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1.
Anal Chim Acta ; 1178: 338849, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482875

RESUMO

Various mesoporous adsorbents are of great promise for enriching small molecules from biological samples based on the size-exclusion effect. At present, the mesoporous adsorbents have adsorption sites distributed uniformly on the internal and external surfaces of mesopores. However, the adsorption sites on the external surface can adsorb proteins, interfering with the enrichment of small molecules. Herein, a novel immobilized-Ti4+ magnetic mesoporous adsorbent removing the adsorption sites on the external surface was facile prepared via the coupling chemistry of isocyanate with amine and consequent hydrolysis of urea linkage by urease. The adsorbent enables fast and selective enrichment of phosphopeptides and nucleotides from biological samples. In addition, sensitive detection methods for phosphopeptides and nucleotides in human serum are developed by coupling the magnetic solid-phase extraction with matrix-assisted laser desorption/ionization time of flight mass spectrometry and liquid chromatography-mass spectrometer, respectively. Under optimal conditions, response is linear (R2 ≥ 0.9923), limits of detection are low (0.41-9.48 ng mL-1), and reproducibility is acceptable (inter- and intra-day assay RSDs of≤15.0%) for six nucleotides. The developed strategy offers an effective method to eliminate the interference of proteins in the enrichment of small molecules from real biological samples.


Assuntos
Nucleotídeos , Fosfopeptídeos , Adsorção , Humanos , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
2.
J Sep Sci ; 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34559936

RESUMO

Through a "one-pot" strategy, a layer of microporous organic polymer was coated onto the surface of monodisperse amino-functionalized silica microsphere via amino-aldehyde condensation reaction with core-shell structure. The change in chemical structure of material before and after modification was determined by Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Due to existence of a large number of amino and aldehyde groups in microporous organic polymer shell, the water contact angle decreased from 56.8° (silica microspheres) to 34.7° (microporous organic polymer-coated silica microspheres). Based on these properties, microporous organic polymer-coated silica microspheres were employed as the stationary phase for capillary liquid chromatography and successfully offered baseline separation of polar small molecules. Additionally, the material could also be served as the sorbent of hydrophilic interaction chromatography to enrich glycopeptides from human serum digest. A total of 470 unique N-glycopeptides and 342 N-glycosylation sites mapped to 112 N-glycosylated proteins were unambiguously identified from 2 µL of human serum, exhibiting a promising application prospect of microporous organic polymer-coated silica microspheres in the pretreatment of proteomics samples.

3.
J Colloid Interface Sci ; 586: 683-691, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33223238

RESUMO

As an important biomarker, the analysis of cytochrome c (Cyt c) plays a crucial role in cell-apoptosis or even cancer diagnosis. This work develops a label-free probe for Cyt c using the nitrogen and fluorine co-doped carbon dots (N, F-CDs) which were facile prepared through solvothermal method with 3, 4-difluorophenylhydrazine as precursor. The N, F-CDs have an average diameter of 3.4 nm, and can form a quite stable colloidal solution. The N, F-CDs show bright yellow-green fluorescence, excitation/emission wavelengths 475/530 nm, and a relatively high fluorescence quantum yield of 16.9%. Interestingly, the N, F-CDs indicate a linear and reversible variation of emission intensity with a sensitivity of -1.11% per ℃ in the temperature range from 25 to 60 ℃. Inner filter effect (IFE) between N, F-CDs and Cyt c turns the fluorescence of N, F-CDs from "on" to "off". The sensor possesses the excellent anti-interference ability towards the main components of plasma. Under optimum conditions, there is a linear relationship between fluorescence intensity function (F0-F) and the concentration of Cyt c in the range of 0.5-25 µΜ with a limit of detection (LOD) (S/N = 3) of 0.25 µM. Finally, the developed method has been successfully used to detect Cyt c in human serum sample with satisfactory recoveries in a range of 93.14-110.40%.


Assuntos
Citocromos c , Pontos Quânticos , Carbono , Flúor , Humanos , Nitrogênio , Temperatura
4.
Mikrochim Acta ; 187(8): 472, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32725323

RESUMO

An immobilized metal affinity (IMA) adsorbent was prepared by grafting bottlebrush polymer pendant with iminodiacetic acid (IDA) from the surface of polydopamine (PDA)-coated magnetic graphene oxide (magGO), via surface-initiated atom transfer radical polymerization (SI-ATRP). Poly(hydroxyethyl methacrylate) (PHEMA) was grafted firstly from the PDA-coated magGO as the backbone, and then poly(glycidyl methacrylate) was grafted from the PHEMA chains via the second SI-ATRP to afford the bottlebrush polymer-grafted magGO Thereafter, IDA was anchored on the nanocomposites to produce the IMA adsorbent after chelating copper ions. The adsorbent was characterized by various physical and physicochemical methods. Its adsorption properties were evaluated by using histidine-rich proteins (bovine hemoglobin, BHb) and other proteins (lysozyme and cytochrome-C). The results show that its maximum adsorption capacity to BHb was 378.6 mg g-1, and the adsorption equilibrium can be quickly reached within 1 h. The adsorbent has excellent reproducibility and reusability. It has been applied to selectively purify hemoglobin from human whole blood, indicating its potential in practical applications. Graphical abstract.


Assuntos
Grafite/química , Hemoglobinas/isolamento & purificação , Adsorção , Animais , Bovinos , Cobre/química , Humanos , Iminoácidos/química , Indóis/química , Extração Líquido-Líquido/métodos , Fenômenos Magnéticos , Poli-Hidroxietil Metacrilato/química , Polímeros/química , Ácidos Polimetacrílicos/química , Reprodutibilidade dos Testes
5.
J Sep Sci ; 43(15): 3110-3119, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32468707

RESUMO

Graphene oxide has received extensive attention because of its unique properties and potential applications. In this study, magnetic nitrogen-doped graphene was prepared by one-step hydrothermal reaction using urea as the dopant and reductant, and ferroferric oxide nanoparticles were in situ deposited on the surface of the nanohybrids. The magnetic nitrogen-doped graphene was characterized using various physical and chemical methods. It was used as a new adsorbent for the magnetic solid-phase extraction of four nonsteroidal anti-inflammatory drugs from the river water. The parameters influencing the extraction efficiency were optimized in detail. Under optimal conditions, this method provided a wide linear range (5-200 ng/mL). The limits of detection were in the range of 1.07-5.10 ng/mL. The recoveries varied from 81.2 to 121.5% with relative standard deviations of less than 10.8%. Overall, we can conclude that the proposed method offers an efficient pretreatment and enrichment and can be successfully applied for the extraction and determination of nonsteroidal anti-inflammatory drugs in complex matrices.


Assuntos
Anti-Inflamatórios não Esteroides/análise , Grafite/química , Nitrogênio/química , Extração em Fase Sólida , Temperatura , Poluentes Químicos da Água/análise , Fenômenos Magnéticos , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
6.
J Sep Sci ; 43(14): 2766-2772, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32419326

RESUMO

Poly(ionic liquid)-modified stationary phases can have multiple interactions with solutes. However, in most stationary phases, separation selectivity is adjusted by changing the poly(ionic liquid) anions. In this work, two poly(ionic liquid)-modified silica stationary phases were prepared by introducing the cyano or tetrazolyl group on the pendant imidazolium cation on the polymer chains. Various analytes were selected to investigate their mechanism of retention in the stationary phases using different mobile phases. Two poly(ionic liquid)-modified stationary phases can provide various interactions toward solutes. Compared to the cyano-functionalized poly(ionic liquid) stationary phase, the tetrazolyl-functionalized poly(ionic liquid) stationary phase provides additional cation-exchange and π-π interactions, resulting in different separation selectivity toward analytes. Finally, applicability of the developed stationary phases was demonstrated by the efficient separation of nonsteroidal anti-inflammatory drugs.

7.
ACS Appl Mater Interfaces ; 12(15): 17815-17823, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32216256

RESUMO

A novel porous organic cage (POC) was prepared via condensation reaction between 1,3,5-triformylbenzene (TFB) and (1R,2R)-4-cyclohexene-1,2-diamine (CHEDA). This POC could pack in either an amorphous structure or a crystalline one. Atomically precise structure determination of POC was achieved through ab initio powder X-ray diffraction (PXRD) structure analysis in the chiral trigonal space group R3. The same atomically precise structure determination of POC from single-crystal X-ray diffraction (SXRD) structure analysis could be obtained independently with a slight difference in cell parameter, indicating that the refinement method through ab initio PXRD structure analysis is reliable and may serve as an essential method for atomically precise structure determination. The cage could adsorb up to 8 mmol/g CO2 at 298 K and 1 bar. Furthermore, 1-thioglycerol and 1-octadecanethiol were chosen to prove that postmodification of this POC was flexible. After post-synthetic modification (PSM) via highly efficient photoinitiated thiol-ene click reaction, the products still kept porous with relatively higher special surface area (337 m2/g of 5T and 156 m2/g of 5O) than mostly reported cages via the reduced-amine approach.

8.
J Chromatogr A ; 1619: 460966, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32070476

RESUMO

Stationary phases with multiple-mode mechanism are beneficial to meet the needs of complex samples, but there are few multiple-mode stationary phases which can adjust the relative strength among multiple-forces imposed on the solutes. This work presents a facile preparation method of reverse-phase/hydrophilic interaction/ion-exchange tri-mode stationary phase, in which three functional monomers, lauryl methacrylate (LMA), hydroxyethyl methylacrylate (HEMA) and dimethylaminoethyl methacrylate (DMAEMA) as co-monomers underwent surface initiated-atom transfer radical polymerization (SI-ATRP) on the surface of silica. The structure of stationary phases was characterized and their chromatographic properties were investigated using various solutes. By comparison with classical single-mode columns, it is found that the newly designed columns can offer multiple interactions including hydrophobic, hydrophilic and electrostatic interactions and show good separation abilities to the tested solutes. Besides, changing the ratios of LMA, HEMA and DMAEMA in SI-ATRP system can easily adjust the relative strength of three interactions imposed on the solutes, inducing adjustable separation selectivity of the columns. The improved separation of multivitamin sample and the successful use of the columns in Per aqueous liquid chromatography indicate the potential of the tri-mode stationary phases.


Assuntos
Cromatografia por Troca Iônica , Cromatografia Líquida , Cromatografia de Fase Reversa , Metacrilatos/química , Polímeros/síntese química , Interações Hidrofóbicas e Hidrofílicas , Polimerização , Dióxido de Silício/química , Eletricidade Estática
9.
Mikrochim Acta ; 187(1): 77, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31894422

RESUMO

Amino-functionalized polyhedral oligomeric silsesquioxanes (POSS-8NH2) were covalently bound to the surface of polydopamine-coated magnetized graphene oxide. It was then reacted with 4-formylphenylboronic acid to prepare a "cubic boronic acid"-bonded magnetic graphene oxide adsorbent. The new adsorbent exhibits better selectivity and much higher adsorption capacity for ortho-phenols over adsorbents where small boronic ligands are directly bound to the surface of the material. It is shown to enable selective and faster enrichment of the catecholamines epinephrine (EP), dopamine (DA) and isoprenaline (IP) with high selectivity over many potential interferents that can occur in urine. The analytes were then quantified by HPLC with fluorometric detection. Under optimal conditions, response is linear (R2 ≥ 0.9907), limits of detection are low (0.54-2.3 ng·mL-1), and reproducibility is acceptable (inter- and intra-day assay RSDs of≤10.9%). The method was successfully applied to the determination of endogenous EP and DA and exogenous IP in urine samples. Graphical abstractSchematic of boronic acid (BA)-modified polyhedral oligomeric silsesquioxanes (POSS) on polydopamine-coated magnetized graphene oxide (magGO). The material (magGO@POSS-BA) has good selectivity and higher adsorption capacity to ortho-phenols and can be applied to enrich the catecholamines in urine.


Assuntos
Ácidos Borônicos/química , Catecolaminas/isolamento & purificação , Grafite/química , Indóis/química , Compostos de Organossilício/química , Polímeros/química , Adsorção , Catecolaminas/urina , Dopamina/isolamento & purificação , Dopamina/urina , Epinefrina/isolamento & purificação , Epinefrina/urina , Isoproterenol/isolamento & purificação , Isoproterenol/urina , Limite de Detecção , Magnetismo , Reprodutibilidade dos Testes
10.
Anal Chim Acta ; 1093: 61-74, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31735216

RESUMO

Covalent organic frameworks (COFs) have been increasingly employed in separation science, including sample preparation. Herein we fabricated the amino bearing core-shell structured COFs nanospheres [Fe3O4@TpBD(NH2)2], and a novel magnetic boronate affinity adsorbent was synthesized by postsynthetic modification of the Fe3O4@TpBD(NH2)2 with 2-formylphenylboronic acid. The magnetic boronate affinity adsorbent possesses fast magnetic response and high binding capacity up to 1037 µmol g-1 for dopamine. Besides, it was used as an adsorbent for extraction of urinary monoamine neurotransmitters at neutral pH. A method for detection of the monoamine neurotransmitters was developed by coupling the magnetic solid phase extraction with high-performance liquid chromatography-fluorescence detection. Under the optimized conditions, a good analytical method was obtained in the linear dynamic range of 2-200 ng mL-1 with R2 between 0.9917 and 0.9966, with low limit of detection (0.31-0.54 ng mL-1) and limit of quantification (1.04-1.80 ng mL-1). The recoveries of the monoamine neurotransmitters were in the range of 86.3-115%, with relative standard deviations of 2.34-10.5% (intra-day) and 2.84-14.4% (inter-day). The method was successfully applied to the determination of the monoamine neurotransmitters in human urine samples. This work is of great importance for preparing functionalized core-shell structured magnetic covalent organic framework nanospheres, it also demonstrates the feasibility of the functionalized magnetic COFs as adsorbents in sample pretreatment.


Assuntos
Monoaminas Biogênicas/urina , Ácidos Borônicos/química , Catecolaminas/urina , Estruturas Metalorgânicas/química , Nanosferas/química , Neurotransmissores/urina , Adsorção , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Limite de Detecção , Nanopartículas de Magnetita/química , Estruturas Metalorgânicas/síntese química , Porosidade , Reprodutibilidade dos Testes , Extração em Fase Sólida/métodos
11.
Se Pu ; 38(4): 424-429, 2020 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-34213224

RESUMO

A novel mixed-mode chromatographic stationary phase was prepared via surface initiated atom transfer radical polymerization using an imidazole side-group functionalized ionic liquid monomer, 1-(4-vinylbenzyl)-3-cyanomethyl bromide. The structure of the stationary phase was characterized by infrared spectroscopy, elemental analysis, and thermogravimetric analysis. The stationary phase showed good separation ability. The retention mechanism of reversed-phase/ion exchange toward solutes on the stationary phase was verified by determining the effect of mobile phase pH on the retention of substances. Compared with octadecylsilyl-bonded silica stationary phase, it is confirmed that the poly(ionic liquid)-modified stationary phase provides π-π interaction toward the retention of the solutes. The results show that the functionalization of imidazole side groups is a feasible method for preparing new ionic liquid stationary phases.

12.
Mikrochim Acta ; 186(10): 683, 2019 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-31529296

RESUMO

A boronate-modified magnetic affinity sorbent was prepared by adopting hyperbranched polyethyleneimine as the scaffold to amplify initiator sites. 3-Acrylamidophenylboronic acid was employed as monomer to proceed in situ free-radical polymerization on magnetite (Fe3O4) nanoparticles. Due to the improved density of boronic acid polymers, the adsorbent exhibited high adsorption capacity, typically (134 ± 8) µg mg-1 for dopamine, (92 ± 7) µg mg-1 for catechol, (363 ± 14) µg mg-1 for ovalbumin and (464 ± 22) µg mg-1 for horseradish peroxidase. These capacities are much higher than those of other adsorbents. The sorbent was applied to the enrichment of catecholamines from spiked human urine. Owing to the high adsorption capacity, only 1.0 mg of adsorbent was sufficient to eliminate the interferences and enrich the targets (dopamine, norepinephrine and epinephrine) within 5 min. They were quantified by HPLC. The recoveries from spiked samples range between 83.5% ~106%, with relative standard deviations of 3.2 ~ 9.4% (n = 5). The separation of glycoproteins from egg white was also accomplished prior to their analysis by PAGE. In the authors' perception, this approach is promising in that the density of functional groups on the adsorbent is strongly increased. Graphical abstract The preparation routine of boronate affinity magnetic adsorbent (Fe3O4@HpAAPBA). The adsorbent is used for the magnetic solid phase extraction of cis-dol compounds from real sample.


Assuntos
Ácidos Borônicos/química , Catecolaminas/urina , Nanopartículas de Magnetita/química , Polietilenoimina/química , Catecóis/química , Cromatografia de Afinidade , Cromatografia Líquida de Alta Pressão , Dopamina/química , Clara de Ovo/química , Epinefrina/química , Glicoproteínas/isolamento & purificação , Peroxidase do Rábano Silvestre/química , Humanos , Norepinefrina/química , Ovalbumina/química , Extração em Fase Sólida
13.
J Sep Sci ; 42(23): 3512-3520, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31556204

RESUMO

In this work, core-shell structured magnetic mesoporous carbon nanospheres were fabricated from the carbonization of metal-polyphenol coordination polymer-coated Fe3 O4 nanoparticles. The preparation method is simple, fast, versatile, and easy to scale up. Magnetic mesoporous carbon nanospheres exhibit a high specific surface area, high superparamagnetism, and high adsorption efficiencies for phthalates. Four phthalates were extracted from aqueous solutions by using magnetic mesoporous carbon nanospheres via magnetic solid phase extraction. Subsequent analysis was performed by using high-performance liquid chromatography with ultraviolet detection. The analytical method has good linearity in the concentration range of 1-200 ng/mL for diethyl phthalate, diisobutyl phthalate, and dicyclohexyl phthalate, and 3-200 ng/mL for dipropyl phthalate. The limits of detection were in the range of 0.10-0.62 ng/mL. Compared with previous methods, this method has a lower detection limit, wider linearity range, and faster adsorption and desorption rates. The results indicate that magnetic mesoporous carbon nanospheres are suitable for the enrichment of hydrophobic substances from aqueous solutions.

14.
J Chromatogr A ; 1607: 460401, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31376983

RESUMO

Boronate affinity is an important method for the enrichment and separation of cis-diol containing compounds, but most of the conventional boronate materials suffer from weak binding strength as well as low binding capacity towards glycoproteins due to the use of single boronic acids as ligands. In this work, a novel multidentate boronate magnetic adsorbent was assembled by using amined polyhedral oligomeric silsesquioxane as spacer and a diboronic acid as ligand. The specially designed adsorbent exhibited high adsorption capacity for cis-diols due to the high density of phenylbronic acid moieties. More interestingly, the dissociation constants toward glycoproteins on the material were lowered to be ∼10-6 M, being at least 3 orders lower than the single boronic acid bonded adsorbents. By comparing the binding properties of small molecules containing one and two pairs of cis-diols, the enhanced binding strength of glycoproteins on the multidentate boronate magnetic adsorbent was attributed to the synergistic binding of glycoproteins on the special interface. The new materials successfully captured glycoproteins from 1000-fold diluted egg white, suggesting that the material could be an optional alternative adsorbent for enriching trace glycoproteins from complex bio-samples.


Assuntos
Ácidos Borônicos/química , Glicoproteínas/química , Fenômenos Magnéticos , Compostos de Organossilício/química , Adenosina/análise , Adsorção , Animais , Galinhas , Cinamatos/análise , Depsídeos/análise , Cinética , Ligantes , Temperatura
15.
Food Chem ; 294: 104-111, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126442

RESUMO

Magnetic solid-phase extraction (MSPE), using a new reversed-phase/weak anion exchange mix-mode mesoporous magnetic SiO2 adsorbent, was assessed as an approach for reducing matrix effects in the analysis of six lipophilic marine biotoxins in shellfish using ultrahigh-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The adsorbent showed greater adsorption capacity and selectivity for the analytes and, thus, the MSPE microspheres reduced the matrix effects significantly in the subsequent analysis. In the UPLC-MS/MS analysis, precursor and product ions of the analytes were monitored quantitatively and qualitatively using multiple reaction monitoring and product ion confirmation modes. The proposed method exhibited a linear correlation of 0.9980-0.9991 in the working range for azaspiracids (2.0-200.0 ng/mL) and okadaic acid and its derivatives dinophysistoxins (4.0-200.0 ng/mL) with satisfactory recoveries (82.8-118.6%, RSD < 12%), lower LODs (0.4-1.0 µg/kg) and LOQs (1.0-4.0 µg/kg) than existing methods. In addition, consumption of the adsorbent was reduced, and the MSPE operation is simple and rapid relative to alternatives. These results suggest the proposed method has potential for use in the analysis of lipophilic marine biotoxins in shellfish samples.


Assuntos
Cromatografia Líquida de Alta Pressão , Magnetismo , Toxinas Marinhas/análise , Microesferas , Ácido Okadáico/análise , Compostos de Espiro/análise , Espectrometria de Massas em Tandem , Óxido Ferroso-Férrico/química , Limite de Detecção , Toxinas Marinhas/isolamento & purificação , Ácido Okadáico/isolamento & purificação , Porosidade , Frutos do Mar/análise , Dióxido de Silício/química , Extração em Fase Sólida , Compostos de Espiro/isolamento & purificação
16.
J Sep Sci ; 42(10): 1896-1904, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30828963

RESUMO

Considering that the determination of pyrethroid residues is of value for the safety of food, a new poly(ionic liquid)-functionalized magnetic mesoporous nanoparticle was designed and used as an adsorbent in magnetic solid-phase extraction for the enrichment of eight pyrethroids. The porous structure and large surface area of the mesoporous silica shell endow the adsorbent with abundant binding sites. In contrast to the reported poly(ionic liquids) with only one kind of functional group in the cationic part, the new poly(ionic liquids) with mixed cyano and phenyl groups in cationic part matched the chemical structure of the analytes to improve extraction efficiency. Under the optimum conditions, an effective method was established for the determination of eight pyrethroids in apples. Adsorption equilibrium can be quickly reached in 1 min, greatly decreasing the extraction time. The linearity range was found to be 10-200 ng/g, and the detection limits ranged from 0.24 to 1.99 ng/g. Recoveries of analytes in apple samples ranged from 87.3 to 119.0%, with relative standard deviations varying in the range of 3-21.2% (intraday) and 0.3-15.2% (interday). The results indicate that the proposed method is a good candidate for pyrethroid residues in apple samples.


Assuntos
Contaminação de Alimentos/análise , Inseticidas/análise , Líquidos Iônicos/química , Nanopartículas de Magnetita/química , Malus , Piretrinas/análise , Adsorção , Sítios de Ligação , Cátions , Inocuidade dos Alimentos , Íons , Limite de Detecção , Magnetismo , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Microesferas , Reprodutibilidade dos Testes , Dióxido de Silício/química , Extração em Fase Sólida , Solventes , Água/análise
17.
Talanta ; 198: 432-439, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30876583

RESUMO

Although various click polymerization reactions (thiol-ene, thiol-yne, thiol-Michael, thiol-epoxy and amine-epoxy) have been utilized to prepare either hybrid or organic monolithic columns with homogeneous network structures, there were few reports on fabrication of monolithic CSPs via click polymerization. Herein, a fast and robust approach was explored to fabricate cinchona-based monolithic hybrid CSPs via photo-initiated thiol-ene polymerization within 10 min in one step. A self-synthesized octakis(3-mercaptopropyl) octasilsesquioxane (POSS-SH) was polymerized with phenylisocyanate cinchonidine (PCD) and (+)-N,N'-diallyl-L-tartardiamide (DATDA) or 1,2,4-trivinylcyclohexane (TVCH). The resulting two kinds of as-synthesized monolithic CSPs, poly(POSS-co-DATDA-co-PCD) and poly(POSS-co-TVCH-co-PCD), were evaluated for cLC enantioseparation of acidic racemates. It was found that they exhibited different enantioseparation ability due to using different multivinyl crosslinkers. The influence of ACN content in mobile phase on the enantioseparation of acidic racemates was investigated. The separation mechanism was also discussed on the basis of a comparison of enantioseparation on two kinds of hybrid monolithic CSPs.

18.
ACS Appl Mater Interfaces ; 11(12): 11706-11714, 2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30848877

RESUMO

There are several researches on the preparation and application of hydrazone-linked covalent organic frameworks (COFs), and all of them generally necessitate rigid aromatic amines. Herein, we report a strategy for design and synthesis of COF with flexible alkyl amine as a building block and intramolecular hydrogen bonding as a knot in the network. The proof-of-concept design was demonstrated by exploring 1,3,5-triformylphloroglucinol and oxalyldihydrazide (ODH) as precursors to synthesize a novel COF material (TpODH), in which different organic building units are combined through hydrazone bonds to form two-dimensional porous frameworks. It should be pointed that irreversible enol-to-keto tautomerism and intramolecular N-H···O═C hydrogen bonding of TpODH would enhance the crystallinity and chemical stability, leading to large specific surface area of 835 m2 g-1. However, another COF synthesized with 1,3,5-triformylbenzene and ODH exhibited less crystallinity and low special surface area (94 m2 g-1). Representatively, the resulting TpODH afforded Cu(II) and Hg(II) capacities of 324 and 1692 mg g-1, respectively, which exceeded that of most COFs previously reported. Moreover, the Fourier-transform infrared and X-ray photoelectron spectroscopy spectra analyses were taken to demonstrate the adsorption mechanism. These results suggested that the materials could be applied to the removal of metallic ions in the future.

19.
Anal Chim Acta ; 1058: 97-106, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-30851859

RESUMO

Owing to their multiscale pore size regimes and unique properties, the materials with hierarchically porous structures have become an important family of functional materials in recent years. They have been applied from energy conversion and storage, catalysis, separation to drug delivery, etc. The synthesis of them is difficult by the need to employ multiple templates and take complicated steps. Herein, we successfully prepared epoxy-functionalized hierarchically porous hybrid monoliths (HPHMs) with micro/meso/macro-structures in an easy way. Firstly, a bulk monolithic material was formed via free radical polymerization between polyhedral oligomeric vinylsilsesquioxanes (vinylPOSS) and allyl glycidyl ether (AGE) in the presence of polycaprolactone (PCL). Then PCL was degraded with hydrochloric acid solution, and the epoxy-functionalized HPHM was obtained. This approach was very simple and suitable for large-scale preparation. Hybrid monoliths with different specific surface area (from 5.4 to 636.7 m2/g) were prepared by adjusting the mole ratio of vinylPOSS to AGE and the content of PCL. The results of several characterization methods, including nitrogen adsorption/desorption measurements, scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP), showed that these materials contained not only micropores and mesopores but also macropores. The materials were further modified with penicillamine to be used as hydrophilic interaction chromatography (HILIC) adsorbents for enriching N-glycopeptides in IgG and serum protein tryptic digests. Up to 23 N-glycopeptides were identified from IgG digest, and 385 N-glycopeptides and 283 N-glycosylation sites were identified from human serum digest.


Assuntos
Cromatografia Líquida/métodos , Glicopeptídeos/sangue , Compostos de Organossilício/química , Polivinil/química , Adsorção , Animais , Bovinos , Compostos de Epóxi/química , Glicopeptídeos/química , Glicosilação , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imunoglobulina G/química , Compostos de Organossilício/síntese química , Penicilamina/química , Poliésteres/síntese química , Poliésteres/química , Polimerização , Polivinil/síntese química , Porosidade , Proteólise , Soroalbumina Bovina/química , Tripsina/química
20.
J Hazard Mater ; 367: 465-472, 2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30616196

RESUMO

Hierarchically porous materials with multiple pore structures have the potential application in catalysis, separation or bioengineering. A concept was introduced to design and fabricate hierarchically porous hybrid materials (HPHMs) simultaneously containing mesopores and macropores. The proof-of-concept design was demonstrated by fabrication of several kinds of hybrid materials by adding degradable polycaprolactone (PCL) additive, which was simple and easy-operating. The specific surface areas of HPHMs prepared with polyhedral oligomeric vinylsilsesquioxanes (vinylPOSS) and 1,4-dithiothreitol (DTT) could reach 727 m2/g by adding 25% PCL additive, while the HPHMs were imperforate prior to degradation of PCL. The characterization further indicated that the macropores could be controlled by the amount of PCL additive. Moreover, the porous properties of HPHMs were influenced by the molecular weight of PCL. Other dithiols compounds were also successful in preparing HPHMs with high specific surface areas over 400 m2/g. Due to hydrophobic interaction and hydrogen bond interaction, the HPHM exhibited good adsorption ability for bisphenol A (BPA) in aqueous solution. Adsorption equilibrium could be achieved within 30 min, and the adsorption capacity was up to 157.4 mg/g. Meanwhile, the removal efficiency was found to be 95.37% for BPA.

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