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1.
Talanta ; 207: 120284, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594616

RESUMO

Magnetic carbon nanotubes (CNTs) with encapsulated Co nanoparticles (Co@CNTs), was synthesized by exploiting the one-step pyrolysis strategy using ZIF-67 as template. The as-synthesized Co@CNTs is provided with the nanopores, a large specific surface area, and strong magnetic response. The obtained Co@CNTs was used as magnetic solid-phase extraction adsorbents to extract two profens including flurbiprofen and ketoprofen. The parameters of extraction efficiency, involving extraction time, sample solution volume, ionic strength, pH and the conditions of desorption efficiency, were optimized in detail. After determined by high-performance liquid chromatography-ultraviolet (HPLC-UV), the results evinced that Co@CNTs showed a high extraction efficiency with high enrichment factors of 832 and 672. The good linear range of both flurbiprofen and ketoprofen were all 5.0-1000 ng L-1, with the limit of detection were 0.60 ng L-1 and 0.70 ng L-1, respectively. Furthermore, a valid method for the extraction of flurbiprofen and ketoprofen from human serum was established. The spiking recoveries of two profens were between 86.74% and 97.22%, and the relative standard deviation was less than 6.55%. Co@CNTs can be repeatedly used at least 10 times, indicating its excellent regeneration and reusability. The results demonstrated that the Co@CNTs materials exhibits high enrichment ability and extraction efficiency, playing great promise in MSPE.


Assuntos
Flurbiprofeno/isolamento & purificação , Cetoprofeno/isolamento & purificação , Imãs/química , Nanotubos de Carbono/química , Compostos Organometálicos/química , Extração em Fase Sólida/métodos , Adsorção , Cobalto/química , Flurbiprofeno/sangue , Flurbiprofeno/química , Humanos , Imidazóis/química , Cetoprofeno/sangue , Cetoprofeno/química , Nanopartículas Metálicas/química
2.
Talanta ; 199: 290-295, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30952260

RESUMO

A chitosan membrane composed by 60% (w/w) chitosan and 40% (w/w) Aliquat®336 has been proposed as a new biopolymeric support for electromembrane extraction. The new support has been characterized by Scanning Electron Microscopy, resulting a 30-35 µm thickness. Amoxicillin, nicotinic acid, hippuric acid, salicylic acid, anthranilic acid, ketoprofen, naproxen and ibuprofen have been successfully extracted using the proposed support. Better enrichment factors were obtained for the acidic polar analytes than for the non-steroidal anti-inflammatory compounds (ranging from 118 for hippuric acid and 20 for ibuprofen). Electromembrane extraction was developed applying a DC voltage of 100 V, 1-octanol as supported liquid membrane and 20 min of extraction. The target analytes have also been satisfactorily extracted from human urine samples, providing high extraction efficiencies. The chitosan membrane is presented as a promising alternative for supporting liquid membrane compared to commonly used materials for this purpose.


Assuntos
Biopolímeros/química , Quitosana , Técnicas Eletroquímicas , Amoxicilina/química , Amoxicilina/isolamento & purificação , Hipuratos/química , Hipuratos/isolamento & purificação , Humanos , Ibuprofeno/química , Ibuprofeno/isolamento & purificação , Cetoprofeno/química , Cetoprofeno/isolamento & purificação , Naproxeno/química , Naproxeno/isolamento & purificação , Niacina/química , Niacina/isolamento & purificação , Ácido Salicílico/química , Ácido Salicílico/isolamento & purificação , ortoaminobenzoatos/química , ortoaminobenzoatos/isolamento & purificação
3.
Talanta ; 179: 601-607, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29310282

RESUMO

The use of polymer inclusion membranes (PIMs) as support of 1-octanol liquid membrane in electromembrane extraction (EME) procedure is proposed. Synthesis of PIMs were optimized to a composition of 29% (w/w) of cellulose triacetate as base polymer and 71% (w/w) of Aliquat®336 as cationic carrier. Flat PIMs of 25µm thickness and 6mm diameter were used. EME protocol was implemented for the simultaneous extraction of four non-steroidal anti-inflammatory drugs (NSAIDs) (salicylic acid, ketoprofen, naproxen and ibuprofen) and four highly polar acidic drugs (anthranilic acid, nicotinic acid, amoxicillin and hippuric acid). Posterior HPLC separation of the extracted analytes was developed with diode array detection. Recoveries in the 81-34% range were obtained. EME procedure was applied to human urine samples.


Assuntos
Anti-Inflamatórios não Esteroides/isolamento & purificação , Celulose/análogos & derivados , Técnicas Eletroquímicas , Compostos de Amônio Quaternário/química , Amoxicilina/isolamento & purificação , Amoxicilina/urina , Anti-Inflamatórios não Esteroides/urina , Celulose/química , Hipuratos/isolamento & purificação , Hipuratos/urina , Ibuprofeno/isolamento & purificação , Ibuprofeno/urina , Cetoprofeno/isolamento & purificação , Cetoprofeno/urina , Membranas Artificiais , Naproxeno/isolamento & purificação , Naproxeno/urina , Niacina/isolamento & purificação , Niacina/urina , Ácido Salicílico/isolamento & purificação , Ácido Salicílico/urina , ortoaminobenzoatos/isolamento & purificação , ortoaminobenzoatos/urina
4.
J Chromatogr A ; 1531: 131-142, 2018 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-29174135

RESUMO

Gradient operation of a simulated moving bed (SMB) can improve the separation and purification performance by adjusting adsorption strength in each individual zone according to its functional role. The feasibility of an internal temperature gradient (ITG) established by a difference between feed and desorbent temperatures for binary separation of ketoprofen enantiomers was investigated based on simultaneous optimization of purity and productivity of S-ketoprofen, the preferentially adsorbed species and desired product. ITG operation with a temperature difference of 20K has a unit productivity higher than isothermal mode by about 20%. Due to the combined effects of temperature transition and downstream dilution, concentration profile may exhibit a remarkable peak and a pattern of two-step drop in the temperature descending and ascending areas, respectively. Both areas, if properly located under optimal conditions, are favorable for unit productivity, which cannot be predicted by the direct use of triangle theory and average Henry's constants. Modifications of the SMB operations to reduce solvent consumption were also discussed based on analyses of parametric sensitivity and internal concentration profiles.


Assuntos
Cetoprofeno/isolamento & purificação , Cetoprofeno/química , Modelos Teóricos , Solventes/química , Estereoisomerismo , Temperatura Ambiente
5.
J Chromatogr A ; 1521: 1-9, 2017 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-28947204

RESUMO

The present work represents a simple and effective preparation of a novel mixed-mode anion-exchange (MAX) sorbent based on porous poly[2-(diethylamino)ethyl methacrylate-divinylbenzene] (poly(DEAEMA-DVB)) spherical particles synthesized by one-step Pickering emulsion polymerization. The poly(DEAEMA-DVB) particles were quaternized with 1,4-butanediol diglycidyl ether (BDDE) followed by triethylamine (TEA) via epoxy-amine reaction to offer strong anion exchange properties. The synthesized MAX sorbent was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, nitrogen adsorption-desorption measurements and elemental analysis. The MAX sorbent possessed regular spherical shape and narrow diameter distribution (15-35µm), a high IEC of 0.54meq/g, with carbon and nitrogen contents of 80.3% and 1.62%, respectively. Compared to poly(DEAEMA-DVB), the MAX sorbent exhibited decreased SBET (390.5 vs. 515.3m2g-1), pore volume (0.74 vs. 0.85cm3g-1) and pore size (16.8 vs. 17.3nm). Moreover, changes of N content for producing the MAX sorbent reveal a successful two-step quaternization, which can be highly related to such a high IEC. Finally, the MAX sorbent was successfully evaluated for selective isolation and purification of some selected acidic pharmaceuticals (ketoprofen, KEP; naproxen, NAP; and ibuprofen, IBP) from neutral (hydrocortisone, HYC), basic (carbamazepine, CAZ; amitriptyline, AMT) pharmaceuticals and other interferences in water samples using solid phase extraction (SPE). An efficient analytical method based on the MAX-based mixed-mode SPE coupled with HPLC-UV was developed for highly selective extraction and cleanup of acidic KEP, NAP and IBP in spiked wastewater samples. The developed method exhibited good sensitivity (0.009-0.085µgL-1 limit of detection), satisfactory recoveries (82.1%-105.5%) and repeatabilities (relative standard deviation < 7.9%, n=3).


Assuntos
Monitoramento Ambiental/métodos , Preparações Farmacêuticas/isolamento & purificação , Extração em Fase Sólida , Águas Residuárias/química , Butileno Glicóis , Emulsões , Monitoramento Ambiental/instrumentação , Ibuprofeno/análise , Ibuprofeno/isolamento & purificação , Cetoprofeno/análise , Cetoprofeno/isolamento & purificação , Limite de Detecção , Naproxeno/análise , Naproxeno/isolamento & purificação , Preparações Farmacêuticas/análise , Polimerização , Reprodutibilidade dos Testes , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação
6.
Anal Chim Acta ; 963: 153-163, 2017 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-28335969

RESUMO

A new class of efficient stationary phase has been investigated for use in the liquid chromatographic separation of low molecular weight analytes and high molecular weight biomolecules, based on the application of immobilised stimuli-responsive polymers (SRPs). To this end, two polymeric units, namely poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) and poly(acrylic acid) (PAA) were tethered to a triazine core. The derived poly(2-dimethyl-aminoethyl methacrylate)-block-poly(acrylic acid) (PDMAEMA-b-PAA), as a diblock co-polymer, was then immobilised onto the surface of porous silica particles. The performance of this microparticulate adsorbent was evaluated under various temperature, ionic strength and/or pH conditions in packed columns in a high-performance liquid chromatography (HPLC) format. Baseline separations of a variety of low molecular weight analytes were achieved at different temperatures with this SRP-based adsorbent using 10 mM sodium phosphate buffer, pH 6.0, as the mobile phase. Moreover, when the ionic strength of the mobile phase was increased to 40 mM sodium phosphate buffer, pH 6.0, similar temperature changes resulted in further increases in resolution for the hydrophobic analytes. In addition, changes in the pH of the mobile phase from pH 6.0 to pH 8.0 led to significant changes in selectivity of the analytes, including reversal in their elution orders. Upon increasing the temperature, the retention times of all analytes decreased but without loss of resolution. These findings can be attributed to the consequence of the immobilised copolymer undergoing a phase transition at its lower critical solution temperature (LCST), which leads to changes in its solvated structure, including how the electrostatic, hydrophilic and hydrophobic regions/domains of the copolymer are exposed to the bulk mobile phase. Thermodynamic data were indicative of a temperature-related re-organisation of the structure of the immobilised PDMAEMA-b-PAA stationary phase with exothermic binding of the analytes occurring at temperatures below the lower critical solution temperature (LCST). In this manner; changes in the system temperature could directly be used to manipulate the adsorption and desorption behaviour of these analytes with this stimuli-responsive, polymer-modified porous silica stationary phase. Additional studies with several proteins further documented the versatility of these stimuli-responsive separation materials. The results indicated that these separations could be tuned by variation of the temperature with fully aqueous mobile phases at specific ionic strength and pH values, without the need to use an organic solvent as a component in the mobile phase.


Assuntos
Resinas Acrílicas/química , Resinas Acrílicas/síntese química , Cromatografia Líquida de Alta Pressão/métodos , Desenho de Drogas , Etilaminas/química , Metacrilatos/química , Amitriptilina/isolamento & purificação , Técnicas de Química Sintética , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Cetoprofeno/isolamento & purificação , Concentração Osmolar , Proteínas/isolamento & purificação , Dióxido de Silício/química , Temperatura Ambiente
7.
Anal Bioanal Chem ; 409(4): 1135-1144, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27866254

RESUMO

A two-dimensional achiral-chiral LC-LC method in heart-cut mode for ketoprofen and its enantiomeric fraction determination was proposed. A C8 column was used in the first dimension, and the chiral column was an α1-acid glycoprotein. The mobile phase of the chiral system was optimized by a factorial design. The effect of temperature on retention and on enantiomeric resolution was studied. Particular attention was paid to mobile phase compatibility for the two columns and to transferring time, using ketoprofen standards. The R-(-) and S-(+)-ketoprofen retention times were 9 and 11 min, respectively; the resolution was higher than 1.1 and enantiomeric fraction close to 0.5. The method was applied to capsules and gels containing ketoprofen. Factorial design was also used to establish the best conditions for gel sample preparation. Recoveries were 84 and 105 % for capsules and gels, respectively. Graphical abstract Two-dimensional chromatogram for KPF and its enantiomers.


Assuntos
Anti-Inflamatórios não Esteroides/isolamento & purificação , Cromatografia Líquida/métodos , Cetoprofeno/isolamento & purificação , Padrões de Referência , Estereoisomerismo , Temperatura Ambiente
8.
Electrophoresis ; 37(2): 274-81, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26530782

RESUMO

This study describes a method to determine nonsteroidal anti-inflammatory drugs (NSAIDs) in urine samples based on the use of single-drop microextraction (SDME) in a three-phase design as a preconcentration technique coupled in-line to capillary electrophoresis. Different parameters affecting the extraction efficiency of the SDME process were evaluated (e.g. type of extractant, volume of the microdroplet, and extraction time). The developed method was successfully applied to the analysis of human urine samples with LODs ranging between 1.0 and 2.5 µg/mL for all of the NSAIDs under study. This method shows RSD values ranging from 8.5 to 15.3% in interday analysis. The enrichment factors were calculated, resulting 27-fold for ketoprofen, 14-fold for diclofenac, 12-fold for ibuprofen, and 44-fold naproxen. Samples were analyzed applying the SDME-CE method and the obtained results presented satisfactory recovery values (82-115%). The overall method can be considered a promising approach for the analysis of NSAIDs in urine samples after minimal sample pretreatment.


Assuntos
Anti-Inflamatórios não Esteroides/urina , Eletroforese Capilar/instrumentação , Microextração em Fase Líquida/instrumentação , Adulto , Anti-Inflamatórios não Esteroides/isolamento & purificação , Diclofenaco/isolamento & purificação , Diclofenaco/urina , Desenho de Equipamento , Humanos , Ibuprofeno/isolamento & purificação , Ibuprofeno/urina , Cetoprofeno/isolamento & purificação , Cetoprofeno/urina , Limite de Detecção , Naproxeno/isolamento & purificação , Naproxeno/urina , Urinálise/instrumentação
9.
J Chromatogr A ; 1393: 1-7, 2015 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-25840660

RESUMO

Polymer monolith microextraction (PMME) based on capillary monolithic column is an effective and useful technique to preconcentrate trace analytes from environmental and biological samples. Here, we report the fabrication of a novel aluminum terephthalate metal-organic framework (MIL-53(Al)) incorporated capillary monolithic column via in situ polymerization for the PMME of non-steroidal anti-inflammatory drugs (NSAIDs) (ketoprofen, fenbufen and ibuprofen) in water and urine samples. The fabricated MIL-53(Al) incorporated monolith was characterized by X-ray powder diffractometry, scanning electron microscopy, Fourier transform infrared spectrometry, and nitrogen adsorption experiment. The MIL-53(Al) incorporated monolith gave larger surface area than the neat polymer monolith. A 2-cm long MIL-53(Al) incorporated capillary monolith was applied for PMME coupled with high-performance liquid chromatography for the determination of the NSAIDs. Potential factors affecting the PMME were studied in detail. Under the optimized conditions, the developed method gave the enhancement factors of 46-51, the linear range of 0.40-200µgL(-1), the detection limits (S/N=3) of 0.12-0.24µgL(-1), and the quantification limits (S/N=10) of 0.40-0.85µgL(-1). The recoveries for spiked NSAIDs (20µgL(-1)) in water and urine samples were in the range of 77.3-104%. Besides, the MIL-53(Al) incorporated monolith was stable enough for 120 extraction cycles without significant loss of extraction efficiency. The developed method was successfully applied to the determination of NSAIDs in water and urine samples.


Assuntos
Anti-Inflamatórios não Esteroides/isolamento & purificação , Ibuprofeno/isolamento & purificação , Cetoprofeno/isolamento & purificação , Metacrilatos , Fenilbutiratos/isolamento & purificação , Ácidos Ftálicos , Extração em Fase Sólida/instrumentação , Adsorção , Alumínio , Anti-Inflamatórios não Esteroides/urina , Cromatografia Líquida de Alta Pressão/métodos , Ibuprofeno/urina , Cetoprofeno/urina , Limite de Detecção , Fenilbutiratos/urina , Sais , Extração em Fase Sólida/métodos , Água/química
10.
Anal Bioanal Chem ; 407(10): 2811-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25682297

RESUMO

The new sample preparation concept "Parallel artificial liquid membrane extraction (PALME)" was evaluated for extraction of the acidic drugs ketoprofen, fenoprofen, diclofenac, flurbiprofen, ibuprofen, and gemfibrozil from human plasma samples. Plasma samples (250 µL) were loaded into individual wells in a 96-well donor plate and diluted with HCl to protonate the acidic drugs. The acidic drugs were extracted as protonated species from the individual plasma samples, through corresponding artificial liquid membranes each comprising 2 µL of dihexyl ether, and into corresponding acceptor solutions each comprising 50 µL of 25 mM ammonia solution (pH 10). The liquid membranes and the acceptor solutions were located in a 96-well filter plate, which was sandwiched with the 96-well donor plate during extraction. Parallel extraction of several samples was performed for 15 to 60 min, followed by high-performance liquid chromatography-ultraviolet detection of the individual acceptor solutions. Important PALME parameters including the chemical composition of the liquid membrane, extraction time, and sample pH were optimized, and the extraction performance was evaluated. Except for flurbiprofen, exhaustive extraction was accomplished from plasma. Linearity was obtained for all six drugs in the range 0.025-10 µg/mL, with r (2) values ranging between 0.998 and 1.000. Precision data were in the range 3-22% RSD, and accuracy data were within 72-130% with spiked plasma samples. Based on the current experiences, PALME showed substantial potential for future high-throughput bioanalysis of non-polar acidic drugs.


Assuntos
Extração Líquido-Líquido/métodos , Membranas Artificiais , Preparações Farmacêuticas/isolamento & purificação , Calibragem , Cromatografia Líquida de Alta Pressão , Diclofenaco/química , Diclofenaco/isolamento & purificação , Desenho de Equipamento , Flurbiprofeno/química , Flurbiprofeno/isolamento & purificação , Genfibrozila/química , Genfibrozila/isolamento & purificação , Humanos , Concentração de Íons de Hidrogênio , Ibuprofeno/química , Ibuprofeno/isolamento & purificação , Cetoprofeno/química , Cetoprofeno/isolamento & purificação , Extração Líquido-Líquido/instrumentação , Preparações Farmacêuticas/química , Polipropilenos/química , Polivinil/química
11.
Water Res ; 68: 510-21, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25462757

RESUMO

This research advances the knowledge of ion-exchange of four non-steroidal anti-inflammatory drugs (NSAIDs) - diclofenac (DCF), ibuprofen (IBP), ketoprofen (KTP), and naproxen (NPX) - and one analgesic drug-paracetamol (PCM) - by strong-base anion exchange resin (AER) in synthetic ureolyzed urine. Freundlich, Langmuir, Dubinin-Astakhov, and Dubinin-Radushkevich isotherm models were fit to experimental equilibrium data using nonlinear least squares method. Favorable ion-exchange was observed for DCF, KTP, and NPX, whereas unfavorable ion-exchange was observed for IBP and PCM. The ion-exchange selectivity of the AER was enhanced by van der Waals interactions between the pharmaceutical and AER as well as the hydrophobicity of the pharmaceutical. For instance, the high selectivity of the AER for DCF was due to the combination of Coulombic interactions between quaternary ammonium functional group of resin and carboxylate functional group of DCF, van der Waals interactions between polystyrene resin matrix and benzene rings of DCF, and possibly hydrogen bonding between dimethylethanol amine functional group side chain and carboxylate and amine functional groups of DCF. Based on analysis of covariance, the presence of multiple pharmaceuticals did not have a significant effect on ion-exchange removal when the NSAIDs were combined in solution. The AER reached saturation of the pharmaceuticals in a continuous-flow column at varying bed volumes following a decreasing order of DCF > NPX ≈ KTP > IBP. Complete regeneration of the column was achieved using a 5% (m/m) NaCl, equal-volume water-methanol solution. Results from multiple treatment and regeneration cycles provide insight into the practical application of pharmaceutical ion-exchange in ureolyzed urine using AER.


Assuntos
Resinas de Troca de Ânions/química , Diclofenaco/química , Ibuprofeno/química , Cetoprofeno/química , Naproxeno/química , Acetaminofen/química , Acetaminofen/isolamento & purificação , Acetaminofen/urina , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/urina , Química Farmacêutica/métodos , Diclofenaco/isolamento & purificação , Diclofenaco/urina , Humanos , Ligações de Hidrogênio , Ibuprofeno/isolamento & purificação , Ibuprofeno/urina , Troca Iônica , Cetoprofeno/isolamento & purificação , Cetoprofeno/urina , Cinética , Estrutura Molecular , Naproxeno/isolamento & purificação , Naproxeno/urina , Eletricidade Estática , Ureia/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/urina
12.
Environ Sci Technol ; 48(22): 13197-206, 2014 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-25353977

RESUMO

Adsorption of three selected pharmaceuticals and personal care products (PPCPs) (ketoprofen (KEP), carbamazepine (CBZ), and bisphenol A (BPA)) by two reduced graphene oxides (rGO1 and rGO2) and one commercial graphene was examined under different solution conditions. Single-walled carbon nanotubes (SWCNTs), multiwalled carbon nanotubes (MWCNTs), and powdered graphite were also investigated for comparison. All adsorption isotherms followed the order of SWCNTs > rGO1 > rGO2 > MWCNTs > graphene > graphite, consistent with the orders of their surface areas and micropore volumes. After surface area normalization, adsorption affinities of the three PPCPs onto graphenes were lower than onto graphite, suggesting incomplete occupation for adsorption sites because of the aggregation of graphene sheets and the presence of oxygen-containing functional groups. The observed pH effects on adsorption correlated well with the pH-regulated distribution of the protonated neutral species of the three PPCPs. Increasing ionic strength from 0 to 20 mM increased KEP adsorption due to the electrostatic screening by Na(+) and Ca(2+). Both humic acid (HA) and sodium dodecylbenzenesulfonate (SDBS) suppressed PPCPs adsorption to all adsorbents, but their impacts onto graphenes were lower than those onto CNTs because of their lower adsorption by graphenes. More severe HA (or SDBS) effect was found on negatively charged KEP at the tested solution pH 6.50 due to the electrostatic repulsion between the same charged KEP and HA (or SDBS). The findings of the present study may have significant implications for the environmental fate assessment of PPCPs and graphene.


Assuntos
Grafite/química , Produtos Domésticos/análise , Nanotubos de Carbono/química , Preparações Farmacêuticas/isolamento & purificação , Adsorção , Benzenossulfonatos/química , Compostos Benzidrílicos/isolamento & purificação , Carbamazepina/isolamento & purificação , Substâncias Húmicas/análise , Concentração de Íons de Hidrogênio , Cetoprofeno/isolamento & purificação , Concentração Osmolar , Oxirredução , Fenóis/isolamento & purificação , Soluções , Espectrofotometria Ultravioleta , Temperatura Ambiente , Difração de Raios X
13.
J Sep Sci ; 37(19): 2696-703, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25044910

RESUMO

With the present contribution, we demonstrate that the baseline separation of ketoprofen enantiomers can be successfully achieved (α = 1.09; R(S) = 1.60) in the reversed-phase mode of elution with a commercially available anion-exchange-based chiral stationary phase, incorporating the quinine 2,6-diisopropylphenyl carbamate derivative as the enantioresolving unit. Focused modification of the eluent composition indicated a stereoselective role of hydrophobic and π-π interactions between the selector and selectand units, besides the prime ionic intermolecular interaction. The mechanistic hypotheses based on the chromatographic data were confirmed by in silico molecular dynamic simulations, which allowed us to establish the network of selector-selectand interactions underlying the stereorecognition process at a molecular level. The validated method was successfully used to evaluate the drug content and release profile of ketoprofen-loaded polymeric film, showing drug homogeneous distribution into the film and no preferential interactions between the polymer and one of the enantiomers, with the racemate released at each time point.


Assuntos
Alcaloides de Cinchona/química , Cetoprofeno/química , Cetoprofeno/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Simulação de Dinâmica Molecular , Estrutura Molecular , Estereoisomerismo
14.
Anal Chem ; 86(2): 1277-81, 2014 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24380495

RESUMO

Homochiral metal-organic frameworks with fine-tuned pore sizes/walls and large surface areas are promising porous materials for enantioseparation considering the traditional zeolite molecular sieves have no chirality. Using enantiopure pyridyl-functionalized salen [(N-(4-Pyridylmethyl)-L-leucine·HBr)] as a starting material, we have prepared a noninterpenetrated three-dimensional homochiral metal organic framework {[ZnLBr]·H2O}n, which was further used as a chiral stationary phase for high-performance liquid chromatography to enantioseparate racemic drugs, showing excellent performances in enantioseparation of drugs. The metal-organic framework can be regarded as a novel molecular sieve-like material with a chiral separation function based on the relative sizes of the chiral channels and the resolved molecules.


Assuntos
Benzoína/isolamento & purificação , Álcoois Benzílicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão/instrumentação , Complexos de Coordenação/química , Ibuprofeno/isolamento & purificação , Cetoprofeno/isolamento & purificação , Naproxeno/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Complexos de Coordenação/síntese química , Etilenodiaminas/química , Porosidade , Piridinas/química , Estereoisomerismo , Zinco/química
15.
Bioresour Technol ; 133: 31-7, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23422300

RESUMO

A model describing ibuprofen and ketoprofen biodegradation by activated sludge from three different wastewater treatment plants (WWTP) was developed in this study. This model successfully described the biodegradation profiles observed at two different initial concentrations of each compound, where a lag-phase was observed prior to the biodegradation of each compound. Twelve ibuprofen and ketoprofen degrading isolates were identified in this study from the WWTP sludge showing the best removal performance. One of these isolates was characterised via another model, where biodegradation was dependent on biomass growth rate as well as the ibuprofen concentration. The fact that different models were needed to describe the biodegradation by activated sludge and a pure culture suggests that the biodegradation of non-steroidal anti-inflammatory drugs (NSAIDs) depends on the microbial community, thus pharmaceutical biodegradation models may require adaptation depending upon the system. This study provides an advance towards modelling pharmaceutical biodegradation in WWTPs.


Assuntos
Anti-Inflamatórios não Esteroides/isolamento & purificação , Bactérias/metabolismo , Modelos Biológicos , Esgotos/microbiologia , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Biodegradação Ambiental , Simulação por Computador , Ibuprofeno/isolamento & purificação , Cetoprofeno/isolamento & purificação , Cinética , Filogenia , Portugal
16.
Chirality ; 25(2): 79-88, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23255364

RESUMO

The enantiomers of ketoprofen were separated by capillary electrophoresis using the (2,3,6-tri-O-methyl)-derivatives of α-, ß-, and γ-cyclodextrin (CyD) as chiral selectors. The affinity pattern of the ketoprofen enantiomers toward these CyDs changed depending on their cavity size. Thus, with hexakis (2,3,6-tri-O-methyl)-α-CyD and heptakis (2,3,6-tri-O-methyl)-ß-CyD, the R enantiomer of the drug migrated first, whereas the enantiomer migration order was reversed in the presence of octakis(2,3,6-tri-O-methyl)-γ-CyD. The change in the migration order was rationalized on the basis of changes in the structure of the complexes between the ketoprofen enantiomers and the chiral selectors as derived from nuclear magnetic resonance spectroscopy experiments.


Assuntos
Ciclodextrinas/química , Eletroforese Capilar/métodos , Cetoprofeno/química , Cetoprofeno/isolamento & purificação , Espectroscopia de Ressonância Magnética , Metilação , Modelos Moleculares , Conformação Molecular , Estereoisomerismo , alfa-Ciclodextrinas/química , beta-Ciclodextrinas/química , gama-Ciclodextrinas/química
17.
Anal Bioanal Chem ; 403(9): 2583-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22555679

RESUMO

A stir membrane liquid phase microextraction procedure working under the three-phase mode is proposed for the first time for the determination of six anti-inflammatory drugs in human urine. The target compounds are isolated and preconcentrated using a special device that integrates the extractant and the stirring element. An alkaline aqueous solution is used as extractant phase while 1-octanol is selected as supported liquid membrane solvent. After the extraction, all the analytes are determined by liquid chromatography (LC) with ultraviolet detection (UV). The analytical method is optimized considering the main involved variables (e.g., pH of donor and acceptor phases, extraction time, stirring rate) and the results indicate that the determination of anti-inflammatory drugs at therapeutic and toxic levels is completely feasible. The limits of detection are in the range from 12.6 (indomethacin) to 30.7 µg/L (naproxen). The repeatability of the method, expressed as relative standard deviation (RSD, n = 5) varies between 3.4% (flurbiprofen) and 5.7% (ketoprofen), while the enrichment factors are in the range from 35.0 (naproxen) to 72.5 (indomethacin).


Assuntos
Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/urina , Cromatografia Líquida/métodos , Microextração em Fase Líquida/métodos , Flurbiprofeno/isolamento & purificação , Flurbiprofeno/urina , Humanos , Indometacina/isolamento & purificação , Indometacina/urina , Cetoprofeno/isolamento & purificação , Cetoprofeno/urina , Limite de Detecção , Naproxeno/isolamento & purificação , Naproxeno/urina
18.
J Chromatogr A ; 1218(37): 6498-504, 2011 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-21803361

RESUMO

One monomer molecularly imprinted polymer coatings were first synthesized in fused silica capillary columns with 2-methacrylamidopropyl methacrylate (MAM) as single functional monomer in addition to a cross-linking monomer. Since MAM may generate no or little EOF, a strategy of precursor of polymerization, which does not interfere with the formation of defined imprints, was used to introduce an ionizable functional monomer to generate a stable electroosmotic flow for electrochromatography (CEC) by post-polymerization hydrolization. The resulting MAM-based open-tubular imprinted capillary was able to separate enantiomers by means of CEC. The resolution of enantiomers separation achieved on S-amlodipine-imprinted capillary was up to 16.1. The strong recognition ability (selectivity factor was 3.23) and high column performance (theory plates was 26,053 plates m(-1)) of template were obtained. The MIP coatings were also prepared using either S-naproxen or S-ketoprofen as template molecule. The resolutions of enantiomers separation were 2.20 and 4.56, respectively. The results illustrate that the synthesis of MIP using one monomer is not only an experimental-simplified process, but also an approach to producing chiral stationary phase with high efficiency and selectivity.


Assuntos
Eletrocromatografia Capilar/métodos , Impressão Molecular , Polímeros/química , Anlodipino/química , Anlodipino/isolamento & purificação , Eletrocromatografia Capilar/instrumentação , Concentração de Íons de Hidrogênio , Cetoprofeno/química , Cetoprofeno/isolamento & purificação , Microscopia Eletrônica de Varredura , Naproxeno/química , Naproxeno/isolamento & purificação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estereoisomerismo
19.
Bull Environ Contam Toxicol ; 87(1): 31-5, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21562834

RESUMO

The fate of pharmaceuticals in a wastewater treatment plant (WWTP) in Kumamoto, Japan with activated sludge treatment is reported. Selected pharmaceuticals were detected in influent. Results from the present study confirmed that Acetaminophen, Amoxicillin, Ampicillin and Famotidine were removed at a high rate (>90% efficiency). In contrast, removal efficiency of Ketoprofen, Losartan, Oseltamivir, Carbamazepine, and Diclofenac was relatively low (<50%). The selected pharmaceuticals were also detected in raw sludge. In digestive process, Indomethacin, Atenolol, Famotidine, Trimethoprim and Cyclofosamide were removed at a high (>70% efficiency). On the other hand, removal of Carbamazepine, Ketoprofen and Diclofenac was not efficient (<50%).


Assuntos
Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Acetaminofen/isolamento & purificação , Amoxicilina/isolamento & purificação , Ampicilina/isolamento & purificação , Carbamazepina/isolamento & purificação , Cromatografia Líquida , Diclofenaco/isolamento & purificação , Famotidina/isolamento & purificação , Japão , Cetoprofeno/isolamento & purificação , Losartan/isolamento & purificação , Espectrometria de Massas , Oseltamivir/isolamento & purificação , Esgotos/química , Trimetoprima/isolamento & purificação
20.
J Chromatogr A ; 1218(24): 3763-70, 2011 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-21555129

RESUMO

We designed and synthesized a cinchonine derivative to be used as a novel chiral monomer. It was employed in a dual role of functional monomer and cross-linking monomer, displaying multi-binding sites for the template (S)-ketoprofen. Monodisperse molecularly imprinted core-shell microspheres were prepared using surface imprinting method on silica gel. The results show a substantial synergistic effect in the enantioselective recognition, confirming our initial hypothesis. Computational simulation of the monomer and template pre-arrangement strongly supports our proposed chiral recognition mechanism for the imprinted microspheres.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Alcaloides de Cinchona/química , Cetoprofeno/química , Microesferas , Impressão Molecular/métodos , Simulação por Computador , Concentração de Íons de Hidrogênio , Cetoprofeno/isolamento & purificação , Microscopia Eletrônica de Varredura , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo
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