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μ–solid-phase-extraction
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Magnetic and electric field assisted electrospun polyamide nanofibers for on-line μ-solid phase extraction and HPLC
, Article RSC Advances ; Vol. 4, Issue. 94 , 2014 , pp. 52590-52597 ; ISSN: 20462069 ; Piri-Moghadam, H ; Rastegar, S ; Sharif University of Technology
Abstract
The effects of applied magnetic and electric fields on electrospinning were investigated to produce more efficient nanofibers. Considering the previous extensive studies, polyamide nanofibers were prepared by a conventional approach and under auxiliary electric and magnetic fields. The first sorbent was synthesized by electrospinning of a solution of 18% polyamide in formic acid. The second and third types of polyamide were prepared similarly while the electrospinning processes were assisted by an electric and a magnetic field. The third type of polyamide contained a magnetic ionic liquid (MIL) to induce sufficient magnetic susceptibility in the polymeric solution. The SEM images revealed...
Simultaneous determination of theophylline, theobromine and caffeine in different tea beverages by graphene-oxide based ultrasonic-assisted dispersive micro solid-phase extraction combined with HPLC-UV
, Article RSC Advances ; Vol. 4, issue. 87 , 2014 , p. 47114-47120 ; Khosraviani, M ; Samadi, S ; Amini-Fazl, M. S ; Sharif University of Technology
Abstract
A simple ultrasound-assisted dispersive micro-solid phase extraction method based on graphene-oxide (GO) nanosorbents (UAD-μ-SPE), followed by high performance liquid chromatography-ultraviolet detection (HPLC-UV) was developed for the simultaneous determination of theophylline, theobromine and caffeine in different infusion tea samples. GO was synthesized by Hummers method and characterized with field emission-scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy. The GO sorbent was dispersed in the sample solution with the assistance of ultrasound to enhance adsorption and desorption performance and rates. The main parameters...
On-line trace enrichment of phenolic compounds from water using a pyrrole-based polymer as the solid-phase extraction sorbent coupled with high-performance liquid chromatography
, Article Analytica Chimica Acta ; Volume 513, Issue 2 , 2004 , Pages 445-449 ; 00032670 (ISSN) ; Mohammadi, A ; Salemi, A ; Sharif University of Technology
2004
Abstract
A pyrrole-based conductive polymer was prepared and applied as new sorbent for on-line solid-phase extraction (SPE) of phenol and chlorophenols from water samples. Polypyrrole (PPy) was synthesized by chemical oxidation of the monomer in non-aqueous solution. The efficiency of this polymer for extraction of phenol and chlorophenols was evaluated using 35 mg of PPy as the sorbent in an on-line SPE system coupled to reversed-phase liquid chromatography with UV detection. The mobile phase were mixture of phosphate buffer-acetonitrile and compounds were eluted by the mobile phase using a six-port switching valve. High volumes of water, up to 160 ml, could be preconcentrated without the loss of...
Conductive polymers as new media for solid-phase extraction: Isolation of chlorophenols from water sample
, Article Journal of Chromatography A ; Volume 986, Issue 1 , 2003 , Pages 111-119 ; 00219673 (ISSN) ; Saraji, M ; Sharif University of Technology
Elsevier
2003
Abstract
Three different conductive polymers, poly-N-methylaniline (PNMA), polyaniline and polydiphenylamine were synthesised and used as sorbents for the solid-phase extraction of some phenolic compounds from water. The separation and determination was, subsequently, performed by gas chromatography-electron-capture and flame ionization detection. Among these easy-made polymers, PNMA gave better recovery for the extraction of the studied analytes. The capability of the PNMA to extract other non-polar compounds such as chloro- and methylbenzene, decane, decanol, cyclohexane and cyclohexanol was also studied. The polymer showed some sort of selectivity towards aromatic compounds than aliphatic....
Electrospun Functionalized Silica / Polyvinyl Alcohol Nanofibers for On-Line μ-Solid Phase Extraction of Estrone and Estradiol in Biological Samples
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
A method for determination of estrogens in biological samples was developed. This method was based on high performance liquid chromatography using online micro-solid phase extraction with 25 mg sorbent synthesized by electrospining of silica/PVA nanofibers. Poly (vinyl alcohol) (PVA) is an easily electrospun polymer with unique properties such as biocompatibility, processability, and hydrophilicity. Silica is biocompatible, thermally stable, and comparatively inert. Incorporation of silica with PVA produces hybrids with enhanced thermal and chemical stability in sample media and elution solvents without relinquishing the biocompatibility of PVA. The sufficient numbers of disc sheets were cut...
Solid phase extraction of trace amounts of Pb(II) in opium, heroin, lipstick, plants and water samples using modified magnetite nanoparticles prior to its atomic absorption determination
, Article Journal of the Iranian Chemical Society ; Volume 9, Issue 2 , 2012 , Pages 171-180 ; 1735207X (ISSN) ; Hatefi Mehrjardi, A ; Mohammadi, S. Z ; Mohadesi, A ; Mazloum Ardakani, M ; Hormozi Nezhad, M. R ; Kabir, A. A ; Sharif University of Technology
2012
Abstract
A new, simple, fast and reliable solid-phase extraction method has been developed for separation/preconcentration of trace amounts of Pb(II) using dithizone/sodium dodecyl sulfate-immobilized on alumina-coated magnetite nanoparticles, and its determination by flame atomic absorption spectrometry (FAAS) and graphite furnace atomic absorption spectrometry (GFAAS) after eluting with 4.0 mol L -1 HNO 3. Optimal experimental conditions including pH, sample volume, eluent concentration and volume, and co-existing ions have been studied and established. Under the optimal experimental conditions, the preconcentration factor, detection limit, linear range and relative standard deviation of Pb(II)...
Electrospun composite of polypyrrole-polyamide as a micro-solid phase extraction sorbent
, Article Analytical and Bioanalytical Chemistry ; 2011 , Pages 1-7 ; 16182642 (ISSN) ; Aghakhani, A ; Akbari, M ; Ayazi, Z ; Sharif University of Technology
Abstract
A micro-solid phase extraction technique was developed using a novel polypyrrole-polyamide nanofiber sheet, fabricated by electrospinning method. The applicability of the new nanofiber sheet was examined as an extracting medium to isolate malathion as a model pesticide from aqueous samples. Solvent desorption was subsequently performed in a microvial, and an aliquot of extractant was injected into gas chromatography-mass spectrometry. Various parameters affecting the electrospinning process including monomer concentration, polyamide content, applied voltage, and electrospinning time were examined. After fabricating the most suitable preparation conditions, influential parameters on the...
Electrospun nanofibers
, Article Solid-Phase Extraction ; 2019 , Pages 311-339 ; 9780128169063 (ISBN) ; Rezvani, O ; Zeinali, S ; Asgari, S ; Golzari Aqda, T ; Manshaei, F ; Sharif University of Technology
Elsevier
2019
Abstract
Electrostatic fiber fabrication technique has evinced more interest and attention in recent years, owing to its versatility, reliability, and potential for applications in diverse fields, particularly separation, extraction, and filtration. The sub-micro fibers are generated by employing strong electric field on polymeric solutions or melt is led to the soft nanometric mats. So far, more than 100 polymers have been Electrospun and this number is gradually increasing. Over recent decades, a remarkable variety of electrospun nanofibers as promising and authentic extracting platforms have been synthesized. They offer various advantages including high surface area-to-volume ratio and tunable...
Electrospun nanofibers
, Article Solid-Phase Extraction ; 2019 , Pages 311-339 ; 9780128169063 (ISBN) ; Rezvani, O ; Zeinali, S ; Asgari, S ; Aqda, T. G ; Manshaei, F ; Sharif University of Technology
Elsevier
2019
Abstract
Electrostatic fiber fabrication technique has evinced more interest and attention in recent years, owing to its versatility, reliability, and potential for applications in diverse fields, particularly separation, extraction, and filtration. The sub-micro fibers are generated by employing strong electric field on polymeric solutions or melt is led to the soft nanometric mats. So far, more than 100 polymers have been Electrospun and this number is gradually increasing. Over recent decades, a remarkable variety of electrospun nanofibers as promising and authentic extracting platforms have been synthesized. They offer various advantages including high surface area-to-volume ratio and tunable...
Evaluation of polyaniline as a sorbent for SPE of a variety of polar pesticides from water followed by CD-MEKC-DAD
, Article Chromatographia ; Volume 59, Issue 5-6 , 2004 , Pages 283-289 ; 00095893 (ISSN) ; Saraji, M ; Barceló, D ; Sharif University of Technology
2004
Abstract
A recently synthesized polyaniline (PANI) has been used and evaluated as a sorbent for solid-phase extraction of a variety of polar pesticides and some of their degradation products from water samples. Several classes of pesticides including phenoxy acids, triazines, ureas, oxime carbamates and carbamates were selected for this study. The determination of these pesticides was carried out using cycladextrin modified micellar electrokinetic chromatography equipped with diode array detection. The recovery results using PANI were compared with those obtained by C18, Isolute ENV+, Oasis HLB and LiChrolut EN. Effect of humic acid, as a major interference, on extraction recovery was also studied....
New polymeric sorbent for the solid-phase extraction of chlorophenols from water samples followed by gas chromatography-electron-capture detection
, Article Journal of Chromatography A ; Volume 910, Issue 1 , 2001 , Pages 87-93 ; 00219673 (ISSN) ; Saraji, M ; Sharif University of Technology
2001
Abstract
A polymeric material, polyaniline, was employed as a new sorbent for solid-phase extraction (SPE) of some environmental pollutants from water samples. Chlorophenols were extracted from aqueous samples by SPE using 120 mg polyaniline and determined by gas chromatography with electron-capture detection. The acetate esters of these phenols were formed by the direct addition of acetic anhydride to the organic extractant in the presence of K2CO3. Different conditions were applied to obtain higher retaining capacity and breakthrough volumes. The results compared with those obtained by other groups. The RSD for a river water sample spiked at sub-ppb level was lower than 10% (n = 3) and detection...
Modified Polystyrene Based Sorbents for Extraction of Trace Organic Pollutants with a Wide Range of Polarity
, Ph.D. Dissertation Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
The main focus of this thesis is based on surface modification of polystyrene in order to prepare extractive phases appropriate for extraction of analytes with a wide polarity range. This goal was achieved by increasing surface polarity. In fact, improved wettability and the possibility of interaction with polar analytes after addition of functional groups on polystyrene surface were the main reason for increased extraction capacity. In the first research, different functional groups including amine, nitro, carboxyl and acetyl were added on polystyrene particles by chemical bonding and to investigate their influence on extraction process, 22 analytes with a wide polarity range (LogP=-2 to...
A chitosan-polypyrrole magnetic nanocomposite as μ-sorbent for isolation of naproxen
, Article Analytica Chimica Acta ; Vol. 816 , 2014 , Pages 1-7 ; ISSN: 00032670 ; Roostaie, A ; Baktash, M. Y ; Sharif University of Technology
Abstract
An extracting medium based on chitosan-polypyrrole (CS-PPy) magnetic nanocomposite was synthesized by chemical polymerization of pyrrole at the presence of chitosan magnetic nanoparticles (CS-MNPs) for micro-solid phase extraction. In this work, magnetic nanoparticles, the modified CS-MNPs and different types of CS-PPy magnetic nanocomposites were synthesized. Extraction efficiency of the CS-PPy magnetic nanocomposite was compared with the CS-MNPs and Fe3O4 nanoparticles for the determination of naproxen in aqueous samples, via quantification by spectrofluorimetry. The scanning electron microscopy images obtained from all the prepared nanocomposites revealed that the CS-PPy magnetic...
An innovative chemometric approach for simultaneous determination of polycyclic aromatic hydrocarbons in oil-contaminated waters based on dispersive micro-solid phase extraction followed by gas chromatography
, Article Microchemical Journal ; Volume 159 , 2020 ; Jabbari, A ; Parastar, H ; Sharif University of Technology
Elsevier Inc
2020
Abstract
In the present study, an analytical strategy was developed using reduced graphene oxide (rGO) as an effective sorbent in dispersive micro-solid phase extraction (DMSPE) for simultaneous determination of seven polycyclic aromatic hydrocarbons (PAHs) combined with gas chromatography (GC-FID). rGO was synthesized using modified Hummer's method and characterized using scanning electron microscope (SEM), atomic force microscope (AFM) and Raman spectroscopy. A rotatable central composite design (CCD) combined with multiple linear regression (MLR) and analysis of variance (ANOVA) was used for designing, modelling and optimization of the extraction procedure. In this regard, principal component...
A stable nitrogen-rich zinc-based metal organic framework to investigate the structural similarity effect on the sorption efficiency of nitrogen-containing compounds
, Article Microchemical Journal ; Volume 170 , 2021 ; 0026265X (ISSN) ; Naderi, M ; Bagheri, H ; Sharif University of Technology
Elsevier Inc
2021
Abstract
A stable porous zinc-based metal organic framework (MOF) containing nitrogen-rich bis-tetrazolate ligand was synthesized to study the role of similar structures concerning both extractive phase and the desired solutes to achieve greater sorption efficiency. With implementing a dispersive micro-solid phase extraction (d-µ-SPE) methodology, the sorption capability and influencing structural parameters i.e., porosity, surface area and interactions types were investigated for the synthesized zinc-bis-tetrazolate (ZnBT) MOF and compared with some synthesized sorbents such as MIL-101, MIL-101-NH2, cadmium naphthalene dicarboxylic acid dimethyl formamide [Cd(NDC)(DMF)], polyaniline and LiChrolut®...
Electrospun titania sol-gel-based ceramic composite nanofibers for online micro- solid-phase extraction with high-performance liquid chromatography
, Article Journal of Separation Science ; Vol. 37, issue. 15 , August , 2014 , pp. 1982-1988 ; ISSN: 16159306 ; Piri-Moghadam, H ; Rastegar, S ; Taheri, N ; Sharif University of Technology
Abstract
Titanium(IV) tetraisopropoxide was employed as a metal oxide sol-gel precursor to prepare ceramic composite nanofibers by the electrospinning system. To facilitate this process and obtain the desired nanofibers with higher aspect ratios and surface area, poly(vinylpyrrolidone) was added to the sol of titania. Four ceramic nanofibers sheets based on titania were prepared while each sheet contained different transition metals such as Fe-Mn, Fe-Ni, Fe-Co, and Fe-Mn-Co-Ni. The scanning electron microscope images showed good homogeneity for all the prepared ceramic composites with a diameter range of 100-250 nm. The sorption efficiency was investigated by a micro-solid-phase extraction setup in...
Dispersive micro-solid phase extraction using magnetic nanoparticle modified multi-walled carbon nanotubes coupled with surfactant-enhanced spectrofluorimetry for sensitive determination of lomefloxacin and ofloxacin from biological samples
, Article Materials Science and Engineering C ; Volume 60 , 2016 , Pages 30-36 ; 09284931 (ISSN) ; Pourghazi, K ; Hajjaran, S ; Sharif University of Technology
Elsevier Ltd
Abstract
A dispersive micro-solid-phase extraction (D-μ-SPE) procedure coupled with surfactant-enhanced spectrofluorimetric detection was developed for determination of ofloxacin and lomefloxacin from biological and environmental samples. The D-μ-SPE procedure was performed using magnetic Fe3O4 nanoparticle grafted multi-walled carbon nanotube as an efficient adsorbent. The main factors affecting the signal enhancement (including surfactant concentration and pH) and extraction efficiency (including pH, extraction time, sample volume, amount of magnetic adsorbent, and desorption conditions) were investigated in detail. Under the optimized conditions, the calibration curves were linear (R2 0.9995) over...
Fe3O4 Nano Particle-Based Magnetic Solid Phase Extraction of Oxadiargy1 and Fluoxetine from Aquatic and Biological Media
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
In this study new magnetic solid phase extraction (MSPE) methods based on Fe3O4 magnetic nanoparticles (NPs) for extraction and preconcentration of oxadiargyl and fuoxetine from aqueous and biological samples were developed. In the first work, Fe3O4 NPs was successfully used as a magnetic nano-sorbent in magnetic micro-solid phase extraction (M-µ-SPE) of oxadiargyl, a newly used pesticide, from environmental water samples prior to gas chromatography-mass spectrometry determination. Oxadiargyl in mild acidic condition has tendency to be adsorbed on Fe3O4 NPs surfaces. Most important parameters that affect the extraction efficiency were also studied. Under optimized condition, the proposed...
On-line SPE of Clodinafop Propargyl Traces from Aquatic Media Using Electrospun Polyamide Nanofibers Disks
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
An on-line solid phase extraction (SPE) method coupled with high performance liquid chromatography (HPLC) was developed using electrospun polyamide (PA) nanofibers as the extractin medium for trace determination of clodinafop propargyl herbicide in environmental aqueous samples. The sufficient numbers of disc sheets were cut from the electrospun PA mat and used as packing material in a cartridge. The homogeneity and the porosity of the prepared PA sheet were studied using the scanning electron microscopy (SEM) and the observed nanofiber diameters and lengths proved that the prepared sorbent possess a high aspect ratio. Major parameters affecting the extraction efficiency were optimized. The...
Electrospinning of Core-shell Nanofibers for Extraction and Determination of Pesticide Residues from Aquatic Media
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
Porosity and high surface area is a profound concept for creating advance materials. Nanofibers are an important class of nano materials which would be used as novel sorbents because of their high surface to volume ratio as a result of long lengths and nano-to-micro-scale diameters. Electrospining is a simple method for producing fine nanofibers from different meterials such as, polymers, composites and ceramics to prepare highly efficient sorbents. Moreover, electrospining has been developed for fabricating nanofibers with core-shell structures. These structures in compared with conventional fibers have gained higher attentions due to their high aspect ratios and flexiblity in surface...