CN108226341B - Method for accurately detecting pesticide residues in agricultural products - Google Patents
Method for accurately detecting pesticide residues in agricultural products Download PDFInfo
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- CN108226341B CN108226341B CN201810001884.0A CN201810001884A CN108226341B CN 108226341 B CN108226341 B CN 108226341B CN 201810001884 A CN201810001884 A CN 201810001884A CN 108226341 B CN108226341 B CN 108226341B
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Abstract
The invention discloses a method for accurately detecting pesticide residues in agricultural products, which comprises the following steps: (1) homogenizing agricultural products by a homogenizer, and adding water and acetonitrile for dispersing; (2) adding magnetic nano materials for continuous oscillation extraction; (3) separating the magnetic nano material for extracting and adsorbing the pesticide from the solution of the agricultural products by using a magnet; (4) eluting the magnetic nano material adsorbed with the pesticide by using an organic reagent, carrying out nitrogen-blowing concentration, and filtering to obtain a solution to be detected; (5) and analyzing and detecting the liquid to be detected by using an ultra-high performance liquid chromatography triple quadrupole tandem mass spectrometer. The method for accurately detecting pesticide residues in agricultural products has the advantages of short operation time, low organic reagent consumption, low analysis cost and accurate analysis result.
Description
Technical Field
The invention relates to the technical field of detection, in particular to an accurate detection method for pesticide residues in agricultural products.
Background
In China, the pesticide residue detection of agricultural products is generally carried out according to GB/T5009.218-2008 for determining the pesticide residue in fruits and vegetables or gas chromatography-mass spectrometry GB 23200.8-2016 for determining the residue of 500 pesticides and related chemicals in fruits and vegetables and gas chromatography-mass spectrometry NY/T1380-2007 for determining the residue of 51 pesticides in vegetables and fruits, on one hand, the reference standards all need to use a large amount of organic reagents with high purity, the reagents inevitably cause health hazards to experimenters, on the other hand, various solid phase adsorption small columns with high price are also needed, the reagents and the small columns need to be properly processed after being used, the time and the labor are wasted on the whole, the cost is high, and the gas chromatography-mass spectrometry instrument is mainly adopted in the determination process, the single-stage quadrupole mass spectrometry only depends on characteristic ions for qualitative determination, and results with inaccurate qualitative determination easily appear in food analysis with relatively complex matrixes, so that a rapid, economic, efficient, environment-friendly, scientific and accurate method and a more accurate detection method are required to be developed for qualitative and quantitative detection of pesticide residues in agricultural products.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a method for accurately measuring various pesticide residues in agricultural products by using an ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometer. The method can solve the technical problem of providing a simpler, more accurate and more green method for measuring the pesticide residue in agricultural products.
The technical problem to be solved by the invention is realized by the following technical scheme:
the invention relates to a method for accurately detecting pesticide residue in agricultural products, which comprises the following steps:
(1) homogenizing agricultural products by a homogenizer, and adding water and acetonitrile for dispersing;
(2) adding magnetic nano materials for continuous oscillation extraction;
(3) separating the magnetic nano material for extracting and adsorbing the pesticide from the solution of the agricultural products by using a magnet;
(4) eluting the magnetic nano material adsorbed with the pesticide by using an organic reagent, carrying out nitrogen-blowing concentration, and filtering to obtain a solution to be detected;
(5) and analyzing and detecting the liquid to be detected by using an ultra-high performance liquid chromatography triple quadrupole tandem mass spectrometer.
Specifically, the accurate method for simultaneously detecting the pesticides in the agricultural products comprises the following steps:
(1) homogenizing 100-110 g of agricultural products by using a homogenizer to obtain slurry; taking 3-10 g of slurry into a 20-70 mL centrifuge tube with a plug, then adding 15-25 mL of deionized water and 1-3 mL of acetonitrile, and shaking for 2-5 minutes;
(2) adding 50-150 mg of magnetic nano material into the centrifuge tube with the plug in the step (1), and continuing to vibrate for 3-10 minutes;
(3) placing a magnet on the side wall of a centrifuge tube, fully adsorbing the pesticide in the agricultural product by the magnetic nano material, adsorbing the magnetic nano material with magnetism on the side wall close to the magnet, discarding a mixed solution of the agricultural product, acetonitrile and water, cleaning the magnetic nano material for 2-3 times by deionized water, and discarding a cleaning solution;
(4) ultrasonically eluting the magnetic nano material in the centrifuge tube with the plug for 5-10 minutes by using 2-5 mL of organic solvent, and eluting the pesticide adsorbed by the magnetic nano particles into the organic solvent to obtain eluent; then, nitrogen is blown to concentrate the eluent to 0.8-1.2 mL, and the eluent is filtered to obtain a solution to be detected; wherein the organic solvent is acetonitrile and methanol in a volume ratio of (3-4): 1;
(5) and (3) loading the agricultural product on a machine, analyzing the liquid to be measured by adopting an ultra-high performance liquid chromatography triple quadrupole tandem mass spectrometer, and performing qualitative and quantitative determination by adopting an external standard working curve method to obtain an accurate determination result of pesticide residues in the agricultural product.
Preferably, the usage amount of the deionized water for cleaning the magnetic nano material in the step (3) is 2-5 mL.
Preferably, the magnetic nano material in the step (2) is Fe3O4@SiO2@ PDA magnetic nano material or Fe3O4@SiO2@ mesoporous SiO2@ PDA describes the magnetic nanomaterial, wherein PDA is polydopamine.
Said Fe3O4@SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 FeCl3·6H2O and ethylene glycol in a solid-to-liquid ratio of 1: (50-60) (g/mL), stirring for 0.5-1 hour at 200-300 r/min under the action of magnetic stirring, and adding FeCl3·6H2Sodium acetate with the weight 2.5-3 times of that of O is continuously stirred for 0.5-1 hour at 200-300 revolutions per minute to obtain a mixed solution; transferring the mixed solution into a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, and heating and reacting for 10-13 hours at 180-200 ℃; separating and collecting the reaction product under the action of an external magnetic field, washing the reaction product by using absolute ethyl alcohol with the weight 40-60 times that of the reaction product, and drying the reaction product for 6-10 hours at the temperature of 40-50 ℃ and the vacuum degree of 0.07-0.09 MPa to obtain black solid Fe3O4Nano-microspheres;
s2 mixing Fe3O4The nano-microsphere is prepared from the following components in a solid-liquid ratio (2-3): 1(mg/mL) is added into hydrochloric acid with the molar concentration of 1-2 mol/L, ultrasonic treatment is carried out for 5-10 minutes under the conditions of the ultrasonic power of 200-500W and the ultrasonic frequency of 25-35 kHz, and then Fe is used3O4Adding 80-200 times of deionized water to the weight of the nano microspheres to obtain Fe3O4Cleaning the nano microspheres; then washing the Fe3O4Adding a mixed solution of ethanol and water with the volume ratio of 4/1, wherein the volume of the mixed solution is 8-12 times that of hydrochloric acid, adding 28% by mass of concentrated ammonia water, the volume of which is 0.09-0.1 times that of the hydrochloric acid, and continuously performing ultrasonic treatment for 10-30 minutes under the conditions of ultrasonic power of 200-500W and ultrasonic frequency of 25-35 kHz to obtain a mixed solution; adding orthosilicate ester with the volume of 0.04-0.05 time of that of hydrochloric acid into the mixed solution, stirring and reacting for 5-7 hours at 25-30 ℃ at 200-300 r/min to complete hydrolysis and polycondensation of the orthosilicate ester, and collecting a reaction product; washing with absolute ethyl alcohol with the weight of 50-70 times of that of the reaction product, and drying for 6-10 hours at the temperature of 50-60 ℃ and the vacuum degree of 0.07-0.09 MPa to obtain Fe3O4@SiO2Magnetic nano-microspheres;
s3 weighing dopamine hydrochloride and Tris buffer solution with the molar concentration of 10mM, and mixing the solution in a solid-to-liquid ratio of 1: (0.8-1.2) (mg/mL); followed by addition of Fe3O4@SiO2Magnetic nanospheres, Fe3O4@SiO2The mass ratio of the magnetic nano microspheres to the dopamine hydrochloride is 1: (4-5), stirring and reacting for 16-20 hours at the temperature of 20-30 ℃ at 200-300 r/min; after the reaction is finished, centrifuging the reaction solution for 10-15 minutes at 2000-3000 r/min, and collectingCollecting bottom solids; washing the bottom solid with absolute ethyl alcohol with the weight 50-70 times that of the bottom solid and deionized water with the weight 100-200 times that of the bottom solid, and drying for 6-10 hours at the temperature of 50-60 ℃ and under the vacuum degree of 0.07-0.09 MPa to obtain the Fe3O4@SiO2@ PDA magnetic nanomaterial.
As an improved technical scheme of the invention, the Fe3O4@SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 FeCl3·6H2O and ethylene glycol in a solid-to-liquid ratio of 1: (50-60) (g/mL), stirring for 0.5-1 hour at 200-300 r/min under the action of magnetic stirring, and adding FeCl3·6H2Sodium acetate with the weight 2.5-3 times of that of O is continuously stirred for 0.5-1 hour at 200-300 r/min; continued addition of FeCl3·6H2Stirring a surfactant with the weight of 1.6-2 times that of O at 200-300 rpm for 15-25 minutes to obtain a mixed solution; transferring the mixed solution into a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, and heating and reacting for 10-13 hours at 180-200 ℃; separating and collecting the reaction product under the action of an external magnetic field, washing the reaction product by using absolute ethyl alcohol with the weight 40-60 times that of the reaction product, and drying the reaction product for 6-10 hours at the temperature of 40-50 ℃ and the vacuum degree of 0.07-0.09 MPa to obtain black solid Fe3O4Nano-microspheres;
s2 mixing Fe3O4The nano-microsphere is prepared from the following components in a solid-liquid ratio (2-3): 1(mg/mL) is added into hydrochloric acid with the molar concentration of 1-2 mol/L, ultrasonic treatment is carried out for 5-10 minutes under the conditions of the ultrasonic power of 200-500W and the ultrasonic frequency of 25-35 kHz, and then Fe is used3O4Adding 80-200 times of deionized water to the weight of the nano microspheres to obtain Fe3O4Cleaning the nano microspheres; then washing the Fe3O4Adding a mixed solution of ethanol and water with the volume ratio of 4/1, wherein the volume of the mixed solution is 8-12 times that of hydrochloric acid, adding 28% by mass of concentrated ammonia water, the volume of which is 0.09-0.1 times that of the hydrochloric acid, and continuously performing ultrasonic treatment for 10-30 minutes under the conditions of ultrasonic power of 200-500W and ultrasonic frequency of 25-35 kHz to obtain a mixed solution; subsequently, adding orthosilicate ester with the volume of 0.04-0.05 time of that of hydrochloric acid into the mixed solutionStirring and reacting at 25-30 ℃ at 200-300 r/min for 5-7 hours to complete hydrolysis and polycondensation of orthosilicate ester, and collecting reaction products; washing with absolute ethyl alcohol with the weight of 50-70 times of that of the reaction product, and drying for 6-10 hours at the temperature of 50-60 ℃ and the vacuum degree of 0.07-0.09 MPa to obtain Fe3O4@SiO2Magnetic nano-microspheres;
s3 weighing dopamine hydrochloride and Tris buffer solution with the molar concentration of 10mM, and mixing the solution in a solid-to-liquid ratio of 1: (0.8-1.2) (mg/mL); followed by addition of Fe3O4@SiO2Magnetic nanospheres, Fe3O4@SiO2The mass ratio of the magnetic nano microspheres to the dopamine hydrochloride is 1: (4-5), stirring and reacting for 16-20 hours at the temperature of 20-30 ℃ at 200-300 r/min; after the reaction is finished, centrifuging the reaction solution for 10-15 minutes at 2000-3000 r/min, and collecting the bottom solid; washing the bottom solid with absolute ethyl alcohol with the weight 50-70 times that of the bottom solid and deionized water with the weight 100-200 times that of the bottom solid, and drying for 6-10 hours at the temperature of 50-60 ℃ and under the vacuum degree of 0.07-0.09 MPa to obtain the Fe3O4@SiO2@ PDA magnetic nanomaterial.
Further preferably, the Fe3O4@SiO2@ mesoporous SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 FeCl3·6H2O and ethylene glycol in a solid-to-liquid ratio of 1: (50-60) (g/mL), stirring for 0.5-1 hour at 200-300 r/min under the action of magnetic stirring, and adding FeCl3·6H2Sodium acetate with the weight 2.5-3 times of that of O is continuously stirred for 0.5-1 hour at 200-300 r/min; continued addition of FeCl3·6H2Stirring a surfactant with the weight of 1.6-2 times that of O at 200-300 rpm for 15-25 minutes to obtain a mixed solution; transferring the mixed solution into a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, and heating and reacting for 10-13 hours at 180-200 ℃; separating and collecting the reaction product under the action of an external magnetic field, washing the reaction product by using absolute ethyl alcohol with the weight 40-60 times of that of the reaction product, and drying the reaction product for 6-10 hours at the temperature of 40-50 ℃ and the vacuum degree of 0.07-0.09 MPa to obtain a black solidFe3O4Nano-microspheres;
s2 mixing Fe3O4The nano-microsphere is prepared from the following components in a solid-liquid ratio (2-3): 1(mg/mL) is added into hydrochloric acid with the molar concentration of 1-2 mol/L, ultrasonic treatment is carried out for 5-10 minutes under the conditions of the ultrasonic power of 200-500W and the ultrasonic frequency of 25-35 kHz, and then Fe is used3O4Adding 80-200 times of deionized water to the weight of the nano microspheres to obtain Fe3O4Cleaning the nano microspheres; then washing the Fe3O4Adding a mixed solution of ethanol and water with the volume ratio of 4/1, wherein the volume of the mixed solution is 8-12 times that of hydrochloric acid, adding 28% by mass of concentrated ammonia water, the volume of which is 0.09-0.1 times that of the hydrochloric acid, and continuously performing ultrasonic treatment for 10-30 minutes under the conditions of ultrasonic power of 200-500W and ultrasonic frequency of 25-35 kHz to obtain a mixed solution; adding orthosilicate ester with the volume of 0.04-0.05 time of that of hydrochloric acid into the mixed solution, stirring and reacting for 5-7 hours at 25-30 ℃ at 200-300 r/min to complete hydrolysis and polycondensation of the orthosilicate ester, and collecting a reaction product; washing with absolute ethyl alcohol with the weight of 50-70 times of that of the reaction product, and drying for 6-10 hours at the temperature of 50-60 ℃ and the vacuum degree of 0.07-0.09 MPa to obtain Fe3O4@SiO2Magnetic nano-microspheres;
s3 mixing Fe3O4@SiO2The magnetic nano-microsphere, absolute ethyl alcohol and deionized water are mixed in a proportion of 1: (60-80): 80(g/mL/mL), and carrying out ultrasonic treatment for 15-20 minutes under the conditions of ultrasonic power of 200-500W and ultrasonic frequency of 25-35 kHz; then adding concentrated ammonia water with the mass fraction of 28% and Fe, wherein the volume of the concentrated ammonia water is 0.17-0.2 times of that of the deionized water3O4@SiO2Stirring cetyl trimethyl ammonium bromide 2-3 times the weight of the magnetic nano microspheres at 200-300 revolutions per minute for 30-40 minutes; continuously adding orthosilicate ester with the volume 0.4-0.5 times of that of ammonia water and 3-aminopropyltriethoxysilane with the volume 0.06-0.07 times of that of the ammonia water, and stirring and reacting at the temperature of 20-30 ℃ at 200-300 r/min for 12-15 hours; after the reaction is finished, centrifuging the reaction solution for 10-15 minutes at 2000-3000 r/min, and collecting bottom sediment; washing the bottom sediment with absolute ethyl alcohol with the weight 50-70 times that of the bottom sediment, and drying for 6-10 hours at the temperature of 40-50 ℃ and the vacuum degree of 0.07-0.09 MPa to obtain the productTo Fe3O4@SiO2@ mesoporous SiO2Magnetic nano-microspheres;
s4 weighing dopamine hydrochloride and Tris buffer solution with the molar concentration of 10mM, and mixing the solution in a solid-to-liquid ratio of 1: (0.8-1.2) (mg/mL); followed by addition of Fe3O4@SiO2@ mesoporous SiO2Magnetic nanospheres, Fe3O4@SiO2The mass ratio of the magnetic nano microspheres to the dopamine hydrochloride is 1: (4-5), stirring and reacting for 16-20 hours at the temperature of 20-30 ℃ at 200-300 r/min; after the reaction is finished, centrifuging the reaction solution for 10-15 minutes at 2000-3000 r/min, and collecting the bottom solid; washing the bottom solid with absolute ethyl alcohol with the weight 50-70 times that of the bottom solid and deionized water with the weight 100-200 times that of the bottom solid, and drying for 6-10 hours at the temperature of 50-60 ℃ and under the vacuum degree of 0.07-0.09 MPa to obtain the Fe3O4@SiO2@ mesoporous SiO2@ PDA magnetic nanomaterial.
By adding Fe3O4@SiO2The surface of the magnetic nano microsphere is plated with a mesoporous silica layer, the obtained magnetic nano material has the separation characteristic of a magnetic material and the large specific surface area characteristic of the mesoporous material, and meanwhile, amino functionalization is carried out on the surface of the mesoporous silica, so that the dispersion performance, the magnetic performance and the adsorption performance of the magnetic material are improved.
The surfactant is one or more of polyethylene glycol, sodium citrate and ethylenediamine.
In some technical schemes of the invention, the ferroferric oxide is prepared without adding a surfactant, and the obtained ferroferric oxide is similar to a sphere in shape, but the surface of the ferroferric oxide has a plurality of defects and incomplete spheres, which influence the magnetic property and the adsorption property of the magnetic material to a certain extent. The ferroferric oxide prepared by adopting polyvinyl alcohol and sodium citrate as surfactants has smooth surface, spherical shape and complete particle size distribution. Particularly, the ferroferric oxide prepared by taking sodium citrate as a surfactant has very uneven particle size distribution which is different from dozens of nanometers to hundreds of nanometers. The ferroferric oxide obtained by using ethylenediamine as a surfactant is approximately spherical, the surface is rough, the size is uniform, and the particle size distribution is very narrow.
The orthosilicate is tetraethyl orthosilicate and/or butyl orthosilicate. Preferably, the orthosilicate is tetraethyl orthosilicate and butyl orthosilicate in a mass ratio of 4: 1, in a mixture of the components.
Compared with the prior art, the invention has the advantages that: the pesticide residues in the agricultural products are pretreated by a magnetic solid-phase extraction method, so that the treatment time and the treatment cost can be greatly reduced, and the measurement is faster and more accurate by adopting an ultra-high performance liquid chromatography triple quadrupole tandem mass spectrometer. Generally, the method of the invention is fast, economical, efficient and accurate, and reduces adverse effects on personnel and the environment.
The method for accurately detecting pesticide residues in agricultural products has the advantages of short operation time, low organic reagent consumption, low analysis cost, accurate analysis result and the like.
Detailed Description
The present invention is further illustrated by the following examples, but the present invention is not limited to the following examples.
The agricultural product is a small green vegetable (the variety is Shanghai green) in the wholesale market of Shanghai agricultural product center.
Tetraethyl orthosilicate, CAS number: 562-90-3, available from jilede new materials science and technology, inc.
Dopamine hydrochloride, CAS number: 62-31-7, available from alfa aesar (china) chemical ltd.
Tris buffer, 10mM in molar concentration, namely Tris (Tris hydroxymethyl aminomethane) buffer, 10mM in molar concentration, was purchased from Nantong, Youzu chemical Co.
Polyethylene glycol, CAS No.: 25322-68-3, available from Shanghai Ringsu Biochemical technology, Inc., with a molecular weight of 8000.
Sodium citrate, CAS No.: 6132-04-3 from Strobel chemical (Shanghai) Co., Ltd.
Ethylenediamine, CAS No.: 107-15-3, available from Shanghai Allantin Biotechnology Ltd.
Cetyl trimethylammonium bromide, CAS number: 57-09-0, available from Afahesar (China) chemical Co.
3-aminopropyltriethoxysilane, CAS No.: 919-30-2, available from Hangzhou geochemistry, Inc.
N-butyl silicate, CAS No.: 4766-57-8, available from Michelle chemical technology, Inc., Shanghai.
The instruments and conditions used for the analysis during the detection were as follows:
a refiner, model BILON, available from shanghai biran instruments manufacturing ltd.
The vortex oscillator is made by Tan Shuihe Korea scientific experimenter, model XH-C.
The detection conditions of the ultra-high performance liquid chromatography are as follows: Waters/ACQUITY/UPLC, USA; a chromatographic column: a Waters/Acquity/UPLC/BE h/C18 chromatographic column with specification of 1.7 μm and 2.1 × 100 mm; the mobile phase A is acetonitrile, and the B is aqueous solution with the volume fraction of formic acid of 0.1 percent; flow rate: 0.4 ml per minute; column temperature: 35 ℃; gradient: in 0-1 minute, A is 5% -10%, and the rest is B; in 1-2 minutes, A is 10% -20%, and the balance is B; in 2-4 minutes, A is 20-40%, and the balance is B; in 4-7 minutes, A is 40% -90%, and the balance is B; 90-70% of A in 7-9 min, 70-5% of A in 9-12 min and the balance of B.
The mass spectrometric detection conditions were as follows: mass spectrometry: Waters/Xevo TQ-S Micro; an electrospray ion source, positive ions and negative ions are scanned simultaneously, a multi-reaction monitoring mode is adopted, the capillary voltage is 3.20kV, the ion source temperature is 150 ℃, desolventizing gas is nitrogen, the temperature is 500 ℃, the drying gas flow rate is 800L/hr r, collision gas is argon, and the argon gas flow rate is 0.16 mL/min;
the multiple reaction monitoring conditions were as follows:
TABLE 1 name of pesticide to be detected and qualitative and quantitative ion information of mass spectrum multiple reaction monitoring
Example 1
The method for accurately detecting pesticide residues in agricultural products comprises the following steps:
(1) homogenizing 100g of small green vegetables with a homogenizer at 9500 rpm for 1 minute to obtain a slurry; taking 5g of slurry in a 50mL centrifuge tube with a plug, then adding 20mL of deionized water and 2mL of acetonitrile, and shaking at 1800 rpm for 2 minutes;
(2) adding 50mg of magnetic nano material into the centrifuge tube with the plug in the step (1), and continuing shaking at 1800 rpm for 4 minutes;
(3) placing a magnet on the side wall of a centrifuge tube, fully adsorbing the pesticide in the agricultural product by the magnetic nano material, adsorbing the magnetic nano material with magnetism on the side wall close to the magnet, discarding the mixed solution of the agricultural product, acetonitrile and water, cleaning the magnetic nano material for 3 times by 2mL of deionized water each time, and discarding the cleaning solution;
(4) ultrasonically eluting the magnetic nano material in the centrifuge tube with the plug by adopting 4mL of organic solvent under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz for 8 minutes, eluting the pesticide adsorbed by the magnetic nano particles into the organic solvent, then concentrating the eluent to 1mL on a nitrogen blowing instrument, and passing through a filter membrane with the aperture of 0.22 mu m to obtain a liquid to be detected; wherein the organic solvent is acetonitrile/methanol in a volume ratio of 3: 1;
(5) and (3) loading the agricultural product on a machine, analyzing the liquid to be measured by adopting an ultra-high performance liquid chromatography triple quadrupole tandem mass spectrometer, and performing qualitative and quantitative determination by adopting an external standard working curve method to obtain an accurate determination result of pesticide residues in the agricultural product.
Said Fe3O4@SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 mixing 1.35g FeCl3·6H2Mixing O and 75mL of glycol, stirring for 0.5 hour at 260 revolutions per minute under the action of a magnetic stirrer, then adding 3.6g of sodium acetate, and continuing stirring for 1 hour at 260 revolutions per minute to obtain a mixed solution; the mixture was transferred to a 200mL Teflon linerHeating and reacting for 12 hours at 200 ℃ in a stainless steel high-pressure reaction kettle; separating and collecting the reaction product under the action of an external magnetic field, cleaning the reaction product by using absolute ethyl alcohol with the weight 60 times that of the reaction product, and drying the reaction product for 8 hours in vacuum at 50 ℃ and the vacuum degree of 0.07MPa to obtain black solid Fe3O4Nano-microspheres;
s2 mixing 50mg Fe3O4Adding the nano-microspheres into 20mL hydrochloric acid with the molar concentration of 2mol/L, carrying out ultrasonic treatment for 5 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz, and then using Fe3O4Deionized water with the weight of 100 times of that of the nano microspheres is used for adding magnetic Fe3O4Cleaning the nano microspheres; then washing the Fe3O4Adding 200mL of ethanol/water solution with the volume ratio of 4/1 into the nano microspheres, adding 2.0mL of 28% concentrated ammonia water by mass fraction, and continuing to perform ultrasonic treatment for 20 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz to obtain a mixed solution; then, adding 1.0mL of tetraethyl orthosilicate into the mixed solution, stirring and reacting at 30 ℃ at 260 revolutions per minute for 6 hours to complete hydrolysis and polycondensation of the tetraethyl orthosilicate, and collecting a reaction product; washing the reaction product with 50 times of anhydrous ethanol, removing blank silicon dioxide particles, vacuum drying at 50 deg.C and 0.07MPa for 8 hr to obtain Fe3O4@SiO2Magnetic nano-microspheres;
s3 weighing 400mg dopamine hydrochloride and 400mL Tris buffer solution with the molar concentration of 10mM and mixing; followed by addition of 100mgFe3O4@SiO2Stirring the magnetic nano microspheres at 25 ℃ at 300 revolutions per minute for reaction for 16 hours; after the reaction was completed, the reaction solution was centrifuged at 2600 rpm for 15 minutes, and the bottom solid was collected; washing the bottom solid with absolute ethyl alcohol with the weight 70 times of that of the bottom solid and deionized water with the weight 200 times of that of the bottom solid, and then carrying out vacuum drying for 10 hours at the temperature of 50 ℃ and the vacuum degree of 0.07MPa to obtain the Fe3O4@SiO2@ PDA magnetic nanomaterial.
Preparing a standard working solution: and respectively taking a proper amount of each pesticide standard substance, and preparing a standard working solution with 7 concentration points within a concentration range of 3-500 mu g/kg relative to the sample by using acetonitrile.
In the detection process, an automatic sample injector is adopted for sample injection, the sample injection volume is 5 mu L, and after the pesticide to be detected is rapidly separated by using ultra-high performance liquid chromatography, the detection is carried out in an electrospray ionization source (ESI) positive and negative ion multi-reaction monitoring mode.
And (3) performing qualitative and quantitative determination by adopting an external standard working curve method, and calculating to obtain results of 15 pesticide residues in agricultural products. Carrying out ultra-high performance liquid chromatography triple quadrupole tandem mass spectrometry on the standard working solution with each concentration gradient, and carrying out regression analysis on the corresponding concentration of each pesticide in the standard working solution according to the chromatographic peak area of the quantitative ion of each pesticide to obtain a standard working curve; and (3) measuring the liquid to be measured in the step (5) under the same condition, measuring the quantitative ion chromatographic peak areas of the 15 pesticides in the liquid to be measured, substituting the quantitative ion chromatographic peak areas into the standard curve to obtain the contents of the 15 pesticides in the liquid to be measured, and calculating the residual quantity of the 15 pesticides in the sample according to the mass of the sample represented by the liquid to be measured.
The detection indexes are shown in table 2.
TABLE 2 Linear range, linear equation, correlation coefficient, detection limit and recovery rate of the tested pesticide
Example 2
Example 2 is essentially the same as example 1, except that:
said Fe3O4@SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 mixing 1.35g FeCl3·6H2Mixing O and 75mL of glycol, stirring for 0.5 hour at 260 revolutions per minute under the action of a magnetic stirrer, then adding 3.6g of sodium acetate, and continuing to stir for 1 hour at 260 revolutions per minute; continuously adding 2.2g of polyethylene glycol, and stirring for 15 minutes at 260 revolutions per minute to obtain a mixed solution; transferring the mixed solution into a polytetrafluoroethylene-lined stainless steel high-pressure reaction kettle with the capacity of 200mL, and heating and reacting for 12 hours at 200 ℃; separating and collecting the reaction product under the action of an external magnetic field, washing the reaction product by using absolute ethyl alcohol with the weight 60 times that of the reaction product,vacuum drying at 50 deg.C and 0.07MPa for 8 hr to obtain black solid Fe3O4Nano-microspheres;
s2 mixing 50mg Fe3O4Adding the nano-microspheres into 20mL hydrochloric acid with the molar concentration of 2mol/L, carrying out ultrasonic treatment for 5 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz, and then using Fe3O4Deionized water with the weight of 100 times of that of the nano microspheres is used for adding magnetic Fe3O4Cleaning the nano microspheres; then washing the Fe3O4Adding 200mL of ethanol/water solution with the volume ratio of 4/1 into the nano microspheres, adding 2.0mL of 28% concentrated ammonia water by mass fraction, and continuing to perform ultrasonic treatment for 20 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz to obtain a mixed solution; then, adding 1.0mL of tetraethyl orthosilicate into the mixed solution, stirring and reacting at 30 ℃ at 260 revolutions per minute for 6 hours to complete hydrolysis and polycondensation of the tetraethyl orthosilicate, and collecting a reaction product; washing the reaction product with 50 times of anhydrous ethanol, removing blank silicon dioxide particles, vacuum drying at 50 deg.C and 0.07MPa for 8 hr to obtain Fe3O4@SiO2Magnetic nano-microspheres;
s3 weighing 400mg dopamine hydrochloride and 400mL Tris buffer solution with the molar concentration of 10mM and mixing; followed by addition of 100mgFe3O4@SiO2Stirring the magnetic nano microspheres at 25 ℃ at 300 revolutions per minute for reaction for 16 hours; after the reaction was completed, the reaction solution was centrifuged at 2600 rpm for 15 minutes, and the bottom solid was collected; washing the bottom solid with absolute ethyl alcohol with the weight 70 times of that of the bottom solid and deionized water with the weight 200 times of that of the bottom solid, and then carrying out vacuum drying for 10 hours at the temperature of 50 ℃ and the vacuum degree of 0.07MPa to obtain the Fe3O4@SiO2@ PDA magnetic nanomaterial.
TABLE 3 Linear Range, Linear equation, correlation coefficient, detection Limit and recovery Rate of spiked pesticide
Example 3
Example 3 is essentially the same as example 1, except that:
said Fe3O4@SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 mixing 1.35g FeCl3·6H2Mixing O and 75mL of glycol, stirring for 0.5 hour at 260 revolutions per minute under the action of a magnetic stirrer, then adding 3.6g of sodium acetate, and continuing to stir for 1 hour at 260 revolutions per minute; continuously adding 2.2g of sodium citrate, and stirring for 15 minutes at 260 revolutions per minute to obtain a mixed solution; transferring the mixed solution into a polytetrafluoroethylene-lined stainless steel high-pressure reaction kettle with the capacity of 200mL, and heating and reacting for 12 hours at 200 ℃; separating and collecting the reaction product under the action of an external magnetic field, cleaning the reaction product by using absolute ethyl alcohol with the weight 60 times that of the reaction product, and drying the reaction product for 8 hours in vacuum at 50 ℃ and the vacuum degree of 0.07MPa to obtain black solid Fe3O4Nano-microspheres;
s2 mixing 50mg Fe3O4Adding the nano-microspheres into 20mL hydrochloric acid with the molar concentration of 2mol/L, carrying out ultrasonic treatment for 5 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz, and then using Fe3O4Deionized water with the weight of 100 times of that of the nano microspheres is used for adding magnetic Fe3O4Cleaning the nano microspheres; then washing the Fe3O4Adding 200mL of ethanol/water solution with the volume ratio of 4/1 into the nano microspheres, adding 2.0mL of 28% concentrated ammonia water by mass fraction, and continuing to perform ultrasonic treatment for 20 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz to obtain a mixed solution; then, adding 1.0mL of tetraethyl orthosilicate into the mixed solution, stirring and reacting at 30 ℃ at 260 revolutions per minute for 6 hours to complete hydrolysis and polycondensation of the tetraethyl orthosilicate, and collecting a reaction product; washing the reaction product with 50 times of anhydrous ethanol, removing blank silicon dioxide particles, vacuum drying at 50 deg.C and 0.07MPa for 8 hr to obtain Fe3O4@SiO2Magnetic nano-microspheres;
s3 weighing 400mg dopamine hydrochlorideMixing with 400mL of Tris buffer solution with the molar concentration of 10 mM; followed by addition of 100mgFe3O4@SiO2Stirring the magnetic nano microspheres at 25 ℃ at 300 revolutions per minute for reaction for 16 hours; after the reaction was completed, the reaction solution was centrifuged at 2600 rpm for 15 minutes, and the bottom solid was collected; washing the bottom solid with absolute ethyl alcohol with the weight 70 times of that of the bottom solid and deionized water with the weight 200 times of that of the bottom solid, and then carrying out vacuum drying for 10 hours at the temperature of 50 ℃ and the vacuum degree of 0.07MPa to obtain the Fe3O4@SiO2@ PDA magnetic nanomaterial.
TABLE 4 Linear range, linear equation, correlation coefficient, detection limit and recovery rate of the tested pesticide
Example 4
Example 4 is essentially the same as example 1, except that:
said Fe3O4@SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 mixing 1.35g FeCl3·6H2Mixing O and 75mL of glycol, stirring for 0.5 hour at 260 revolutions per minute under the action of a magnetic stirrer, then adding 3.6g of sodium acetate, and continuing to stir for 1 hour at 260 revolutions per minute; continuously adding 2.2g of ethylenediamine, and stirring for 15 minutes at 260 revolutions per minute to obtain a mixed solution; transferring the mixed solution into a polytetrafluoroethylene-lined stainless steel high-pressure reaction kettle with the capacity of 200mL, and heating and reacting for 12 hours at 200 ℃; separating and collecting the reaction product under the action of an external magnetic field, cleaning the reaction product by using absolute ethyl alcohol with the weight 60 times that of the reaction product, and drying the reaction product for 8 hours in vacuum at 50 ℃ and the vacuum degree of 0.07MPa to obtain black solid Fe3O4Nano-microspheres;
s2 mixing 50mg Fe3O4The nano-microspheres are added into 20mL hydrochloric acid with the molar concentration of 2mol/L, and the ultrasonic frequency is controlled at the ultrasonic power of 300WSonicated at a rate of 25kHz for 5 minutes, then treated with Fe3O4Deionized water with the weight of 100 times of that of the nano microspheres is used for adding magnetic Fe3O4Cleaning the nano microspheres; then washing the Fe3O4Adding 200mL of ethanol/water solution with the volume ratio of 4/1 into the nano microspheres, adding 2.0mL of 28% concentrated ammonia water by mass fraction, and continuing to perform ultrasonic treatment for 20 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz to obtain a mixed solution; then, adding 1.0mL of tetraethyl orthosilicate into the mixed solution, stirring and reacting at 30 ℃ at 260 revolutions per minute for 6 hours to complete hydrolysis and polycondensation of the tetraethyl orthosilicate, and collecting a reaction product; washing the reaction product with 50 times of anhydrous ethanol, removing blank silicon dioxide particles, vacuum drying at 50 deg.C and 0.07MPa for 8 hr to obtain Fe3O4@SiO2Magnetic nano-microspheres;
s3 weighing 400mg dopamine hydrochloride and 400mL Tris buffer solution with the molar concentration of 10mM and mixing; followed by addition of 100mgFe3O4@SiO2Stirring the magnetic nano microspheres at 25 ℃ at 300 revolutions per minute for reaction for 16 hours; after the reaction was completed, the reaction solution was centrifuged at 2600 rpm for 15 minutes, and the bottom solid was collected; washing the bottom solid with absolute ethyl alcohol with the weight 70 times of that of the bottom solid and deionized water with the weight 200 times of that of the bottom solid, and then carrying out vacuum drying for 10 hours at the temperature of 50 ℃ and the vacuum degree of 0.07MPa to obtain the Fe3O4@SiO2@ PDA magnetic nanomaterial.
TABLE 5 Linear Range, Linear equation, correlation coefficient, detection Limit and recovery Rate of spiked pesticide
Example 5
Example 5 is essentially the same as example 1, except that:
said Fe3O4@SiO2@ mesoporous SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 mixing 1.35g FeCl3·6H2Mixing O and 75mL of glycol, stirring for 0.5 hour at 260 revolutions per minute under the action of a magnetic stirrer, then adding 3.6g of sodium acetate, and continuing to stir for 1 hour at 260 revolutions per minute; continuously adding 2.2g of ethylenediamine, and stirring for 15 minutes at 260 revolutions per minute to obtain a mixed solution; transferring the mixed solution into a polytetrafluoroethylene-lined stainless steel high-pressure reaction kettle with the capacity of 200mL, and heating and reacting for 12 hours at 200 ℃; separating and collecting the reaction product under the action of an external magnetic field, cleaning the reaction product by using absolute ethyl alcohol with the weight 60 times that of the reaction product, and drying the reaction product for 8 hours in vacuum at 50 ℃ and the vacuum degree of 0.07MPa to obtain black solid Fe3O4Nano-microspheres;
s2 mixing 50mg Fe3O4Adding the nano-microspheres into 20mL hydrochloric acid with the molar concentration of 2mol/L, carrying out ultrasonic treatment for 5 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz, and then using Fe3O4Deionized water with the weight of 100 times of that of the nano microspheres is used for adding magnetic Fe3O4Cleaning the nano microspheres; then washing the Fe3O4Adding 200mL of ethanol/water solution with the volume ratio of 4/1 into the nano microspheres, adding 2.0mL of 28% concentrated ammonia water by mass fraction, and continuing to perform ultrasonic treatment for 20 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz to obtain a mixed solution; then, adding 1.0mL of tetraethyl orthosilicate into the mixed solution, stirring and reacting at 30 ℃ at 260 revolutions per minute for 6 hours to complete hydrolysis and polycondensation of the tetraethyl orthosilicate, and collecting a reaction product; washing the reaction product with 50 times of anhydrous ethanol, removing blank silicon dioxide particles, vacuum drying at 50 deg.C and 0.07MPa for 8 hr to obtain Fe3O4@SiO2Magnetic nano-microspheres;
s3 mixing Fe3O4@SiO2The magnetic nano-microsphere, absolute ethyl alcohol and deionized water are mixed in a proportion of 1: 70: 80(g/mL/mL), and carrying out ultrasonic treatment for 15 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25 kHz; then concentrated ammonia water with the mass fraction of 28 percent and Fe with the volume 0.17 time of the deionized water are added3O4@SiO2Cetyl trimethyl ammonium bromide which is 3 times of the weight of the magnetic nano microsphere is stirred for 30 minutes at 260 revolutions per minute; adding ammonia water in an amount of 0.5 times the volume of the solutionTetraethyl orthosilicate and 3-aminopropyltriethoxysilane with 0.07 time of ammonia volume are stirred and reacted for 12 hours at the temperature of 25 ℃ at the speed of 300 r/min; after the reaction is finished, centrifuging the reaction solution at 2000 rpm for 10 minutes, and collecting bottom sediment; washing the bottom precipitate with 70 times of anhydrous ethanol, and drying at 50 deg.C and 0.07MPa for 8 hr to obtain Fe3O4@SiO2@ mesoporous SiO2Magnetic nano-microspheres;
s4 weighing 400mg dopamine hydrochloride and 400mL Tris buffer solution with the molar concentration of 10mM and mixing; then 100mg of Fe was added3O4@SiO2@ mesoporous SiO2Stirring the magnetic nano microspheres at 25 ℃ at 300 revolutions per minute for reaction for 16 hours; after the reaction was completed, the reaction solution was centrifuged at 2600 rpm for 15 minutes, and the bottom solid was collected; washing the bottom solid with absolute ethyl alcohol with the weight 70 times of that of the bottom solid and deionized water with the weight 200 times of that of the bottom solid, and then carrying out vacuum drying for 10 hours at the temperature of 50 ℃ and the vacuum degree of 0.07MPa to obtain the Fe3O4@SiO2@ mesoporous SiO2@ PDA magnetic nanomaterial.
TABLE 6 Linear range, linear equation, correlation coefficient, detection limit and recovery rate of pesticides tested
Example 6
Example 6 is essentially the same as example 1, except that:
said Fe3O4@SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 mixing 1.35g FeCl3·6H2Mixing O and 75mL of glycol, stirring for 0.5 hour at 260 revolutions per minute under the action of a magnetic stirrer, then adding 3.6g of sodium acetate, and continuing to stir for 1 hour at 260 revolutions per minute; continuously adding 2.2g of ethylenediamine, and stirring for 15 minutes at 260 revolutions per minute to obtain a mixed solution; transferring the mixed solution into a polytetrafluoroethylene-lined stainless steel high-pressure reaction kettle with the capacity of 200mL, and heating and reacting for 12 hours at 200 ℃; reacting the reaction productSeparating and collecting under the action of an external magnetic field, cleaning with anhydrous ethanol 60 times the weight of the reaction product, and vacuum drying at 50 deg.C and 0.07MPa for 8 hr to obtain black solid Fe3O4Nano-microspheres;
s2 mixing 50mg Fe3O4Adding the nano-microspheres into 20mL hydrochloric acid with the molar concentration of 2mol/L, carrying out ultrasonic treatment for 5 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz, and then using Fe3O4Deionized water with the weight of 100 times of that of the nano microspheres is used for adding magnetic Fe3O4Cleaning the nano microspheres; then washing the Fe3O4Adding 200mL of ethanol/water solution with the volume ratio of 4/1 into the nano microspheres, adding 2.0mL of 28% concentrated ammonia water by mass fraction, and continuing to perform ultrasonic treatment for 20 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz to obtain a mixed solution; then, adding 1.0mL of n-butyl silicate into the mixed solution, stirring and reacting for 6 hours at 30 ℃ at 260 revolutions per minute, and collecting a reaction product; washing the reaction product with 50 times of anhydrous ethanol, removing blank silicon dioxide particles, vacuum drying at 50 deg.C and 0.07MPa for 8 hr to obtain Fe3O4@SiO2Magnetic nano-microspheres;
s3 mixing Fe3O4@SiO2The magnetic nano-microsphere, absolute ethyl alcohol and deionized water are mixed in a proportion of 1: 70: 80(g/mL/mL), and carrying out ultrasonic treatment for 15 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25 kHz; then concentrated ammonia water with the mass fraction of 28 percent and Fe with the volume 0.17 time of the deionized water are added3O4@SiO2Cetyl trimethyl ammonium bromide which is 3 times of the weight of the magnetic nano microsphere is stirred for 30 minutes at 260 revolutions per minute; continuously adding n-butyl silicate with the volume of 0.5 time of that of ammonia water and 3-aminopropyltriethoxysilane with the volume of 0.07 time of that of the ammonia water, and stirring at the temperature of 25 ℃ at 300 r/min for reaction for 12 hours; after the reaction is finished, centrifuging the reaction solution at 2000 rpm for 10 minutes, and collecting bottom sediment; washing the bottom precipitate with 70 times of anhydrous ethanol, and drying at 50 deg.C and 0.07MPa for 8 hr to obtain Fe3O4@SiO2@ mesoporous SiO2Magnetic nano-microspheres;
s4 weighing 400mg dopamine hydrochloride and 400mL Tris buffer solution with the molar concentration of 10mM and mixing; then 100mg of Fe was added3O4@SiO2@ mesoporous SiO2Stirring the magnetic nano microspheres at 25 ℃ at 300 revolutions per minute for reaction for 16 hours; after the reaction was completed, the reaction solution was centrifuged at 2600 rpm for 15 minutes, and the bottom solid was collected; washing the bottom solid with absolute ethyl alcohol with the weight 70 times of that of the bottom solid and deionized water with the weight 200 times of that of the bottom solid, and then carrying out vacuum drying for 10 hours at the temperature of 50 ℃ and the vacuum degree of 0.07MPa to obtain the Fe3O4@SiO2@ mesoporous SiO2@ PDA magnetic nanomaterial.
TABLE 7 Linear Range, Linear equation, correlation coefficient, detection Limit and recovery Rate of pesticides tested
Example 7
Example 7 is essentially the same as example 1, except that:
said Fe3O4@SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 mixing 1.35g FeCl3·6H2Mixing O and 75mL of glycol, stirring for 0.5 hour at 260 revolutions per minute under the action of a magnetic stirrer, then adding 3.6g of sodium acetate, and continuing to stir for 1 hour at 260 revolutions per minute; continuously adding 2.2g of ethylenediamine, and stirring for 15 minutes at 260 revolutions per minute to obtain a mixed solution; transferring the mixed solution into a polytetrafluoroethylene-lined stainless steel high-pressure reaction kettle with the capacity of 200mL, and heating and reacting for 12 hours at 200 ℃; separating and collecting the reaction product under the action of an external magnetic field, cleaning the reaction product by using absolute ethyl alcohol with the weight 60 times that of the reaction product, and drying the reaction product for 8 hours in vacuum at 50 ℃ and the vacuum degree of 0.07MPa to obtain black solid Fe3O4Nano-microspheres;
s2 mixing 50mg Fe3O4Adding the nano-microspheres into 20mL hydrochloric acid with the molar concentration of 2mol/L, carrying out ultrasonic treatment for 5 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz, and then using Fe3O4Deionized water with the weight of 100 times of that of the nano microspheres is used for adding magnetic Fe3O4Cleaning the nano microspheres; then washing the Fe3O4Adding 200mL of ethanol/water solution with the volume ratio of 4/1 into the nano microspheres, adding 2.0mL of 28% concentrated ammonia water by mass fraction, and continuing to perform ultrasonic treatment for 20 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25kHz to obtain a mixed solution; subsequently, 1.0mL of orthosilicate ester is added into the mixed solution, the mixture is stirred and reacted for 6 hours at the temperature of 30 ℃ at 260 revolutions per minute, and a reaction product is collected; washing the reaction product with 50 times of anhydrous ethanol, removing blank silicon dioxide particles, vacuum drying at 50 deg.C and 0.07MPa for 8 hr to obtain Fe3O4@SiO2Magnetic nano-microspheres; wherein the orthosilicate is tetraethyl orthosilicate and butyl orthosilicate in a mass ratio of 4: 1;
s3 mixing Fe3O4@SiO2The magnetic nano-microsphere, absolute ethyl alcohol and deionized water are mixed in a proportion of 1: 70: 80(g/mL/mL), and carrying out ultrasonic treatment for 15 minutes under the conditions of ultrasonic power of 300W and ultrasonic frequency of 25 kHz; then concentrated ammonia water with the mass fraction of 28 percent and Fe with the volume 0.17 time of the deionized water are added3O4@SiO2Cetyl trimethyl ammonium bromide which is 3 times of the weight of the magnetic nano microsphere is stirred for 30 minutes at 260 revolutions per minute; adding orthosilicate ester with the volume 0.5 time of that of ammonia water and 3-aminopropyltriethoxysilane with the volume 0.07 time of that of ammonia water continuously, and stirring at 25 ℃ at 300 r/min for reaction for 12 hours; after the reaction is finished, centrifuging the reaction solution at 2000 rpm for 10 minutes, and collecting bottom sediment; washing the bottom precipitate with 70 times of anhydrous ethanol, and drying at 50 deg.C and 0.07MPa for 8 hr to obtain Fe3O4@SiO2@ mesoporous SiO2Magnetic nano-microspheres; wherein the orthosilicate is tetraethyl orthosilicate and butyl orthosilicate in a mass ratio of 4: 1;
s4 weighing 400mg dopamine hydrochloride and 400mL Tris buffer solution with the molar concentration of 10mM and mixing; then 100mg of Fe was added3O4@SiO2@ mesoporous SiO2Magnetic nano-microsphere, stirring at 25 deg.C at 300 r/minReacting for 16 hours; after the reaction was completed, the reaction solution was centrifuged at 2600 rpm for 15 minutes, and the bottom solid was collected; washing the bottom solid with absolute ethyl alcohol with the weight 70 times of that of the bottom solid and deionized water with the weight 200 times of that of the bottom solid, and then carrying out vacuum drying for 10 hours at the temperature of 50 ℃ and the vacuum degree of 0.07MPa to obtain the Fe3O4@SiO2@ mesoporous SiO2@ PDA magnetic nanomaterial.
TABLE 8 Linear Range, Linear equation, correlation coefficient, detection Limit and recovery Rate of pesticides tested
The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be made by those skilled in the art without inventive work within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope defined by the claims.
Claims (4)
1. The method for accurately detecting pesticide residues in agricultural products is characterized by comprising the following steps of:
firstly, homogenizing 100-110 g of agricultural products by using a homogenizer to obtain slurry; taking 3-10 g of slurry into a 20-70 mL centrifuge tube with a plug, then adding 15-25 mL of deionized water and 1-3 mL of acetonitrile, and shaking for 2-5 minutes;
secondly, adding 50-150 mg of magnetic nano material into the centrifuge tube with the plug in the step I, and continuing to vibrate for 3-10 minutes;
placing a magnet on the side wall of the centrifuge tube, fully adsorbing the pesticide in the agricultural product by the magnetic nano material, adsorbing the magnetic nano material on the side wall close to the magnet, discarding the mixed liquid of the agricultural product, acetonitrile and water, cleaning the magnetic nano material for 2-3 times by using deionized water, and discarding the cleaning liquid;
ultrasonically eluting the magnetic nano material in the centrifuge tube with the plug for 5-10 minutes by adopting 2-5 mL of organic solvent, and eluting the pesticide adsorbed by the magnetic nano particles into the organic solvent to obtain eluent; then, nitrogen is blown to concentrate the eluent to 0.8-1.2 mL, and the eluent is filtered to obtain a solution to be detected; wherein the organic solvent is acetonitrile and methanol in a volume ratio of 3-4: 1;
fifthly, loading the agricultural product on a machine, analyzing the liquid to be measured by adopting an ultra-high performance liquid chromatography triple quadrupole tandem mass spectrometer, and performing qualitative and quantitative determination by adopting an external standard working curve method to obtain an accurate determination result of pesticide residues in the agricultural product;
the magnetic nano material is Fe3O4@SiO2@ mesoporous SiO2@ PDA magnetic nanomaterial, wherein PDA is polydopamine;
said Fe3O4@SiO2@ mesoporous SiO2The specific synthesis process of the @ PDA magnetic nano material is as follows:
s1 FeCl3·6H2O and ethylene glycol in a solid-to-liquid ratio of 1: mixing 50-60 g/mL, stirring at 200-300 rpm for 0.5-1 h under the action of magnetic stirring, and adding FeCl3·6H2Sodium acetate with the weight 2.5-3 times of that of O is continuously stirred for 0.5-1 hour at 200-300 r/min; continued addition of FeCl3·6H2Stirring a surfactant with the weight of 1.6-2 times that of O at 200-300 rpm for 15-25 minutes to obtain a mixed solution; transferring the mixed solution into a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, and heating and reacting for 10-13 hours at 180-200 ℃; separating and collecting the reaction product under the action of an external magnetic field, washing the reaction product by using absolute ethyl alcohol with the weight 40-60 times that of the reaction product, and drying the reaction product for 6-10 hours at the temperature of 40-50 ℃ and the vacuum degree of 0.07-0.09 MPa to obtain black solid Fe3O4Nano-microspheres;
s2 mixing Fe3O4The nano-microspheres are prepared from the following raw materials in a solid-to-liquid ratio of 2-3: adding 1mg/mL of the solution into hydrochloric acid with the molar concentration of 1-2 mol/L, carrying out ultrasonic treatment for 5-10 minutes under the conditions of ultrasonic power of 200-500W and ultrasonic frequency of 25-35 kHz, and then using Fe3O4Adding 80-200 times of deionized water to the weight of the nano microspheres to obtain Fe3O4Cleaning the nano microspheres; then washing the Fe3O4B, adding 8-12 times of hydrochloric acid into the nano microspheresAdding 28 mass percent concentrated ammonia water with the volume 0.09-0.1 times that of hydrochloric acid into a mixed solution with the volume ratio of alcohol to water of 4/1, and continuing performing ultrasonic treatment for 10-30 minutes under the conditions of ultrasonic power of 200-500W and ultrasonic frequency of 25-35 kHz to obtain a mixed solution; adding orthosilicate ester with the volume of 0.04-0.05 time of that of hydrochloric acid into the mixed solution, stirring and reacting for 5-7 hours at 25-30 ℃ at 200-300 r/min to complete hydrolysis and polycondensation of the orthosilicate ester, and collecting a reaction product; washing with absolute ethyl alcohol with the weight of 50-70 times of that of the reaction product, and drying for 6-10 hours at the temperature of 50-60 ℃ and the vacuum degree of 0.07-0.09 MPa to obtain Fe3O4@SiO2Magnetic nano-microspheres;
s3 mixing Fe3O4@SiO2The magnetic nano-microsphere, absolute ethyl alcohol and deionized water are mixed in a proportion of 1: 60-80: mixing 80g/mL/mL, and carrying out ultrasonic treatment for 15-20 minutes under the conditions of ultrasonic power of 200-500W and ultrasonic frequency of 25-35 kHz; then adding concentrated ammonia water with the mass fraction of 28% and Fe, wherein the volume of the concentrated ammonia water is 0.17-0.2 times of that of the deionized water3O4@SiO2Stirring cetyl trimethyl ammonium bromide 2-3 times the weight of the magnetic nano microspheres at 200-300 revolutions per minute for 30-40 minutes; continuously adding orthosilicate ester with the volume 0.4-0.5 times of that of ammonia water and 3-aminopropyltriethoxysilane with the volume 0.06-0.07 times of that of the ammonia water, and stirring and reacting at the temperature of 20-30 ℃ at 200-300 r/min for 12-15 hours; after the reaction is finished, centrifuging the reaction solution for 10-15 minutes at 2000-3000 r/min, and collecting bottom sediment; washing the bottom sediment with absolute ethyl alcohol with the weight 50-70 times that of the bottom sediment, and drying for 6-10 hours at the temperature of 40-50 ℃ and the vacuum degree of 0.07-0.09 MPa to obtain Fe3O4@SiO2@ mesoporous SiO2Magnetic nano-microspheres;
s4 weighing dopamine hydrochloride and Tris buffer solution with the molar concentration of 10mM, and mixing the solution in a solid-to-liquid ratio of 1: mixing at 0.8-1.2 mg/mL; followed by addition of Fe3O4@SiO2@ mesoporous SiO2Magnetic nanospheres, Fe3O4@SiO2The mass ratio of the magnetic nano microspheres to the dopamine hydrochloride is 1: 4-5, stirring and reacting for 16-20 hours at the temperature of 20-30 ℃ at 200-300 r/min; after the reaction is finished, centrifuging the reaction solution for 10-15 minutes at 2000-3000 r/min, and collecting the bottom solid; bottom with a coverWashing the partial solid with absolute ethyl alcohol with the weight of 50-70 times of that of the bottom solid and deionized water with the weight of 100-200 times of that of the bottom solid, and drying for 6-10 hours at the temperature of 50-60 ℃ and under the vacuum degree of 0.07-0.09 MPa to obtain the Fe3O4@SiO2@ mesoporous SiO2@ PDA magnetic nanomaterial.
2. The method for accurately detecting pesticide residues in agricultural products according to claim 1, wherein the amount of deionized water used for cleaning the magnetic nano material every time in the step (c) is 2-5 mL.
3. The method for accurately detecting pesticide residues in agricultural products according to claim 1, wherein the surfactant is one or more of polyethylene glycol, sodium citrate and ethylenediamine.
4. The method for accurately detecting pesticide residues in agricultural products according to any one of claims 1 to 3, wherein the orthosilicate is tetraethyl orthosilicate and butyl orthosilicate in a mass ratio of 4: 1, in a mixture of the components.
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| CN108918736B (en) * | 2018-08-08 | 2021-06-04 | 上海谱实生态环境科技有限公司 | Method for detecting pesticide residues on fruits and vegetables by using magnetic solid-phase extraction technology |
| CN109297777A (en) * | 2018-09-29 | 2019-02-01 | 浙江省农业科学院 | A kind of pre-treating method that grape pesticide residual detects and its purification adsorbent material used and application |
| CN114042440A (en) * | 2021-09-17 | 2022-02-15 | 中国药科大学 | Magnetic solid phase extraction adsorbent, preparation method and application |
| CN116448927B (en) * | 2023-04-10 | 2023-10-10 | 广东维安检测科技有限公司 | Method for detecting organic chlorine pesticide residues in astragalus |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101670107A (en) * | 2009-09-29 | 2010-03-17 | 哈尔滨工程大学 | Multifunctional nuclear shell structure drug carrier material and preparation method thereof |
| CN102706993A (en) * | 2012-05-31 | 2012-10-03 | 华中师范大学 | Method for determining residue of triazine pesticide in tea by dispersive liquid-liquid micro-extraction and magnetic solid-phase extraction |
| CN104237414A (en) * | 2014-09-22 | 2014-12-24 | 衢州出入境检验检疫局综合技术服务中心 | Method for simultaneously detecting various preservatives remaining in orange with liquid chromatograph/mass spectrometer |
| CN105664936A (en) * | 2016-01-07 | 2016-06-15 | 上海工程技术大学 | Method for preparing nano composite material having core-shell structure with dopamine as carbon source |
| CN105823766A (en) * | 2016-03-22 | 2016-08-03 | 北京大学 | Method for real-time quantitative fluorescent monitoring of molecular imprinting process and application |
| CN106496416A (en) * | 2016-11-10 | 2017-03-15 | 河北科技大学 | Mix the preparation method and applications of four template magnetic imprinted polymers |
| CN106622160A (en) * | 2017-01-05 | 2017-05-10 | 中国科学院理化技术研究所 | Multifunctional water-purifying sand, and preparation method and application thereof |
| CN106918656A (en) * | 2015-12-28 | 2017-07-04 | 天士力制药集团股份有限公司 | A kind of 153 kinds of methods of residues of pesticides in detection Yixinfumai particle |
| CN107037163A (en) * | 2017-04-13 | 2017-08-11 | 浙江省农业科学院 | The pre-treating method of many residues of pesticides during a kind of determination of the environment is biological |
| CN107286304A (en) * | 2017-07-06 | 2017-10-24 | 湖北大学 | Acryloyl group beta cyclodextrin POSS Fe3O4Magnetic particle is synthesized and applied |
-
2018
- 2018-01-02 CN CN201810001884.0A patent/CN108226341B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101670107A (en) * | 2009-09-29 | 2010-03-17 | 哈尔滨工程大学 | Multifunctional nuclear shell structure drug carrier material and preparation method thereof |
| CN102706993A (en) * | 2012-05-31 | 2012-10-03 | 华中师范大学 | Method for determining residue of triazine pesticide in tea by dispersive liquid-liquid micro-extraction and magnetic solid-phase extraction |
| CN104237414A (en) * | 2014-09-22 | 2014-12-24 | 衢州出入境检验检疫局综合技术服务中心 | Method for simultaneously detecting various preservatives remaining in orange with liquid chromatograph/mass spectrometer |
| CN106918656A (en) * | 2015-12-28 | 2017-07-04 | 天士力制药集团股份有限公司 | A kind of 153 kinds of methods of residues of pesticides in detection Yixinfumai particle |
| CN105664936A (en) * | 2016-01-07 | 2016-06-15 | 上海工程技术大学 | Method for preparing nano composite material having core-shell structure with dopamine as carbon source |
| CN105823766A (en) * | 2016-03-22 | 2016-08-03 | 北京大学 | Method for real-time quantitative fluorescent monitoring of molecular imprinting process and application |
| CN106496416A (en) * | 2016-11-10 | 2017-03-15 | 河北科技大学 | Mix the preparation method and applications of four template magnetic imprinted polymers |
| CN106622160A (en) * | 2017-01-05 | 2017-05-10 | 中国科学院理化技术研究所 | Multifunctional water-purifying sand, and preparation method and application thereof |
| CN107037163A (en) * | 2017-04-13 | 2017-08-11 | 浙江省农业科学院 | The pre-treating method of many residues of pesticides during a kind of determination of the environment is biological |
| CN107286304A (en) * | 2017-07-06 | 2017-10-24 | 湖北大学 | Acryloyl group beta cyclodextrin POSS Fe3O4Magnetic particle is synthesized and applied |
Non-Patent Citations (6)
| Title |
|---|
| Carbonized polydopamine as coating for solid-phase microextraction of organochlorine pesticides;Huang, Z. 等;《Journal of Chromatography A》;20150619;第1399卷;第8-17页 * |
| 孙婷.石墨烯复合材料的制备及其在样品前处理中的应用研究.《中国博士学位论文全文数据库 工程科技Ⅰ辑》.2016,(第8期),第B015-52页. * |
| 改性磁性纳米粒子用于有机农药萃取和富集的研究;杨露;《中国优秀硕士学位论文全文数据库工程科技Ⅰ辑》;20160215(第2期);第B014-995页 * |
| 氨基化修饰介孔Fe_3O_4@SiO_2@mSiO_2磁性吸附剂的制备及吸附性能的研究;成岳 等;《功能材料》;20171231;第48卷(第12期);第12135-12141页 * |
| 王远鹏.新型磁性微萃取技术的开发及其在食品中农药残留检测的应用研究.《中国博士学位论文全文数据库 工程科技Ⅰ辑》.2016,(第8期),第B014-398页. * |
| 磁性多壁碳纳米管净化技术快速测定甘蓝中10 种农药残留;曹慧 等;《分析试验室》;20151231;第34卷(第12期);第1480-1484页 * |
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