Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 65
Filtrar
1.
J Sep Sci ; 46(17): e2300206, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37385796

RESUMEN

The addition of bisphenol A has been frequently used in industrial manufacturing because it imparts plastic products with characteristics such as transparency, durability, and excellent impact resistance. However, its widespread use raises concerns about potential leakage into the surrounding environment, which poses a significant risk to human health. In this study, molecularly imprinted polymers with specific recognition of bisphenol A were synthesized through surface-initiated atom transfer radical polymerization using poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) as the substrate, bisphenol A as the template molecule, 4-vinylpyridine as the monomer, and ethylene glycol dimethacrylate as the cross-linker. The bisphenol A adsorption capacity was experimentally investigated, and the kinetic analysis of the molecularly imprinted polymers produced an adsorption equilibrium time of 25 min, which is consistent with the pseudo-second-order kinetic model. The results of the static adsorption experiments exhibited consistency with the Langmuir adsorption model, revealing a maximum adsorption capacity of 387.2 µmol/g. The analysis of molecularly imprinted polymers-enriched actual samples using high-performance liquid chromatography demonstrated excellent selectivity for bisphenol A, with a linear range showing 93.4%-99.7% recovery and 1.1%-6.4% relative standard deviation, demonstrating its high potential for practical bisphenol A detection and enrichment applications.

2.
Mikrochim Acta ; 190(12): 463, 2023 11 10.
Artículo en Inglés | MEDLINE | ID: mdl-37945941

RESUMEN

A carbon dot (CD) was prepared by using tryptophan as a single carbon source and demonstrated its good selective fluorescence quenching effect on tetracycline (TC). The modified metal-organic frameworks (MOF) NH2-MIL-101 was chosen as matrix, doped with CD, molecularly imprinted polymer (MIP) prepared with TC as the template, and finally CD-MOF-MIP complexes (CD@MIP) was synthesized. For comparison, MIP were also prepared without CD as well as non-imprinted polymers and their ability was tested, respectively. CD@MIP is a nanomaterial with bright fluorescence under the irradiation of ordinary UV equipment (λ = 360 nm), which has a fast and stable fluorescence quenching for TC and a good linear relationship for TC in the concentration range 0-400 µmol L-1. The quantum yield of CD@MIP was 12.75% and the 3σ limit of detection (LOD) for CD@MIP was 0.59 µmol L-1. The maximum adsorption capacity of CD@MIP reached 304.6 mg g-1 and the adsorption equilibrium was reached after about 75 min. The adsorption of CD@MIP to tetracycline spiked in milk samples reached 90.0 mg g-1 within 2 h, which was much higher than that of NIP (48.4 mg g-1) under the same conditions, as demonstrated by high performance liquid chromatography (HPLC). The results obtained showed that CD@MIP combined the high adsorption capacity of MOF, the specific adsorption of molecular imprinting and the fluorescence properties of CD, can determine and rapidly removeTC in the environment.


Asunto(s)
Estructuras Metalorgánicas , Impresión Molecular , Adsorción , Carbono/química , Tetraciclina/análisis , Antibacterianos , Impresión Molecular/métodos , Polímeros Impresos Molecularmente
3.
J Sep Sci ; 45(4): 976-983, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34933417

RESUMEN

Using monodisperse poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) as the matrix, and pefloxacin template molecules, a novel restricted-access medium molecularly imprinted polymers with Bovine serum albumin crosslinked on its surface was prepared through reversible addition-fragmentation chain-transfer polymerization. Then, the obtained material was employed in dispersive solid-phase extraction to analyze the fluoroquinolones in untreated egg samples by high-performance liquid chromatography-ultraviolet detection. Adsorption performance revealed a good binding amount (40.72 mg/g), fast binding kinetics (25 min), satisfactory selectivity, and good ability to eliminate matrix interference. The reusability experiments indicated the materials have good reusable performance after repetition. Under the optimized conditions, restricted access media-molecularly imprinted polymers-dispersive solid-phase extraction was combined with high-performance liquid chromatography-ultraviolet to enrich fluoroquinolones in untreated eggs, good limit of detection (1.31-3.15 µg/L) and high recovery (89.5-96.8%) were obtained. The results showed that the prepared restricted-access material is promising for the direct detection of antibiotics in complex samples.

4.
Mikrochim Acta ; 189(11): 405, 2022 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-36197509

RESUMEN

Enrichment of phosphopeptides before mass spectrometry (MS) analysis is essential due to the limitations of low abundance and poor ionization efficiency in complex biological samples. Immobilized metal affinity chromatography (IMAC), especially titanium ion (Ti4+)-IMAC, has become a popular strategy for enrichment of phosphopeptides due to high selectivity and sensitivity. Conventional Ti4+-immobilized macroporous adsorption resin (MAR) fabricated by monolayer modification can preferentially capture mono-phosphopeptide over multi-phosphopeptides, which takes on more functions in the regulation of cell behaviors of organism. In this paper, a kind of monodisperse MAR microsphere with functional polymer brush (Ti4+-Brush@MAR) was prepared and modified via surface-initiated atom transfer radical polymerization (SI-ATRP). Compared with common Ti4+-MAR without polymer brush, Ti4+-Brush@MAR exhibited high enrichment specificity not only for mono-phosphopeptides but also for multi-phosphopeptides in ß-casein or milk digest samples. As a result, a total of 93 unique phosphopeptides mapped to 18 phosphoproteins were identified from 5 µL milk, and the limit of detection is 10 fmol. It is expected that Ti4+-Brush@MAR would be utilized to enrich both multi-phosphopeptides and mono-phosphopeptides in additional biological or food samples.


Asunto(s)
Leche , Titanio , Animales , Caseínas/química , Cromatografía de Afinidad/métodos , Leche/química , Fosfopéptidos/análisis , Polímeros , Titanio/química
5.
Mikrochim Acta ; 189(3): 124, 2022 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-35226167

RESUMEN

A kind of core-shell composite microsphere (CM) with nano-on-micro structure was synthesized via grafting amine-modified nanodiamonds onto the surface of monodisperse nonporous polymeric microsphere. In this way, the agglomeration of nanodiamond particles in the solution was avoided. After modification with pyrogallol groups, CM could chelate titanium ions (Ti4+) and thus be utilized as immobilized metal affinity chromatography (IMAC) sorbent to enrich phosphopeptides from biological samples. The resulting Ti4+-CM exhibited high enrichment efficiency and specificity to phosphopeptides. A total of 106 of unique phosphopeptides mapped to 29 phosphoproteins were clearly identified from 5 µL of a milk digest after enrichment. Owing to the strong chelation between Ti4+ and pyrogallol ligands, the Ti4+ is not released from the sorbent after completion of the enrichment process. As a result, the Ti4+-CM sorbent could be reused, and no significant loss of enrichment efficiency occurred even on the fourth run employing a ß-casein digest as the sample. The strategy adopted presents a new way to prepare a high-performance reusable IMAC sorbent.


Asunto(s)
Nanodiamantes , Fosfopéptidos , Caseínas/química , Cromatografía de Afinidad/métodos , Microesferas , Fosfopéptidos/análisis
6.
Water Sci Technol ; 86(9): 2465-2481, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36378193

RESUMEN

In this study, activated carbon (AC) was chemically activated using sodium hydroxide (NaOH), and polyethyleneimine (PEI) was grafted onto the AC using glutaraldehyde as a cross-linking agent. Then the modified AC was applied to treat water samples containing copper ions (Cu2+). Preparation of AC-NaOH@PEI. The grafted AC was characterized, demonstrating that the specific surface area of material decreased from 959.3 to 556.9 m2/g. The ζ-potential changed from -27.2 to 10.4 mV, and the presence of a distinct flocculation on the surface of the AC was observed via scanning electron microscopy. The results demonstrated that PEI was successfully grafted onto the surface of AC. Furthermore, the adsorption results indicated that the Cu2+ adsorption capacity of AC-NaOH@PEI was greatly enhanced with increasing PEI loading. The adsorption amount of Cu2+ by the grafted AC-NaOH@PEI-200 increased from 20.02 to 47.8 mg/g. In addition, the adsorption of Cu2+ by AC-NaOH@PEI was a pH dependent process. At a pH of 6, the maximum removal rate reached 93%. The adsorption process is better described by the Langmuir and quasi-second order adsorption models, signifying that the adsorption of Cu2+ on AC@PEI consists of monolayer adsorption and chemisorption. After four adsorption-desorption cycles, AC@PEI exhibited high adsorption capacity for Cu2+, indicating that it has good regeneration ability. It is a promising adsorbent material.


Asunto(s)
Carbón Orgánico , Contaminantes Químicos del Agua , Adsorción , Aguas Residuales , Polietileneimina/química , Cobre/química , Hidróxido de Sodio , Cinética , Iones/química , Concentración de Iones de Hidrógeno
7.
Water Sci Technol ; 84(12): 3916-3927, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34928852

RESUMEN

The objective of this work was to study the treatment of wastewater containing cadmium ions (Cd2+). Activated carbon (AC) was modified with potassium hydroxide (KOH) and polyethylene polyamine (PEPA). The structure and morphology of the modified AC was characterized. The effect of pH on adsorption was investigated, and the binary competitive adsorption and the reusability of the modified AC were studied. Subsequently the modified AC was used as an adsorbent for the removal of Cd2+ from wastewater. The adsorption capacity of optimized modified AC was 9.7 times that of unmodified AC. Kinetic adsorption curves were in accordance with pseudo-second-order kinetics, and the isothermal curves were in accordance with the Langmuir equation. The results indicate that the AC has potential in the treatment of the wastewater containing Cd2+ discharged from chemical plants during battery manufacturing.


Asunto(s)
Carbón Orgánico , Aguas Residuales , Adsorción , Cadmio , Iones , Poliaminas , Polietilenos
8.
J Sep Sci ; 43(17): 3520-3533, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32579267

RESUMEN

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 ß-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 17ß-estradiol in milk samples. The recovery of 17ß-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 17ß-estradiol directly from complex samples.


Asunto(s)
Estradiol/análisis , Leche/química , Impresión Molecular , Extracción en Fase Sólida , Animales , Cromatografía Líquida de Alta Presión , Polímeros/química , Propiedades de Superficie
9.
J Sep Sci ; 42(21): 3302-3310, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31452342

RESUMEN

In this work, a novel surface molecularly imprinted polymer with high adsorption capacity, high adsorption rate, and high selectivity for fluoroquinolones was prepared on the surface of UiO-66-NH2 , which is a kind of metal-organic framework. The surface morphology and adsorption properties of this molecularly imprinted polymer were investigated. The maximum adsorption capacity was 99.19 mg/g, and adsorption equilibrium was achieved within 65 s. Combined with reversed-phase high-performance liquid chromatography, the molecularly imprinted polymer was used to selectively enrich, separate and analyze fluoroquinolones present in lake water. The results showed that the recoveries of the four fluoroquinolones were 92.6-100.5%, and the relative standard deviations were 2.9-6.4% (n = 3). The novel molecularly imprinted polymer is an excellent adsorbent and has broad application prospects in the enrichment and separation of trace analytes in complex samples.


Asunto(s)
Fluoroquinolonas/análisis , Estructuras Metalorgánicas/química , Impresión Molecular , Polímeros/química , Extracción en Fase Sólida , Contaminantes Químicos del Agua/química , Lagos/química , Estructuras Metalorgánicas/síntesis química , Tamaño de la Partícula , Polímeros/síntesis química , Porosidad , Propiedades de Superficie
10.
J Sep Sci ; 42(15): 2491-2499, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31106511

RESUMEN

We prepared ofloxacin restricted access media molecularly imprinted polymers using surface-initiated atom transfer radical polymerization on the surface of brominated silica gel using ofloxacin as a template molecule, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a crosslinking agent. We then characterized and studied the surface morphology and adsorption properties of the polymer. Experimental results show that saturation is reached within 25 min, and that the saturated adsorption capacity was 80.67 mg/g and the imprinting factor was 1.94. Our findings also showed that the polymer surface had good hydrophilicity and an excellent protein exclusion rate, which was 98.49%. The restricted access media molecularly imprinted polymers were then successfully applied to the enrichment and separation of ofloxacin in bovine serum. When combined with high-performance liquid chromatography, and the average recovery of ofloxacin was 95.6%, and the relative standard deviation was in the range of 2.47-3.38%. In a word, the restricted access media molecularly imprinted polymers is a method that involves a simple preparation procedure that results in excellent performance, which is a great improvement in the speed of detection of antibiotics. These qualities are what bestow upon this method its great potential for broad application.


Asunto(s)
Impresión Molecular , Ofloxacino/sangre , Polímeros/química , Animales , Bovinos , Cromatografía Líquida de Alta Presión
11.
J Sep Sci ; 38(7): 1254-61, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25619938

RESUMEN

A novel 17ß-estradiol molecularly imprinted polymer was grafted onto the surface of initiator-immobilized silica by surface-initiated atom transfer radical polymerization. The resulting molecularly imprinted polymer was characterized by elemental analysis and thermogravimetric analysis. The binding property of molecularly imprinted polymer for 17ß-estradiol was also studied with both static and dynamic methods. The results showed that the molecularly imprinted polymer possessed excellent recognition capacity for 17ß-estradiol (180.65 mg/g at 298 K), and also exhibited outstanding selectivity for 17ß-estradiol over the other competitive compounds (such as testosterone and progesterone). Then, the determination of trace 17ß-estradiol in beef samples was successfully developed by using molecularly imprinted polymer solid-phase extraction coupled with high-performance liquid chromatography. The limit of detection was 0.25 ng/mL, and the amount of 17ß-estradiol in beef samples was detected at 2.83 ng/g. This work proposed a sensitive, rapid, reliable, and convenient approach for the determination of trace 17ß-estradiol in complicated beef samples.


Asunto(s)
Estradiol/química , Polimerizacion , Adsorción , Animales , Bovinos , Cinética , Productos de la Carne/análisis , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Termogravimetría
12.
Food Chem ; 439: 138167, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38071847

RESUMEN

The work provided a method for synthesizing a simple fluorescent molecularly imprinted polymer by surface-initiated atom transfer radical polymerization (SI-ATRP) and its application in real sample. Poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres were selected as a matrix, 4-vinylpyridine, ethylene glycol dimethacrylate, 2,4-dichlorophenoxyacetic acid (2,4-D) as functional monomer, cross-linker and template molecule, respectively, to fabricate MAR@MIP with core-shell structure. For comparison, carbon dot (CD) as a fluorescence source was synthesized with o-phenylenediamine and tryptophan as precursors via hydrothermal method and integrated into MIP to acquire MAR@CD-MIP. MAR@CD-NIP was also prepared without adding the template molecule. The adsorption capacity of MAR@CD-MIP reached 104 mg g-1 for 2,4-D, which was higher than that of MAR@MIP (60 mg g-1). However, the adsorption capacity of MAR@CD-NIP was only 13.2 mg g-1. The linear range of fluorescence detection for 2,4-D was 18-72 µmol/L, and the limit of detection (LOD) was 0.35 µmol/L. The fluorescent MAR@CD-MIP was successfully applied in enrichment of lettuce samples. The recoveries of the three spiked concentrations of 2,4-D in lettuce were tested by fluorescence spectrophotometry and ranged in 97.3-101.7 %. Meanwhile, the results were also verified by HPLC. As a result, bi-functional molecularly imprinted resin was successfully fabricated to detect and enrich 2,4-D in real samples, and exhibited good selectivity, sensitivity and great application prospect in food detection.


Asunto(s)
Herbicidas , Impresión Molecular , Carbono , Lactuca , Polímeros/química , Fenoxiacetatos , Ácido 2,4-Diclorofenoxiacético , Impresión Molecular/métodos
13.
Materials (Basel) ; 16(2)2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36676426

RESUMEN

In this paper, Ganoderma lucidum bran was explored as the precursor to fabricate biomass activated carbon. When potassium hydroxide was selected as an activator (1:6, mass ratio of AC-12 to potassium hydroxide), and the activation condition was 700 °C at 5 h, the highest specific surface area reached 3147 m2 g-1. Carbon dots were prepared with citric acid monohydrate and thiourea as precursors and then loaded onto the surface of activated carbon by a simple and green method. Activated carbon for dual-functional had a high adsorption capacity. Additionally, based on its unique optical properties, the fluorescence response for detecting copper ion was established. The fluorescence intensity of the materials decreased linearly with the increase of copper ion concentration, in the range of 10-50 nmol L-1. The research opened up a new way for applying biomass activated carbon in the field of adsorption and detection. Highlights: (1) Carbon dots were loaded on the surface of activated carbon; (2) the simultaneous adsorption and detection were realized; (3) it provides a way for the preparation of dual-functional materials.

14.
RSC Adv ; 13(7): 4275-4302, 2023 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-36760304

RESUMEN

Due to the rapid development of the social economy and the massive increase in population, human beings continue to undertake processing, and commercial manufacturing activities of heavy metals, which has caused serious damage to the environment and human health. Heavy metals lead to serious environmental problems such as soil contamination and water pollution. Human health and the living environment are closely affected by the handling of heavy metals. Researchers must find several simple, economical and practical methods to adsorb heavy metals. Adsorption technology has been recognized as an efficient and economic strategy, exhibiting the advantages of recovering and reusing adsorbents. Biomass-derived activated carbon adsorbents offer large adjustable specific surface area, hierarchically porous structure, strong adsorption capacity, and excellent high economic applicability. This paper focuses on reviewing the preparation methods of biomass-derived activated carbon in the past five years. The application of representative biomass-derived activated carbon in the adsorption of heavy metals preferentially was described to optimize the critical parameters of the activation type of samples and process conditions. The key factors of the adsorbent, the physicochemical properties of the heavy metals, and the adsorption conditions affecting the adsorption of heavy metals are highlighted. In addition, the challenges faced by biomass-derived activated carbon are also discussed.

15.
RSC Adv ; 13(31): 21199-21210, 2023 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-37456551

RESUMEN

Removal of heavy metal pollution is an endless topic, because heavy metals can cause irreversible damage to the human body and environment. It is urgent to develop novel materials for detection and adsorption of heavy metal ions. In this paper, waste wolfberry straw was utilized as a carbon source, and two simple methods were developed to successfully prepare activated carbon (AC) and carbon quantum dots (CQDs). The fabrication conditions were optimized by adjusting the mass ratio of precursor to activator, type of activator and activation times. When sodium hydroxide (NaOH) was selected as an activator (6 : 1, mass ratio of NaOH to AC-precursor), and the activation was performed at 600 °C for 1 h, the highest specific surface area of the obtained AC-NaOH-3 reached 3016 m2 g-1. The adsorption capacity for copper ions (Cu2+) reached 68.06 mg g-1. The preparation conditions for CQDs were also optimized by adjusting the concentration of wolfberry stem, reaction time and temperature. When the wolfberry stem concentration was 7.5 g L-1, and the activation was performed at 200 °C for 24 h, the obtained CQDs exhibited strong fluorescence emission in the blank and 12 kinds of metal ion solutions, respectively, however, the fluorescence intensity was remarkably decreased after adding Cu2+. In the range of 10-80 nM, the linear correlation coefficient between the concentration of Cu2+ and fluorescence intensity of CQDs was 0.992, and the limit of detection was 2.83 nmol L-1. Thus, these two kinds of materials were prepared from wolfberry stem, which opened up a new way for the application in adsorption and detection of copper ions.

16.
RSC Adv ; 13(21): 14506-14516, 2023 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-37188255

RESUMEN

Ganoderma lucidum bran (GB) has a broad application prospect in the preparation of activated carbon, livestock feed, and biogas, but the preparation of carbon dots (CDs) from GB has never been reported. In this work, GB was applied as a carbon source and nitrogen source to prepare both blue fluorescent CDs (BCDs) and green fluorescent CDs (GCDs). The former were prepared at 160 °C for 4 h by a hydrothermal approach, while the latter were acquired at 25 °C for 24 h by chemical oxidation. Two kinds of as-synthesized CDs exhibited unique excitation-dependent fluorescence behavior and high fluorescent chemical stability. Based on the fantastic optical behavior of the CDs, they were utilized as probes for fluorescent determination of copper ions (Cu2+). In the range of 1-10 µmol L-1, the fluorescent intensity of BCDs and GCDs decreased linearly with the increase of Cu2+ concentration; the linear correlation coefficient reached 0.9951 and 0.9982, and the limit of detection (LOD) was 0.74 and 1.08 µmol L-1, respectively. In addition, these CDs remained stable in 0.001-0.1 mmol L-1 salt solutions; BCDs were more stable in the neutral pH range, but GCDs were more stable in neutral to alkaline conditions. The CDs prepared from GB are not only simple and low-cost, but also can realize the comprehensive utilization of biomass.

17.
J Chromatogr A ; 1689: 463774, 2023 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-36630850

RESUMEN

A hydrophilic adsorbent (Cys@poly(AMA)@MAR) was successfully prepared for the enrichment of N-glycopeptides via surface-initiated atom transfer radical polymerization (SI-ATRP) and photo-initiated "thiol-ene" reaction using monodisperse macroporous adsorbent resin (MAR) as adsorption matrix. Due to the presence of electron-deficient acrylic groups and electron-rich vinyl groups in allyl methacrylate (AMA), both of them can participate in free radical reaction. Therefore, the polymerization time of SI-ATRP was optimized. The resulting poly(AMA)@MAR was modified with l-cysteine (L-Cys) via photo-initiated "thiol-ene" reaction, and the amount of vinyl retained was determined by measuring the adsorption of Cu2+. The Cys@poly(AMA)@MAR pendant brushes with high density of amine and carboxyl groups could capture N-glycopeptides from IgG digest and human serum digest by hydrophilic interaction. The 22 N-glycopeptides were identified from IgG digest and the limit of detection reached 10 fmol. The 319 N-glycosylation sites and 583 N-glycopeptides were identified from 2 µL human serum digest and mapped to 147 glycoproteins. It demonstrates great potential and commercialization prospects for the enrichment of N-glycopeptides.


Asunto(s)
Glicopéptidos , Compuestos de Sulfhidrilo , Humanos , Polimerizacion , Química Clic/métodos , Adsorción , Cisteína , Inmunoglobulina G , Interacciones Hidrofóbicas e Hidrofílicas
18.
Food Chem ; 418: 135988, 2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37001354

RESUMEN

High-selectivity and high-exclusion restricted access materials (RAMs) benefit the analysis of biological samples. Herein, triblock copolymer-functionalized poly(4-vinylbenzyl chloride-co-divinylbenzene) (PVBC/DVB) microspheres were prepared via the sequential surface-initiated atom radical polymerization of hydrophobic styrene (St), ionic vinylimidazole (VIm), and zwitterionic sulfobetaine methacrylate (SBMA), affording RAMs with multiple interaction-adsorption sites and zwitterionic polymer exclusion sites on the internal and external surfaces of PVBC/DVB. The preferential extraction of fluoroquinolones (FQs) is realized based on the hydrophobic/π-π/ion exchange interactions due to the grafted poly-St-VIm, and the zwitterionic poly-SBMA block in the triblock copolymers can efficiently exclude various proteins. A sensitive detection method for FQs in chicken was established by solid phase extraction with RAMs as adsorbent combined with UPLC-MS/MS, achieving wide linearity (2.0-200.0 ng mL-1), low limit of detection (0.5 µg kg-1) and limit of quantification (1.5 µg kg-1), and good inter- and intraday precision with satisfactory recoveries (104.1%-117.7% and 115.3%-121.2% with RSDs < 12%).


Asunto(s)
Fluoroquinolonas , Polímeros , Fluoroquinolonas/análisis , Cromatografía Liquida , Polímeros/química , Espectrometría de Masas en Tándem , Extracción en Fase Sólida/métodos
19.
Anal Bioanal Chem ; 404(5): 1477-84, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22772141

RESUMEN

A novel imidazole-functionalized stationary phase for hydrophilic interaction chromatography (HILIC) was prepared via surface-initiated atom transfer radical polymerization (SI-ATRP). 1-Vinylimidazole as a monomer was polymerized on the surface of initiator-immobilized silica by SI-ATRP using CuCl and 2,2'-bipyridyl as a catalyst. The graft chain length and polymer grafting density were controlled by varying the ratio of monomer to initiator. The resulting materials were characterized by elemental analysis and thermogravimetric analysis. Then, high-performance liquid chromatography separation of eight nucleobases/nucleosides was performed on the imidazole-functionalized chromatographic column in HILIC mode. The effects of mobile phase composition, buffer pH, and column temperature on the separation of nucleobases/nucleosides were investigated, and the retention mechanisms were studied. Chromatographic parameters were calculated, and the results showed that surface adsorption through hydrogen bonding and electrostatic interaction dominated the retention behavior of the solutes in HILIC mode. Lastly, the stationary phase was successfully used to determine the nucleobases and nucleosides from Cordyceps militaris.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Imidazoles/química , Nucleósidos/aislamiento & purificación , Dióxido de Silicio/química , Adsorción , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Polimerizacion , Electricidad Estática , Temperatura
20.
Anal Methods ; 14(12): 1221-1231, 2022 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-35237778

RESUMEN

A chromatographic technique based on a chiral stationary phase (CSP) has been explored for enantioseparation. Herein, poly(glycidyl methacrylate) (poly(GMA)) brushes were grafted on the surface of silica gel via surface-initiated atom transfer radical polymerization (SI-ATRP), followed by the introduction of vancomycin as a chiral selector. The as-synthesized material was characterized by elemental analysis, scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) and thermogravimetric analysis (TGA), proving the formation of vancomycin-immobilized brushes. Then the resulting CSP was explored to separate 7 racemic drugs (bicalutamide, 1-benzyl-5-phenylbarbituric acid, chlorpheniramine maleate, fluoxetine hydrochloride, verapamil hydrochloride, benzoxazocine hydrochloride and isoprenaline hydrochloride) in high performance liquid chromatography (HPLC). Several factors affecting the enantioseparation performance of the vancomycin-immobilized CSP, including the triethylamine (TEA) content in the buffer, pH value, content of organic solvent in the mobile phase, flow rate and injection volume, were mainly optimized. Under the optimal conditions, baseline separation of fluoxetine hydrochloride (RS = 2.52) was achieved, which was better than that on a commercial Chirobiotic V column, while enantioseparation of bicalutamide (RS = 1.01), chlorpheniramine maleate (RS = 0.77), 1-benzyl-5-phenylbarbituric acid (RS = 0.67), isoprenaline hydrochloride (RS = 0.73), verapamil hydrochloride (RS = 0.91) and benzoxazocine hydrochloride (RS = 1.03) was partly achieved. It was concluded that SI-ATRP is a robust way to fabricate vancomycin-based CSPs for enantioseparation.


Asunto(s)
Clorfeniramina , Vancomicina , Cromatografía Líquida de Alta Presión/métodos , Fluoxetina , Isoproterenol , Polimerizacion , Espectroscopía Infrarroja por Transformada de Fourier , Estereoisomerismo , Vancomicina/química , Verapamilo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA