CN115963212A - Method for detecting phthalate and metabolite thereof in agricultural products - Google Patents

Abstract

The invention provides a method for detecting phthalate and metabolites thereof in agricultural products, which comprises the following steps: adding the crop sample into acetonitrile for ultrasonic extraction, centrifuging, taking supernatant liquid, blowing nitrogen, fixing volume with methanol, and filtering to obtain sample analysis liquid; and carrying out qualitative and quantitative analysis on 18 phthalate esters and 7 phthalate ester metabolites by using UPLC-MS/MS on the obtained sample analysis liquid. The detection method provided by the invention is simple, convenient and quick, has high sensitivity, good repeatability and high qualitative and quantitative accuracy, and is very suitable for measuring phthalate and phthalate metabolites in crops, especially peanuts.

Description

Method for detecting phthalate and metabolite thereof in agricultural products

Technical Field

The invention belongs to the technical field of plasticizer residue detection, and particularly relates to a method for determining phthalate and metabolites thereof in agricultural products by combining UPLC-MS/MS.

Background

Peanuts are important oil crops in China, and the plastic film mulching cultivation is an indispensable important measure for ensuring high and stable yield of the peanuts. In the production process of the mulching film, phthalate as an additive is largely used, and as the plastic ages, the phthalate plasticizer is slowly released and finally enters soil and is easily absorbed by plants, so that the quality safety of agricultural products and the human health risk possibly caused by the phthalate plasticizer are paid much attention by domestic scholars.

The phthalate determination method mainly comprises a gas chromatography-mass spectrometry combination method, a liquid chromatography-mass spectrometry combination method, a gas chromatography, a liquid chromatography, an immune rapid analysis method and the like. The measurement of 18 kinds of phthalate is generally carried out by GC-MS (gas chromatography-mass spectrometry) according to the national standard GB 5009.271-2016 phthalate determination in food safety national standard food, and the determination of phthalate metabolites is not concerned. Phthalate metabolites generally do not represent a resolution of phthalate toxicity, and instead are more toxic. The method adopts solvent extraction, avoids complex pretreatment processes of other methods, reduces cost consumption, and can simultaneously determine 25 phthalate plasticizers and metabolites thereof in the peanuts.

Disclosure of Invention

Aiming at the problems, the invention provides a method for determining 25 phthalate residues and metabolite residues thereof in agricultural products by combining UPLC-MS/MS. The method is rapid, efficient, simple and convenient, and the extraction rate, the detection limit and the quantification limit all accord with the standard.

The method for detecting the phthalate and the metabolites thereof in the agricultural products comprises the following steps: 1) Adding an agricultural crop sample into acetonitrile for ultrasonic extraction, centrifuging, taking supernatant liquid for nitrogen blowing, fixing volume by using methanol, and filtering to obtain sample analysis liquid; 2) And (2) carrying out qualitative and quantitative analysis on 18 phthalate esters and 7 phthalate ester metabolites by using UPLC-MS/MS on the sample analysis liquid obtained in the step 1).

The phthalate and the metabolites thereof comprise 18 phthalate esters and 7 metabolites; specifically, the 18 phthalates are each: dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di-n-butyl phthalate, di (2-methoxy) ethyl phthalate, di (4-methyl-2-pentyl) phthalate, di (2-ethoxy) ethyl phthalate, dipentyl phthalate, dihexyl phthalate, butylbenzyl phthalate, di (2-butoxy) ethyl phthalate, dicyclohexyl phthalate, di (2-ethyl) hexyl phthalate, diphenyl phthalate, di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, diallyl phthalate; the 7 phthalate metabolites were respectively: monomethyl phthalate, monoethyl phthalate, monobutyl phthalate, monobenzyl phthalate, monocyclohexyl phthalate, monoethylhexyl phthalate, monoisononyl phthalate.

Adding the crop sample into acetonitrile for ultrasonic extraction, specifically, grinding the crop, wherein the adding proportion of the ground crop sample to the acetonitrile is 1/mL (g/mL) and 8, and performing ultrasonic extraction for 20min after 1min of vortex.

The centrifugation is performed at the rotation speed of 4000rpm for 5min, the nitrogen blowing of the supernatant is performed at the temperature of 40 ℃ until the supernatant is nearly dried, the volume is determined to be 1ml by using methanol, and the filtration is performed by using a 0.22-micron needle filter.

The quantitative analysis is that 18 phthalate esters and 7 phthalate ester metabolites are subjected to quantitative analysis by adopting a standard curve method.

The process was carried out using a UPLC-MS/MS, in particular an ACQUITY UPLC BEH C18 column, and 0.1% formic acid water/methanol as mobile phase.

The beneficial effects of the invention are as follows:

1) The invention adopts the acetonitrile pretreatment method to extract 18 phthalic acid esters and 7 phthalic acid ester metabolites, reduces the small column purification procedures, has extraction rate meeting the standard (70.2-100.3%), reduces the cost, shortens the extraction time, improves the efficiency, and is suitable for pretreatment of a large number of samples.

2) The invention adopts an ACQUITYUPLC BEH C18 chromatographic column and 0.1 percent formic acid water/methanol as a mobile phase, 18 phthalic acid esters and 7 phthalic acid ester metabolites can achieve good sensitivity, the detection limit of 25 phthalic acid esters and metabolites thereof is 0.1-100.0 mu g/kg, and the quantitative limit is 0.2-300 mu g/kg.

In a word, the method is simple, convenient and quick, has high sensitivity, good repeatability and high qualitative and quantitative accuracy, has detection limit and quantitative limit greatly lower than the requirements of GB 5009.271-2016, meets the standard, is very suitable for measuring phthalate and phthalate metabolites in agricultural products, particularly peanuts, and has important significance for guaranteeing the quality safety of the agricultural products and maintaining the health of human bodies.

Drawings

FIG. 1 is a standard curve of 25 phthalates and their metabolites, wherein (1) dihexyl phthalate (DHXP); (2) di-n-butyl phthalate (DBP); (3) diethyl phthalate (DEP); (4) Butyl Benzyl Phthalate (BBP); (5) dimethyl phthalate (DMP); (6) di (2-ethyl) hexyl phthalate (DEHP); (7) dicyclohexyl phthalate (DCHP); (8) Di (2-ethoxy) ethyl phthalate (DEEP); (9) Di (2-butoxy) ethyl phthalate (DBEP); (10) Di (4-methyl-2-pentyl) phthalate (BMPP); (11) Diphenyl phthalate (DPhP) 3-hydroxy carbofuran; (12) Di (2-methoxy) ethyl phthalate (DMEP); (13) diamyl phthalate (DPP); (14) diallyl phthalate (DAP); (15) dibutyl phthalate (DIBP); (16) dinonyl phthalate (DNP); (17) diisononyl phthalate (DINP); (18) di-n-octyl phthalate (DNOP); (19) monocyclohexyl phthalate (MCHP); (20) Mono Ethyl Phthalate (MEP); (21) monobenzyl phthalate (MBzP); (22) monoisononyl phthalate (mirp); (23) monoethylhexyl phthalate (MEHP); (24) Mono Butyl Phthalate (MBP); (25) monomethyl phthalate (MMP).

FIG. 2 is a mass spectrum of 18 phthalates and 7 metabolites, wherein: (1) dihexyl phthalate (DHXP); (2) di-n-butyl phthalate (DBP); (3) diethyl phthalate (DEP); (4) Butyl Benzyl Phthalate (BBP); (5) dimethyl phthalate (DMP); (6) di (2-ethyl) hexyl phthalate (DEHP); (7) dicyclohexyl phthalate (DCHP); (8) Di (2-ethoxy) ethyl phthalate (DEEP); (9) Di (2-butoxy) ethyl phthalate (DBEP); (10) Di (4-methyl-2-pentyl) phthalate (BMPP); (11) Diphenyl phthalate (DPhP) 3-hydroxy carbofuran; (12) Di (2-methoxy) ethyl phthalate (DMEP); (13) diamyl phthalate (DPP); (14) diallyl phthalate (DAP); (15) dibutyl phthalate (DIBP); (16) dinonyl phthalate (DNP); (17) diisononyl phthalate (DINP); (18) di-n-octyl phthalate (DNOP); (19) monocyclohexyl phthalate (MCHP); (20) Mono Ethyl Phthalate (MEP); (21) monobenzyl phthalate (MBzP); (22) monoisononyl phthalate (mirp); (23) monoethylhexyl phthalate (MEHP); (24) Mono Butyl Phthalate (MBP); (25) monomethyl phthalate (MMP).

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The following examples are given to illustrate the technical aspects of the present invention, but the present invention is not limited to the following examples.

The experimental methods and the detection methods in the following examples are conventional methods unless otherwise specified; the medicaments and materials, if not specified, are commercially available; the index data are conventional measurement methods unless otherwise specified.

Example 1

This example provides the sensitivity, precision and recovery of the method of the invention for detecting phthalates and their metabolites.

1 materials and methods

1.1 materials and reagents

Standard products of dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), bis (2-methoxy) ethyl phthalate (DMEP), bis (4-methyl-2-pentyl) phthalate (BMPP), bis (2-ethoxy) ethyl phthalate (DEEP), diamyl phthalate (DPP), dihexyl phthalate (DHXP), butylbenzyl phthalate (BBP), bis (2-butoxy) ethyl phthalate (DBEP), dicyclohexyl phthalate (DCHP), bis (2-ethyl) hexyl phthalate (DEHP), diphenyl phthalate (DPhP), dinonyl phthalate (DNP), diisononyl phthalate (DINP), diallyl phthalate (DAP) were purchased from Beijing university institute of North America metering technology. Dibutyl phthalate (DIBP) and di-n-octyl phthalate (DNOP) were purchased from shanghai' an spectral laboratory science and technology ltd. Monomethyl Phthalate (MMP), monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), monocyclohexyl phthalate (MCHP), monoethylhexyl phthalate (MEHP), monoisononyl phthalate (MiNP) standards were purchased from AccuStandard, inc. (USA). The phthalate stock solution (1000 mg/L) and the phthalate metabolite stock solution (100 mg/L) were stored at-4 ℃. Methanol, acetonitrile and formic acid used for HPLC analysis were all HPLC grade. A series of standard solutions (1 mg/L) containing various standard mixtures diluted with methanol were prepared. All water used was from MilliQ-Plus ultrapure water system (Milford, USA) from Millipore corporation throughout the study.

1.2 Standard solution preparation

A standard stock solution of a mixture of 18 phthalates at a concentration of 5. Mu.g/mL and 7 phthalate metabolites at a concentration of 100. Mu.g/mL was prepared by adding 18 phthalates and 7 phthalate metabolites to methanol and stored at 4 ℃. And diluting with methanol to prepare a series of standard working solutions, and drawing standard curves of the corresponding standard solutions by using the standard working solutions.

1.3 sample extraction and purification

Preparation of peanut samples: grinding and homogenizing peanut, putting 0.5g of the ground and homogenized sample into a glass centrifuge tube, adding 4mL of acetonitrile, vortexing for 1min, ultrasonically extracting for 20min, centrifuging for 5min at 4000rpm of a centrifuge, taking supernatant, blowing nitrogen to be nearly dry at 40 ℃, fixing the volume to 1mL by using methanol, filtering by using a 0.22 mu m Biosharp BS-QT-013 (13mm 0.22 mu m) needle filter, and bottling to be put on a machine.

1.4 instrumental methods

Chromatographic conditions are as follows: waters I-class ultra high liquid chromatograph, ACQUITYUPLC BEH C18 (2.1 mm. Times.100 mm, particle size 1.7 μm), column temperature: the temperature of the sample chamber is 20 ℃ at 35 ℃; sample introduction volume: 3 mu L of the solution;

mobile phase A:0.1% aqueous formic acid, mobile phase B: methanol, flow rate: 0.3mL/min.

The gradient elution procedure was as follows: 0-1min: mobile phase B increased linearly from 20% to 40%;1-3min, mobile phase B increased linearly from 40% to 60%;3-5min: mobile phase B increased linearly from 60% to 80%;5-7min: mobile phase B increased linearly from 80% to 90%;7-9min: mobile phase B increased linearly from 90% to 95%, equilibrating for 4min;13-13.5min: mobile phase B decreased linearly from 95% to 50%;13.5-14min: mobile phase B decreased linearly from 50% to 20%.

Mass spectrum conditions: an AB5500 type triple quadrupole tandem mass spectrometer, an Electrospray (ESI) ion source, and a positive and negative ion scanning mode; the parameters are as follows: ion spray voltage: 4.5kV, air curtain pressure: 35psi, atomizing gas pressure: 55psi, auxiliary heating gas pressure: 55psi, ion source heating temperature: 550-600 ℃.

Declustering voltage and collision energy as shown in table 1 were set and optimized using analyst1.6.2 software. Data were collected in a Multiple Reaction Monitoring (MRM) mode to ensure adequate collection points (at least 12 per peak). Quantitative ion pairs and qualitative ion pairs of 25 phthalates and their metabolites are shown in table 1.

Table 125 MRM parameters of phthalate esters and their metabolites

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2 method verification

2.1 analytical methods

The standard curve of each phthalate and the metabolite thereof needs to be established by analyzing the phthalate and the metabolite thereof, selecting 5 concentrations for the standard curve of each substance, and establishing the standard curve of each phthalate and the metabolite thereof by drawing the relation curve of the peak area (y axis) and the concentration (x axis) of each phthalate and the metabolite thereof in LC/MS/MS (see figure 1).

The precision of the standard solution was analyzed by calculating the change of peak area of the standard solution within and between days and the relative standard deviation. The sensitivity of the LC/MS/MS analysis method was determined using LOD and LOQ.

2.2 method validation

Adding different phthalic acid esters and metabolites thereof at a concentration level of 5-12500 ng/mL to establish a standard curve shown in Table 2, and giving a linear equation and a detection limit of the standard curve, wherein the R value is higher than 0.9990 in an experimental concentration range, the standard curve has good linearity, the detection limit and the quantitative limit of each phthalic acid ester and the metabolites thereof are respectively 3 times and 10 times of the signal-to-noise ratio, the detection limit of the phthalic acid esters and the metabolites thereof in a sample is 0.1-100.0 mu g/kg, and the quantitative limit is 0.2-300 mu g/kg. The results show that: the method is sensitive to detecting phthalate and metabolites thereof in peanuts.

TABLE 2 Linear, detection and quantitation limits of 25 phthalates and their metabolites

2.3 precision and recovery

The standard adding recovery test is carried out by adding mixed standard substances of phthalic acid ester and metabolites thereof at three concentration levels of low (100 mu g/kg), medium (200 mu g/kg) and high (400 mu g/kg) in a peanut blank sample for measurement, thereby analyzing the accuracy of the method.

The changes in peak area over and over the day and relative standard deviations were calculated to analyze their precision, and the average recovery and relative standard deviations of the analytes are given in table 3. As can be seen in table 3, the average recovery of all phthalates and their metabolites using this method was between 70.2% and 100.3%, all relative standard deviations were below 15%.

TABLE 3 precision and recovery of phthalate esters and their metabolites analytical methods

3. Results and discussion

3.1 optimization of sample processing methods

After phthalic acid ester in food in GB 5009.271-2016 is extracted, the food is purified and loaded on a machine through a PSA/Silica composite filler glass column, but after the purification column is applied, most of 7 phthalic acid ester metabolites cannot be recovered; also, the application of solid phase extraction columns Oasis MAX, oasis HLB and Sep-Pak Silica is tried, which do not reach the satisfactory effect, the purification steps are reduced by the method, and experiments prove that: the simplified method is an optimal pretreatment method for detecting 25 phthalic acid esters and metabolites thereof in the peanuts, and the recovery rate of each phthalic acid ester and the metabolite thereof is good.

Fully crushing and uniformly mixing the sample, accurately weighing 0.5g (accurate to 0.0001 g) in a 10mL centrifuge tube with a plug, adding 4mL acetonitrile, carrying out vortex for 1min, carrying out ultrasonic extraction for 20min, carrying out 4000r/min, centrifuging for 5min, and collecting the supernatant. Blowing at 40 ℃ with nitrogen, adding 1mL of methanol to a constant volume, filtering with a 0.22 mu m filter membrane, and loading on a machine. Blank control was also set.

3.2 optimization of high liquid chromatography conditions

After establishing the MS/MS parameters, the liquid phase method was optimized. Comparing the effects of the UPLC BEH C18 column and the UPLC HSS T3 column, adding 0.1% acetic acid to the mobile phase, adjusting the gradient of methanol and acetic acid water, can achieve better sensitivity, as shown in fig. 2, a better separation effect can be obtained with mass spectrometry.

4. Conclusion

The invention establishes an UPLC-MS/MS method for simultaneously and rapidly extracting and measuring 25 phthalic acid esters and metabolites thereof (dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, di (2-methoxy) ethyl phthalate, di (4-methyl-2-pentyl) phthalate, di (2-ethoxy) ethyl phthalate, dipentyl phthalate, dihexyl phthalate, butyl benzyl phthalate, di (2-butoxy) ethyl phthalate, dicyclohexyl phthalate, di (2-ethyl) hexyl phthalate, diphenyl phthalate, dinonyl phthalate, diisononyl phthalate, diallyl phthalate, dibutyl phthalate, di-n-octyl phthalate, monomethyl phthalate, monoethyl phthalate, monobutyl phthalate, monobenzyl phthalate, monocyclohexyl phthalate, monoethyl hexyl phthalate, monoisononyl phthalate) in peanuts. The method is simple, convenient and rapid, has high sensitivity, good repeatability and high qualitative and quantitative accuracy, and the detection limit and the quantitative limit of the phthalic acid ester are obviously lower than the national standard GB 5009.271-2016.

Example 2

This example provides sensitivity, precision and recovery for the detection of 25 phthalates and their metabolites using conventional detection methods.

1 materials and methods

1.1 materials, reagents, standard solutions were prepared as in example 1.

1.2 sample extraction and purification

Preparation of peanut samples: accurately weighing 0.5g (accurate to 0000.1 g) of sample into a 25mL centrifuge tube with a plug mill, adding 125 μ L of isotope internal standard solution, adding 2 mL-5 mL of distilled water, uniformly mixing by vortex, accurately adding 10mL of n-hexane, vortex for 1min, violently shaking for 1min, ultrasonically extracting for 30min, centrifuging for 5min at 1000r/min, and taking the supernatant for GC-MS analysis.

1.3 instrumental methods

1.3.1 Instrument

Gas chromatography-mass spectrometer (GC-MS); analytical balance: precision (0.0001 g); a nitrogen blowing instrument; a vortex oscillator; an ultrasonic generator; the rotating speed of the centrifuge is more than or equal to 4000r/min; a pulverizer; a Solid Phase Extraction (SPE) device; solid phase extraction column: PSA/Silica composite packed glass column (1000mg, 6 mL).

1.3.2 methods

A chromatographic column: 5% phenyl-methyl polysiloxane quartz capillary chromatography column, column length: 30m, inner diameter: 0.25mm, film thickness: 0.25 μm, or equivalent performance. Sample inlet temperature: at 260 ℃.

Temperature programming: keeping the initial column temperature at 60 ℃ for 1min; heating to 220 deg.C at 20 deg.C/min, and maintaining for 1min; heating to 250 deg.C at 5 deg.C/min, and maintaining for 1min; then the temperature is raised to 290 ℃ at a speed of 20 ℃/min and is kept for 7.5min.

Carrier gas: high purity nitrogen (purity > 99.999%), flow rate: 1.0mL/min; and (3) sample introduction mode: no-shunt sample introduction; sample injection amount: 1 μ L.

An ionization mode: electron impact ionization source (EI); ionization energy is 70eV; transmission line temperature: 280 ℃; ion source temperature: 230 ℃; the monitoring mode comprises the following steps: a selective ion Scan (SIM); solvent retardation: and 7min.

Example 3

This example provides the results of the measurement of the actual sample by the conventional method and the detection method provided by the present invention.

The residual amounts of phthalate and its metabolites, the contamination rates of phthalate and its metabolites, and the average and maximum values of positive samples in 54 peanut samples collected using the method provided in example 1 are shown in table 4. The results show that: 7 phthalic acid esters and metabolites thereof are detected in 54 peanut samples, the highest pollution rate can reach 57.41 percent (diamyl phthalate), then monobutyl phthalate (31.48 percent) and monoisononyl phthalate (29.63 percent) are detected in 10 peanut samples, and the maximum concentration can reach 611.90 mu g/kg. The Ministry of public health reports the maximum residual amount of phthalic acid esters (sanitary supervision letter [ 2011 ] 551) in food and food additives, and the maximum residual amount of di-n-butyl phthalate (DBP) in food and food additives is 0.3mg/kg. The exceeding rate reaches 7.4 percent.

TABLE 4 results of the present invention on 54 peanut samples

The results show that the pollution level of phthalate in peanuts is higher, and the qualitative and quantitative accuracy of the detection method provided by the invention is high.

The residual amounts of phthalate and its metabolites, the contamination rates of phthalate and its metabolites, and the average and maximum values of positive samples in 54 peanut samples collected using the method provided in example 2 are shown in table 5.

TABLE 5 results of 54 peanut samples tested by conventional testing method

The results show that: 4 phthalates can be detected from 54 peanut samples, phthalate metabolites can not be detected, the highest pollution rate can reach 51.85% (dipentyl phthalate), di-n-butyl phthalate can be detected from 8 peanut samples, and the maximum concentration can reach 589.32 mu g/kg.

The traditional detection method can not detect phthalate metabolites, can not detect all phthalates, can detect the contamination rate of the phthalates and the metabolites, and the average value and the maximum value of positive samples are lower than the result of the detection method provided by the invention.

According to the traditional detection method, the determination of 18 phthalic acid esters is carried out by adopting GC-MS (gas chromatography-mass spectrometry) according to the national standard GB 5009.271-2016 food safety national standard food determination, peanut samples need SPE (solid phase extraction) purification, the traditional detection method does not pay attention to the determination of phthalate metabolites, and the phthalate metabolites cannot be detected after purification according to the national standard. The detection method provided by the invention is simple, convenient and quick, has high sensitivity, good repeatability and high qualitative and quantitative accuracy, and is very suitable for measuring the phthalate and the phthalate metabolite in the crops, especially peanuts.

The above description is only for the purpose of illustrating the embodiments of the present invention, and the scope of the present invention should not be limited thereto, and any modifications, equivalents and improvements made by those skilled in the art within the technical scope of the present invention as disclosed in the present invention should be covered by the scope of the present invention.

Claims (6)

1. A method for detecting phthalates and metabolites thereof in agricultural products, comprising the steps of:

1) Adding the crop sample into acetonitrile for ultrasonic extraction, centrifuging, taking supernatant liquid, blowing nitrogen, fixing volume with methanol, and filtering to obtain sample analysis liquid;

2) Carrying out qualitative and quantitative analysis on 18 phthalate esters and 7 phthalate ester metabolites by using UPLC-MS/MS on the sample analysis solution obtained in the step 1);

the 18 phthalates are: dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di-n-butyl phthalate, di (2-methoxy) ethyl phthalate, di (4-methyl-2-pentyl) phthalate, di (2-ethoxy) ethyl phthalate, dipentyl phthalate, dihexyl phthalate, butylbenzyl phthalate, di (2-butoxy) ethyl phthalate, dicyclohexyl phthalate, di (2-ethyl) hexyl phthalate, diphenyl phthalate, di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, diallyl phthalate;

the 7 phthalate metabolites were: monomethyl phthalate, monoethyl phthalate, monobutyl phthalate, monobenzyl phthalate, monocyclohexyl phthalate, monoethylhexyl phthalate, monoisononyl phthalate.

2. The detection method according to claim 1, wherein the method for ultrasonic extraction by adding the crop sample into acetonitrile is as follows: grinding crops, adding the ground crop sample and acetonitrile in a g/mL ratio of 1.

3. The detection method according to claim 1, wherein in the step 1), the centrifugation is performed at 4000rpm for 5min, the nitrogen of the supernatant is blown to near dryness at the temperature of 40 ℃, the volume is increased to 1ml by using methanol, and the filtration is performed by using a 0.22 μm needle filter.

4. The detection method according to claim 1, wherein the quantitative analysis is a quantitative analysis of 18 phthalate esters and 7 phthalate ester metabolites using a standard curve method.

5. The detection method according to claim 1, wherein said UPLC-MS/MS uses an acquityupplcbehc 18 column with 0.1% formic acid/methanol as mobile phase.

6. The detection method of claim 1, wherein the agricultural product comprises peanuts.

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