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1.
Anal Chim Acta ; 1312: 342780, 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38834272

RESUMEN

BACKGROUND: The convenient preparation and application of functionalized organic-inorganic hybrid monolithic materials have obtained substantial interest in the pretreatment of complex samples by solid-phase extraction (SPE). Compared to the in-tube solid-phase microextraction in fused-silica capillaries, micro SPE in plastic pipette tips have fascinating merits for the easily operated enrichment of trace target analytes from biological samples. However, the poor compatibility of organic-inorganic hybrid monoliths with plastics leads to the rare appearance of commercial hybrid monolithic pipette tips (HMPTs). Therefore, how to synthesize the organic-inorganic hybrid monolithic materials with better extraction performance in plastic pipette tips becomes a challenge. RESULTS: We develop a facile and cheap strategy to immobilize organic-inorganic hybrid monoliths in pipette tips. Melamine sponge was employed as the supporting skeleton to in situ assemble amine- and thiol-bifunctionalized hybrid monolithic material via "one pot" in a pipette tip, and gold nanoparticles (GNPs) and thiol-modified aptamer against human α-thrombin were sequentially attached to the hybrid monolith within the HMPTs. The average coverage density of the aptamer with GNPs as an intermediary reached as high as 818.5 pmol µL-1. The enriched thrombin concentration was determined by a sensitive enzymatic chromogenic assay with the limit of detection of 2 nM. The extraction recovery of thrombin at 10 nM in human serum was 86.1 % with a relative standard deviation of 6.1 %. This proposed protocol has been applied to the enrichment and determination of thrombin in real serum sample with strong anti-interference ability, low limit of detection and high recovery. SIGNIFICANCE: The amine- and thiol-bifunctionalized HMPTs prepared with sponge as the skeleton frame provided a novel substrate material to decorate aptamers for efficient enrichment of proteins. This enlightens us that we can take advantage of the tunability of sponge assisted HMPTs to produce and tailor a variety of micro SPE pipette tips for broader applications on the analysis of trace targets in complex biological, clinic and environmental samples.


Asunto(s)
Aptámeros de Nucleótidos , Trombina , Triazinas , Triazinas/química , Triazinas/aislamiento & purificación , Aptámeros de Nucleótidos/química , Humanos , Trombina/análisis , Trombina/aislamiento & purificación , Oro/química , Nanopartículas del Metal/química , Extracción en Fase Sólida/métodos
2.
J Sep Sci ; 46(18): e2300396, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37582653

RESUMEN

Organic-silica hybrid monoliths attracted attention as an alternative to extensively researched organic polymer-based and silica-based counterparts. The development and applications of these materials as extraction and separation media in capillary liquid chromatography and capillary electrochromatography were previously reviewed in several manuscripts. In this review, we will concentrate on work published since mid-2016 focusing on advances in their development using sol-gel chemistry of tetra- and trialkoxysilanes and subsequent surface modification with organic monomers, and "one-pot" strategy incorporating sol-gel chemistry of alkoxysilanes and free-radical polymerization, ring-opening polymerization, or thiol-based click polymerization with organic monomers. Approaches adapted to the preparation of hybrid monoliths made with polyhedral oligomeric silsesquioxanes will be covered as well.

3.
Talanta ; 259: 124452, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37054623

RESUMEN

Enrichment of perfluoroalkyl phosphonic acids (PFPAs) is of great significance and challenging for environmental monitoring, due to their toxic and persistent nature, highly fluorinated character as well as low concentration. Herein, novel metal-organic frameworks (MOFs) hybrid monolithic composites were prepared via metal oxide-mediated in situ growth strategy and utilized for capillary microextraction (CME) of PFPAs. A porous pristine monolith was initially obtained by copolymerization of the zinc oxide nanoparticles (ZnO-NPs)-dispersed methacrylic acid (MAA) with ethylenedimethacrylate (EDMA) and dodecafluoroheptyl acrylate (DFA). Afterwards, nanoscale-facilitated transformation of ZnO nanocrystals into the zeolitic imidazolate framework-8 (ZIF-8) nanocrystals was successfully realized via the dissolution-precipitation of the embedded ZnO-NPs in the precursor monolith in the presence of 2-methylimidazole. Experimental and spectroscopic results (SEM, N2 adsorption-desorption, FT-IR, XPS) revealed that the coating of ZIF-8 nanocrystals significantly increased the surface area of the obtained ZIF-8 hybrid monolith and endowed the material abundant surface-localized unsaturated zinc sites. The proposed adsorbent showed highly enhanced extraction performance for PFPAs in CME, which was mainly ascribed to the strong fluorine affinity, Lewis acid/base complexing, anion-exchange, and weakly π-CF interaction. The coupling of CME with LC-MS enables effective and sensitive analysis of ultra-trace PFPAs in environment water and human serum. The coupling method demonstrated low detection limits (2.16-4.12 ng L-1) with satisfactory recoveries (82.0-108.0%) and precision (RSDs ≤6.2%). This work offered a versatile route to design and fabricate selective materials for emerging contaminant enrichment in complicated matrices.

4.
J Sep Sci ; 45(24): 4460-4468, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36239158

RESUMEN

Exploiting adsorbents with highly efficient extraction performance is of great promise for extracting small organic molecules from biological samples. In this work, a novel Zn2+ -immobilized chitosan@silica hybrid monolith was prepared through a simple self-assembly Zn2+ -immobilization process. Exploited as an adsorbent in solid-phase micro-extraction for extracting trace ß-agonists, the monolith exhibited high extraction efficiencies for salbutamol, clenbuterol, and ractopamine with the enrichment factors approaching 120, 85, and 52, respectively. These could be attributed to the effective interaction between Zn2+ ions and the target molecule via coordination or other intermolecular interactions. Under optimized extraction operations, a sensitive determination was successfully developed coupling with high-performance liquid chromatography-ultraviolet detection. The linear range was 0.17-58.8, 0.12-68.5, and 0.18-65.5 ng/ml for salbutamol, clenbuterol, and ractopamine. The limits of detection of the ß-agonists were from 0.04 to 0.07 ng/ml, and the limits of quantification were from 0.12 to 0.18 ng/ml. The recoveries of spiking in mutton samples were observed in the range of 85.9%-95.7%, with relative standard deviations <8.0% (n = 3). Application tests demonstrated this newly developed determination was practical, accurate, and convenient for detecting trace content ß-agonists in meat.


Asunto(s)
Clenbuterol , Dióxido de Silicio , Extracción en Fase Sólida , Cromatografía Líquida de Alta Presión , Albuterol , Zinc
5.
Methods Mol Biol ; 2500: 43-53, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35657586

RESUMEN

High-performance separation of proteoforms plays an important role in top-down proteomic ananlysis due to high complexity of the proteome. To this end, the functionalized ethylene-bridged hybrid monolithic materials have been developed for reversed-phase liquid chromatographic separation of proteoforms followed by online combination with high-resolution mass spectrometry (MS) for top-down proteomic analysis. Such monoliths have advantages of homogenously distributed functional groups in the framework, good chemical stability, and high permeability and, thus, show high resolution, good reproducibility, and low backpressure for proteoform separation. This chapter describes in detail the preparation of such monoliths and online combination with high-resolution MS for proteoform separation and identification.


Asunto(s)
Proteómica , Espectrometría de Masas en Tándem , Cromatografía de Fase Inversa/métodos , Proteoma/análisis , Proteómica/métodos , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/métodos
6.
Mikrochim Acta ; 189(3): 92, 2022 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-35132465

RESUMEN

A novel coating based on hybrid monolith with metal-organic framework (MOF) onto conventional Teflon-coated magnetic stir bars was developed. For this purpose, the external surface of the Teflon stir bar was firstly vinylized in order to immobilize a glycidyl methacrylate (GMA)-based polymer onto the magnet. Then, an amino-modified MOF of type MIL-101 (NH2-MIL-101(Al)) was covalently attached to the GMA-based monolith. After the synthesis process, several parameters affecting extraction of target estrogens by stir bar sorptive extraction (SBSE) including pH, ionic strength, extraction time, stirring rate, desorption solvent, and desorption time were also investigated. The resulting hybrid monolith was evaluated as SBSE sorbent for extraction of three estrogens (estrone, 17ß-estradiol, estriol) and synthetic 17ß-ethinylestradiol from water and human urine samples followed by HPLC with fluorescence detection (excitation and emission wavelengths, 280 and 310 nm, respectively). Under the optimal experimental conditions, the analytical figures of the method were established, achieving satisfactory limits of detection in the range of 0.015-0.58 µg L-1, recovery results ranging from 70 to 95% with RSD less than 6%, and precision values (intra- and inter-extraction units) below 6%.


Asunto(s)
Disruptores Endocrinos/análisis , Compuestos Epoxi/química , Estrógenos/análisis , Estructuras Metalorgánicas/química , Metacrilatos/química , Contaminantes Químicos del Agua/análisis , Cromatografía Liquida , Humanos
7.
Food Chem ; 374: 131775, 2022 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-34896942

RESUMEN

An on-line in-tube solid-phase microextraction (in-tube SPME) coupled with high-performance liquid chromatography (HPLC) method was proposed based on a novel polyhedral oligomeric silsesquioxane (POSS)-hybrid monolith for the determination of four bisphenols (BPs) in milk. The monolith was synthesized using acrylamide (AM) and monomethacrylate-functionalized POSS (mono-MA-POSS) as functional monomers to copolymerize with ethylene dimethacrylate (EDMA). Due to the abundant hydrogen bonding, π-π and hydrophobic interaction sites, the synthetic monolith displayed satisfying extraction performance for target BPs. Under the optimized conditions, the developed on-line in-tube SPME-HPLC method exhibited low limits of detection (LODs) (0.030-0.055 ng mL-1). The spiked recoveries were between 85.4 % and 111.8 %, and the relative standard deviations (RSDs) were less than 3.5 % for all the analytes. The results showed that the proposed method provided alternative for the analysis of BPs in complex samples.


Asunto(s)
Leche , Microextracción en Fase Sólida , Animales , Cromatografía Líquida de Alta Presión , Interacciones Hidrofóbicas e Hidrofílicas , Límite de Detección
8.
Food Chem ; 355: 129662, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-33799255

RESUMEN

A facile in-tube solid phase microextraction (in-tube SPME) procedure was developed to enrich ractopamine before HPLC-UV analysis. This was achieved by employing amide groups modified polysaccharide-silica hybrid monolith as an efficient sorbent. The monolith was synthesized by a simple reaction with agarose oxide and tetramethoxylisane, followed by the modification of amide groups via subsequent ring opening, "thiol-ene" click and dehydration reactions. Under the optimized extraction conditions, the enrichment factors for ractopamine, dopamine, clenbuterol, para-methylphenol and phenol were determined to be 50.5, 32.2, 4.8, 2.1 and 1.8, respectively. The monolithic column has ideal selectivity for ractopamine. Coupled with HPLC-UV, this method demonstrated a linearity within 2.0-800 ng/g for ractopamine with spiking in pork muscles (R2 = 0.9958). The LOD was 0.64 ng/g (S/N = 3) and recoveries ranged from 85.2 to 108.1% (n = 3). This approach provides a feasible way for analysis of trace ractopamine in biological samples.


Asunto(s)
Cromatografía Líquida de Alta Presión , Análisis de los Alimentos/métodos , Músculos/química , Fenetilaminas/análisis , Carne de Cerdo/análisis , Dióxido de Silicio/química , Microextracción en Fase Sólida , Amidas/química , Animales , Fenetilaminas/aislamiento & purificación , Porcinos
9.
Nano Lett ; 20(3): 2034-2046, 2020 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-32019311

RESUMEN

Tin-based composites hold promise as anodes for high-capacity lithium/sodium-ion batteries (LIBs/SIBs); however, it is necessary to use carbon coated nanosized tin to solve the issues related to large volume changes during electrochemical cycling, thus leading to the low volumetric capacity for tin-based composites due to their low packing density. Herein, we design a highly dense graphene-encapsulated nitrogen-doped carbon@Sn (HD N-C@Sn/G) compact monolith with Sn nanoparticles double-encapsulated by N-C and graphene, which exhibits a high density of 2.6 g cm-3 and a high conductivity of 212 S m-1. The as-obtained HD N-C@Sn/G monolith anode exhibits ultrahigh and durable volumetric lithium/sodium storage. Specifically, it delivers a high volumetric capacity of 2692 mAh cm-3 after 100 cycles at 0.1 A g-1 and an ultralong cycling stability exceeding 1500 cycles at 1.0 A g-1 with only 0.019% capacity decay per cycle in lithium-ion batteries. Besides, in situ TEM and ex situ SEM have revealed that the unique double-encapsulated structure effectively mitigates drastic volume variation of the tin nanoparticles during electrode cycling. Furthermore, the full cell using HD N-C@Sn/G as an anode and LiCoO2 as a cathode displays a superior cycling stability. This work provides a new avenue and deep insight into the design of high-volumetric-capacity alloy-based anodes with ultralong cycle life.

10.
Talanta ; 209: 120566, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-31892018

RESUMEN

In this work, a simple device for extraction glutathione (GSH) in biological fluids using a hybrid monolithic material within a polypropylene syringe is developed. For this purpose, glycidyl methacrylate-based monolith was firstly prepared within this housing material, and the polymer was modified with different ligands (ammonia, cysteamine and cystamine). The resulting materials (containing amine or thiol groups, respectively) were then functionalized with gold nanoparticles (AuNPs). The hybrid material that gave the largest AuNPs coverage was selected as solid-phase (SPE) sorbent and several variables affecting the extraction recovery of this compound were investigated. Under optimal conditions, GSH was quantitatively retained at pH 6.0, and then it was desorbed with aqueous dithiothreitol solution and determined, after derivatization with o-phthaldialdehyde, via reversed-phase LC with fluorometric detection. The limit of detection was ca. 1.5 ng mL-1, and the reproducibility between extraction units was below 8% (expressed as relative standard deviation), which demonstrates the robustness of the method. The developed material was also applied for the extraction of GSH in saliva and urine samples yielding recoveries ranging from 86 to 105%.


Asunto(s)
Glutatión/aislamiento & purificación , Oro/química , Nanopartículas del Metal/química , Extracción en Fase Sólida/métodos , Cromatografía Líquida de Alta Presión/métodos , Compuestos Epoxi/química , Glutatión/análisis , Glutatión/orina , Humanos , Límite de Detección , Metacrilatos/química , Reproducibilidad de los Resultados , Saliva/química , Jeringas
11.
Talanta ; 209: 120526, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-31892036

RESUMEN

A fast and robust approach was developed to fabricate and modify hybrid monolithic columns via two-step photo-initiated reactions. At first, acrylopropyl polyoctahedral silsesquioxane (acryl-POSS) and 3-(triallyl silyl) propyl acrylate (TAPA) were chosen as precursors to synthesize poly (POSS-co-TAPA) monolithic column (monolith I) via photo-initiated free-radical polymerization within 10 min, which left lots of allyl groups on the surface of monolith. Secondly, two thiol-containing compounds, penicillamine and 1-octadecanethiol (ODT), were introduced to modify the prepared poly (POSS-co-TAPA) column via photo-initiated thiol-ene click reaction within 20 min. Finally, three resulting monolithic columns were applied to separate phenolic, anilines and antibiotics mixtures. These mixtures were baseline-separated on the monolith modified with penicillamine (monolith II), exhibiting better selectivity than both pristine monolith I and that modified with ODT (monolith III). Additionally, these columns were further used for separation of tryptic digest of HeLa cells by cLC-MS/MS. The 5071 unique peptides mapped to 2442 proteins were identified from HeLa cells digest on monolith II, which were superior over those on monolith III, but slightly lower than those on monolith I. These results demonstrated that these POSS-containing columns exhibited great separation ability for complex samples.

12.
Mikrochim Acta ; 187(2): 109, 2020 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-31915938

RESUMEN

An in-situ approach is described for synthesis of poly(sulfobetaine-co-polyhedral oligomeric silsesquioxane) [poly(sulfobetaine-co-POSS)] that can be used in a hybrid monolithic column as a hydrophilic liquid chromatography (HILIC) stationary phase. Synthesis involves (a) radical polymerization of octa(propyl methacrylate)-polyhedral oligomeric silsesquioxane (MA-POSS) and organic monomers such as dimethylaminopropyl methacrylate or vinyl imidazole, and (b) in-situ ring-opening quaternization between 1,4-butane sultone and the organic monomers. The sulfobetaine groups are generated in-situ monolith. This obviates the need for synthesis of sulfobetaine monomer previously. The pore size and permeability of the material can be tuned by using a binary porogenic system (polyethyleneglycol 600 and acetonitrile) and via the composition of the polymerization mixture. The optimized hybrid monolith owns its merits to the presence of POSS and sulfobetaine groups with good mechanical stability, the lack of residual silanol groups, and adequate hydrophilicity. The column filled with the monoliths was evaluated as a stationary phase for HILIC. Several kinds of polar compounds (including nucleosides, bases, phenols, aromatic acids and amides) were separated by using mobile phases with high organic solvent fractions in capillary liquid chromatography. Graphical abstractAn in-situ approach is described for synthesis of poly(sulfobetaine-co-polyhedral oligomeric silsesquioxane) hybrid monolithic column for use in hydrophilic liquid chromatography. The optimized monolith owns good mechanical stability, the lack of residual silanol groups and adequate hydrophilicity. Baseline separation of several kinds of polar compounds is achieved on the column. MA-POSS: octa(propyl-methacrylate) polyhedral oligomeric silsesquioxane; DMAEMA: dimethylaminoethyl methacrylate; AIBN: azodiisobutyronitrile. Poly(DMABS-co-POSS): poly(N-(4-sulfobutyl)-N-methacryloxypropyl- N,N-dimethylammonium-betaine-co-polyhedral oligomeric silsesquioxane).

13.
Electrophoresis ; 40(23-24): 3132-3139, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31591731

RESUMEN

The successful fabrication of monolithic capillary columns for enantiomer separations was achieved within vinylized fused silica capillaries via fast "one-pot" photo-initiated free radical polymerization reaction. A mixture consisting of polyhedral oligomeric silsesquioxane, O-[2-(methacryloyloxy)ethylcarbamoyl]-10,11-dihydroquinidine was copolymerized in the presence of n-butanol, ethylene glycol and photo-initiator 2,2-dimethoxy-2-phenylacetophenone. The morphology of the resultant polymeric hybrid inorganic-organic material and its permeability as well as porosity can be controlled by adjusting the composition of the monomers and binary porogenic solvent. The chromatographic characteristics of the columns have been investigated. Separation factors of N-acetyl-phenylalanine (Ac-Phe) and dichlorprop dropped with decrease of chiral functional monomer. Permeability was better when the macroporogen ethyleneglycol was present at higher concentrations during the polymerization. In general, the chiral compounds were well separated (dichlorprop: α = 1.53, Rs up to 4.14; Ac-Phe: α = 1.36, Rs up to 2.69) by nano-HPLC with an optimized enantioselective monolithic capillary column which can be prepared within a few minutes.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Nanotecnología/métodos , Compuestos de Organosilicio/química , Quinidina/química , Ácido 2,4-Diclorofenoxiacético/análogos & derivados , Procesos Fotoquímicos , Polimerizacion , Estereoisomerismo
14.
Molecules ; 24(9)2019 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-31035579

RESUMEN

This work describes the direct coupling of the in-tube solid-phase microextraction (in-tube SPME) technique to a tandem mass spectrometry system (MS/MS) to determine amino acids (AA) and neurotransmitters (NT) (alanine, serine, isoleucine, leucine, aspartic acid, glutamic acid, lysine, methionine, tyrosine, and tryptophan) in plasma samples from schizophrenic patients. An innovative organic-silica hybrid monolithic capillary with bifunctional groups (amino and cyano) was developed and evaluated as an extraction device for in-tube SPME. The morphological and structural aspects of the monolithic phase were evaluated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), nitrogen sorption experiments, X-ray diffraction (XRD) analyses, and adsorption experiments. In-tube SPME-MS/MS conditions were established to remove matrix, enrich analytes (monolithic capillary) and improve the sensitivity of the MS/MS system. The proposed method was linear from 45 to 360 ng mL-1 for alanine, from 15 to 300 ng mL-1 for leucine and isoleucine, from 12 to 102 ng mL-1 for methionine, from 10 to 102 ng mL-1 for tyrosine, from 9 to 96 ng mL-1 for tryptophan, from 12 to 210 ng mL-1 for serine, from 12 to 90 ng mL-1 for glutamic acid, from 12 to 102 ng mL-1 for lysine, and from 6 to 36 ng mL-1 for aspartic acid. The precision of intra-assays and inter-assays presented CV values ranged from 1.6% to 14.0%. The accuracy of intra-assays and inter-assays presented RSE values from -11.0% to 13.8%, with the exception of the lower limit of quantification (LLOQ) values. The in-tube SPME-MS/MS method was successfully applied to determine the target AA and NT in plasma samples from schizophrenic patients.


Asunto(s)
Aminoácidos/análisis , Aminoácidos/aislamiento & purificación , Técnicas Biosensibles , Cromatografía Líquida de Alta Presión , Lansoprazol , Ligandos , Gel de Sílice , Microextracción en Fase Sólida , Adsorción , Aminoácidos/sangre , Cromatografía Líquida de Alta Presión/métodos , Humanos , Lansoprazol/química , Gel de Sílice/síntesis química , Gel de Sílice/química , Microextracción en Fase Sólida/métodos , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
15.
Anal Chim Acta ; 1058: 97-106, 2019 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-30851859

RESUMEN

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.


Asunto(s)
Cromatografía Liquida/métodos , Glicopéptidos/sangre , Compuestos de Organosilicio/química , Polivinilos/química , Adsorción , Animales , Bovinos , Compuestos Epoxi/química , Glicopéptidos/química , Glicosilación , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Inmunoglobulina G/química , Compuestos de Organosilicio/síntesis química , Penicilamina/química , Poliésteres/síntesis química , Poliésteres/química , Polimerizacion , Polivinilos/síntesis química , Porosidad , Proteolisis , Albúmina Sérica Bovina/química , Tripsina/química
16.
Talanta ; 198: 330-336, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-30876569

RESUMEN

In this study, polyhedral oligomeric silsesquioxane (POSS)-based capillary monoliths with short alkyl chain ligand in the form of butyl (C4) were synthesized via two different polymerization routes, namely UV-initiated free radical copolymerization of methacrylate-derivatized POSS (POSS-MA) with butylmethacrylate (BMA) and UV-initiated thiol-methacrylate copolymerization of POSS-MA with butanethiol (BT). An organosilicon monolith with a pore size distribution lying on both mesoporous and macroporous scales, a lower mean pore size and a higher specific surface area was obtained with UV-initiated thiol-methacrylate polymerization. Both monoliths were then comparatively evaluated for gradient separation of proteins under reversed phase conditions in nano-liquid chromatography. The chromatographic performance was defined in terms of peak-resolution and peak capacity. Four carbon (C4) functionalized-poly(POSS-MA) monolith produced by UV-initiated thiol-methacrylate polymerization exhibited better separation performance with higher peak resolutions and peak capacities. Both, the morphological characterization of monoliths and the results of gradient separation of proteins showed that thiol-methacrylate polymerization was more suitable for the synthesis of C4 functionalized organosilicon based stationary phases for reversed-phase protein separation. The monolith prepared by thiol-methacrylate polymerization was also successfully applied for impurity analysis of two important hormones, namely insulin and genotropin. A comparison with a commercial poly(styrene-co-divinylbenzene) monolith documented the good chromatographic performance of the new BT-attached poly(POSS-MA) monolith.


Asunto(s)
Hormona de Crecimiento Humana/aislamiento & purificación , Insulina/aislamiento & purificación , Nanotecnología , Compuestos de Organosilicio/química , Cromatografía Liquida , Hormona de Crecimiento Humana/química , Insulina/química , Metacrilatos/química , Compuestos de Organosilicio/síntesis química , Procesos Fotoquímicos , Polimerizacion , Compuestos de Sulfhidrilo/química
17.
Talanta ; 198: 432-439, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-30876583

RESUMEN

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.
J Chromatogr A ; 1593: 63-72, 2019 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-30712817

RESUMEN

An O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine (MQD)-silica hybrid monolithic column was prepared by a facile "one-step" strategy within a 100 µm I.D. capillary. The influence of the methanol, ethylene glycol and water volume ratio, reaction temperature and time, cetyltrimethylammonium bromide and MQD monomers content and volume ratio of tetramethoxysilane and vinyltrimethoxysilane was investigated to obtain a satisfactory morphology of monolithic columns. The optimized MQD-silica hybrid monolithic column was evaluated in terms of permeability, stability, efficiency, reproducibility, and was characterized by scanning electron microscopy and nano-liquid chromatography. Among the 52 N-derivatized protein and non-protein amino acids, a total of 44 analytes could be baseline enantioseparated using the optimized conditions in either reversed phase mode (RPM) or polar organic phase mode (POM). The results showed that POM (ACN/MeOH/HAc/TEA (60/40/0.055/0.005, v/v/v/v)) offered better performance than RPM (10 mM ammonium acetate/ACN (30/70, v/v) (apparent pH=5.3)) in terms of enantioresolution and efficiency with shorter analysis times.


Asunto(s)
Aminoácidos , Cromatografía Liquida , Nanotecnología/instrumentación , Quinidina/análogos & derivados , Silanos/química , Aminoácidos/análisis , Aminoácidos/química , Aminoácidos/aislamiento & purificación , Cromatografía Liquida/instrumentación , Cromatografía Liquida/métodos , Quinidina/química , Estereoisomerismo
19.
J Chromatogr A ; 1588: 33-40, 2019 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-30587346

RESUMEN

A novel molecularly imprinted inorganic-organic hybrid monolith (MIP hybrid monolith) was fabricated through a facile single-step polymerization strategy with levofloxacin (LEV) as the template, 3-aminopropyltriethoxysilane-methacrylic acid as the hybrid functional monomer and ethylene glycol dimethacrylate as the crosslinker in a mixed porogen of methanol, toluene and dodecanol. The optimized LEV-MIP hybrid monolith was characterized using scanning electron microscopy and fourier transform-infrared spectroscopy. Uniform monolithic matrix with large through-pores in the network skeleton of LEV-MIP hybrid monolith was observed. The influence of polymerization conditions on the specific recognition behavior of the resulting monolith was systematically investigated. The LEV-MIP hybrid monolith exhibited much better adsorption (3.62 times) and selectivity towards LEV in comparison with non-imprinted hybrid monolith. Furthermore, the LEV-MIP hybrid monolith based solid-phase extraction combining with liquid chromatography-mass spectrometry was applied for the selective determination of fluoroquinolones (FQs) in infant formula powder. The average recoveries of six FQs in milk powders spiked at 20, 50 and 100 µg kg-1 were in the range of 82.91-102.00% with the precision of 1.04-7.39%. The limit of detection and limit of quantitation of the proposed method were in a range of 0.19-1.24 µg kg-1 and 0.63-4.13 µg kg-1, respectively.


Asunto(s)
Fluoroquinolonas/análisis , Análisis de los Alimentos/métodos , Fórmulas Infantiles/química , Polvos/química , Adsorción , Cromatografía Líquida de Alta Presión , Levofloxacino/química , Metacrilatos/química , Microscopía Electrónica de Rastreo , Polimerizacion , Extracción en Fase Sólida , Espectrometría de Masas en Tándem
20.
Talanta ; 191: 149-155, 2019 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-30262044

RESUMEN

A successful copolymerization of the single-walled carbon nanohorns (SWNHs) with methacrylate monomers was achieved via thermal initiated free-radical polymerization because of the high reactivity of the SWNHs in comparison with other carbon nanostructures. The hybrid solids were deeply characterized in terms of morphology, by scanning electron microscopy (SEM). The effect of the incorporation of the bare or oxidized (o-SWNHs) carbon nanoparticles at different percentages (0-0.5 wt%) in polymerization mixtures to obtain hybrid monolithic capillary columns has been evaluated. In addition, their impact both in the polymerization step and in the extraction capacity was deeply studied. Final hybrid monoliths were applied for the extraction of polycyclic aromatic hydrocarbons and nonsteroidal anti-inflammatory drugs in water and biological samples, respectively. The precision was calculated both intra- and inter-capillaries obtaining satisfactory RSD values of less than 19.1%, which indicated the high robust reproducibility of the extraction procedure and the synthesis method. The accuracy of the method was also evaluated through a recovery study giving good recovery values, which varied between 78% and 112% for PAHs in waters, and 90-114% for NSAIDs in human urine samples.

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