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1.
Talanta ; 275: 126102, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38692043

RESUMO

High interference and narrow application range are key of bottleneck of recent fluorescence analysis methods, which limit their wide application in the sensing field. Therefore, to overcome these disadvantages, a ratiometric fluorescence sensing system utilizing berberine (BER) and silver nanoclusters protected by dihydrolipoic acid (DHLA-AgNCs) was constructed for the first time in this work, to achieve determination of BER and daunorubicin (Dau). BER aqueous solution (non-planar conformation) has no fluorescence emission. When it was mixed with DHLA-AgNCs, the conformation of BER became planar, producing fluorescence emission at 515 nm besides the fluorescence emission peak of DHLA-AgNCs at 653 nm. With the increase of BER concentration added in system, the fluorescence intensity of BER (planar conformation) at 515 nm increased obviously and the fluorescence intensity of DHLA-AgNCs decreased slightly. Therefore, the dual emission fluorescence sensing system was constructed based on a fluorescence substance and non fluorescence substance, to achieve determination of BER. Meanwhile, based on the bridging effect of BER and fluorescence resonance energy transfer effect from Dau, the altering of two peaks intensity was utilized to achieve determination of Dau. Thus, this dual emission sensing system can not only be used for fluorescence analysis of BER and its analogues, but also based on the bridging effect of BER, allowing the determination of Dau and its analogues that could not be directly measured with silver nanoclusters, expanding the application range of traditional dual emission detection systems. Meanwhile, this system has strong anti-interference ability and low toxicity to the human body and less pollution to the sample and environment. This provides a new direction and universal research strategy for the construction of new fluorescence sensing systems in the future for the analysis of target substances that cannot be directly detected with conventional fluorescence analysis methods.

2.
Int J Biol Macromol ; 265(Pt 1): 130914, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38492702

RESUMO

An innovative and simple nanocomposite denoted as MHNTs@PEI was synthesized for gallic acid (GA) analytical sample pretreatment. Polyethyleneimine (PEI) functionalized was binded onto magnetic halloysite nanotubes (MHNTs) to inhence adsorption capacity. MHNTs@PEI was obtained only through two steps modification (amination and PEI modification). Characterizations showed that there are layers of synthetic PEI on the tubular structure of the material and magnetic spheres on its surface, both indicating successful synthesis of the nanocomposite. Furthermore, the adsorption isotherms and kinetic modeling showed that the Langmuir model and pseudo-first-order model fit the adsorption data, respectively. MHNTs@PEI achieved an adsorption capacity of 158 mg·g-1. Overall, the abundant adsorption sites significantly improved the adsorption performance of the MHNTs@PEI. Regeneration tests demonstrated that the MHNTs@PEI exhibits effective adsorption, even after undergoing five consecutive cycles. Optimization of key parameters (ratio, volume of elution, elution time and frequency) in the process of adsorption and desorption was also conducted. The limit of detection (LOD) and that of the quantification (LOQ) were 0.19 and 0.63 µg·mL-1, respectively, and the recoveries were 95.67-99.43 %. Finally, the excellent magnetism (43.5 emu·g-1) and the adsorption feature of MHNTs@PEI enabled its successful utilization in analytical sample pretreatment through the extraction of GA from green tea.


Assuntos
Nanotubos , Poluentes Químicos da Água , Argila , Polietilenoimina/química , Ácido Gálico , Chá , Nanotubos/química , Adsorção , Fenômenos Magnéticos , Cinética
3.
J Environ Manage ; 353: 120142, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38306855

RESUMO

The effective removal of heavy metal ions from sewage remains a critical issue, and applying the operability of magnetic materials to large volume wastewater treatment has been a significant challenge. In this paper, metal ions adsorption induced aggregation strategy is proposed to solve this contradiction. The intelligent magnetic fluid designed in this study is a well-dispersed fluid state when treating sewage, and can efficiently adsorb heavy metal ions in wastewater with high adsorption capacity and ultra-fast adsorption kinetics. More importantly, after saturation of adsorption, the magnetic fluid will transform from a well-dispersed fluid state to an agglomeration state which is easy to precipitate and separate via external magnetic field. In a simple and effective way, the particles size of magnetic nanoparticles was precisely controlled by cellulose derivatives modification to obtain a stable magnetic fluid in water. The Freundlich model best described Cu2+ adsorption on magnetite nanoparticles, the correlation coefficients from the Cu2+ adsorption on the two magnetic fluids are 0.9554 and 0.9336, n are 1.868 and 2.117, revealing a favorable adsorption of Cu2+ onto magnetic fluids. The pseudo second-order model fitted the adsorption kinetic data better, the qe are 0.1948 and 0.1315 mmol/g and the R2 are 0.9999, indicating that the adsorption of Cu2+ onto the magnetic fluid was dominated by chemisorption. Moreover, the removal rate of Cu2+ in tap water and lake water was more than 97.1%, and the removal rate of large volume sewage was 81.7%. The synthetic magnetic fluid has high adsorption capacity, ultra-fast adsorption kinetics, reusability and easy separation, indicating its potential application for the removal of heavy metal ions from large-volume sewage.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Cobre/análise , Esgotos , Adsorção , Íons , Água , Fenômenos Magnéticos , Cinética , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio
4.
Mikrochim Acta ; 191(1): 70, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38165510

RESUMO

A smartphone-assisted, paper-based ratio fluorescence probe is presented for the rapid, low-cost and on-site quantification of total flavonol glycosides in Ginkgo biloba extracts (GBE). The Al3+/Eu-MOF/paper-based probe utilizes lanthanide metal-organic framework (Ln-MOF) nanoparticles immobilized on Whatman filter paper along with Al3+ for detecting flavonols, which are the hydrolyzed products of flavonol glycosides. The color change of the paper-based fluorescence image from red to orange depends on the concentration of the target analyte in the sample solution. The smartphone equipped with a red, green, blue (RGB) color detector measured the fluorescence signal intensity on the paper substrate after adding flavonol. The analytical variables affecting the performance of the probe, including the addition sequence of the aluminum nitrate solution, its concentration, that of the Ln-MOF solution, the drying time of the paper probe, the reaction time and the sensitivity parameters of the mobile phone camera (ISO), were optimized. Under optimal conditions, the Al3+/Eu-MOF/paper-based probe has good linear response in the concentration range 7 ~ 80 µg mL- 1 and a lower detection limit of 2.07 µg mL- 1. The results obtained with the paper-based ratio fluorescence probe and smartphone combination were validated by comparing them with high-performance liquid chromatography (HPLC) measurements. This study provides a potential strategy for fabricating Al3+/Eu-MOF/paper-based probe used for total flavonol glycosides determination.


Assuntos
Elementos da Série dos Lantanídeos , Estruturas Metalorgânicas , Smartphone , Diagnóstico por Imagem , Flavonóis , Glicosídeos , Extratos Vegetais
5.
J Sep Sci ; 46(11): e2300037, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37004155

RESUMO

In the classical natural product extraction and separation process, it is tedious and requires large amounts of reagents and time. In this study, an efficient coaxial liquid centrifugal oil-water-oil triple-liquid-phase system with a simple structure and convenient operation was successfully constructed and used to extract flavonoids from Platycladi Cacumen. The results showed that the coaxial liquid centrifugal platform constructed in this study had good stability and 6 ml was the minimum volume of the middle phase for 1000 rpm to stabilize the system. Besides, it was easy to repeat the operation: the relative standard deviations of the extraction yields of flavonoids and sugar in six parallel operations were all less than 10%. Moreover, it was only one-tenth of the time required for this method as traditional liquid-liquid extraction while reducing the use of volatile organic reagents. Finally, the new method was more selective than the traditional method for the extraction of flavonoids. Therefore, this study provides a possibility for the coaxial liquid centrifugal platform to be used in multi-liquid phase systems to achieve the simultaneous extraction of different parts of natural products by different liquid phases. It is expected to provide a reliable reference for further expansion of small-scale experimental operations to industrial production.


Assuntos
Produtos Biológicos , Flavonoides/análise , Extração Líquido-Líquido , Cromatografia Líquida de Alta Pressão
6.
Chirality ; 34(8): 1094-1119, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35676772

RESUMO

The attention to chiral drugs has been raised to an unprecedented level as drug discovery and development strategies grow rapidly. However, separation of enantiomers is still a huge task, which leads to an increasing significance to equip a wider range of expertise in chiral separation science to meet the current and future challenges. In the last few decades, remarkable progress of chiral resolution has been achieved. This review summarizes and classifies chiral resolution methods in analytical scale and preparative scale systematically and comprehensively, including crystallization-based method, inclusion complexation, chromatographic separation, capillary electrophoresis, kinetic resolution, liquid-liquid extraction, membrane-based separation, and especially one bold new progress based on chiral-induced spin selectivity theory. The advances and recent applications will be presented in detail, in which the contents may bring more thinking to wide-ranging readers in various professional fields, from analytical chemistry, pharmaceutical chemistry, natural medicinal chemistry, to manufacturing of drug production.


Assuntos
Cromatografia , Eletroforese Capilar , Eletroforese Capilar/métodos , Preparações Farmacêuticas , Estereoisomerismo
7.
Nanoscale Res Lett ; 16(1): 167, 2021 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-34837561

RESUMO

With the rapid development of nanotechnology, new types of fluorescent nanomaterials (FNMs) have been springing up in the past two decades. The nanometer scale endows FNMs with unique optical properties which play a critical role in their applications in bioimaging and fluorescence-dependent detections. However, since low selectivity as well as low photoluminescence efficiency of fluorescent nanomaterials hinders their applications in imaging and detection to some extent, scientists are still in search of synthesizing new FNMs with better properties. In this review, a variety of fluorescent nanoparticles are summarized including semiconductor quantum dots, carbon dots, carbon nanoparticles, carbon nanotubes, graphene-based nanomaterials, noble metal nanoparticles, silica nanoparticles, phosphors and organic frameworks. We highlight the recent advances of the latest developments in the synthesis of FNMs and their applications in the biomedical field in recent years. Furthermore, the main theories, methods, and limitations of the synthesis and applications of FNMs have been reviewed and discussed. In addition, challenges in synthesis and biomedical applications are systematically summarized as well. The future directions and perspectives of FNMs in clinical applications are also presented.

8.
J Mater Chem B ; 9(44): 9076-9099, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34668920

RESUMO

Magnetic carbon nanotubes (MCNTs), consisting of carbon nanotubes (CNTs) and magnetic nanoparticles (MNPs), have enormous exploration and application potentials due to their superior physical and chemical properties, such as unique magnetism and high enrichment performance. This review concentrates on the rapid advances in the synthesis and application of magnetic carbon nanotubes. Great progress has been made in the preparation of MCNTs by developing methods including chemical vapor deposition, pyrolysis procedure, sol-gel process, template-based synthesis, filling process and hydrothermal/solvothermal method. Various applications of MCNTs as a mediator of the adsorbent in magnetic solid-phase extraction, sensors, antibacterial agents, and imaging system contrast agents, and in drug delivery and catalysis are discussed. In order to overcome the drawbacks of MCNTs, such as sidewall damage, lack of convincing quantitative characterization methods, toxicity and environmental impact, and deficiency of extraction performance, researchers proposed some solutions in recent years. We systematically review the latest advances in MCNTs and discuss the direction of future development.


Assuntos
Nanopartículas de Magnetita/química , Nanotubos de Carbono/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Técnicas Biossensoriais/métodos , Catálise , Meios de Contraste/química , Portadores de Fármacos/química , Técnicas Eletroquímicas/métodos , Humanos , Fenômenos Magnéticos , Extração em Fase Sólida/métodos
9.
J Fluoresc ; 31(2): 509-516, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33449252

RESUMO

Fluorescent carbon nanoparticles exhibit merits in terms of photochemical stability, functional modification flexibility and excellent biocompatibility. Currently, fluorescent carbon nanoparticles are often obtained by bottom-up or up-bottom strategies. So far, there has been no literature concerning spontaneous formation of fluorescent carbon nanoparticles. However, we have successfully found that fluorescent carbon nanoparticles can form spontaneously in the glutaraldehyde solution. Then further investigations were conducted on the storage time, pH and temperature, which could affect the fluorescence intensity of glutaraldehyde solution. The results indicate that the value of the fluorescence intensity will increase with the extension of the storage time. Moreover, the fluorescence mechanism of the glutaraldehyde solution was studied according to its properties and experiment results. Transmission electron microscopy was used to demonstrate nanoparticles in the glutaraldehyde solution. It's assumed that such phenomenon is probably attributed to the conjugated structure resulting from the polymerization of glutaraldehyde and the quantum confinement effect owing to the nanoparticles formed by the aggregation of polymers. Therefore, the spontaneous fluorescence produced by glutaraldehyde solution provides a simple and environmentally-friendly way to prepare fluorescent carbon nanoparticles.

10.
Drug Des Devel Ther ; 14: 5611-5622, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33376305

RESUMO

PURPOSE: Pulmonary surfactants (eg, sinapultide) are widely used for the treatment of lung injury diseases; however, they generally induce poor therapeutic efficacy in clinics. In this study, sinapultide-loaded microbubbles (MBs) were prepared and combined with ultrasound (US) treatment as a new strategy for improved treatment of lung injury diseases. METHODS: The combination treatment strategy of MBs combined with ultrasound was tested in a lipopolysaccharide (LPS)-induced mouse model of alveolar epithelial cells (AT II) and acute lung injury. Firstly, cytotoxicity, cytokines, and protein levels in LPS-mediated AT II cells were assessed. Secondly, the pathological morphology of lung tissue, the wet/dry (W/D) weight ratio, cytokines, and protein levels in LPS-mediated acute lung injury mice after treatment with the MBs were evaluated. Moreover, histology examination of the heart, liver, spleen, lung and kidney of mice treated with the MBs was performed to initially evaluate the safety of the sinapultide-loaded MBs. RESULTS: Sinapultide-loaded MBs in combination with ultrasound treatment significantly reduced the secretion of inflammatory cytokines and increased the expression of surfactant protein A (SP-A) in AT II cells. Furthermore, the pathological morphology of lung tissue, the wet/dry (W/D) weight ratio, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and SP-A expression level of mice treated with MBs and ultrasound were significantly improved compared to those of non-treated mice. In addition, the histology of the examined organs showed that the MBs had a good safety profile. CONCLUSION: Sinapultide-loaded MBs combined with ultrasonic treatment may be a new therapeutic option for lung injury diseases in the clinic.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Lipopolissacarídeos/antagonistas & inibidores , Peptídeos/uso terapêutico , Ondas Ultrassônicas , Lesão Pulmonar Aguda/induzido quimicamente , Animais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microbolhas
11.
Mikrochim Acta ; 187(7): 399, 2020 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-32572580

RESUMO

Fluorescent nanomaterials (FNMs) and molecular imprinted polymers (MIPs) have been widely used in analytical chemistry for determination. However, low selectivity of FNMs and low sensitivity of MIPs hinder their applications. Combining the merits of FNMs and MIPs, FNMs coated with MIPs (FNMs@MIPs) were proposed to solve those problems. Carbon dots, semiconductor quantum dots, noble metal nanoparticles, silica nanoparticles, and covalent-organic frameworks have been reported to be coated with MIPs. In order to overcome challenges for FNMs@MIPs, such as the lack of handy synthesis routes, incompatibility with aqueous solutions, heterogeneous size of particles, leakage of template molecules, the biocompatibility of FNMs@MIPs, and the inference between FNMs and MIPs, scientists proposed some solutions in recent years. We comprehensively review the newest advances of the FNMs@MIPs, and predict the direction of the future development. Graphical abstract.

12.
Mikrochim Acta ; 185(4): 247, 2018 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-29619574

RESUMO

This review (with 154 refs.) describes the current status of using molecularly imprinted polymers in the extraction and quantitation of illicit drugs and additives. The review starts with an introduction into some synthesis methods (lump MIPs, spherical MIPs, surface imprinting) of MIPs using illicit drugs and additives as templates. The next section covers applications, with subsections on the detection of illegal additives in food, of doping in sports, and of illicit addictive drugs. A particular focus is directed towards current limitations and challenges, on the optimization of methods for preparation of MIPs, their applicability to aqueous samples, the leakage of template molecules, and the identification of the best balance between adsorption capacity and selectivity factor. At last, the need for convincing characterization methods, the lack of uniform parameters for defining selectivity, and the merits and demerits of MIPs prepared using nanomaterials are addressed. Strategies are suggested to solve existing problems, and future developments are discussed with respect to a more widespread use in relevant fields. Graphical abstract This review gives a comprehensive overview of the advances made in molecularly imprinting of polymers for use in the extraction and quantitation of illicit drugs and additives. Methods for syntheses, highlighted applications, limitations and current challenges are specifically addressed.


Assuntos
Aditivos Alimentares/análise , Drogas Ilícitas/análise , Polímeros/química , Limite de Detecção , Impressão Molecular/métodos , Nanoestruturas/química , Polímeros/síntese química
13.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1068-1069: 24-32, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29028615

RESUMO

In this research, a novel insoluble sorbent based on cyclodextrin and rigid aromatic groups tetrafluoroacetonitrile was designed for dispersive insoluble solid-phase extraction (DSPE). Due to its high adsorption capacity, this obtained polymer was applied to separation and concentration of trace quinolones in wastewater before HPLC determination. Various parameters influencing the extraction performance were studied and optimized. A DSPE approach coupled with high performance liquid chromatography was developed for the determination of four quinolones in wastewater samples. The limit of quantitation of fleroxacin, ciprofloxacin, gatifloxacin, norfloxacin were 2.67, 3.17, 4.75, 5.50ngmL-1, respectively. The recoveries of four quinolones range from 96.43 to 103.3% with relative standard deviations less than 4.5%. These results demonstrated that the proposed approach based on CDP was efficient, low-cost for extraction of quinolones from wastewater.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Quinolonas/análise , Extração em Fase Sólida/métodos , Águas Residuárias/química , beta-Ciclodextrinas/química , Limite de Detecção , Modelos Lineares , Quinolonas/química , Quinolonas/isolamento & purificação , Reprodutibilidade dos Testes
14.
J Chromatogr A ; 1524: 49-56, 2017 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-29030037

RESUMO

In this study, a novel solid phase extraction based on porous magnetic graphene oxide-cyclodextrin polymers (MGO-CD) was developed with aromatic linker and used for the simultaneous extraction and preconcentration of trace antiepileptic drugs in plasma. The characteristics of MGO-CD were assessed by Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller surface areas (BET), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). Magnetic cyclodextrin polymeric material exhibited a high specific surface area (187m2g-1), large pore volume (0.12cm3g-1), good saturated magnetization (37.68emug-1), and excellent dispersibility in aqueous solution. Various parameters influencing the extraction recovery of drugs were studied. The method exhibited good linearity in the range of 1-50µgmL-1, and the limit of quantitation of carbamazepine, phenytoin, diazepam was 11.89, 47.10 and 16.17ngmL-1, respectively. The recoveries of three antiepileptic drugs range from 78.49 to 100.93% with relative standard deviations less than 5.5%. These analytical results demonstrated that the proposed approach based on MGO-CD was applicable for analysis of antiepileptic drugs in plasma samples.


Assuntos
Anticonvulsivantes/sangue , Análise Química do Sangue/métodos , Celulose/química , Cromatografia Líquida de Alta Pressão , Ciclodextrinas/química , Grafite/química , Magnetismo , Óxidos/química , Extração em Fase Sólida , Humanos , Óxidos/análise , Polímeros , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química , Difração de Raios X
15.
J Pharm Sci ; 106(10): 3150-3155, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28625724

RESUMO

Coamorphous systems have gained success in stabilizing amorphous drugs and improving their solubility and dissolution. Here we proposed to confine a binary mixture of drug and coformer (CF) within nanopores to obtain a nanoconfined coamorphous (NCA) system. For proving feasibility of this proposal, a poorly water-soluble drug (ibuprofen) and a frequently used pharmaceutical CF (nicotinamide) were loaded into nanopores of mesoporous silica microspheres. The solid state of NCA system was characterized by differential scanning calorimetry, X-ray powder diffraction, infrared spectrum, and solid-state nuclear magnetic resonance. With large numbers of nanopores, mesoporous silica microspheres appear to be a feasible carrier to transform a cocrystal system into coamorphism by nanoscale confinement. Benefiting from both nanoscale confinement and CF, the NCA system of ibuprofen achieved synchronic increase in dissolution properties and physical stability. Consequently, the NCA strategy is effective in achieving coamorphous state and offers a promising alternative for formulating poorly water-soluble drugs.


Assuntos
Ibuprofeno/química , Nanopartículas/química , Niacinamida/química , Varredura Diferencial de Calorimetria/métodos , Cristalização/métodos , Microesferas , Porosidade , Difração de Pó/métodos , Dióxido de Silício/química , Solubilidade , Água/química , Difração de Raios X/métodos
16.
Sci Rep ; 6: 38106, 2016 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-27924944

RESUMO

Simple, accurate and high-throughput pretreatment method would facilitate large-scale studies of trace analysis in complex samples. Magnetic mixed hemimicelles solid-phase extraction has the power to become a key pretreatment method in biological, environmental and clinical research. However, lacking of experimental predictability and unsharpness of extraction mechanism limit the development of this promising method. Herein, this work tries to establish theoretical-based experimental designs for extraction of trace analytes from complex samples using magnetic mixed hemimicelles solid-phase extraction. We selected three categories and six sub-types of compounds for systematic comparative study of extraction mechanism, and comprehensively illustrated the roles of different force (hydrophobic interaction, π-π stacking interactions, hydrogen-bonding interaction, electrostatic interaction) for the first time. What's more, the application guidelines for supporting materials, surfactants and sample matrix were also summarized. The extraction mechanism and platform established in the study render its future promising for foreseeable and efficient pretreatment under theoretical based experimental design for trace analytes from environmental, biological and clinical samples.

17.
J Chromatogr A ; 1473: 1-9, 2016 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-28029366

RESUMO

In this work, a novel magnetic ultra-thin dummy molecularly imprinted polymer (MMIP) for morphine (MO) was prepared. In order to obtain highly selective recognition cavities, the MMIP has been designed using semi-flexible docking to screen the optimal monomer and its ratio to morphine from six representative monomers. Furthermore, the dummy template was creatively screened by semi-flexible docking method from opioid drugs. The system of dihydrocodeine (DI) as dummy template, methacrylamide (MAC) as founctional monomer, ethyleneglycol dimethacrylate (EGDMA) as crosslinker was chosen for MO imprinting. The morphological and magnetic properties of MMIP were characterized by FT-IR, TEM and VSM. The results suggested that molecularly imprinted polymer (MIP) was synthesized evenly on Fe3O4 surface. The adsorption experiments revealed that MMIP showed better extraction capacity and selectivity toward MO and its analogues than the non-imprinted polymer (NIP). The MMIP possessed adsorption capacity of 14.71mg/g for MO and the imprinting factor was 2.10 at separate adsorption and 1.87 at competitive adsorption. A magnetic molecularly imprinted solid phase extraction coupled with HPLC method (M-MISPE-HPLC) has been established for the analysis of MO in urine sample. The developed method was validated for its linearity (0.038-100mgL-1 R2=0.9937), precision (1.07%-3.72%) and accuracy (83.62%-100.37%).


Assuntos
Cromatografia Líquida de Alta Pressão , Morfina/isolamento & purificação , Morfina/urina , Polímeros/química , Extração em Fase Sólida , Urinálise/métodos , Acrilamidas/química , Adsorção , Humanos , Magnetismo , Metacrilatos/química , Impressão Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Urinálise/normas
18.
J Chromatogr A ; 1454: 1-8, 2016 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-27266334

RESUMO

A novel mixed hemimicelles solid phase extraction based on magnetic graphene oxide (Fe3O4/GO) and ionic liquid (IL) was developed for the simultaneous extraction and determination of trace cephalosporins in spiked human urine. The high surface area and excellent adsorption capacity of the graphene oxide after modification with1-hexadecyl-3-methylmidazoliumbromide(C16mimBr) were utilized adequately in the solid phase extraction(SPE) process. A comprehensive study of the parameters affecting the extraction recovery, such as the zeta-potential of magnetic graphene oxide, amounts of magnetic graphene oxide and surfactant, pH of solution, ionic strength, extraction time, and desorption condition were optimized. A comparative study on the use of different surfacant-coated Fe3O4/GO NPs as sorbents was presented. Good linearity (R(2)>0.9987) for all calibration curves was obtained. The LODs were ranged between 0.6 and 1.9ng mL(-1) for the cephalosporins and the LOQs were 1.5 to 5.5, respectively. Satisfactory recoveries(84.3% to 101.7%)and low relative standard deviations from 1.7% to 6.3% in biological matrices were achieved. The mixed hemimicelles magnetic SPE (MSPE) method based on ILs and Fe3O4/GO NPs magnetic separation has ever been successfully used for pretreatment of complex biological samples.


Assuntos
Cefalosporinas/urina , Cromatografia Líquida de Alta Pressão/métodos , Grafite/química , Nanopartículas de Magnetita/química , Extração em Fase Sólida/métodos , Cefalosporinas/isolamento & purificação , Humanos , Líquidos Iônicos/química
19.
J Sep Sci ; 39(2): 383-90, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26541792

RESUMO

In this study, molecularly imprinting technology and stir bar absorption technology were combined to develop a microextraction approach based on a molecularly imprinted polymeric stir bar. The molecularly imprinted polymer stir bar has a high performance, is specific, economical, and simple to prepare. The obtained naftopidil-imprinted polymer-coated bars could simultaneously agitate and adsorb naftopidil in the sample solution. The ratio of template/monomer/cross-linker and conditions of template removal were optimized to prepare a stir bar with highly efficient adsorption. Fourier transform infrared spectroscopy, scanning electron microscopy, selectivity, and extraction capacity experiments showed that the molecularly imprinted polymer stir bar was prepared successfully. To utilize the molecularly imprinted polymer stir bar for the determination of naftopidil in complex body fluid matrices, the extraction time, stirring speed, eluent, and elution time were optimized. The limits of detection of naftopidil in plasma and urine sample were 7.5 and 4.0 ng/mL, respectively, and the recoveries were in the range of 90-112%. The within-run precision and between-run precision were acceptable (relative standard deviation <7%). These data demonstrated that the molecularly imprinted polymeric stir bar based microextraction with high-performance liquid chromatography was a convenient, rapid, efficient, and specific method for the precise determination of trace naftopidil in clinical analysis.


Assuntos
Naftalenos/isolamento & purificação , Piperazinas/isolamento & purificação , Polímeros/química , Extração em Fase Sólida/métodos , Adsorção , Cromatografia Líquida de Alta Pressão , Humanos , Impressão Molecular , Naftalenos/sangue , Naftalenos/urina , Piperazinas/sangue , Piperazinas/urina , Polímeros/síntese química , Extração em Fase Sólida/instrumentação
20.
J Mol Recognit ; 28(5): 277-84, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25732346

RESUMO

In this work, molecularly imprinted magnetic carbon nanotubes (MCNTs@MIPs) was prepared with surface imprinting technique for extraction of levofloxacin in serum samples. The preparation of molecularly imprinted polymers (MIPs) used levofloxacin as template, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross-linker, and the magnetic carbon nanotubes (MCNTs) was synthesized by solvothermal method. The prepared polymers not only can be separated and collected easily by an external magnetic, but also exhibited high specific surface area and high selectivity to template molecules. Kinetic adsorption and static adsorption capacity investigations indicated that the synthesized MCNTs@MIPs had excellent recognition towards levofloxacin. Furthermore, magnetic solid phase extraction (MSPE) using the prepared MCNTs@MIPs as sorbent was then investigated, and an efficient sample cleanup was obtained with recoveries ranged from 78.7 ± 4.8 % to 83.4 ± 4.1%. In addition, several parameters, including the pH of samples, the amount of MCNTs@MIPs, the adsorption and desorption times, and the eluent, were investigated to obtain optimal extraction efficiency. Under the optimal extraction conditions, the stability of the polymer was also evaluated, and the average recovery reduced less than 7.6% after 5 cycles. MCNTs@MIPs successfully applied in the preconcentration and determination of levofloxacin in serum sample suggested that the MSPE method based on the novel polymers could be a promising alternative for selective and efficient extraction of trace amounts of pharmaceutical substances in bio-matrix samples.


Assuntos
Antibacterianos/isolamento & purificação , Levofloxacino/isolamento & purificação , Adsorção , Antibacterianos/sangue , Cromatografia Líquida de Alta Pressão , Humanos , Levofloxacino/sangue , Fenômenos Magnéticos , Impressão Molecular , Nanotubos de Carbono/química , Ácidos Polimetacrílicos/química , Extração em Fase Sólida
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