CN111007186A - Method for measuring pesticide and metabolite residues in tea - Google Patents
Method for measuring pesticide and metabolite residues in tea Download PDFInfo
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- CN111007186A CN111007186A CN201911407108.1A CN201911407108A CN111007186A CN 111007186 A CN111007186 A CN 111007186A CN 201911407108 A CN201911407108 A CN 201911407108A CN 111007186 A CN111007186 A CN 111007186A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/26—Conditioning of the fluid carrier; Flow patterns
- G01N30/28—Control of physical parameters of the fluid carrier
- G01N30/30—Control of physical parameters of the fluid carrier of temperature
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/26—Conditioning of the fluid carrier; Flow patterns
- G01N30/28—Control of physical parameters of the fluid carrier
- G01N30/34—Control of physical parameters of the fluid carrier of fluid composition, e.g. gradient
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/62—Detectors specially adapted therefor
- G01N30/72—Mass spectrometers
Abstract
The invention relates to a method for measuring pesticide and metabolite residues in tea, which comprises the following steps: step S1, extracting; and step S2, purification. The organic reagent consumption is reduced, toluene is not used, and the harm to the environment and experimenters is reduced; the operation flow is improved, and the production efficiency is obviously improved; the consumption of consumables and equipment is reduced, and the cost is reduced.
Description
Technical Field
The invention relates to the technical field related to food safety detection, in particular to a method for measuring pesticide and metabolite residues in tea.
Background
With the increasing demand of drinking tea at home and abroad, the problem of pesticide residue becomes a problem of food safety and ecology, so that the pesticide residue in the tea leaves must be actively and effectively detected. Various detection methods for pesticide residues in tea have been developed at present, and with the increasing detection requirements, new requirements on the aspects of efficiency, cost and the like of the detection methods are provided.
The national standard GB23200.13-2016 specifies a method for measuring the residual quantity of 448 pesticides and related chemicals in tea. The method comprises the steps of extracting with acetonitrile, purifying with a solid phase extraction column, eluting pesticides and related chemicals with acetonitrile-toluene solution (3+1), detecting with a liquid chromatography-tandem mass spectrometer, and quantifying by an external standard method. The specific operation is as follows:
extraction: 10g of sample (exactly 0.01g) are weighed into a 50mL centrifuge tube, 30mL of acetonitrile solution are added, homogenized and extracted for 1min at 15000r/min on a high-speed tissue triturator, centrifuged for 5min at 4200r/min, and the supernatant is transferred into a heart-shaped flask. Adding 30mL of acetonitrile into the residue, homogenizing for 1min, centrifuging at 4200r/min for 5min, adding the supernatant into a heart-shaped bottle, adding 20mL of acetonitrile into the residue, repeatedly extracting once, adding the supernatant into the heart-shaped bottle, carrying out water bath at 45 ℃, carrying out rotary concentration until the supernatant is nearly dry, blowing nitrogen to the dry, adding 5mL of acetonitrile into the mixture to dissolve the residue, and taking 1mL of the solution to be purified.
Purifying: about 2cm of high anhydrous sodium sulfate was added to the Cleanet-TPT column and the column was placed into a holder followed by a heart-shaped bottle. The column was pre-washed with 5mL of acetonitrile-toluene solution before loading, and when the liquid level reached the top of the sodium sulfate, the sample extract was quickly transferred to the purification column and received by changing a new heart-shaped vial. Adding a 50mL liquid reservoir on a Cleanert TPT column, eluting pesticides and related chemicals by using 25mL acetonitrile-toluene solution, combining the pesticides and the related chemicals in a heart-shaped bottle, performing rotary concentration in a water bath at 45 ℃ to about 0.5mL, performing nitrogen blow-drying at 35 ℃, dissolving residues by using 1mL acetonitrile-water solution, filtering by using a 0.2 mu m microporous filter membrane, and performing liquid chromatography-tandem mass spectrometry.
The prior art has the following disadvantages:
1. the organic reagent is used more, and the carcinogenic reagent toluene is contained, so that the harm to the environment and experimenters is great;
2. the operation flow is complicated, three times of organic reagents are required to be added in the extraction process for concentration and enrichment, a solid phase extraction column is used for purification in the purification process, the column is required to be pre-washed, sample liquid is loaded on the column, elution, concentration, nitrogen blow-drying, redissolution filtration and other steps are required, and the consumed time is long;
3. the reagent consumption is large, and the cost is higher.
In view of the above-mentioned drawbacks, the present designer has made active research and innovation to develop a method for measuring the residual amounts of pesticide and metabolites thereof in tea leaves, so that the method has industrial utility value.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide a method for measuring the residual quantity of pesticides and metabolites thereof in tea.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for measuring pesticide and metabolite residues in tea comprises the following steps:
step S1, extraction: weighing 2g of sample in a 50mL centrifuge tube, adding 10mL of water, manually shaking, standing for 10min, adding a certain amount of internal standard solution and 10mL of acetonitrile, tightly covering a cover, horizontally placing on a shaking table, shaking for 10min at 300r/min, adding a prepared buffer salt mixture, tightly covering the cover, immediately manually shaking for 10s to avoid agglomeration of magnesium sulfate, horizontally placing on the shaking table, shaking for 20min at 300r/min, and centrifuging for 5min at 4000 rpm;
step S2, purge: sucking 1.5mL of the extractive solution, placing into a 2mL small centrifuge tube containing 20mg of PSA, 7.5mg of GCB and 143mg of magnesium sulfate, covering the cover tightly, vortexing for 10s, centrifuging at 14, 200RCF for 5min by a high-speed refrigerated centrifuge, taking the supernatant, transferring to a sample bottle through a 0.22 μm organic phase filtration membrane, and performing LC-MS/MS detection.
As a further improvement of the present invention, the liquid phase system: agilent1260 series; a chromatographic column: luna C18, 5um, 150 x 2 mm; mobile phase: a: water + 0.05% acetic acid + 0.05% ammonium acetate, B: methanol + 0.05% acetic acid; sample introduction volume: 10 uL; temperature of the column oven: 30 ℃; wherein the mobile phase gradient is as follows:
as a further improvement of the present invention, a mass spectrometry system: applied Biosystems API 4500; an ionization mode: carrying out electric spraying; ionization mode: positive & negative; spraying voltage: + 5500V/-4500V.
As a further development of the invention, the buffer salt mixture: 4g of anhydrous magnesium sulfate, 1g of sodium chloride, 1g of trisodium citrate dihydrate and 0.5g of disodium citrate hydrate.
As a further improvement of the invention, 10 μ L of 5% acetic acid/acetonitrile was added to the vial to increase the stability of a portion of the pesticide.
By the scheme, the invention at least has the following advantages:
1. the use amount of the organic reagent is reduced, and toluene is not used, so that the harm to the environment and experimenters is reduced;
2. the operation flow is improved, and the production efficiency is obviously improved;
3. the consumption of consumables and equipment is reduced, and the cost is reduced;
4. the stability and the extraction efficiency of pesticides with different properties are ensured by adopting a buffer salt system;
5. the production efficiency is improved by adopting dispersed solid phase extraction purification;
6. the stability of part of the pesticide is improved by adding a small amount of acetic acid.
The foregoing is a summary of the present invention, and in order to provide a clear understanding of the technical means of the present invention and to be implemented in accordance with the present specification, the following is a detailed description of the preferred embodiments of the present invention.
Detailed Description
The following examples are given to further illustrate the embodiments of the present invention. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention that are generally shown herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
Examples
The experimental conditions of the method for measuring the residual quantity of the pesticide and the metabolite thereof in the tea are as follows:
the detection principle is as follows: extracting a sample in a buffer salt environment by using water and acetonitrile, performing dispersed solid phase extraction and purification, detecting by using a liquid chromatogram-tandem mass spectrometer, and quantifying by using an external standard method.
Reagents/consumables: all reagents and chemicals were in chromatographic order, except for special indications.
Water for analytical experiments, acetonitrile, methanol, glacial acetic acid, anhydrous sodium sulfate, AR grade, sodium bicarbonate, analytical grade, ammonium acetate (analytical grade), anhydrous magnesium sulfate (analytical grade), sodium chloride (analytical grade), disodium citrate 1.5 hydrate (analytical grade), trisodium citrate dihydrate (analytical grade), PSA (ethylenediamine-N-propylsilane), GCB (graphitized carbon black), 50mL centrifuge tube, sample injection glass bottle, 2mL centrifuge tube, 2mL needleless syringe, 0.22 μm organic phase needle filter (nylon).
The instrument equipment comprises:
centrifuge 1 (suitable for 50mL centrifuge tube and rotation speed is more than or equal to 3000rpm), centrifuge 2 (suitable for 2mL centrifuge tube and rotation speed is more than or equal to 6000 rmp).
An analytical balance (precision 0.02g), a bottle mouth liquid distributor, a liquid transfer device (range is 10-100 muL, 200-.
Step S1, extraction: weigh 2g of sample (exactly 0.01g) into a 50mL centrifuge tube, add 10mL of water, shake by hand and then stand for 10 min. Adding a certain amount of internal standard solution and 10mL of acetonitrile, tightly covering the cover, horizontally placing on a shaking table at 300r/min, and shaking for 10 min. The prepared buffer salt mixture (4g of anhydrous magnesium sulfate, 1g of sodium chloride, 1g of trisodium citrate dihydrate and 0.5g of disodium citrate hydrate) was added, the lid was closed, the mixture was immediately shaken manually for about 10s to avoid agglomeration of the magnesium sulfate, the mixture was horizontally placed on a shaker at 300r/min for 20min, and centrifuged at 4000rpm for 5 min.
Step S2, purge: 1.5mL of the extract was aspirated and put into a 2mL small centrifuge tube containing 20mg of PSA, 7.5mg of GCB, and 143mg of magnesium sulfate. The lid was closed, vortexed for about 10 seconds, centrifuged at 14, 200RCF for 5min in a high speed refrigerated centrifuge, and the supernatant was transferred through a 0.22 μm organic phase filtration membrane to a sample vial (10 μ L of 5% acetic acid/acetonitrile was added to the vial to improve partial pesticide stability) for LC-MS/MS detection.
Setting an instrument:
liquid phase system: agilent1260 series
A chromatographic column: luna C18, 5um, 150 x 2mm
Mobile phase: a: water + 0.05% acetic acid + 0.05% ammonium acetate, B: methanol + 0.05% acetic acid
Gradient:
sample introduction volume: 10uL
Temperature of the column oven: 30 deg.C
Mass spectrometry system: applied Biosystems API 4500
An ionization mode: electrospray ionization
Ionization mode: plus & minus
Spraying voltage: +5500V/-4500V
A method for measuring pesticide and metabolite residues in tea comprises the following steps:
step S1, extraction: weighing 2g of sample in a 50mL centrifuge tube, adding 10mL of water, manually shaking, standing for 10min, adding a certain amount of internal standard solution and 10mL of acetonitrile, tightly covering a cover, horizontally placing on a shaking table, shaking for 10min at 300r/min, adding a prepared buffer salt mixture, tightly covering the cover, immediately manually shaking for 10s to avoid agglomeration of magnesium sulfate, horizontally placing on the shaking table, shaking for 20min at 300r/min, and centrifuging for 5min at 4000 rpm;
step S2, purge: sucking 1.5mL of the extractive solution, placing into a 2mL small centrifuge tube containing 20mg of PSA, 7.5mg of GCB and 143mg of magnesium sulfate, covering the cover tightly, vortexing for 10s, centrifuging at 14, 200RCF for 5min by a high-speed refrigerated centrifuge, taking the supernatant, transferring to a sample bottle through a 0.22 μm organic phase filtration membrane, and performing LC-MS/MS detection.
Preferably, the liquid phase system: agilent1260 series; a chromatographic column: luna C18, 5um, 150 x 2 mm; mobile phase: a: water + 0.05% acetic acid + 0.05% ammonium acetate, B: methanol + 0.05% acetic acid; sample introduction volume: 10 uL; temperature of the column oven: 30 ℃; wherein the mobile phase gradient is as follows:
preferably, the mass spectrometry system: applied Biosystems API 4500; an ionization mode: carrying out electric spraying; ionization mode: positive & negative; spraying voltage: + 5500V/-4500V.
Preferably, the buffer salt mixture: 4g of anhydrous magnesium sulfate, 1g of sodium chloride, 1g of trisodium citrate dihydrate and 0.5g of disodium citrate hydrate.
Preferably, 10 μ L of 5% acetic acid/acetonitrile is added to the vial to improve partial pesticide stability.
The method for measuring the pesticide and metabolite residues in the tea specifically has the following advantages:
1. the use amount of the organic reagent is reduced, and toluene is not used, so that the harm to the environment and experimenters is reduced;
2. the operation flow is improved, and the production efficiency is obviously improved;
3. the consumption of consumables and equipment is reduced, and the cost is reduced;
4. the stability and the extraction efficiency of pesticides with different properties are ensured by adopting a buffer salt system;
5. the production efficiency is improved by adopting dispersed solid phase extraction purification;
6. the stability of part of the pesticide is improved by adding a small amount of acetic acid.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.
Claims (5)
1. A method for measuring pesticide and metabolite residual quantity in tea is characterized by comprising the following steps:
step S1, extraction: weighing 2g of sample in a 50mL centrifuge tube, adding 10mL of water, manually shaking, standing for 10min, adding a certain amount of internal standard solution and 10mL of acetonitrile, tightly covering a cover, horizontally placing on a shaking table, shaking for 10min at 300r/min, adding a prepared buffer salt mixture, tightly covering the cover, immediately manually shaking for 10s to avoid agglomeration of magnesium sulfate, horizontally placing on the shaking table, shaking for 20min at 300r/min, and centrifuging for 5min at 4000 rpm;
step S2, purge: sucking 1.5mL of the extractive solution, placing into a 2mL small centrifuge tube containing 20mg of PSA, 7.5mg of GCB and 143mg of magnesium sulfate, covering the cover tightly, vortexing for 10s, centrifuging at 14, 200RCF for 5min by a high-speed refrigerated centrifuge, taking the supernatant, transferring to a sample bottle through a 0.22 μm organic phase filtration membrane, and performing LC-MS/MS detection.
2. The method for measuring the residual quantity of the pesticide and the metabolite thereof in the tea leaves as claimed in claim 1, wherein the liquid phase system comprises: agilent1260 series; a chromatographic column: luna C18, 5um, 150 x 2 mm; mobile phase: a: water + 0.05% acetic acid + 0.05% ammonium acetate, B: methanol + 0.05% acetic acid; sample introduction volume: 10 uL; temperature of the column oven: at 30 ℃.
3. The method for measuring the residual quantity of the pesticide and the metabolites thereof in the tea leaves as claimed in claim 1, wherein the mass spectrometry system comprises: applied biosystems api 4500; an ionization mode: carrying out electric spraying; ionization mode: positive & negative; spraying voltage: + 5500V/-4500V.
4. The method for measuring the residual amount of the pesticide and the metabolite thereof in the tea leaves as claimed in claim 1, wherein the buffer salt mixture: 4g of anhydrous magnesium sulfate, 1g of sodium chloride, 1g of trisodium citrate dihydrate and 0.5g of disodium citrate hydrate.
5. The method for measuring the residual quantity of the pesticides and metabolites thereof in the tea leaves as claimed in claim 1, wherein 10 μ L of 5% acetic acid/acetonitrile is added into the sample injection bottle to improve the stability of part of pesticides.
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| CN201911407108.1A CN111007186A (en) | 2019-12-31 | 2019-12-31 | Method for measuring pesticide and metabolite residues in tea |
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| CN201911407108.1A CN111007186A (en) | 2019-12-31 | 2019-12-31 | Method for measuring pesticide and metabolite residues in tea |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112630087A (en) * | 2020-12-14 | 2021-04-09 | 锐德检测技术(天津)有限公司 | Method for determining fat in food |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107300598A (en) * | 2017-08-22 | 2017-10-27 | 福建出入境检验检疫局检验检疫技术中心 | It is a kind of to be used for the pre-treating method of Multiple Pesticides residue detection in tealeaves |
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- 2019-12-31 CN CN201911407108.1A patent/CN111007186A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107300598A (en) * | 2017-08-22 | 2017-10-27 | 福建出入境检验检疫局检验检疫技术中心 | It is a kind of to be used for the pre-treating method of Multiple Pesticides residue detection in tealeaves |
Non-Patent Citations (4)
| Title |
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| XUE LIU 等: "Pesticide Multi-Residue Analysis in Tea Using d-SPE Sample Cleanup with Graphene Mixed with Primary Secondary Amine and Graphitized Carbon Black Prior to LC-MS/MS", 《CHROMATOGRAPHIA》 * |
| 张桂云等: "分散固相萃取-超高效液相色谱串联质谱法测定茶叶中的7种农药残留", 《福州大学学报(自然科学版)》 * |
| 王敬 等: "液相色谱-串联质谱法测定植物源性食品中16种氨基甲酸酯类农药及其代谢物", 《食品安全质量检测学报》 * |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112630087A (en) * | 2020-12-14 | 2021-04-09 | 锐德检测技术(天津)有限公司 | Method for determining fat in food |
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Application publication date: 20200414 |