Search for: limit-of-quantitation
Total 32 records
Article ACS Sensors ; Volume 5, Issue 2 , 2020 , Pages 580-587 ; Kirsanov, D ; Sharif University of Technology
American Chemical Society 2020
Multisensor arrays employing various sensing principles are a rapidly developing field of research as they allow simple and inexpensive quantification of various parameters in complex samples. Quantitative analysis with such systems is based on multivariate regression techniques, and deriving of traditional analytical figures of merit (e.g., sensitivity, selectivity, limit of detection, and limit of quantitation) for such systems is not obvious and straightforward. Nevertheless, it is absolutely needed for further development of the multisensor research field and for introducing these instruments into the general context of analytical chemistry. Here, we report on the protocol for...
Article Chromatographia ; Vol. 77, issue. 5-6 , 2014 , pp. 397-403 ; ISSN: 00095893 ; Banihashemi, S ; Sharif University of Technology
A rapid, convenient and reliable method for microextraction in packed syringe (MEPS) of the loop diuretic furosemide (FUR) in urine along with high-performance liquid chromatography (HPLC) was developed. A nanocomposite based on silver nanoparticles/polyaniline (Ag-NPs/PANI) was synthesized and used as the MEPS packing material. This nanocomposite was prepared conveniently using interfacial polymerization without the need for any templates or functional dopants. The feasibility of the synthesized nanocomposites was examined by isolation of FUR from diluted urine samples. After extraction, the analyte was desorbed by 200 μL of methanol. It was then dried and the residue was dissolved in 30 μL...
On-line micro solid-phase extraction of clodinafop propargyl from water, soil and wheat samples using electrospun polyamide nanofibers, Article Chromatographia ; Vol. 77, issue. 9-10 , May , 2014 , p. 723-728 ; Asgari, S ; Piri-Moghadam, H ; Sharif University of Technology
An on-line extraction/determination set up was designed for micro solid-phase extraction of clodinafop propargyl from water, soil and wheat samples using electrospun polyamide nanofiber mats. The prepared mats were packed in a stainless steel tube which conveniently acted as a high-performance liquid chromatography injection loop. Influential parameters affecting the extraction efficiency were optimized using a distilled water sample fortified with 25 μg L-1 of clodinafop propargyl. An enrichment factor of 440 was achieved for clodinafop propargyl indicating the ability of the whole procedure. Under the optimum conditions, the linearity for the analyte was in the range of 6-700 μg L-1, while...
Preconcentration and determination of pantoprazole by solid-phase extraction coupled with spectrophotometry using iron oxide nanoparticles modified with cetyltrimethylammonium bromide, Article Nano Biomedicine and Engineering ; Volume 7, Issue 3 , 2015 , Pages 102-110 ; 21505578 (ISSN) ; Naghian, E ; Sahebi, H ; Asgari, S ; Sharif University of Technology
Open Access House of Science and Technology 2015
Solid phase extraction coupled with spectrophotometric detection was applied to trace amounts of Pantoprazole (PP) drug using Cetyltrimethylammonium bromide coated-iron oxide magnetite nanoparticles CTAB@Fe3O4 MNPs. After characterization of the prepared nano-adsorbents, experimental parameters affecting the extraction efficiency of the developed method were optimized. The results obtained showed that this proposed approach is applicable in concentrations ranging from 0.1 to 1.5 μg/ml (R2 = 0.9958) indicating that follows Beer's-Lambert law. The limit of detection and the limit of quantification calculated to be 0.014 and 0.04 μg/ml, respectively. The repeatability of the proposed method was...
Microwave-assisted extraction and high-throughput monolithic-polymer-based micro-solid-phase extraction of organophosphorus, triazole, and organochlorine residues in apple, Article Journal of Separation Science ; Volume 39, Issue 3 , 2016 , Pages 576-583 ; 16159306 (ISSN) ; Es Haghi, A ; Basiri Pour, F ; Sharif University of Technology
A high-throughput micro-solid-phase extraction device based on a 96-well plate was constructed and applied to the determination of pesticide residues in various apple samples. Butyl methacrylate and ethylene glycol dimethacrylate were copolymerized as a monolithic polymer and placed in the cylindrically shaped stainless-steel meshes of 96-micro-solid-phase extraction device and used as an extracting unit. Before the micro-solid-phase extraction, microwave-assisted extraction was employed to facilitate the transfer of the pesticide residues from the apple matrix to liquid media. Then, 1 mL of the aquatic samples was transferred into the 96-well plate and the 96-micro-solid-phase extraction...
Analysis of alternative new pesticide (fluopyram, flupyradifurone, and indaziflam) residues in pistachio, date, and soil by liquid chromatography triple quadrupole tandem mass spectrometry, Article Soil and Sediment Contamination ; Volume 30, Issue 4 , 2021 , Pages 373-383 ; 15320383 (ISSN) ; Keikavousi Behbahan, A ; Moradi, F ; Aboul Enein, H. Y ; Sharif University of Technology
Bellwether Publishing, Ltd 2021
Fluopyram, flupyradifurone, and indaziflam are novel systemic pesticides developed by Bayer. Based on available data, these pesticides appears to have a favorable safety profile in the case of pesticide residue problems. Herein, we report an effective analytical method for the determination of novel pesticides were developed using ultra-high performance liquid chromatography with tandem mass spectrometry coupled with a quick, easy, cheap, effective, rugged, and safe procedure. These target compounds were extracted with acetonitrile and cleaned up with PSA, and were separated successfully between 10.2 and 18.3 min using a C18 chromatographic column connected to an electrospray ionization...
Second-order calibration for simultaneous determination of pharmaceuticals in water samples by solid-phase extraction and fast high-performance liquid chromatography with diode array detector, Article Chemometrics and Intelligent Laboratory Systems ; Vol. 137, issue , 2014 , pp. 146-154 ; ISSN: 01697439 ; Parastar, H ; Sharif University of Technology
A fast high-performance liquid chromatography-diode array detection (HPLC-DAD) approach combined to solid phase extraction (SPE) as a pre-concentration step is developed for simultaneous determination of five selected pharmaceuticals (carbamazepine, naproxen, diclofenac, gemfibrozil and mefenamic acid) in water samples. The effective factors on the efficiency of SPE procedure are optimized using faced-centered central composite design (FCCD). In addition, multi-response optimization by using Derringer's desirability function is used to find the optimum experimental conditions for extraction of analytes from well and river waters. Due to the complexity of water matrices and the presence of...
A high-throughput approach for the determination of pesticide residues in cucumber samples using solid-phase microextraction on 96-well plate, Article Analytica Chimica Acta ; Volume 740 , 2012 , Pages 36-42 ; 00032670 (ISSN) ; Es'haghi, A ; Eshaghi, A ; Mesbahi, N ; Sharif University of Technology
A high-throughput solid-phase microextraction (SPME) on 96-well plate together with gas chromatography-mass spectrometry (GC-MS) was developed for the determination of some selected pesticides in cucumber samples. Pieces with the length of 1.0cm of silicon tubing were precisely prepared and then coated on the end part of stainless steel wires. The prepared fibers were positioned in a home-made polytetrafluoroethylene (PTFE)-based constructed ninety-six holes block to have the possibility of simultaneous immersion of the SPME fibers into the center of individual wells. Pesticides such as diazinon, penconazol, tebuconazol, bitertanol, malathion, phosalone and chlorpyrifos-methyl were selected...
Article Journal of Separation Science ; Volume 40, Issue 19 , 2017 , Pages 3857-3865 ; 16159306 (ISSN) ; Najafi Mobara, M ; Roostaie, A ; Baktash, M. Y ; Sharif University of Technology
A thin film microextraction method using elecrospun magnetic polybutylene terephthalate nanofibers is developed and implemented to isolate some selected triazines. Due to the high mechanical stability of these nanofibers, they are repeatedly used under harsh magnetic stirring and ultrasonic conditions without any damage and structure degradation. The presence of magnetic nanoparticles within the nanofiber structure increases the extraction efficiency while the fibers could be collected by an external magnet. The synthesized nanocomposite showed strong affinity toward the selected analytes. Apart from the concentration of magnetic nanoparticles within the nanocomposite network, the effect of...
A patient specific finite element simulation of intramedullary nailing to predict the displacement of the distal locking hole, Article Medical Engineering and Physics ; Volume 55 , May , 2018 , Pages 34-42 ; 13504533 (ISSN) ; Farahmand, F ; Behzadipour, S ; Yeganeh, A ; Aghighi, M ; Sharif University of Technology
Elsevier Ltd 2018
Distal locking is a challenging subtask of intramedullary nailing fracture fixation due to the nail deformation that makes the proximally mounted targeting systems ineffective. A patient specific finite element model was developed, based on the QCT data of a cadaveric femur, to predict the position of the distal hole of the nail postoperatively. The mechanical interactions of femur and nail (of two sizes) during nail insertion was simulated using ABAQUS in two steps of dynamic pushing and static equilibrium, for the intact and distally fractured bone. Experiments were also performed on the same specimen to validate the simulation results. A good agreement was found between the model...
Amine/phenyl gradient derived base layer as a comprehensive extractive phase for headspace cooled in–tube microextraction of volatile organic compounds in saliva, Article Journal of Pharmaceutical and Biomedical Analysis ; Volume 191 , 2020 ; Bagheri, H ; Rostami, A ; Sharif University of Technology
Elsevier B.V 2020
A gradient derived base layer extractive phase was synthesized and applied for the determination of volatile organic compounds (VOCs) in saliva samples using the headspace cooled in–tube microextraction (HS–CITME) method. The base layers from three different sols of phenyltriethoxysilane (PTES), octyltrimethoxysilane (OTMS) and methyltrimethoxysilane (MTMS) as nonpolar precursors were individually dip coated on the stainless steel wires (SSW). Then, the hydrolyzed polar precursor aminopropyltriethoxysilane (APTES) reacted with the silanol groups already formed on the surface of SSWs via controlled rate infusion (CRI) method. The presence of polar and non–polar functional groups on the...
Grafting the sol-gel based sorbents by diazonium salts: A novel approach toward unbreakable capillary microextraction, Article Journal of Chromatography A ; Volume 1318 , November , 2013 , Pages 58-64 ; 00219673 (ISSN) ; Bayat, P ; Piri Moghadam, H ; Sharif University of Technology
The present work deals with a novel approach for grafting a sol-gel based sorbent, using diazonium salts for preparation of an unbreakable capillary microextraction (CME) device in on-line combination with high performance liquid chromatography (HPLC). The use of diazonium salts modifier allowed all types of metallic and non-metallic substrates to be used without any limitation. Substrates including copper, brass, stainless steel and polytetrafluoroethylene (PTFE) were chosen to be functionalized by chemical or electrochemical reduction of 4-amino phenyl acetic acid. Then, 3-(trimethoxysilyl)propylamine (3TMSPA) was selected as the precursor and the only reagent for preparation of the...
A novel magnetic poly(aniline-naphthylamine)-based nanocomposite for micro solid phase extraction of rhodamine B, Article Analytica Chimica Acta ; Volume 794 , 2013 , Pages 38-46 ; 00032670 (ISSN) ; Daliri, R ; Roostaie, A ; Sharif University of Technology
A novel Fe3O4-poly(aniline-naphthylamine)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for micro solid phase extraction. The scanning electron microscopy images of the synthesized nanocomposite revealed that the copolymer posses a porous structure with diameters less than 50nm. The extraction efficiency of this sorbent was examined by isolation of rhodamine B, a mutagenic and carcinogenic dye, from aquatic media in dispersion mode. Among different synthesized polymers, Fe3O4/poly(aniline-naphthylamine) nanocomposite showed a prominent efficiency. Parameters including the desorption solvent, amount of sorbent, desorption time, sample...
Article Analytica Chimica Acta ; Volume 713 , 2012 , Pages 63-69 ; 00032670 (ISSN) ; Aghakhani, A ; Sharif University of Technology
A headspace adsorptive microextraction technique was developed using a novel polyaniline-nylon-6 (PANI-N6) nanofiber sheet, fabricated by electrospinning. The homogeneity and the porosity of the prepared PANI-N6 sheet were studied using the scanning electron microscopy (SEM) and nanofibers diameters were found to be around 200nm. The novel nanofiber sheet was examined as an extracting medium to isolate some selected chlorobenzenes (CBs), as model compounds, from aquatic media. The extracted analytes were desorbed using μL-amounts of solvent and eventually an aliquot of extractant was injected into gas chromatography-mass spectrometry (GC-MS). Various parameters affecting the extraction and...
Chemometric-based determination of polycyclic aromatic hydrocarbons in aqueous samples using ultrasound-assisted emulsification microextraction combined to gas chromatography-mass spectrometry, Article Journal of Chromatography A ; Volume 1413 , September , 2015 , Pages 117-126 ; 00219673 (ISSN) ; Sereshti, H ; Parastar, H ; Sharif University of Technology
In the present research, ultrasonic-assisted emulsification-microextraction (USAEME) coupled with gas chromatography-mass spectrometry (GC-MS) has been proposed for analysis of thirteen environmental protection agency (EPA) polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. Tetrachloroethylene was selected as extraction solvent. The main parameters of USAEME affecting the efficiency of the method were modeled and optimized using a central composite design (CCD). Under the optimum conditions (9 μL for extraction solvent, 1.15% (w/v) NaCl (salt concentration) and 10min for ultrasonication time), preconcentration factor (PF) of the PAHs was in the range of 500-950. In order to have a...
Sol-gel-based silver nanoparticles-doped silica - Polydiphenylamine nanocomposite for micro-solid-phase extraction, Article Analytica Chimica Acta ; Volume 886 , July , 2015 , Pages 56-65 ; 00032670 (ISSN) ; Banihashemi, S ; Sharif University of Technology
A nanocomposite of silica-polydiphenylamine doped with silver nanoparticles (Ag-SiO
2-PDPA) was successfully synthesized by the sol-gel process. For its preparation, PDPA was mixed with butanethiol capped Ag nanoparticles (NPs) and added to the silica sol solution. The Ag NPs were stabilized as a result of their adsorption on the SiO 2 spheres. The surface characteristic of nanocomposite was investigated using scanning electron microscopy (SEM). In this work the Ag-SiO 2-PDPA nanocomposite was employed as an efficient sorbent for micro-solid-phase extraction (μ-SPE) of some selected pesticides. An amount of 15 mg of the prepared sorbent was used to extract and...
Joint approximate diagonalization of eigenmatrices as a high-throughput approach for analysis of hyphenated and comprehensive two-dimensional gas chromatographic data, Article Journal of Chromatography A ; Volume 1524 , 2017 , Pages 188-201 ; 00219673 (ISSN) ; Parastar, H ; Sharif University of Technology
The objective of the present work is development of joint approximate diagonalization of eigenmatrices (JADE) as a member of independent component analysis (ICA) family, for the analysis of gas chromatography-mass spectrometry (GC–MS) and comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC–MS) data to address incomplete separation problem occurred during the analysis of complex sample matrices. In this regard, simulated GC–MS and GC × GC–MS data sets with different number of components, different degree of overlap and noise were evaluated. In the case of simultaneous analysis of multiple samples, column-wise augmentation for GC–MS and column-wise super-augmentation...
An imprinted interpenetrating polymer network for microextraction in packed syringe of carbamazepine, Article Journal of Chromatography A ; Volume 1491 , 2017 , Pages 1-8 ; 00219673 (ISSN) ; Bagheri, H ; Es haghi, A ; Amini Tabrizi, R ; Sharif University of Technology
An imprinted interpenetrating polymer network (IPN) was synthesized and used as a medium for isolation of carbamazepine from urine samples. The polymer network consisted of a homogeneous polystyrene–sol gel hybrid constructed by in–situ radical polymerization method. In this process, within the sol–gel reaction duration, styrene monomer could penetrate into the reaction mixture and after the polymerization initiation, a monolithic IPN structure was prepared. The scanning electron microscopy (SEM) image and energy dispersive spectroscopy (EDX) are indications of the polystyrene dispersion at nano- to micro-meter level in the sol gel matrix. Eventually, the synthesized IPN was used as a...
Implementing a superhydrophobic substrate in immersed solvent–supported microextraction as a novel strategy for determination of organic pollutants in water samples, Article Ecotoxicology and Environmental Safety ; Volume 163 , 2018 , Pages 104-110 ; 01476513 (ISSN) ; Asem Yousefi, A ; Bagheri, H ; Sharif University of Technology
Academic Press 2018
In this research, a new approach for extraction and determination of polycyclic aromatic hydrocarbons from sea and rain water samples was developed by implementing a superhydrophobic substrate and consuming the least amount of solvent. This version of solvent–supported microextraction enabled us to perform the procedure in the immersion mode with the slightest troubles arising from water leakage into the gas chromatography. The superhydrophobic property leads to the fixation of extracting solvent on the substrate surface during water sampling. To prepare a superhydrophobic substrate, a piece of melamine foam was coated by tannic acid and silica nanoparticles using methyltrimethoxysilane and...
Gradient extractive phase prepared by controlled rate infusion method: An applicable approach in solid phase microextraction for non–targeted analysis, Article Journal of Chromatography A ; Volume 1574 , 2018 , Pages 130-135 ; 00219673 (ISSN) ; Kazemi, E ; Bagheri, H ; Sharif University of Technology
Elsevier B.V 2018
The aim of this study is to introduce an extractive phase based on gradient concept by continuous changing in chemical functional groups for non–targeted analysis. For this purpose, three different two–component coatings containing (3–aminopropyl)trimethoxysilane (APTES) as polar and either phenyltriethoxysilane (PTES), octyl–trimethoxysilane (OTMS) or methyltrimethoxysilane (MTMS) as nonpolar precursors were formed on the modified stainless steel wires using controlled rate infusion (CRI) method. The presence of polar and/or non–polar functional groups on the surface of substrate was evaluated by Fourier–transform infrared spectroscopy (FTIR) together with contact angles determined...