CN104725547B - It is a kind of to distill the method that precipitation polymerization prepares melamine molecular engram polymer - Google Patents
It is a kind of to distill the method that precipitation polymerization prepares melamine molecular engram polymer Download PDFInfo
- Publication number
- CN104725547B CN104725547B CN201510060046.7A CN201510060046A CN104725547B CN 104725547 B CN104725547 B CN 104725547B CN 201510060046 A CN201510060046 A CN 201510060046A CN 104725547 B CN104725547 B CN 104725547B
- Authority
- CN
- China
- Prior art keywords
- melamine
- molecular engram
- engram polymer
- polymerization reaction
- polymer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
The present invention discloses a kind of method that distillation precipitation polymerization prepares melamine molecular engram polymer, and this method comprises the following steps：（1）Melamine, polymerization reaction monomer and divinylbenzene are dissolved in acetonitrile, stood；（2）To step（1）Solution in add initiator, deoxygenation, heating distills out acetonitrile；（3）Step（2）After distillation terminates, reacting liquid filtering after filter residue is extracted with methanol acetic acid mixed-liquor return, is dried, obtains melamine molecular engram polymer.The inventive method solves the molecularly imprinted polymer particle diameter heterogeneity that existing method is obtained, size is difficult to control, the problem of binding capacity is low, the inventive method is simple to operate, without complicated last handling process, the molecular blotting polymer microsphere of gained has good monodispersity, and binding capacity is up to 32~44 mg/g, available for the melamine for separating, detecting in sample.
Description
Technical field
The invention belongs to molecularly imprinted polymer field, and in particular to one kind distillation precipitation polymerization prepares melamine molecule
The method of imprinted polymer.
Background technology
Melamine（Melamine, MEL）, " extract of protein " is commonly called as, is a kind of important azacyclo- Organic Chemicals,
Nitrogen content is in 66% or so, the significantly larger than average nitrogen content of protein.Due to the defect of Various Methods for Determing Different Proteins, melamine
Amine is often doped into food or feed by illegal businessman, to improve the protein content index in food or feed detection.Animal
Experiment proves that long-term intake melamine can cause calculi in urinary system, or even can induce carcinoma of urinary bladder.It is 2008, well-known
It is exactly that milk powder is polluted by melamine that baby milk powder poisoning, which is traced it to its cause,.The Ministry of Public Health and relevant department's joint issue are public
Accuse, formulate melamine in breast and the temporary control and education value in dairy products：The Limited Doses of melamine are 1 in milk power for infant and young children
mg/kg.However, melamine event breaks out again after 2 years, the production and sales to China's Dairy Industry are brought seriously
Negative effect.Therefore, the detection method that trace melamine is remained in a kind of food samples such as dairy produce is set up, for ensureing
Consumer is healthy and safeguards that the stabilization of economic society is of great practical significance.
The detection method of current melamine mainly has high performance liquid chromatography, efficient liquid phase-mass spectrography, gas phase-mass spectrum
Method.But no matter which kind of method is used, all pre-treatment should be carried out to actual sample first.SPE is place before conventional sample
Reason technology, but conventional solid-phase extraction column is due to lacking the specific selection adsorption capacity to target components to be measured, it is difficult to effectively
Exclude interference of the complex sample matrix to component to be measured.
Molecular imprinting technology artificial synthesized can have the molecularly imprinted polymer of predetermined selectivity to target molecule
（Molecularly imprinted polymers, MIPs）, resulting MIPs has the corresponding of " lock-key " with target molecule
Identification relation, so with high selectivity.Secondly, MIPs also has high intensity（That is high temperature resistant, organic solvent-resistant, acid and alkali-resistance etc.）
Advantage.Therefore, the technology is quickly grown in recent years, be widely used to medical separation, food and environment measuring, antibody or by
The numerous areas such as body simulation catalysis, sensor, show good application prospect.Melamine molecular engram polymer can be right
Melamine in powdered milk sample effectively purify and be enriched with, and realizes that melamine is fast and accurately detected.
At present both at home and abroad it has been reported that close melamine molecular engram polymer preparation method mainly have precipitation polymerization and
Suspension polymerisation etc..Yang Weihai, the precipitation polymerization method for guarding the uses such as thunder rigidly are prepared for the molecularly imprinted polymer of melamine.Precipitation
Monomer used by reaction, crosslinking agent, initiator are generally dissolved in suitable solvent by polymerization, and the polymer produced in reaction is not because
It is dissolved in solvent and is precipitated with microballoon form.The usually used quantity of solvent of this method is larger, and the concentration of function monomer is relatively low, solvent
Selection it is more harsh.Wang Xindi is prepared for melamine imprinted material using suspension polymerization, and uses it for before milk powder
Processing.Suspension polymerization is typically that reactant is dissolved in organic solvent, is then transferred into the aqueous phase containing dispersion stabilizer, stirs
Mix and initiation reaction.But there is the stabilizers such as surfactant and be difficult to remove, the shortcomings of obtained component of polymer is complicated.
And the melamine molecular engram polymer and the binding capacity highest of melamine obtained using these above-mentioned methods is not yet
To 20 mg/g.
The content of the invention
The purpose of the present invention is that the above mentioned problem for overcoming prior art to exist is prepared there is provided one kind by distilling precipitation polymerization
The method of melamine molecular engram polymer.
The present invention realizes that the technical scheme that above-mentioned purpose is used is as follows：
It is a kind of to distill the method that precipitation polymerization prepares melamine molecular engram polymer, comprise the following steps：
（1）Melamine, polymerization reaction monomer and divinylbenzene are dissolved in acetonitrile, stood；
（2）To step（1）Solution in add initiator, deoxygenation, heating distills out acetonitrile；
（3）Step（2）After distillation terminates, reacting liquid filtering, filter residue is extracted with methanol-acetic acid mixed-liquor return, and elution is removed
Melamine molecule is removed, dries, obtains melamine molecular engram polymer.
Further, the mol ratio of the melamine and polymerization reaction monomer is preferably 1: (2 ~ 16).Preferred mole
Than for 1: (2 ~ 5).
Further, step（1）Solution in, the total volume concentration of polymerization reaction monomer and divinylbenzene is 5 ~ 7%, is gathered
The mol ratio for closing reaction monomers and divinylbenzene is 1: (4 ~ 7).
Further, the polymerization reaction monomer is methacrylic acid or methyl methacrylate.
Step（1）The standing stands 10 ~ 20 h preferably under conditions of lucifuge.
Further, the initiator is azodiisobutyronitrile or benzoyl peroxide.
Further, the initiator is preferably the 1 ~ 5% of polymerization reaction monomer and divinylbenzene gross mass.
Further, step（2）Distillation speed control steamed the acetonitrile of half in 1.5 ~ 2 hours.
Further, step（3）The volume ratio of methanol and acetic acid is preferably (10 ~ 8) in the methanol-acetic acid mixed liquor: 1.
The melamine molecular engram polymer prepared according to the above method is applied to the separation and detection of melamine.
The inventive method operation is relatively simple, and preparation condition is easily controllable, without complicated last handling process, and institute's score
Sub- imprinted polymer is that monodispersity is good, the microballoon of uniform particle diameter, and the particle diameter of microballoon is in 0.5~5 μm or so, binding capacity
Up to 32~44 mg/g.
Brief description of the drawings
Fig. 1 is the electron microscopic picture of the polymer of embodiment 1.
Fig. 2 is the infrared spectrogram of polymer.
Fig. 3 is the electron microscopic picture of the polymer of embodiment 2.
Fig. 4 is the combination isothermal curve of polymer and melamine.
Fig. 5 is the high-efficient liquid phase chromatogram of addition melamine (1 μ g/g) in powdered milk sample.
Embodiment
The present invention is described in further details below in conjunction with drawings and Examples.
The synthesis I of the MEL imprinted polymers of embodiment 1
Take melamine（MEL）0.22 g, the mL of methacrylic acid 0.60, the mL of divinylbenzene 5.0 are dissolved in 80 mL acetonitriles
In, ultrasonic 2 min is allowed to well mixed, and lucifuge is placed in there-necked flask after standing 12 h, then adds azodiisobutyronitrile
0.13 g, is passed through and is stirred after the min of argon gas deoxygenation 5 with 120 r/min speed and start heating water bath, about 30 min in room temperature
Acetonitrile boiling point is inside heated to, now starts to collect distillate, by controlling temperature, when steaming 40 mL acetonitriles in 1.5~2 h
Terminate reaction.It polymerize obtained emulsion, after ultrasound, suction filtration, filter residue is washed 3 times with methanol, uses methanol-acetic acid（9∶1,v/v）
24 h are extracted in cable type extractor according as eluant, eluent, are rinsed for several times with methanol afterwards, 50 DEG C of dryings of baking oven obtain trimerization
Cyanamide molecularly imprinted polymer（Molecularly imprinted polymers, MIPs）.In addition to template molecule MEL is not added with,
Non- imprinted polymer（Non-imprinted polymers, NIPs）Preparation method ibid.
Resulting polymers are as shown in Figure 1（A1 is MIPs, and A2 is NIPs）, it is seen that it can obtain that particle diameter is more uniform, single dispersing
The preferable microballoon of property.
Infrared spectrogram before and after elution is as shown in Figure 2（A is MEL, and b is the MIPs before elution, after c is elution
MIPs）, before elution, still there is MEL characteristic peak in polymer, after elution, MEL characteristic peak disappears in polymer, illustrates MEL
Through removing.
The synthesis II of the MEL imprinted polymers of embodiment 2
Methacrylic acid consumption is that 0.43 mL, divinylbenzene consumption are 3.57 mL, other condition be the same as Examples 1, institute
Obtain polymer as shown in Figure 3（B1 is MIPs, and B2 is NIPs）.
The synthesis III of the MEL imprinted polymers of embodiment 3
Take melamine（MEL）0.22 g, the mL of methyl methacrylate 0.80, the mL of divinylbenzene 5.0 are dissolved in 80 mL
In acetonitrile, ultrasonic 2 min is allowed to well mixed, and lucifuge is placed in there-necked flask after standing 12 h, then adds benzoyl peroxide first
The g of acyl 0.19, is passed through and is stirred after the min of argon gas deoxygenation 5 with 120 r/min speed and start heating water bath, about 30 in room temperature
Acetonitrile boiling point is heated in min, now starts to collect distillate, by controlling temperature, 40 mL acetonitriles is steamed in 1.5~2 h
When terminate reaction.Other conditions be the same as Example 1.The maximum binding capacity of the MEL imprinted polymers is 32.75 mg/g（Test side
Method be the same as Example 4）.
The binding capacity experiment of the MEL imprinted polymers of embodiment 4
Weigh 9 parts of MIPs or NIPs made from embodiment 1（50 mg）In 10 mL centrifuge tubes, except portion adds 5 mL first
Alcohol is as blank, and another 8 parts are separately added into concentration and are followed successively by 1.00,2.00,4.00,7.00,10.00,13.00,16.00,20.00
The mg/mL mL of MEL methanol solutions 5.The seal of tube will be centrifuged, 25 DEG C of h of constant temperature oscillation 24 in oscillator are put into, centrifugation is taken out, inhaled
Take supernatant high performance liquid chromatograph to determine MEL contents, calculate the binding capacities of MEL on polymer, draw static combination etc.
Warm line, as shown in Figure 4.
MIPs, NIPs combination thermoisopleth trend can be seen that with the increase of MEL concentration from Fig. 4, MIPs and NIPs's
Adsorbance is all in increase, still, and MIPs adsorbance is significantly greater than NIPs, MIPs and NIPs maximal absorptive capacities be respectively MIPs with
NIPs maximum binding capacity is respectively 44.04 mg/g and 17.05 mg/g, and this is due to MIPs with the sky with template molecule
Between the complementary three-dimensional hole of structure and functional group binding sites, these holes can be specifically bound with MEL, when these holes
After being all occupied, that is, it is adsorbed onto up to balance.And NIPs can only rely on non-specific adsorption, therefore MIPs has higher to MEL
Adsorption capacity, mainly trace effect result.
The selective binding experiment of the MEL imprinted polymers of embodiment 5
3 part of 50 mg MIPs is weighed into 10 mL centrifuge tubes, each mL of MEL methanol solutions 5 for adding 3.00 mg/mL；Together
When weigh 3 part of 50 mg MIPs in centrifuge tube, each cyanuric acid for adding 3.00 mg/mL（CYA）Methanol solution.By two groups
Sample liquid is placed in oscillator, is sampled after 25 DEG C of constant temperature oscillation 3h, and centrifugation determines the content of each material in supernatant.NIPs is by same
Sample operation is carried out.It the results are shown in Table 1.
MIPs the and NIPs binding abilities of table 1 compare
。
MIPs generally uses static allocation coefficient to the selection recognition performance of moleculeK P, separation factorα 、Relative separation factorsβ
To characterize.Static allocation coefficientK PDefinition be：
KP=Ci/Cj (1)
In formula,C i、C jConcentration of the substrate in polymer and solution is represented respectively.K PMIPs is embodied to Binding Capacity
The size of ability, bigger explanation binding ability is stronger.
Separation factorαDefinition be：
α=KP’/KP’’ (2)
K
P ’ WithK P ’’ The static allocation coefficient of template molecule and competition molecule is represented respectively.αShow MIPs to mould more greatly
The selection selectivity of plate molecule is better.Ifα<1 or near 1, then show MIPs to substrate without selectivity；Ifα>1 table
Bright, MIPs has certain selectivity to substrate.
Relative separation factorsβIt is defined as follows：
β=αm/αn (3)
Whereinα mWithα nSeparation factors of the MIPs and NIPs to substrate is represented respectively.βMIPs and NIPs is embodied to divide
Difference in son identification and selection performance, that is, embody the quality of imprinting effect.βShow that imprinting effect is better more greatly.
As seen in Table 1, MIPs and NIPsK P(MEL)Significantly greater thanK P(CYA), illustrate that MIP is stronger to MEL binding ability.α MEL=2.8891>1,α CYA=0.9497, close to 1, show that MIP has certain selectivity to template molecule MEL, and to CYA not
With selectivity.
The SPE experiment of the MEL imprinted polymers of embodiment 6
Step 1：The preparation of molecular imprinted solid phase extraction cartridge
Each 0.2 g of MIPs and NIPs made from embodiment 1 are weighed, are respectively charged into polystyrene pillar（Column capacity 5
ML, the mm of diameter 8）, rinsed repeatedly with methanol, obtain solid phase extraction column, infiltrated with acetonitrile, it is standby.
Step 2：The preparation of sample solution
Four parts of 2 g commercially available dried milk powder is weighed, is respectively placed in 10 mL centrifuge tubes, three parts add high, medium and low concentration thereto
MEL standard items, the 4th part addition solvent acetonitrile-water（75: 25, v/v）It is used as blank control.It is subsequently added 10 mL acetonitrile-waters
（75: 25, v/v）, after the min of ultrasonic extraction 20,10 min are centrifuged with 10000 r/min, take supernatant standby.
Step 3：SPE
The above-mentioned mL of gained supernatant 5 is taken to be added to 1 mL/min speed in solid phase extraction column, with 2.0 mL second
Nitrile-methanol（3: 1, v/v）For leacheate, 3.0 mL methanol-ammoniacal liquor（9: 1, v/v）Extracted for eluent, finally will elution
Liquid is dried up with nitrogen, and 100 μ L are settled to mobile phase, high performance liquid chromatography detection is used.
SPE result
Such as Fig. 5（Before a is extraction, b is NIPs column extractings, and c is MIPs column extractings）It is shown, without the milk powder sample of SPE
Product are difficult to realize MEL detection, after SPE（MIPs and NIPs posts）, analyte MEL concentration all increases, can
Quantified.However, after MIPs column solid phase extractions, MEL concentration is bigger compared with through NIPs posts, illustrates MIPs posts enrichment degree more
Height, this comes from the MIPs affinities higher to MEL.Average recovery measurement result to MEL in powdered milk sample is shown in Table 2, MEL
Average recovery be 92.3~100.1%, RSD≤6.4%, detection be limited to 0.01 μ g/g.
MEL average recovery in the powdered milk sample of table 2（n=3）
。
Claims (6)
1. a kind of distill the method that precipitation polymerization prepares melamine molecular engram polymer, comprise the following steps：
（1）Melamine, polymerization reaction monomer and divinylbenzene are dissolved in acetonitrile, stood；
（2）To step（1）Solution in add initiator, deoxygenation, heating distills out acetonitrile；
（3）Step（2）After distillation terminates, reacting liquid filtering after filter residue is extracted with methanol-acetic acid mixed-liquor return, is dried, obtained
Melamine molecular engram polymer；
The mol ratio of the melamine and polymerization reaction monomer is 1: (2~16)；
Step（1）Solution in, the total volume concentration of polymerization reaction monomer and divinylbenzene is 5~7%, polymerization reaction monomer
Mol ratio with divinylbenzene is 1: (4~7)；
The initiator amount is the 1~5% of polymerization reaction monomer and divinylbenzene gross mass；
Step（2）Distillation speed control steamed the acetonitrile of half in 1.5~2 hours.
2. the method that distillation precipitation polymerization prepares melamine molecular engram polymer according to claim 1, its feature exists
In the polymerization reaction monomer is methacrylic acid or methyl methacrylate.
3. the method that distillation precipitation polymerization prepares melamine molecular engram polymer according to claim 1, its feature exists
In the initiator is azodiisobutyronitrile or benzoyl peroxide.
4. the method that distillation precipitation polymerization prepares melamine molecular engram polymer according to claim 1, its feature exists
In step（3）The volume ratio of methanol and acetic acid is (10~8) in the methanol-acetic acid mixed liquor: 1.
5. prepare melamine molecular engram polymer according to any methods describeds of claim 1-4.
6. melamine molecular engram polymer described in claim 5 is applied to the separation and detection of melamine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510060046.7A CN104725547B (en) | 2015-02-05 | 2015-02-05 | It is a kind of to distill the method that precipitation polymerization prepares melamine molecular engram polymer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510060046.7A CN104725547B (en) | 2015-02-05 | 2015-02-05 | It is a kind of to distill the method that precipitation polymerization prepares melamine molecular engram polymer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104725547A CN104725547A (en) | 2015-06-24 |
| CN104725547B true CN104725547B (en) | 2017-07-14 |
Family
ID=53450014
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510060046.7A Expired - Fee Related CN104725547B (en) | 2015-02-05 | 2015-02-05 | It is a kind of to distill the method that precipitation polymerization prepares melamine molecular engram polymer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104725547B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109503842A (en) * | 2018-11-16 | 2019-03-22 | 天津工业大学 | A kind of preparation method of the collosol and gel molecular engram microsphere for melamine detection |
| CN109839466A (en) * | 2019-01-24 | 2019-06-04 | 唐玉乐 | A method of testing melamine content in milk powder is detected based on three-dimensional magnetic molecularly imprinted polymer |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101559352A (en) * | 2009-05-15 | 2009-10-21 | 华南农业大学 | Molecularly imprinted polymers (MIPs) for inspecting melamine and preparation method thereof |
| CN101560277A (en) * | 2009-06-03 | 2009-10-21 | 中国农业科学院农业质量标准与检测技术研究所 | Melamine molecular engram polymer and method for preparing same |
| CN102000549A (en) * | 2010-09-28 | 2011-04-06 | 济南大学 | Preparation method and application of novel melamine molecule imprinting adsorbing material |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050276781A1 (en) * | 2004-06-09 | 2005-12-15 | Ross Edward A | Molecularly imprinted phosphate binders for therapeutic use |
-
2015
- 2015-02-05 CN CN201510060046.7A patent/CN104725547B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101559352A (en) * | 2009-05-15 | 2009-10-21 | 华南农业大学 | Molecularly imprinted polymers (MIPs) for inspecting melamine and preparation method thereof |
| CN101560277A (en) * | 2009-06-03 | 2009-10-21 | 中国农业科学院农业质量标准与检测技术研究所 | Melamine molecular engram polymer and method for preparing same |
| CN102000549A (en) * | 2010-09-28 | 2011-04-06 | 济南大学 | Preparation method and application of novel melamine molecule imprinting adsorbing material |
Non-Patent Citations (2)
| Title |
|---|
| Kaiguang Yang et al.One-Pot Synthesis of Hydrophilic molecularly imprinted nanoparticles.《Macromolecules》.2009,第8739-8746页. * |
| 沉淀聚合法制备三聚氰胺分子印迹聚合物微球;杨卫海等;《高分子学报》;20101031(第10期);第1163-1169页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104725547A (en) | 2015-06-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109293938A (en) | Prepare the composite material of metallic framework compound binding molecule imprinted polymer | |
| CN105233801B (en) | A kind of preparation method of the affine dual identification molecular engram material of boron | |
| CN106810638A (en) | The preparation method and application of Sulfonamides hydrophilic magnetic molecular engram material | |
| Cai et al. | Preparation of monodisperse, restricted-access, media-molecularly imprinted polymers using bi-functional monomers for solid-phase extraction of sarafloxacin from complex samples | |
| CN104193875B (en) | The preparation method of stilboestrol magnetic molecularly imprinted polymer and application thereof | |
| Zhu et al. | Development and characterization of molecularly imprinted polymer microspheres for the selective detection of kaempferol in traditional Chinese medicines | |
| Javanbakht et al. | Extraction and purification of penicillin G from fermentation broth by water-compatible molecularly imprinted polymers | |
| CN102924645A (en) | Preparation method and application of molecularly imprinted polymer of penicillin antibiotics and intermediate of penicillin antibiotics | |
| CN108452784A (en) | Catecholamine Solid Phase Extraction functional composite material and its preparation method and application | |
| CN104725547B (en) | It is a kind of to distill the method that precipitation polymerization prepares melamine molecular engram polymer | |
| Qiu et al. | Fabrication of novel stir bar sorptive extraction coating based on magnetic molecularly imprinted polymer through atom transfer radical polymerization for trace analysis of estrogens in milk | |
| CN103949228A (en) | Preparation method of molecularly-imprinted magnetic silica microsphere with hydrophilic external surface | |
| CN101337960A (en) | Process for extracting matrine form Chinese traditional medicine extract | |
| CN104174390B (en) | The preparation method and application of ethopabate molecular imprinted solid phase extraction cartridge | |
| CN105498721A (en) | Aflatoxin molecularly imprinted material and preparation method thereof | |
| CN104910339A (en) | Magnetic molecular imprinting polyion liquid for detecting ractopamine as well as preparation method and application of magnetic molecular imprinting polyion liquid | |
| Luo et al. | Molecularly imprinted layer-coated monodisperse spherical silica microparticles toward affinity-enrichment of isoflavonoid glycosides from Radix puerariae | |
| CN109046278A (en) | A kind of preparation method and application of the hollow micro- shell of gang form molecularly imprinted polymer | |
| CN106279488B (en) | The preparation for the molecularly imprinted polymer that three kinds of alkaloids of sandliving sophora seed extract at the same time and extracting process | |
| CN100586965C (en) | Method of preparing benzodiazepines pharmaceutical molecular engram solid phase extractant | |
| CN105801751A (en) | Preparation and application of MIP (molecularly imprinted polymer) with tropane alkaloid drug specificity | |
| CN107552018A (en) | A kind of Acetamiprid molecularly imprinted solid phase extraction column and its preparation method and application | |
| CN105289532A (en) | Molecularly-imprinted solid-phase extraction magnetic material for vitamin B12 and preparation method and application thereof | |
| CN103520955B (en) | Molecular-imprinting integral stirring and adsorbing bar and preparation method thereof | |
| Lu et al. | Surface molecularly imprinted polymers prepared by two‐step precipitation polymerization for the selective extraction of oleanolic acid from grape pomace extract |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20170714 Termination date: 20180205 |