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1.
Photoirradiation surface molecularly imprinted polymers for the separation of 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin were synthesized using functionalized silica as a matrix, 4‐(phenyldiazenyl)phenol as a light‐sensitive monomer, and 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin as a template. Fourier transform infrared spectroscopy results indicated that 4‐(phenyldiazenyl)phenol was grafted onto the surface of functionalized silica. The obtained imprinted polymers exhibited specific recognition toward 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin. Equilibrium binding experiments showed that the photoirradiation surface molecularly imprinted polymers obtained the maximum adsorption amount of 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin at 20.5 mg/g. In binding kinetic experiments, the adsorption reached saturation within 2 h with binding capacity of 72.8%. The experimental results showed that the adsorption capacity and selectivity of imprinted polymers were effective for the separation of 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin, indicating that imprinted polymers could be used to isolate 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin from a conversion mixture containing β‐cyclodextrin and maltose. The results showed that the imprinted polymers prepared by this method were very promising for the selective separation of 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin.  相似文献   

2.
Molecularly imprinted polymers were synthesized using mixed tea saponins as a template and acrylamide‐β‐cyclodextrin as a cofunctional monomer for the specific binding and purification of tea saponins from the defatted cake extract of Camellia oleifera. The adsorption properties of the prepared polymers were systematically evaluated including adsorption kinetics, adsorption isotherms, and selective recognition characteristics. It showed that the adsorption kinetics followed the pseudo first‐order kinetic model (R2 = 0.995) with an equilibrium time of 3 h, adsorption isotherm data fitted well with the Langmuir–Freundlich model (R2 = 0.984) with an adsorption capacity of 14.23 mg/g. The relative selectivity coefficient (k´) in the presence of the analogues glycyrrhizic acid and glycyrrhetinic acid were 1.16 and 17.21, respectively. The performance of the molecularly imprinted polymers as solid‐phase extraction materials was investigated and the results indicated that using acrylamide‐β‐cyclodextrin as a cofunctional monomer improved both the adsorption capacity and active sites stability of the imprinted polymers. The solid‐phase extraction using the polymers as packing materials was subsequently applied for the separation of tea saponins in raw C. oleifera press extract, and targets were obtained with a purity reaching 89%.  相似文献   

3.
Erythromycin‐imprinted polymers with excellent recognition properties were prepared by an innovative strategy called distillation–precipitation polymerization. The interaction between erythromycin and methacrylic acid was studied by ultraviolet absorption spectroscopy, and the as‐prepared materials were characterized by Fourier‐transform infrared spectroscopy and scanning electron microscopy. Moreover, their binding performances were evaluated in detail by static, kinetic and selective sorption tests. It was found that the molecularly imprinted polymers afforded good morphology, monodispersity, and high adsorption capacity when the fraction of the monomers was 7 vol% in the whole reaction system, and the adsorption data for imprinted polymers correlated well with the Langmuir model. The maximum capacity of the imprinted and the non‐imprinted polymers for adsorbing erythromycin is 44.03 and 19.95 mg/g, respectively. The kinetic studies revealed that the adsorption process fitted a pseudo‐second‐order kinetic model. Furthermore, the imprinted polymers display higher affinity toward erythromycin, compared with its analogue roxithromycin.  相似文献   

4.
Magnetic molecularly imprinted polymers have attracted significant interest because of their multifunctionality of selective recognition of target molecules and rapid magnetic response. In this contribution, magnetic molecularly imprinted polymers were synthesized via surface‐initiated reversible addition addition‐fragmentation chain transfer polymerization using diethylstilbestrol as the template for the enrichment of synthetic estrogens. The uniform imprinted surface layer and the magnetic property of the magnetic molecularly imprinted polymers favored a fast binding kinetics and rapid analysis of target molecules. The static and selective binding experiments demonstrated a desirable adsorption capacity and good selectivity of the magnetic molecularly imprinted polymers in comparison to magnetic non‐molecularly imprinted polymers. Accordingly, a corresponding analytical method was developed in which magnetic molecularly imprinted polymers were employed as magnetic solid‐phase extraction materials for the concentration and determination of four synthetic estrogens (diethylstilbestrol, hexestrol, dienestrol, and bisphenol A) in fish pond water. The recoveries of these synthetic estrogens in spiked fish pond water samples ranged from 61.2 to 99.1% with a relative standard deviation of lower than 6.3%. This study provides a versatile approach to prepare well‐defined magnetic molecularly imprinted polymers sorbents for the analysis of synthetic estrogens in water solution.  相似文献   

5.
The first use of yeast as a support in the molecular imprinting field combined with atom transfer radical polymerization was described. Then, the as‐prepared molecularly imprinted polymers were characterized by Fourier transmission infrared spectrometry, scanning electron microscope, thermogravimetric analysis, and elemental analysis. The obtained imprinted polymers demonstrated elliptical‐shaped particles with the thickness of imprinting layer of 0.63 μm. The batch mode experiments were adopted to investigate the adsorption equilibrium, kinetics, and selectivity. The kinetic properties of imprinted polymers were well described by the pseudo‐second‐order kinetic equation, indicating the chemical process was the rate‐limiting step for the adsorption of cefalexin (CFX). The equilibrium data were well fitted by the Freundlich isotherm, and the multimolecular layers adsorption capacity of imprinted polymers was 34.07 mg g?1 at 298 K. The selectivity analysis suggested that the imprinted polymers exhibited excellent selective recognition for CFX in the presence of other compounds with related structure. Finally, the analytical method based on the imprinted polymers extraction coupled with high‐performance liquid chromatograph was successfully used for CFX analysis in spiked pork and water samples.  相似文献   

6.
Molecularly imprinted polymeric microspheres with a high recognition ability toward the template molecule, ellagic acid, were synthesized based on distillation–precipitation polymerization. The as‐obtained polymers were characterized by scanning electron microscopy, infrared spectroscopy, and thermogravimetric analysis. Static, dynamic, and selective binding tests were adopted to study the binding properties and the molecular recognition ability of the prepared polymers for ellagic acid. The results indicated that the maximum static adsorption capacity of the prepared polymers toward ellagic acid was 37.07 mg/g and the adsorption equilibrium time was about 100 min when the concentration of ellagic acid was 40 mg/mL. Molecularly imprinted polymeric microspheres were also highly selective toward ellagic acid compared with its analogue quercetin. It was found that the content of ellagic acid in the pomegranate peel extract was enhanced from 23 to 86% after such molecularly imprinted solid‐phase extraction process. This work provides an efficient way for effective separation and enrichment of ellagic acid from complex matrix, which is especially valuable in industrial production.  相似文献   

7.
Thermo‐responsive magnetic molecularly imprinted polymers were prepared by simple surface molecular imprinting polymerization for the selective adsorption and enrichment of formononetin from Trifolium pretense by temperature regulation. Using formononetin as a template, N‐isopropylacrylamide as the thermo‐responsive functional monomer, and methacrylic acid as an assisting functional monomer, the polymers were synthesized on the surface of the magnetic substrate. The results show that imprinted polymers attained controlled adsorption of formononetin in response to the temperature change, with large adsorption capacity (16.43 mg/g), fast kinetics (60 min) and good selectivity at 35°C compared with that at 25 and 45°C. The selectivity experiment indicated that the materials had excellent recognition ability for formononetin and the selectivity factors were between 1.32 and 2.98 towards genistein and daidzein. The excellent linearity was attained in the range of 5–100 μg/mL, with low detection limits and low quantitation limits of 0.017 and 0.063 μg/mL, respectively. Furthermore, the thermo‐responsive magnetic molecularly imprinted polymers were successfully utilized for enriching and purifying formononetin from Trifolium pretense. The analytical results indicate that the imprinted polymers are promising materials for selective identification and enrichment of formononetin in complicated herbal medicines by simple temperature‐responsive regulation.  相似文献   

8.
We developed a facile approach to the construction of bio‐recognition sites in silica nanoparticles for efficient separation of bovine hemoglobin based on amino‐functionalized silica nanoparticles grafting by 3‐aminopropyltriethoxylsilane providing hydrogen bonds with bovine hemoglobin through surface molecularly imprinting technology. The resulting amino‐functionalized silica surface molecularly imprinted polymers were characterized using scanning electron microscope, transmission electronic microscopy, Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and thermogravimetric analysis. Results showed that the as‐synthesized imprinted polymers exhibited spherical morphology and favorable thermal stability. The binding adsorption experiments showed that the imprinted polymers can reach equilibrium within 1 h. The Langmuir isotherm and pseudo‐second‐order kinetic model fitted the adsorption data well. Meanwhile, the imprinted polymers possessed a maximum binding capacity up to 90.3 mg/g and highly selectivity for the recognition of bovine hemoglobin. Moreover, such high binding capacity and selectivity retained after eight cycles, indicating the good stability and reusability of the imprinted polymers. Finally, successful application in the selective recognition of bovine hemoglobin from a real bovine blood sample indicated that the imprinted polymers displayed great potentials in efficient purification and separation of target proteins.  相似文献   

9.
In this study, novel photo‐stimulated molecularly imprinted polymers based on magnetic mesoporous carrier surface were developed for selective identification and intelligent separation of sulfamerazine in complex samples. The photosensitive monomer of the molecularly imprinted polymers was azobenzene derivative 5‐[(4‐(methacryloyloxy)phenyl) diazenyl] isophthalic acid with stimulus reaction mechanisms, which has photoisomerization between trans and cis for N=N bonds. Further, the properties of the photo‐stimulated molecularly imprinted polymers were further evaluated through several sets of adsorption experiments. It illustrated that the maximum adsorption amount is 0.45 mmol/L. By ultraviolet spectrophotometry, the material reaches typical characteristic peaks of photo sensitivity, and the cycle time is 16 min. Three adsorption and desorption processes were repeated, the adsorption rate reached 34.4%. Overall, the photo‐stimulated molecularly imprinted polymers can enrich and separate determine sulfamerazine with high selectivity, which have good recovery for real samples.  相似文献   

10.
In this study, novel monodisperse restricted access media‐molecularly imprinted polymers were successfully prepared by surface initiated reversible addition‐fragmentation chain transfer polymerization using monodisperse crosslinked poly (glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) microspheres as the carrier and acryloyl chloride‐modified β‐cyclodextrin as the hydrophilic functional monomer. The surface morphology, protein exclusion, and adsorption properties of the molecularly imprinted polymers were investigated. The results show that the material has excellent monodispersity and hydrophilicity, and simultaneously exhibit high adsorption capacity, fast binding kinetics, high selectivity, and significant thermal stability. The molecularly imprinted polymers as dispersive solid‐phase extraction adsorbent combined with reversed‐phase high‐performance liquid chromatography was used to selectively enrich, separate, and analyze trace 17β‐estradiol in milk samples. The recovery of 17β‐estradiol is 88–95% with relative standard deviation of <4%, and the limits of detection and quantification of this method are 2.08 and 9.29 µg/L, respectively. The novel restricted access media‐molecularly imprinted polymer adsorbents provide an effective method for the selective extraction and detection of 17β‐estradiol directly from complex samples.  相似文献   

11.
Ginsenoside Rg1 is a valuable bioactive molecule but its high polarity and low concentration in complex mixtures makes it a challenge to separate Ginsenoside Rg1 from other saponins with similar structures, resulting in low extraction efficiency. The successful development of effective Rg1 molecularly imprinted polymers that exhibit high selectivity and adsorption may offer an improved method for the enrichment of active compounds. In this work, molecularly imprinted polymers were prepared with two different methods, precipitation polymerization or surface imprinted polymerization. Comparison of the adsorption abilities showed higher adsorption of the surface molecularly imprinted polymers prepared by surface imprinted polymerization, 46.80 mg/g, compared to the 27.74 mg/g observed for the molecularly imprinted polymers prepared by precipitation polymerization. Therefore, for higher adsorption of the highly polar Rg1, surface imprinted polymerization is a superior technique to make Rg1 molecularly imprinted polymers. The prepared surface molecularly imprinted polymers were tested as a solid‐phase extraction column to directionally enrich Rg1 and its analogues from ginseng tea and total ginseng extracts. The column with surface molecularly imprinted polymers showed higher enrichment efficiency and better selectivity than a C18 solid‐phase extraction column. Overall, a new, innovative method was developed to efficiently enrich high‐polarity bioactive molecules present at low concentrations in complex matrices.  相似文献   

12.
Magnetic molecularly imprinted polymer nanoparticles for di‐(2‐ethylhexyl) phthalate were synthesized by surface imprinting technology with a sol–gel process and used for the selective and rapid adsorption and removal of di‐(2‐ethylhexyl) phthalate from aqueous solution. The prepared magnetic molecularly imprinted polymer nanoparticles were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and vibrating sample magnetometry. The adsorption of di‐(2‐ethylhexyl) phthalate onto the magnetic molecularly imprinted polymer was spontaneous and endothermic. The adsorption equilibrium was achieved within 1 h, the maximum adsorption capacity was 30.7 mg/g, and the adsorption process could be well described by Langmuir isotherm model and pseudo‐second‐order kinetic model. The magnetic molecularly imprinted polymer displayed a good adsorption selectivity for di‐(2‐ethylhexyl) phthalate with respect to dibutyl phthalate and di‐n‐octyl phthalate. The reusability of magnetic molecularly imprinted polymer was demonstrated for at least eight repeated cycles without significant loss in adsorption capacity. The adsorption efficiencies of the magnetic molecularly imprinted polymer toward di‐(2‐ethylhexyl) phthalate in real water samples were in the range of 98–100%. These results indicated that the prepared adsorbent could be used as an efficient and cost‐effective material for the removal of di‐(2‐ethylhexyl) phthalate from environmental water samples.  相似文献   

13.
In this work, dummy molecularly imprinted polymers with high selectivity and affinity to capsaicin and dihydrocapsaicin are designed using N‐vanillylnonanamide as a dummy template. The performance of dummy molecularly imprinted polymers and nonimprinted polymers was evaluated using adsorption isotherms, adsorption kinetics, and selective recognition capacity. Dummy molecularly imprinted polymers were found to exhibit good site accessibility, taking just 20 min to achieve adsorption equilibrium; they were also highly selective toward capsaicin and dihydrocapsaicin. We successfully used dummy molecularly imprinted polymers as a specific sorbent for selectively enriching capsaicin and dihydrocapsaicin from chili pepper samples. In a scaled‐up experiment, the selective recovery of capsaicinoids was calculated to be 77.8% using solid‐phase extraction. To the best of our knowledge, this is the first example of the use of N‐vanillylnonanamide as a dummy template in molecularly imprinted polymers to simultaneously enrich capsaicin and dihydrocapsaicin.  相似文献   

14.
A novel type of magnetic molecularly imprinted polymer was prepared for the selective enrichment and isolation of chelerythrine from Macleaya cordata (Willd) R. Br. The magnetic molecularly imprinted polymers were prepared using functional Fe3O4@SiO2 as a magnetic support, chelerythrine as template, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross‐linker. Density functional theory at the B3LYP/6‐31G (d, p) level with Gaussian 09 software was applied to calculate the interaction energies of chelerythrine, methacrylic acid and the complexes formed from chelerythrine and methacrylic acid in different ratios. The structural features and morphology of the synthesized polymers were characterized by using Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, and vibration sample magnetometry. Adsorption experiments revealed that the magnetic molecularly imprinted polymers possessed rapid kinetics, high selectivity, and a higher binding capacity (7.96 mg/g) to chelerythrine than magnetic molecularly non‐imprinted polymers (2.36 mg/g). The adsorption process was in good agreement with the Langmuir adsorption isotherm and pseudo‐second‐order kinetics models. Furthermore, the magnetic molecularly imprinted polymers were successfully employed as adsorbents for the extraction and enrichment of chelerythrine from Macleaya cordata (Willd) R. Br. The results indicated that the magnetic molecularly imprinted polymers were suitable for the selective adsorption of chelerythrine from complex samples such as natural medical plants.  相似文献   

15.
A novel molecularly imprinted solid‐phase extraction with spectrofluorimetry method has been developed for the selective extraction of telmisartan from human urine. Molecularly imprinted polymers were prepared by a noncovalent imprinting approach through UV‐radical polymerization using telmisartan as a template molecule, 2‐dimethylamino ethyl methacrylate as a functional monomer, ethylene glycol dimethacrylate as a cross‐linker, N,N‐azobisisobutyronitrile as an initiator, chloroform as a porogen. Molecularly imprinted polymers and nonimprinted control polymer sorbents were dry‐packed into solid‐phase extraction cartridges, and eluates from cartridges were analyzed using a spectrofluorimeter. Limit of detection and limit of quantitation values were 11.0 and 36.0 ng/mL, respectively. A very high imprinting factor (16.1) was achieved and recovery values for the telmisartan spiked in human urine were in the range of 76.1–79.1%. In addition, relatively low within‐day (0.14–1.6%) and between‐day (0.11–1.31%) precision values were obtained. Valsartan was used to evaluate the selectivity of sorbent as well. As a result, a sensitive, selective, and simple molecularly imprinted solid‐phase extraction with spectrofluorimetry method has been developed and successfully applied to the direct determination telmisartan in human urine.  相似文献   

16.
A type of surface imprinting over magnetic Fe3O4 nanoparticles utilizing erythromycin‐A as a template for use in the separation and recovery of erythromycin was developed and investigated. As the intermolecular forces play a key role in the performance of imprinted materials, differential scanning calorimetry, and 1H NMR spectroscopy was employed to evaluate the interactions between erythromycin and the functional monomer β‐cyclodextrin. To synthesize the surface imprinted polymers, magnetic Fe3O4 nanoparticles, the core materials, were modified with a free radical initiator to initialize polymerization in a “grafting from” manner. Then using acryloyl‐modified β‐cyclodextrin as the functional monomer and ethyleneglycol dimethacrylate as the cross‐linker, thin erythromycin‐imprinted films were fabricated by the radical‐induced graft copolymerization of monomers on the surface of the Fe3O4 nanoparticles. Selectivity experiments showed that the erythromycin‐A‐imprinted materials had recognition ability toward erythromycin derivatives. Finally, these magnetic molecularly imprinted particles were successfully used for the separation and enrichment of erythromycin from the mother liquor. The recovery, detected by high‐performance liquid chromatography and differential pulse voltammetry, approached 97%. The combination of the specific selectivity of the imprinted material and the magnetic separation provided a powerful tool that is simple, flexible, and selective for the separation and recovery of erythromycin.  相似文献   

17.
Molecularly imprinted polymers for strobilurin fungicides were prepared by precipitation polymerization employing azoxystrobin as template molecular together with methacrylic acid monomer and trimethylolpropane triacrylate cross‐linker. Morphological characterization showed molecularly imprinted polymers were uniform spherical particles with about 0.2 μm in diameter, while the morphologies of nonimprinted polymers were irregular bulk. The equilibrium binding and selective experiments proved that molecularly imprinted polymers possessed a higher affinity toward four fungicides compared to nonimprinted polymers and heterogeneous binding sites were found in the molecularly imprinted polymers. Molecularly imprinted solid‐phase extraction conditions, including sample loading solvents, selective washing, and elution solvents, were carefully optimized. The developed method showed good recoveries (70.0–114.0%) with relative standard deviations in range of 1.0–9.8% (n  =  3) for samples (cucumber and peach) spiked at three different levels (10, 50, and 100 μg/ kg). The detection limit (signal/noise = 3) ranged from 0.01 to 0.08 μg/kg. The results demonstrated good potential use of this convenient and highly efficient method for determining trace strobilurin fungicides in agricultural products.  相似文献   

18.
Estrone molecularly imprinted polymers were synthesized through the self‐polymerization of dopamine on the surface of silica gels, which had the characteristics of mild polymerization conditions, simple reaction procedure and good specific recognition ability for estrone. The estrone molecularly imprinted polymers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and nitrogen adsorption–desorption tests. The characterization confirmed that the imprinted polymers were successfully grafted on the surface of silica gels. Through investigating the adsorption performance, the prepared estrone molecularly imprinted polymers exhibited high adsorption capacity, fast mass transfer, as well as excellent selectivity toward estrone. The estrone molecularly imprinted polymers as the solid‐phase extraction adsorbent coupled with high‐performance liquid chromatography was developed to determine estrone from the milk samples. The developed estrone molecularly imprinted polymer solid‐phase extraction with high‐performance liquid chromatography method exhibited satisfactory specificity, precision, accuracy and good linearity relationship in the range of 0.2–20 μg/mL. The developed method is simple, fast, effective and high specificity method and it provides a new method to detect the residues of estrone in animal foods.  相似文献   

19.
Molecularly imprinted polymers (MIPs) for citrinin (Cit) with 1‐hydroxy‐2‐naphthoic acid (HNA) as mimic template were prepared and the molecularly imprinted SPE method was developed for the detection of Cit in rice with HPLC. The adsorption properties of HNA and Cit on the MIPs and nonimprinted polymers were investigated. It proved that MIPs showed higher selectivity adsorption to HNA and Cit than nonimprinted polymers were. The recoveries of Cit in rice were in the range of 86.7–97.7%. The spiked rice samples and five rice samples in Beijing market were detected using molecularly imprinted SPE method and satisfied results were obtained as discussed in this article.  相似文献   

20.
A simple, selective, and reproducible molecularly imprinted SPE coupled with HPLC method was developed for monitoring quinoxaline‐1,4‐dioxides in feeds. Molecularly imprinted polymers were synthesized in methanol using mequindox (MEQ) as template molecule and acrylamide as functional monomer by bulk polymerization. Under the optimum SPE conditions, the novel polymer sorbents can selectively extract and enrich carbadox, MEQ, quinocetone, and cyadox from a variety of feeds. The molecularly imprinted SPE cartridge was better than nonimprinted, C18, and HLB cartridges in terms of both recovery and precision. Mean recoveries of four quinoxaline‐1,4‐dioxides from six kinds of feeds spiked at 1.0, 10, and 100 mg/kg ranged between 75.2 and 94.7% with RSDs of less than 10%. The decision limits (CCαs) and the detection capabilities (CCβs) of four analytes were 0.15–0.20 mg/kg and 0.44–0.56 mg/kg, respectively. The class selectivity of the polymers was evaluated by checking three drugs with different molecular structures to that of MEQ.  相似文献   

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