Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
RSC Adv ; 14(17): 11977-11985, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38623288

RESUMEN

A green method based on magnetic micro-solid phase extraction (MNP-TW-µ-SPE) of tea waste impregnated with magnetic nanoparticles (MNP-TW) was developed for the extraction of ibuprofen (IBP) in water samples prior to UV-Vis spectrophotometric analysis. Experimenting parameters that affect the extraction efficiency of IBP, such as pH of the sample solution, sorbent dosage, extraction time, ionic strength, volume of the sample, type of desorption solvent, desorption time, and desorption volume, were studied and optimized in detail. The characterization studies for the MNP-TW were carried out by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectrometry (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, a vibrating sample magnetometer (VSM), and thermogravimetric analysis (TGA). Under the optimum conditions, the linearity ranges from 30 to 700 µg L-1 for IBP, with determination coefficients (R2) of 0.9983. The limit of detection (LOD) and limit of quantification (LOQ) were 9.40 µg L-1 and 28.50 µg L-1, respectively. The method also demonstrated good precision in reproducibility (RSD ≤ 1.53%), repeatability (RSD ≤ 1.48%), and recovery (86-115%). This method represents the advantages of low solvent consumption, flexibility, and better sensitivity compared to other studies employing spectrophotometric analysis. The usage of tea waste in the extraction process presents many advantages, as it is biodegradable, versatile, and contributes to an intelligent and sustainable economic strategy projected toward a circular economy approach.

2.
Artículo en Inglés | MEDLINE | ID: mdl-38466777

RESUMEN

Poly(methyl methacrylate-vinyl imidazole bromide) (poly-MMA-IL)-grafted magnetic nanoparticles were successfully developed and applied in the micro-magnetic solid phase extraction (µ-MSPE) for 16 types of polycyclic aromatic hydrocarbons (PAHs) from tea, fried food, and grilled food samples via gas chromatography flame ionization detector (GC-FID). One variable at a time (OVAT) and response surface methodology (RSM) were used for efficient optimization. The validation method showed a good coefficient of determination (R2) ranging from 0.9901 to 0.9982 (n = 3) with linearity of 0.2 µg L-1-500 µg L-1. Detection and quantification limits were 0.06 µg L-1-0.32 µg L-1 and 0.18 µg L-1-0.97 µg L-1. Additionally, satisfactory reproducibility was attained with intra-day and inter-day precisions having RSD ranges of 3.6%-11.1%. The spiked recovery value of 16 PAHs in fried food, grilled food and tea samples obtained from the night market in Malaysia ranged from 80%-12%, respectively.


Asunto(s)
Análisis de los Alimentos , Contaminación de Alimentos , Líquidos Iónicos , Nanopartículas de Magnetita , Hidrocarburos Policíclicos Aromáticos , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/química , Contaminación de Alimentos/análisis , Nanopartículas de Magnetita/química , Líquidos Iónicos/química , Microextracción en Fase Sólida , Extracción en Fase Sólida , Té/química , Polímeros/química
3.
Talanta ; 254: 124188, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36521327

RESUMEN

A paper-based polymeric ionic liquid (p-Poly-(MMA-IL)) was successfully developed by grafting the polymeric ionic liquid on the surface of commercial filter paper (FP) by using the dipping method, presenting a new cost-effective film. The newly developed p-Poly-(MMA-IL) FP was then applied as a paper-based thin-film microextraction (p-TFME) analytical device to extract 14 compounds as representative of five groups of antibiotic drugs, which were sulfonamides, tetracyclines, fluoroquinolones, penicillin and macrolides in environmental water samples. Besides, p-Poly-(MMA-IL) FP, p-Poly-(MMA) FP, and unmodified filter paper were successfully characterised by FTIR, NMR, FESEM, TGA, and XRD techniques. They underwent significant parameters optimisation, which affected the extraction efficiency. Under optimal conditions, the proposed (p-Poly-(MMA-IL) FP-TFME) device method was evaluated and applied to analyse multi-class antibiotic drugs in environmental water samples by using a liquid chromatography-mass spectrometry (LC-MS). The validation method showed that a good linearity (0.1 µg L-1 - 500 µg L-1) was noted (R2 > 0.993, n = 3). Detection and quantification limits were within 0.05 µg L-1 - 4.52 µg L-1 and 0.15 µg L-1 - 13.6 µg L-1, respectively. The relative standard deviation (RSD) values ranged at 1.4%-12.2% (intra-day, n = 15) and 4.4%-11.0% (inter-day, n = 10). The extraction recoveries of environmental water samples ranged from 79.1% to 126.8%, with an RSD of less than 15.4% (n = 3). The newly developed paper-based polymeric ionic liquid (p-Poly-(MMA-IL) FP) for analysis of multi-class antibiotic drugs under the p-TFME analytical device procedure was successfully achieved with limited sample volume and organic solvent, fast extraction, and feasible in daily analysis. The detection concentration and relative RSD of multi-class antibiotics determined in various environmental water samples by the proposed method (n = 5) were within 0.44 µg L-1 - 54.41 µg L-1 and 0.69%-15.56%, respectively. These results signified the potential of the p-Poly-(MMA-IL) FP-TFME device as an efficient, sensitive and environmentally friendly approach for analysing antibiotics.


Asunto(s)
Líquidos Iónicos , Microextracción en Fase Líquida , Cromatografía Liquida/métodos , Antibacterianos , Cromatografía Líquida de Alta Presión , Líquidos Iónicos/química , Espectrometría de Masas en Tándem/métodos , Agua/química , Microextracción en Fase Líquida/métodos , Límite de Detección
4.
J Chromatogr A ; 1685: 463616, 2022 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-36335907

RESUMEN

Realising the need to devise a simple, sensitive, and reliable detection method, this study investigated the development of a dual-stacking transient isotachophoresis (t-ITP) and sweeping in micellar electrokinetic chromatography with diode array detector (t-ITP/sweeping-MEKC-DAD) for the determination of selected non-steroidal anti-inflammatory drugs (NSAIDs); ketoprofen, diclofenac and naproxen from aqueous matrices. Prior to the system setup, various parameters were optimised to assess the potential use of the t-ITP paired with the sweeping stacking technique in micellar background electrolyte for dual preconcentration and separation of trace amounts of NSAIDs. Once the optimum conditions have been established, the method performance was validated and applied to 17 environmental water samples. Based on the results, the combined t-ITP and sweeping approach significantly improved the stacking and separation sensitivity. A large volume of samples could also be introduced and subsequently separated by MEKC with greater focusing effects due to the sweeping. Under optimised conditions, the developed method exhibited excellent linearity at a high range (0.1-500 ng/mL, r2 ≥ 0.998), low limits of detection (LODs) of 0.01-0.07 ng/mL, and a remarkable relative recovery (RR) of 99.6-101.9% with a relative standard deviation (RSD) of 1.4-8.6% (n = 9). Ultimately, the sensitivity enhancement factors improved up to 666-fold using the optimised method. Therefore, the proposed method presents a simplified yet effective and suitable for the determination of NSAIDs from aqueous matrices.


Asunto(s)
Cromatografía Capilar Electrocinética Micelar , Isotacoforesis , Cromatografía Capilar Electrocinética Micelar/métodos , Micelas , Antiinflamatorios no Esteroideos , Agua
5.
Pharmaceuticals (Basel) ; 15(10)2022 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-36297340

RESUMEN

The development of new antibiotics is urgently needed to combat the threat of bacterial resistance. New classes of compounds that have novel properties are urgently needed for the development of effective antimicrobial agents. The extract of Cannabis sativa L. has been used to treat multiple ailments since ancient times. Its bioactivity is largely attributed to the cannabinoids found in its plant. Researchers are currently searching for new anti-infective agents that can treat various infections. Although its phytocannabinoid ingredients have a wide range of medical benefits beyond the treatment of infections, they are primarily associated to psychotropic effects. Different cannabinoids have been demonstrated to be helpful against harmful bacteria, including Gram-positive bacteria. Moreover, combination therapy involving the use of different antibiotics has shown synergism and broad-spectrum activity. The purpose of this review is to gather current data on the actions of Cannabis sativa (C. sativa) extracts and its primary constituents such as terpenes and cannabinoids towards pathogens in order to determine their antimicrobial properties and cytotoxic effects together with current challenges and future perspectives in biomedical application.

6.
Food Chem ; 396: 133670, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-35853378

RESUMEN

The current study discussed the use of silicone surfactant-based deep eutectic solvent as a surface modifier for magnetic iron particles (Fe3O4) to produce a novel adsorbent and its application for the extraction of organophosphorus pesticides (OPPs) in vegetable samples. A deep eutectic solvent (DES) was prepared using low toxic and inexpensive substances such as silicone surfactant (SS) and dodecanoic acid (DoAc). This new eco-friendly SS:DoAc based DES was explored as a substitution to traditional organic reagents for surface modification of Fe3O4 to increase the adsorption capacity and to reduce the matrix interferences, hazardous waste generation and environmental pollution. The newly synthesized SS:DoAc@Fe3O4 adsorbent was successfully characterized and applied in magnetic solid phase extraction (MSPE). Under optimized conditions, the proposed approach exhibited excellent linearity ranging from 0.1 to 200 µg/kg (R2 ≥ 0.9970), low detection limit (0.03-0.1 µg/kg) and acceptable relative recovery (80-119 %) for the studied OPPs.


Asunto(s)
Plaguicidas , Cromatografía de Gases , Disolventes Eutécticos Profundos , Hierro , Límite de Detección , Fenómenos Magnéticos , Compuestos Organofosforados , Plaguicidas/análisis , Siliconas , Tensoactivos , Verduras
7.
Food Chem ; 368: 130835, 2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-34416487

RESUMEN

A novel deep eutectic solvents (DES) was successfully applied as an emulsifier in vortex assisted liquid-liquid microextraction (VALLME) coupled with gas chromatography-mass spectrometry for the determination of organophosphorus pesticides in honey and fruit samples. Based on the result of toxicity study, DES provides new opportunities for the safe delivery and application. The predominant parameters affecting extraction efficiency were thoroughly optimized and studied in detail. Under optimum parameters, the calibration curve was determined in the concentration range of 0.1 to 200 µgL-1 with excellent determination coefficients values of 0.9989 to 0.9999. Limit of detection and limit of quantification were found to be 0.01 - 0.09 µgL-1 and 0.03 - 0.2 µgL-1, respectively. Application of the developed method to honey and fruit samples gave acceptable recovery values 83 - 109% with relative standard deviation below than 9.5%. The suggested approach has also proven to be simple, cost-effective, rapid, and non-toxic in nature.


Asunto(s)
Miel , Microextracción en Fase Líquida , Plaguicidas , Frutas/química , Miel/análisis , Límite de Detección , Compuestos Organofosforados/toxicidad , Plaguicidas/análisis , Plaguicidas/toxicidad , Solventes
8.
Chirality ; 33(1): 37-50, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33197086

RESUMEN

A chiral separation method coupled with capillary electrophoresis (CE) analysis for ketoconazole and miconazole enantiomers using chiral selectors such as ß-cyclodextrin (ß-CD) and hydroxypropyl-ß-CD (HP-ß-CD) was developed in this study, which included the optimisation, validation and application of the method on the antifungal cream samples. The formation of inclusion complex between the hosts (ß-CD and HP-ß-CD) and guests (ketoconazole and miconazole) were compared and analysed using ultraviolet-visible spectrophotometry, nuclear magnetic resonance (NMR) spectroscopy and molecular docking methods. Results from the study showed that in a concentration that ranged between 0.25 and 50 mg L-1 , the linear calibration curves of each enantiomer had a high coefficient of regression (R2 > 0.999), low limit of detection (0.075 mg L-1 ) and low limit of quantification (0.25 mg L-1 ). The relative standard deviation (RSD) of the intraday and interday analyses ranged from 0.79% to 8.01% and 3.30% to 11.43%, respectively, while the recoveries ranged from 82.0% to 105.7% (RSD < 7%, n = 3). The most probable structure of the inclusion complexes was proposed based on the findings from the molecular docking studies conducted using the PatchDock server.

9.
Carbohydr Res ; 497: 108138, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32911205

RESUMEN

The behavior of the inclusion behavior of guanosine (GU) with beta-cyclodextrin (ß-CD) in the liquid, solid and virtual state were investigated. The absorption and fluorescence spectral were used to determine the inclusion behavior in liquid state. FT-IR, NMR, TGA, DSC, PXRD and FESEM techniques were used to investigate the inclusion behavior in solid-state, meanwhile the virtual state studies are done by molecular docking. The solid inclusion complex (GU: ß-CD) was prepared by using the co-precipitation method. The binding constant (K) of (GU: ß-CD) was calculated by using Benesi-Hildebrand. Besides that, the 1:1 stoichiometric ratio of inclusion complex was confirmed by using the Benesi-Hildebrand plot and Job's plot of continuous variation method. The most preferable model of GU: ß-CD that suggested via molecular docking studies was in good agreement with experimental results. The inclusion complex of GU: ß-CD exerted its toxicity effects towards HepG2 cell lines based on the reduced number of cell viability and lowest IC50 value compared to the GU and ß-CD viability.


Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Guanosina/química , Guanosina/farmacología , beta-Ciclodextrinas/química , Proliferación Celular/efectos de los fármacos , Células Hep G2 , Humanos , Conformación Molecular , Simulación del Acoplamiento Molecular
10.
J Sep Sci ; 43(16): 3294-3303, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32519432

RESUMEN

In this work, a simple, fast, sensitive, and environmentally friendly method was developed for preconcentration and quantitative measurement of bisphenol A in water samples using gas chromatography with mass spectrometry. The preconcentration approach, namely biosorption-based dispersive liquid-liquid microextraction with extractant removal by magnetic nanoparticles was performed based on the formation of microdroplet of rhamnolipid biosurfactant throughout the aqueous samples, which accelerates the mass transfer process between the extraction solvent and sample solution. The process is then followed by the application of magnetic nanoparticles for easy retrieval of the analyte-containing extraction solvent. Several important variables were optimized comprehensively including type of disperser solvent and desorption solvent, rhamnolipid concentration, volume of disperser solvent, amount of magnetic nanoparticles, extraction time, desorption time, ionic strength, and sample pH. Under the optimized microextraction and gas chromatography with mass spectrometry conditions, the method demonstrated good linearity over the range of 0.5-500 µg/L with a coefficient of determination of R2  = 0.9904, low limit of detection (0.15 µg/L) and limit of quantification (0.50 µg/L) of bisphenol A, good analyte recoveries (84-120%) and acceptable relative standard deviation (1.8-14.9%, n = 6). The proposed method was successfully applied to three environmental water samples, and bisphenol A was detected in all samples.

11.
R Soc Open Sci ; 7(4): 200143, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32431904

RESUMEN

This work describes the development of a new methodology based on magnetic nanoparticles assisted dispersive liquid-liquid microextraction (DLLME-MNPs) for preconcentration and extraction of chloramphenicol (CAP) antibiotic residues in water. The approach is based on the use of decanoic acid as the extraction solvent followed by the application of MNPs to magnetically retrieve the extraction solvent containing the extracted CAP. The coated MNPs were then desorbed with methanol, and the clean extract was analysed using ultraviolet-visible spectrophotometry. Several important parameters, such as the amount of decanoic acid, extraction time, stirring rate, amount of MNPs, type of desorption solvent, salt addition and sample pH, were evaluated and optimized. Optimum parameters were as follows: amount of decanoic acid: 200 mg; extraction time: 10 min; stirring rate: 800 rpm; amount of MNPs: 60 mg; desorption solvent: methanol; salt: 10%; and sample pH, 8. Under the optimum conditions, the method demonstrated acceptable linearity (R 2 = 0.9933) over a concentration range of 50-1000 µg l-1. Limit of detection and limit of quantification were 16.5 and 50.0 µg l-1, respectively. Good analyte recovery (91-92.7%) and acceptable precision with good relative standard deviations (0.45-6.29%, n = 3) were obtained. The method was successfully applied to tap water and lake water samples. The proposed method is rapid, simple, reliable and environmentally friendly for the detection of CAP.

12.
Environ Geochem Health ; 42(10): 3079-3099, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32180058

RESUMEN

The research study was carried out to evaluate trace metals (Pb, Cd, Se, Al, Mn, Cu, Zn, Fe, As, Ni, Cr, and Ag) concentrations in groundwater of Lorong Serai 4, Hulu Langat, Selangor, Malaysia. Additionally, the research study focused on determining non-carcinogenic and carcinogenic health risks, sources of the contaminants, and effective remediation methods. The results show that the concentration levels of Pb, Cd, Se, Al, Cu, Zn, Ni, Cr, and Ag are lower than their corresponding permissible limits, while Fe, Mn, and As concentrations exceed their acceptable limit. The hazard index of the groundwater in the area exceeded the acceptable limit, showing the rate of carcinogenic and non-carcinogenic health effects associated with the water. The findings also indicate that the lifetime cancer risk is high compared to the maximum limits of lifetime cancer risk from the drinking water (10-6 to 10-4). The groundwater geochemical data of the area are used in establishing the source of Fe, Mn, and As metal ions. Evaluation of Fe2+/Fe3+ and S2-/SO42- redox couples and thermodynamic modelling indicates that the groundwater of the area is in redox disequilibrium. The groundwater samples contain aqueous iron sulphate, which is supersaturated, ferrous carbonate and aluminium sulphate that are saturated. The main state of redox disequilibrium is governed by mineral precipitation and dissolution. Aqueous arsenic and manganese are possibly derived from the dissolution of pyrite (arsenopyrite) and amorphous oxide-hydroxides, respectively. The high concentration of iron in the shallow groundwater in the area is primarily the result of silicate rock weathering of ferroan igneous and metamorphic minerals with a minor contribution from the oxidation of iron sulphides. Magnetite coated with graphene oxide (Fe3O4-GO) nanoparticles (NPs) was synthesized and characterized, and the adsorption preliminary experiments were carried out; and the Fe3O4-GO NPs show enhanced removal (Fe > As > Mn) capacity over graphene oxide (GO).


Asunto(s)
Restauración y Remediación Ambiental , Metales/análisis , Oligoelementos/análisis , Contaminantes Químicos del Agua/análisis , Adsorción , Monitoreo del Ambiente , Malasia
13.
Food Chem ; 314: 126214, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31972404

RESUMEN

Poly(ß-cyclodextrin-ionic liquid) grafted magnetic nanoparticles combined with 1-octanol as supramolecular solvents (SUPRASs) presenting new ferrofluid was developed and successfully applied in the dispersive liquid-phase microextraction of seven representative polycyclic aromatic hydrocarbons. One variable at-a-time (OVAT) analysis and response surface methodology (RSM) were used for efficient optimization of the main variables. The calibration curves were found to be linear in the range of 0.1-150 ng mL-1 with correlation of determinations (R2) ranging from 0.9944 to 0.9986. Detection limits ranged at 0.02-0.07 ng mL-1 for all studied PAHs. The intra and inter-day precision values (RSD %) were in the range of 1.80%-7.56% and 2.97%-8.23%, respectively. The ferrofluid showed a satisfactory reproducibility between 1.72% and 5.90%, and acceptable recovery values at 84%-110% were obtained for the real samples analysis. The optimized method was successfully applied to access the content safety of the PAHs studied in a variety of commercial food and beverages available in Malaysia.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos/análisis , beta-Ciclodextrinas/química , Cromatografía de Gases , Coloides , Líquidos Iónicos , Límite de Detección , Microextracción en Fase Líquida , Fenómenos Magnéticos , Reproducibilidad de los Resultados
14.
Food Chem ; 278: 322-332, 2019 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-30583379

RESUMEN

Poly(ß-cyclodextrin functionalized ionic liquid) immobilized magnetic nanoparticles (Fe3O4@ßCD-Vinyl-TDI) as sorbent in magnetic µ-SPE was developed for the determination of selected polycyclic aromatic hydrocarbons (PAHs) in rice samples coupled with gas chromatographic-flame ionization detector (GC-FID). The nanocomposite was characterized by various tools and significant parameters that affected the extraction efficiency of PAHs were investigated. The calibration curves were linear for the concentration ranging between 0.1 and 500 µg kg-1 with correlation determinations (R2) from 0.9970 to 0.9982 for all analytes. Detection limits ranged at 0.01-0.18 µg kg-1 in real matrix. The RSD values ranged at 2.95%-5.34% (intra-day) and 4.37%-7.05% (inter-day) precision for six varied days. The sorbents showed satisfactory reproducibility in 2.9% to 9.9% range and acceptable recovery values at 80.4%-112.4% were obtained for the real sample analysis. The optimized method was successfully applied to access content safety of selected PAHs for 24 kinds of commercial rice available in Malaysia.


Asunto(s)
Contaminación de Alimentos/análisis , Nanocompuestos/química , Oryza/química , Hidrocarburos Policíclicos Aromáticos/análisis , Microextracción en Fase Sólida/métodos , Cromatografía de Gases , Líquidos Iónicos/química , Límite de Detección , Magnetismo , Malasia , Reproducibilidad de los Resultados , Extracción en Fase Sólida/métodos , Microextracción en Fase Sólida/instrumentación , beta-Ciclodextrinas/química
15.
RSC Adv ; 8(45): 25617-25635, 2018 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-35539765

RESUMEN

This study investigated the effectiveness of ionic liquids (ILs) loaded onto the surface of a polymeric adsorbent (ßCD-TDI) grafted with modified magnetic nanoparticles (MNPs) via an analysis of water treatment, which resulted in high removal of selected endocrine-disrupting chemicals (parabens). The syntheses of MNPs, MNP-ßCD-TDI, and IL-MNP-ßCD-TDI were characterised and compared using Fourier transform infrared (FT-IR) spectroscopy, carbon-hydrogen-nitrogen (CHN) analysis, vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the Brunauer-Emmett-Teller (BET) method, thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The results of SEM and TEM indicated that the pore size distribution exhibited mesoporous characteristics with a small surface area (BET analysis: 42.95 m2 g-1). Furthermore, a preliminary sorption experiment demonstrated the ability of IL-MNP-ßCD-TDI to enhance not only the sorption capacity, but also the removal of propyl paraben (PP), butyl paraben (BP), and benzyl paraben (ArP). The adsorption process appeared to be pH-dependent, and hence the optimum pH of 6 was selected for a subsequent batch adsorption study of all the studied parabens with an equilibrium time of 80 min. Next, in an attempt to investigate the interactions that occur between the adsorbent and the adsorbates, adsorption kinetics and isotherm studies were performed. All the studied parabens were found to best fit pseudo-second-order kinetics and the Freundlich isotherm with R 2 > 0.98 at room temperature (298 K). The interaction of the host-guest inclusion complex and the π-π interaction between ßCD and a selected paraben compound (ArP) were identified by performing 1H nuclear magnetic resonance (NMR), together with ultraviolet-visible (UV-vis) spectroscopic analysis. Finally, the adsorption efficiency of the developed material was practically tested on tap water, drain water, and industrial wastewater, which revealed a significant removal of parabens of up to 60-90% in comparison with a prior analysis.

16.
RSC Adv ; 8(58): 33180-33192, 2018 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-35548133

RESUMEN

Polyaniline (PANI) modified magnetic nanoparticle (MNP) nanocomposites coated with newly synthesized dicationic ionic liquid (DICAT) forming MNP-PANI-DICAT were successfully synthesized as a potential material for the removal of Rhodamine B (RB) from water samples. The synthesized material was successfully characterized using a few techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), thermo gravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), and transmission electron microscopy (TEM) analysis. Several parameters have been optimized to enhance the efficiency of the removal process. The adsorption kinetics were investigated and the results showed that MNP-PANI-DICAT was best fitted to a pseudo-second order model for the adsorption of RB. As for the isotherm studies, Temkin's model was found to fit well with the adsorption isotherm of RB on MNP-PANI-DICAT. Other than that, thermodynamics results showed negative values of ΔG° for the adsorption of RB, which indicated that the process is thermodynamically feasible, spontaneous and chemically controlled at lower temperature. The negative value of enthalpy ΔH° (-40.41) indicated that the adsorption was an exothermic process. The percentage removal of RB was found to be 94.7% by MNP-PANI-DICAT under optimized conditions.

17.
Crit Rev Anal Chem ; 47(5): 454-467, 2017 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-28453309

RESUMEN

The growth in driving force and popularity of cyclodextrin (CDs) and ionic liquids (ILs) as promising materials in the field of analytical chemistry has resulted in an exponentially increase of their exploitation and production in analytical chemistry field. CDs belong to the family of cyclic oligosaccharides composing of α-(1,4) linked glucopyranose subunits and possess a cage-like supramolecular structure. This structure enables chemical reactions to proceed between interacting ions, radical or molecules in the absence of covalent bonds. Conversely, ILs are an ionic fluids comprising of only cation and anion often with immeasurable vapor pressure making them as green or designer solvent. The cooperative effect between CD and IL due to their fascinating properties, have nowadays contributed their footprints for a better development in analytical chemistry nowadays. This comprehensive review serves to give an overview on some of the recent studies and provides an analytical trend for the application of CDs with the combination of ILs that possess beneficial and remarkable effects in analytical chemistry including their use in various sample preparation techniques such as solid phase extraction, magnetic solid phase extraction, cloud point extraction, microextraction, and separation techniques which includes gas chromatography, high-performance liquid chromatography, capillary electrophoresis as well as applications of electrochemical sensors as electrode modifiers with references to recent applications. This review will highlight the nature of interactions and synergic effects between CDs, ILs, and analytes. It is hoped that this review will stimulate further research in analytical chemistry.


Asunto(s)
Técnicas Biosensibles/métodos , Técnicas de Química Analítica/métodos , Ciclodextrinas/química , Líquidos Iónicos/química , Animales , Fraccionamiento Químico/métodos , Cromatografía de Gases/métodos , Cromatografía Líquida de Alta Presión/métodos , Técnicas Electroquímicas/métodos , Electroforesis Capilar/métodos , Humanos
18.
Talanta ; 130: 155-63, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25159393

RESUMEN

Cyclodextrin-ionic liquid polymer (ßCD-BIMOTs-TDI) is a new class of macroporous material and has great potential to be used as an SPE adsorbent material for extraction of phenols in river water samples. Six phenols, as model analytes, were extracted on a ßCD-BIMOTs-TDI SPE cartridge, and then, eluted with 2 mL of methanol containing 1% acetic acid. The optimum experimental condition was 15 mL of sample volume (sample at pH 6) and 2 mL of methanol containing 1% acetic acid as an eluent solvent. The eluent concentration was determined by using Gas Chromatography-Flame Ionization Detector (GC-FID). Under optimized condition, high sensitivity (detection limits 0.23-0.35 µg/L) and good recoveries (87-116%) were achieved with satisfactory relative standard deviation (RSD) (0.1-1.7%). The developed ßCD-BIMOTs-TDI-SPE was then compared with other adsorbents, and the obtained results showed that the ßCD-BIMOTs-TDI exhibited higher extraction recovery due to the unique structure and properties. Finally, the ßCD-BIMOTs-TDI was applied as a solid phase extraction sorbent for phenols determination under optimized condition, in river and tap waters, prior to the GC-FID separation.


Asunto(s)
Fenoles/análisis , Fenoles/aislamiento & purificación , Polímeros/química , Ríos/química , Extracción en Fase Sólida/métodos , Contaminantes Químicos del Agua/análisis , beta-Ciclodextrinas/química , Adsorción , Cromatografía de Gases , Ionización de Llama , Líquidos Iónicos
19.
Int J Mol Sci ; 14(12): 24531-48, 2013 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-24351832

RESUMEN

A cloud point extraction (CPE) process using non-ionic surfactant (DC193C) to extract selected paraben compounds from water samples was investigated using reversed phase high performance liquid chromatography (RP-HPLC). The CPE process with the presence of ß-cyclodextrin (ßCD) functionalized ionic liquid as a modifier (CPE-DC193C-ßCD-IL) is a new extraction technique that has been applied on the optimization of parameters, i.e., pH, ßCD-IL concentration and phase volume ratio. This CPE-DC193C-ßCD-IL method is facilitated at 30 °C, showing great losses of water content in the surfactant-rich phase, resulting in a high pre-concentration factor and high distribution coefficient. The developed method CPE-DC193C-ßCD-IL did show enhanced properties compared to the CPE method without the modifier (CPE-DC193C). The developed method of CPE-DC193C-ßCD-IL gives an excellent performance on the detection of parabens from water samples with the limit of detection falling in the range of 0.013-0.038 µg mL-1. Finally, the inclusion complex formation, hydrogen bonding, and π-π interaction between the ßCD-IL, benzyl paraben (ArP), and DC 193C were proven using 1H NMR and 2D NOESY spectroscopy.


Asunto(s)
Cromatografía Líquida de Alta Presión , Líquidos Iónicos/química , Parabenos/análisis , Tensoactivos/química , beta-Ciclodextrinas/química , Cromatografía de Fase Inversa , Concentración de Iones de Hidrógeno , Parabenos/aislamiento & purificación , Agua/química
20.
Int J Mol Sci ; 15(1): 100-19, 2013 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-24366065

RESUMEN

ß-Cyclodextrin-ionic liquid polymer (CD-ILP) was first synthesized by functionalized ß-cyclodextrin (CD) with 1-benzylimidazole (BIM) to form monofunctionalized CD (ßCD-BIMOTs) and was further polymerized using a toluene diisocyanate (TDI) linker to form insoluble CD-ILP (ßCD-BIMOTs-TDI). The ßCD-BIMOTs-TDI polymer was characterized using various tools and the results obtained were compared with those derived from the native ß-cyclodextrin polymer (ßCD-TDI). The SEM result shows that the presence of ionic liquid (IL) increases the pore size, while the thermo gravimetric analysis (TGA) result shows that the presence of IL increases the stability of the polymer. Meanwhile, Brunauer-Emmett-Teller (BET) results show that ßCD-BIMOTs-TDI polymer has 1.254 m(2)/g surface areas and the Barret-Joyner-Halenda (BJH) pore size distribution result reveals that the polymer exhibits macropores with a pore size of 77.66 nm. Preliminary sorption experiments were carried out and the ßCD-BIMOTs-TDI polymer shows enhanced sorption capacity and high removal towards phenols and As(V).


Asunto(s)
Arsénico/química , Celulosa/química , Ciclodextrinas/química , Líquidos Iónicos/química , Fenoles/química , beta-Ciclodextrinas/química , Adsorción , Arsénico/aislamiento & purificación , Rastreo Diferencial de Calorimetría , Celulosa/síntesis química , Ciclodextrinas/síntesis química , Imidazoles/química , Espectroscopía de Resonancia Magnética , Fenoles/aislamiento & purificación , Porosidad , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA