the above detection steps, 30 random wheat samples were tested and analyzed for quinclorac residues, and the residues were all <0.01 mg / kg.

[0042] Example 2

[0043] 1. Main instruments and equipment (same as Example 1)

[0044] 2. Determination method

[0045] (1) Drawing of standard curve (same as Example 1)

[0046] (2) Sample extraction

[0047] Weigh 5.0 g of the crushed corn sample, add 8 mL of water and 15 ml of acetonitrile, vortex for 2 min, then add 7 g of sodium chloride, vortex for 1 min, centrifuge for 3 min, and separate the acetonitrile phase and the aqueous phase;

[0048] (3) Purification

[0049] Pipette 5 mL of the acetonitrile solution to be purified and pass it directly through the amino solid phase extraction column, collect the filtrate and test it;

[0050] (4) Recovery rate determination

[0051] Weigh 15 portions of 5.0 g of crushed corn samples, add three levels of 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg, repeat steps (2) and (3), repeat each addition concentration 5 times, perform liquid chromatography tandem mass spectrometry analysis, obtain the quinclorac determination value, and calculate the recovery rate. The data are shown in Table 2.

[0052] (5) Determination of quinclorac content in samples

[0053] The quinclorac content detected in step (3) is compared with the quinclorac standard curve in step (1) and calculated to obtain the actual residual quinclorac content in the sample to be tested.

[0054] The instrument conditions of liquid chromatography tandem mass spectrometry are the same as those in Example 1.

[0055] Table 2 Recovery and precision of quinclorac

[0056]

[0057] According to the above detection steps, 10 random corn samples were tested and analyzed for quinclorac residues, and the residues were all <0.01 mg / kg.

[0058] Example 3

[0059] 1. Main instruments and equipment (same as Example 1)

[0060] 2. Determination method

[0061] (1) Drawing of standard curve (same as Example 1)

[0062] (2) Sample extraction

[0063] Weigh 10.0 g of the crushed celery sample, add 5 mL of water and 10 ml of acetonitrile, vortex for 2 min, then add 5 g of sodium chloride, vortex for 1 min, centrifuge for 3 min, and separate the acetonitrile phase and the aqueous phase;

[0064] (3) Purification

[0065] 4 mL of the acetonitrile solution to be purified was directly passed through a polystyrene-divinylbenzene solid phase extraction column, and the filtrate was collected for testing;

[0066] (4) Recovery rate determination

[0067] Weigh 15 portions of 10.0 g of crushed celery blank sample, add three levels of 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg, repeat steps (2) and (3), repeat each addition concentration 5 times, perform liquid chromatography tandem mass spectrometry analysis, obtain the quinclorac determination value, and calculate the recovery rate. The data are shown in Table 3.

[0068] (5) Determination of quinclorac content in samples

[0069] The quinclorac content detected in step (3) is compared with the quinclorac standard curve in step (1) and calculated to obtain the actual residual quinclorac content in the sample to be tested.

[0070] The instrument conditions of liquid chromatography tandem mass spectrometry are the same as those in Example 1.

[0071] Table 3 Recovery and precision of quinclorac

[0072]

[0073] According to the above detection steps, 20 random celery samples were tested and analyzed for quinclorac residues, and the residues were all <0.01 mg / kg.

[0074] Example 4

[0075] 1. Main instruments and equipment (same as Example 1)

[0076] 2. Determination method

[0077] (1) Drawing of standard curve (same as Example 1)

[0078] (2) Sample extraction

[0079] Weigh 5.0 g of the crushed pepper sample, add 5 mL of water and 10 ml of acetonitrile, vortex for 2 min, then add 6 g of sodium chloride, vortex for 1 min, centrifuge for 3 min, and separate the acetonitrile phase and the aqueous phase;

[0080] (3) Purification

[0081] Pipette 5 mL of the acetonitrile solution to be purified and pass it directly through the amino solid phase extraction column, collect the filtrate and test it;

[0082] (4) Recovery rate determination

[0083] Weigh 15 portions of 5.0 g of crushed pepper blank samples, add three levels of 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg, repeat steps (2) and (3), repeat each addition concentration 5 times, perform liquid chromatography tandem mass spectrometry analysis, obtain the quinclorac determination value, and calculate the recovery rate. The data are shown in Table 4.

[0084] (5) Determination of quinclorac content in samples

[0085] The quinclorac content detected in step (3) is compared with the quinclorac standard curve in step (1) and calculated to obtain the actual residual quinclorac content in the sample to be tested.

[0086] The instrument conditions of liquid chromatography tandem mass spectrometry are the same as those in Example 1.

[0087] Table 4 Recovery and precision of quinclorac

[0088]

[0089] According to the above detection steps, 20 random pepper samples were tested and analyzed for quinclorac residues, and the residues were all <0.01 mg / kg.

[0090] Example 5

[0091] 1. Main instruments and equipment (same as Example 1)

[0092] 2. Determination method

[0093] (1) Drawing of standard curve (same as Example 1)

[0094] (2) Sample extraction

[0095] Weigh 8.0 g of the crushed apple sample, add 8 mL of water and 20 ml of acetonitrile, vortex for 2 min, then add 7 g of sodium chloride, vortex for 1 min, centrifuge for 3 min, and separate the acetonitrile phase and the aqueous phase;

[0096] (3) Purification

[0097] Pipette 4 mL of the acetonitrile solution to be purified directly through the amino solid phase extraction column, and collect the filtrate for testing;

[0098] (4) Recovery rate determination

[0099] Weigh 15 portions of 8.0 g of blank samples of crushed apples, add three levels of 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg, repeat steps (2) and (3), repeat each addition concentration 5 times, perform liquid chromatography tandem mass spectrometry analysis, obtain the quinclorac determination value, and calculate the recovery rate. The data are shown in Table 5.

[0100] (5) Determination of quinclorac content in samples

[0101] The quinclorac content detected in step (3) is compared with the quinclorac standard curve in step (1) and calculated to obtain the actual residual quinclorac content in the sample to be tested.

[0102] The instrument conditions of liquid chromatography tandem mass spectrometry are the same as those in Example 1.

[0103] Table 5 Recovery and precision of quinclorac

[0104]

[0105] According to the above detection steps, 20 random apple samples were tested and analyzed for quinclorac residues, and the residues were all <0.01 mg / kg.

[0106] Example 6

[0107] 1. Main instruments and equipment (same as Example 1)

[0108] 2. Determination method

[0109] (1) Drawing of standard curve (same as Example 1)

[0110] (2) Sample extraction

[0111] Weigh 9.0 g of the crushed citrus sample, add 9 mL of water and 18 ml of acetonitrile, vortex for 2 min, then add 8 g of sodium chloride, vortex for 1 min, centrifuge for 3 min, and separate the acetonitrile phase and the aqueous phase;

[0112] (3) Purification

[0113] 3 mL of the acetonitrile solution to be purified was directly passed through a polystyrene-divinylbenzene solid phase extraction column, and the filtrate was collected for testing;

[0114] (4) Recovery rate determination

[0115] Weigh 15 portions of 9.0 g of crushed citrus blank samples, add three levels of 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg, repeat steps (2) and (3), repeat each addition concentration 5 times, perform liquid chromatography tandem mass spectrometry analysis, obtain the quinclorac determination value, and calculate the recovery rate. The data are shown in Table 6;

[0116] (5) Determination of quinclorac content in samples

[0117] The quinclorac content detected in step (3) is compared with the quinclorac standard curve in step (1) and calculated to obtain the actual residual quinclorac content in the sample to be tested.

[0118] The instrument conditions of liquid chromatography tandem mass spectrometry are the same as those in Example 1.

[0119] Table 6 Recovery and precision of quinclorac

[0120]

[0121] According to the above detection steps, 20 random citrus samples were tested and analyzed for quinclorac residues, and the residues were all <0.01 mg / kg.

[0122] Example 7

[0123] 1. Main instruments and equipment (same as Example 1)

[0124] 2. Determination method

[0125] (1) Drawing of standard curve (same as Example 1)

[0126] (2) Sample extraction

[0127] Weigh 10.0 g of the crushed shiitake mushroom sample, add 10 mL of water and 20 ml of acetonitrile, vortex for 2 min, then add 8 g of sodium chloride, vortex for 1 min, centrifuge for 3 min, and separate the acetonitrile phase and the aqueous phase;

[0128] (3) Purification

[0129] 4 mL of the acetonitrile solution to be purified was directly passed through a polystyrene-divinylbenzene solid phase extraction column, and the filtrate was collected for testing;

[0130] (4) Recovery rate determination

[0131] Weigh 15 portions of 10.0 g of blank samples of crushed shiitake mushrooms, add three levels of 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg, repeat steps (2) and (3), repeat each addition concentration 5 times, perform liquid chromatography tandem mass spectrometry analysis, obtain the quinclorac determination value, and calculate the recovery rate. The data are shown in Table 7;

[0132] (5) Determination of quinclorac content in samples

[0133] The quinclorac content detected in step (3) is compared with the quinclorac standard curve in step (1) and calculated to obtain the actual residual quinclorac content in the sample to be tested.

[0134] The instrument conditions of liquid chromatography tandem mass spectrometry are the same as those in Example 1.

[0135] Table 7 Recovery and precision of quinclorac

[0136]

[0137] According to the above detection steps, 20 random shiitake mushroom samples were tested and analyzed for quinclorac residues, and the residues were all <0.01 mg / kg.

[0138] Example 8

[0139] 1. Main instruments and equipment (same as Example 1)

[0140] 2. Determination method

[0141] (1) Drawing of standard curve (same as Example 1)

[0142] (2) Sample extraction

[0143] Weigh 2.0 g of the crushed green tea sample, add 10 mL of water and 20 ml of acetonitrile, vortex for 2 min, then add 8 g of sodium chloride, vortex for 1 min, centrifuge for 3 min, and separate the acetonitrile phase and the aqueous phase;

[0144] (3) Purification

[0145] 5 mL of the acetonitrile solution to be purified was directly passed through a polystyrene-divinylbenzene solid phase extraction column, and the filtrate was collected for testing;

[0146] (4) Recovery rate determination

[0147] Weigh 15 portions of 2.0 g of crushed green tea blank samples, add three levels of 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg, repeat steps (2) and (3), repeat each addition concentration 5 times, perform liquid chromatography tandem mass spectrometry analysis, obtain the quinclorac determination value, and calculate the recovery rate. The data are shown in Table 8;

[0148] (5) Determination of quinclorac content in samples

[0149] The quinclorac content detected in step (3) is compared with the quinclorac standard curve in step (1) and calculated to obtain the actual residual quinclorac content in the sample to be tested.

[0150] The instrument conditions of liquid chromatography tandem mass spectrometry are the same as those in Example 1.

[0151] Table 8 Recovery and precision of quinclorac

[0152]

[0153] According to the above detection steps, 20 random green tea samples were tested and analyzed for quinclorac residues, and the residues were all <0.01 mg / kg.

[0154] Example 9

[0155] 1. Main instruments and equipment (same as Example 1)

[0156] 2. Determination method

[0157] (1) Drawing of standard curve (same as Example 1)

[0158] (2) Sample extraction

[0159] Weigh 2.0 g of the crushed pepper sample, add 10 mL of water and 12 ml of acetonitrile, vortex for 2 min, then add 8 g of sodium chloride, vortex for 1 min, centrifuge for 3 min, and separate the acetonitrile phase and the aqueous phase;

[0160] (3) Purification

[0161] Pipette 4 mL of the acetonitrile solution to be purified directly through the amino solid phase extraction column, and collect the filtrate for testing;

[0162] (4) Recovery rate determination

[0163] Weigh 15 portions of 2.0 g blank sample of crushed Zanthoxylum bungeanum, add three levels of 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg, repeat steps (2) and (3), repeat each addition concentration 5 times, perform liquid chromatography tandem mass spectrometry analysis, obtain the quinclorac determination value, and calculate the recovery rate. The data are shown in Table 9;

[0164] (5) Determination of quinclorac content in samples

[0165] The quinclorac content detected in step (3) is compared with the quinclorac standard curve in step (1) and calculated to obtain the actual residual quinclorac content in the sample to be tested.

[0166] The instrument conditions of liquid chromatography tandem mass spectrometry are the same as those in Example 1.

[0167] Table 9 Recovery and precision of quinclorac

[0168]

[0169] According to the above detection steps, 20 random pepper samples were tested and analyzed for quinclorac residues, and the residues were all <0.01 mg / kg.

[0170] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0171] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0172] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for detecting quinclorac residues in plant-derived foods with low matrix effect, characterized in that The specific steps include: (1) Drawing of standard curve: Weigh the quinclorac standard and dilute it with methanol to obtain a 10 mg / L quinclorac solution. Dilute the 10 mg / L quinclorac solution with methanol to obtain a 0.01 mg / L to 0.2 mg / L quinclorac standard solution. Perform liquid chromatography-tandem atmospheric pressure chemical ionization source mass spectrometry analysis and detection. The linear correlation is good. Regression is performed with concentration as the horizontal axis and peak area as the vertical axis to obtain a quinclorac standard curve; (2) Sample extraction: Weigh the crushed sample to be tested, add water and acetonitrile, vortex for 2 minutes, add sodium chloride, continue vortexing for 1 minute, and finally centrifuge at room temperature for 3 minutes to separate the acetonitrile phase and the aqueous phase; (3) Purification: Absorb the sample to be purified The acetonitrile solution is directly passed through a solid phase extraction column, and the filtrate is collected for testing; (4). Recovery determination: weigh the blank sample after crushing, add quinclorac standard solution at 0.01 mg / kg, 0.05 mg / kg and 0.1 mg / kg respectively, repeat steps (2) and (3), perform liquid chromatography-tandem atmospheric pressure chemical ionization source mass spectrometry analysis, compare with the quinclorac standard curve in step (1), calculate, obtain the quinclorac determination value, and calculate the recovery rate; (5). Determination of quinclorac content in the sample: compare and calculate the quinclorac content detected in step (3) with the quinclorac standard curve in step (1) to obtain the actual quinclorac content in the sample to be tested; In the step (3), 3 to 5 mL of the acetonitrile solution to be purified is drawn, and the solid phase extraction column used is a polystyrene-divinylbenzene solid phase extraction column or an amino solid phase extraction column; In the steps (1) and (4), the liquid chromatography conditions are as follows: chromatographic column: ZORBAX SB C18 2.1×50mm×3.5μm; column temperature 40°C; mobile phase A: 0.1% formic acid in water, mobile phase B: 0.1% formic acid in methanol; mobile phase gradient: 0-1.0min 10% B, 1.0-5.0min 10% B-95% B, 5.0-8.0min 95% B, 8.1min 10% B; flow rate is 0.8mL / min; injection volume is 1μL; mass spectrometry conditions are atmospheric pressure chemical ionization positive ion mode; desolvation tube temperature is 200℃; heating module temperature is 200℃; ion source temperature is 350℃; drying gas flow rate is 5L / min, nebulizing gas flow rate is 3L / min, collision gas pressure is 230kPa; scanning mode is multiple reaction monitoring; quinclorac quantitative ion pair: 419 / 281 qualitative ion pairs: 419 / 69 and 419 / 111.

2. The method for detecting quinclorac residues in plant-derived foods with low matrix effect according to claim 1, characterized in that: In the step (1), the specific concentration range of good linear correlation is: quinclorac has good linearity between 0.01 mg / L and 0.2 mg / L.

3. The method for detecting quintriol residues in plant-derived foods with low matrix effect as claimed in claim 1, characterized in that: In the step (1), the standard curve of quinclorac is: Y=657938X-44, and the correlation coefficient r=0.9999.

4. The method for detecting quinclorac residues in plant-derived foods with low matrix effect as claimed in claim 1, characterized in that: In the step (2), the mass of the sample to be tested is weighed to be 2.0-10.0 g, 5-10 mL of water is added, 10-20 mL of acetonitrile is added, and the amount of sodium chloride added is 5-8 g.

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