Zarrin Es’hagi; Effat Esmaeili-Shahri
Volume 5, Issue 1 , March 2018, , Pages 25-32
Abstract
Hollow fiber-solid phase microextraction (HF-SPME) technique containing multiwalled carbon nanotubes (MWCNTs) reinforced sol-gel nanocomposite coupled with UV–Vis spectrophotometry was applied for preconcentration and determination of lead, zinc and silver in water samples. In this technique, ...
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Hollow fiber-solid phase microextraction (HF-SPME) technique containing multiwalled carbon nanotubes (MWCNTs) reinforced sol-gel nanocomposite coupled with UV–Vis spectrophotometry was applied for preconcentration and determination of lead, zinc and silver in water samples. In this technique, a high efficiency sorbent containing mixture of MWCNTs and a microporous gel was injected into a piece of a polypropylene hollow fiber for in situ gelation. The method validation was included and satisfying results were obtained. It owes large surface area and porosity of the nano-adsorbent. Under the optimal conditions, linear calibration curves were established for the concentration of Pb2+, Zn2+ and Ag+ in the range of 0.2–7.0, 0.3–7.0 and 2.0–50 µg/mL respectively. The limits of detection were 0.032, 0.057 and 0.325 µg/mL for Pb2+, Zn2+ and Ag+. The relative standard deviations (RSDs) were found to be less than 8.0 %.
Nosrat Madadi Mahani; Maryam Alibeigi
Abstract
A quantitative Structure-Activity Relationship (QSAR) model was applied to the prediction of the antimicrobial activity of 22 derivatives 2, 4, 6-s-triazine as anti-malarial agents. The antimicrobial activity of 22 2, 4, 6-s-triazine derivatives were modeled with the descriptors of quantum-chemical ...
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A quantitative Structure-Activity Relationship (QSAR) model was applied to the prediction of the antimicrobial activity of 22 derivatives 2, 4, 6-s-triazine as anti-malarial agents. The antimicrobial activity of 22 2, 4, 6-s-triazine derivatives were modeled with the descriptors of quantum-chemical calculations with density functional theory (DFT) method at B3LYP/6‒31G level and topological descriptors. This study was conducted using the multiple linear regressions (MLR), the partial least square analysis (PLS) and the principal component regression (PCR) method. Results displayed that the MLR method predicted of antimicrobial activity good enough. The best model, with six descriptors was selected. Also it indicates very good consistency towards data variations for the validation methods. The predicted values of antimicrobial activity are in suitable agreement with the experimental results. The obtained results suggested that the PLS method could be more helpful to predict the antimicrobial activity of 2, 4, 6-s-triazine derivatives. This study to be usable to predict the activity of other derivatives in the same groups.
Nigussie Fikre
Abstract
Physicochemical characterization was carried out for the determination of the quality of drinking tap water from Masha, and Mizan-Aman town southwest Ethiopia. Known volume of tap water samples were digested by Standard Method 3030K microwave digestion system using 5 mL concentrated of HNO3 for 20 minutes ...
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Physicochemical characterization was carried out for the determination of the quality of drinking tap water from Masha, and Mizan-Aman town southwest Ethiopia. Known volume of tap water samples were digested by Standard Method 3030K microwave digestion system using 5 mL concentrated of HNO3 for 20 minutes at variable temperature (160-170 oC). After digestion with microwave acid digestion, some selected metals (Mg, Ca, Cu, Mn, Fe, Zn, Cd & Pb) were determined by Flame Atomic Absorption Spectrophotometer and the common anions were determined as follows, Ortho phosphorous (PO43-) by APHA4500-PC.Vanadomolybdphosphoric method, Chloride (Cl-) by APHA4500-Cl-B. Argentometric method, Carbonate(CO3-2) by APHA 2330B.Titration method, Nitrate (NO3-) and ammonia (NH3) by WTD photometer method (WAG PHOT-24).The concentration of these metals and common anions obtained in this study were found to be within the range of WHO and other international guideline lines except Cd. Levels of these metals concentration in this study was that, in all water samples, Mg was found in higher concentration followed by Ca, Fe, Mn, Zn, Cu and Cd respectively. Concentration of Pb was below the method detection limit in all water samples. Under this investigation, at p = 0.05, the physicochemical parameters of all water samples which were taken from different sites were significantly different among the distribution points and distribution systems. The concentrations of the selected metals and common anions were significantly different in between the distribution points and distribution systems except Zn in Mizan, Mn, Fe and Cd in Aman, NH3 in Masha, and Aman sites and in respective of the physical parameters, temperature and electrical conductivity of all the water samples were significantly different except in Masha site. pH and total hardness of all water samples were not significantly different in all sites except total hardness in Masha site.
Ehsan Zolfonoun; Seyed Reza Yousefi
Abstract
A ligandless on-line solid phase extraction method was developed for the preconcentration of lead prior to quantitation by inductively coupled plasma-optical emission spectrometry. In this method, the sample solution was passed through a syringe membrane filter coated with graphitic carbon nitride and ...
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A ligandless on-line solid phase extraction method was developed for the preconcentration of lead prior to quantitation by inductively coupled plasma-optical emission spectrometry. In this method, the sample solution was passed through a syringe membrane filter coated with graphitic carbon nitride and Pb(II) ions were directly adsorbed on the surface of g-C3N4 particles. The adsorbed Pb(II) ions were subsequently eluted from the membrane and transferred directly into the ICP-OES nebulizer with nitric acid solution. Under the optimized conditions and preconcentration of 25 mL of sample, the enhancement factor of 110 and the detection limit of 0.12 μg L-1 were obtained. The proposed procedure was applied for the preconcentration and determination of lead in environmental water samples.
Homa Shafieekhani; Ali Moadelli; Firoozeh Aminipour
Abstract
In this paper, magnetic nanoparticles functionalized by triazene ligand were prepared for extraction/preconcentration of trace amounts of mercury ions in water samples former on its determination with UV-Vis spectrophotometry. The modified magnetic nanoparticles were characterized by the various techniques ...
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In this paper, magnetic nanoparticles functionalized by triazene ligand were prepared for extraction/preconcentration of trace amounts of mercury ions in water samples former on its determination with UV-Vis spectrophotometry. The modified magnetic nanoparticles were characterized by the various techniques such as Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM) and X –Ray Diffractometry (XRD). In the separation process, aqueous solution of Hg2+ ion was mixed with Fe3O4 magnetite nanoparticles modified with (E)-1-(2-Ethoxyphenyl)-3-(4-nitrophenyl)triaze-1-ene (ENT), (MNPs@SiO2-ENT) and then external magnetic field was applied for isolation of magnetite nanoparticles containing mercury ions. Experimental conditions for effective adsorption including pH, ENT amount, Fe3O4 NPs amounts, and eluent type have been studied and established. Under the optimal extraction and preconcentration conditions, calibration curve was linear in the range of 4–80 µgL-1 with r2 = 0.9992 (n=20), the limit of detection (LOD) 1.05µg L-1 and enrichment factor was 38, respectively. This technique was successfully used for the determination of Hg (II) in aqueous samples.
S. Javad Aghili; Ali Sheibani; M. Reza Shishehbore
Abstract
In this paper, a simple, sensitive and economical method is described for the extraction and determination of sesame oil oxidation by dynamic headspace extraction combined to ion mobility spectrometry (IMS). Hexanal as a reaction product of oxidation, is used to follow the progress of oil oxidation. ...
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In this paper, a simple, sensitive and economical method is described for the extraction and determination of sesame oil oxidation by dynamic headspace extraction combined to ion mobility spectrometry (IMS). Hexanal as a reaction product of oxidation, is used to follow the progress of oil oxidation. The optimization of different variables for the extraction step including: extraction temperature, extraction time and flow rate of carrier gas and also for the determination step by IMS including: drift and corona voltages, flow rate of carrier and drift gases, cell and injection temperatures, and pulse width were performed. Under optimum conditions, the calibration curve was linear in the range of 0.10 to 0.50 ng g-1 and also the relative standard deviation was 3.0%. The detection and quantification limits were 0.03 and 0.12 ng g-1, respectively. The recovery results for spiked samples (90.0-104.0%) demonstrated the potential of the proposed method for determining of oxidation in sesame oil samples.
Hamidreza Zare-mehrjardi
Abstract
In this study, the surface of the glassy carbon electrode (GCE) is modified with the nanocomposite of graphene oxide (GO)/ ionic liquid (1-Butyl-3-methylimidazolium tetrafluoroborate; [BMIM]BF4). The electrochemical behavior of ascorbic acid (AA) and dopamine (DA) at the surface of the modified glassy ...
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In this study, the surface of the glassy carbon electrode (GCE) is modified with the nanocomposite of graphene oxide (GO)/ ionic liquid (1-Butyl-3-methylimidazolium tetrafluoroborate; [BMIM]BF4). The electrochemical behavior of ascorbic acid (AA) and dopamine (DA) at the surface of the modified glassy carbon electrode was studied using the differential pulse and cyclic voltammetric methods (DPV and CV). The results show good response sensitivity to AA and DA. The acceleration of the electron transfer rate and enhancement of the electroactive surface area is obtained due to a synergistic effect in the concurrent presence of GO and [BMIM]BF4 at the surface of the electrode. The presence of GO caused to a higher specific surface of the electrode, and ionic liquid ([BMIM]BF4) increased the ion conductivity and dispersibility in the modifier layer at the surface of the GCE. These results obtained in optimum conditions, show good peak separation for AA and DA (more than 300 mV), and the sub-micromolar detection limits for them. The obtained results in this work, make the modified GCE very effective in the manufacture of simple devices for the detection of AA and DA in human urine samples.
Hooshang Hamidian; Mahbobeh Mosavi Farahbakhsh; Rasool Roohparvar; Mohammad Reza Akhgar
Volume 3, Issue 1 , March 2016, , Pages 42-48
Abstract
The present study shows that the eggshell powder can be used as a natural adsorbent for the removal of alizarin (1,2-dihydroxyanthraquinone) and 2-aminoanthraquinone from aqueous solutions. Experiments were carried out as a function of contact time, concentration, temperature, pH and dosage. The amount ...
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The present study shows that the eggshell powder can be used as a natural adsorbent for the removal of alizarin (1,2-dihydroxyanthraquinone) and 2-aminoanthraquinone from aqueous solutions. Experiments were carried out as a function of contact time, concentration, temperature, pH and dosage. The amount of dye uptake was found to vary with increasing initial solution pH and maximum adsorption was observed at pH=7. The equilibrium was attained in 30 min. The amount of dye uptake (mg/g) was found to increase with increase in dye concentration and contact time. The percent of adsorption was found to decrease with increase in amount of adsorbent. The data were fitted with the Langmuir and Freundlich equations to describe the equilibrium isotherms.
Zarrin Es’haghi; Fatemeh Moeinpour
Volume 1, Issue 2 , September 2014, , Pages 58-64
Abstract
An efficient separation-preconcentration procedure namely hollow fiber solid/liquid phase microextraction (HF-SLPME) was developed for determination of trace amounts of palladium in water samples by differential pulse voltammetry. In this method, a hybrid sorbent utilizing functionalized nanoparticles ...
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An efficient separation-preconcentration procedure namely hollow fiber solid/liquid phase microextraction (HF-SLPME) was developed for determination of trace amounts of palladium in water samples by differential pulse voltammetry. In this method, a hybrid sorbent utilizing functionalized nanoparticles incorporated in an organic solvent was used as the extractor phase. The nanoparticle dispersed in the organic solvent is held in the pores and lumen of a porous polypropylene hollow fiber. It is in contact directly with the aqueous donor phase. The influence of the various analytical parameters such as pH, kind and amounts of nanoparticle and matrix effects, sample volume, extraction time, etc. were studied for the quantitative recoveries of the analyte ions. Under the optimized experimental conditions, the calibration curves for Pd (II) was linear from 0.1 to 500 ng/mL. The relative standard deviation for seven replicate determinations of 0.1 mg/mL palladium in the standard solutions was 3.95 %. The detection limit based on 3Sb for Pd (II) in the standard solutions was 0.01 ng/mL. The proposed method has been applied for determination of trace amounts of palladium in the real water samples and satisfactory results were obtained.
Ghasem Karim-Nezhad; Sara Pashazadeh
Volume 2, Issue 2 , September 2015, , Pages 100-107
Abstract
In the present study, silver oxyfluoride modified silver electrode was employed to electrocatalytic oxidation of isoniazid. The process of oxidation and its kinetics were established by using cyclic voltammetry, chronoamperometry and amperometry techniques. The modified electrode shows a stable and linear ...
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In the present study, silver oxyfluoride modified silver electrode was employed to electrocatalytic oxidation of isoniazid. The process of oxidation and its kinetics were established by using cyclic voltammetry, chronoamperometry and amperometry techniques. The modified electrode shows a stable and linear response in the concentration range of 3×10−4 to 2.1×10−3 mol L-1 with a correlation coefficient of 0.9953. The overall number of electrons involved in the catalytic oxidation of isoniazid was found 4 electrons. The diffusion coefficient of 3.11×10−5 cm2 s-1 for isoniazid was also estimated using chronoamperometry study. It has been shown that using the silver oxyfluoride modified silver electrode, isoniazid can be determined by amperometry method with limit of detection of 3.85 µmol L–1. The method was successfully applied for analysis of isoniazid in solid pharmaceutical formulations. The results of the analysis suggest that the proposed method has promise for the routine determination of isoniazid in the products examined.
Sedigheh Kamran
Volume 3, Issue 2 , September 2016, , Pages 105-115
Abstract
Fe3O4 nanoparticles and their binary mixtures ([C8MIM]-Fe3O4) with 1-Octyl-3-methylimidazolium bromide were prepared and characterized as ionic liquid for using in the adsorption of phenylalanine, tryptophan, and tyrosine. The characteristics of [C8MIM]-Fe3O4 nanoparticles were investigated via ...
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Fe3O4 nanoparticles and their binary mixtures ([C8MIM]-Fe3O4) with 1-Octyl-3-methylimidazolium bromide were prepared and characterized as ionic liquid for using in the adsorption of phenylalanine, tryptophan, and tyrosine. The characteristics of [C8MIM]-Fe3O4 nanoparticles were investigated via using TEM, XRD and FTIR techniques. The pH of the point of zero charge (pHpzc) of both Fe3O4 and [C8MIM]-Fe3O4 were obtained based on the experimental curves corresponding to the immersion technique. Experimental results were obtained under optimum operational conditions of: nanoparticle amount of 0.015 g and a contact times of 5, 10, 15 minutes for tryptophan (Trp), tyrosine (Tyr) and phenylalanine (Phe), respectively, when initial concentration of each amino acid was 5.0×10−4 mol L−1. The isotherm evaluations revealed that the Freundlich model attained better fits to the equilibrium data than the Dubinin-Radushkevich model. The maximum obtained adsorption capacities of Tyr, Trp and Phe were 12.74, 3.55 and 35.62 mg amino acid per gram of adsorbent, respectively. The applicability of pseudo-first order and pseudo-second order kinetic models was estimated on the basis of comparative analysis of the corresponding rate parameters, equilibrium adsorption capacity and correlation coefficients. Furthermore, the adsorption processes were found endothermic. Both phenylalanine and tyrosine were desorbed from [C8MIM]-Fe3O4 nanoparticles by using NaOH aqueous solution with concentrations of 1.0 and 2.0 mol L−1, respectively. Tryptophan was completely desorbed in the presence of a mixture of 1.0 mol L−1 NaCl and 1.0 mol L−1 NaOH. The nanoparticles thus were recycled.
Jahanbakhsh Raoof; Mohammad Ali Karimi; Leila Asadian-Zarrinabadi; Mohaddeseh Amiri-Aref
Volume 1, Issue 1 , March 2014, , Pages 12-19
Abstract
The electrochemical oxidation and determination of tryptophan (Trp) and glutathione (GSH) in the presence of catechol as a homogeneous redox in the aqueous medium were investigated at the surface of a carbon paste electrode modified with multi-walled carbon nanotube (MWCNT-CPE) using cyclic voltammetry ...
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The electrochemical oxidation and determination of tryptophan (Trp) and glutathione (GSH) in the presence of catechol as a homogeneous redox in the aqueous medium were investigated at the surface of a carbon paste electrode modified with multi-walled carbon nanotube (MWCNT-CPE) using cyclic voltammetry (CV), double step potential chronoamperometry and differential pulse voltammetry (DPV) techniques. The results of differential pulse voltammetry showed two well-resolved anodic peaks for glutathione and tryptophan, which leads to voltammetric determination of each of them. The results shows the electrooxidation peak currents of GSH and Trp is linear in the concentration range of 2×10-6 M-5×10-5 M and 4×10-6 M-6×10-5 M, respectively. The kinetic parameters such as: the chemical reaction rate constant (kh) and transfer coefficient (α) were calculated 2.01×102 cm3 mol-1 s-1 and 0.31, respectively. Also, the apparent diffusion coefficient, Dapp, for GSH was found to be 1.95×10-6 cm2 s-1 in aqueous buffered solution. The proposed method was successfully applied for determination of glutathione and tryptophan in real sample using standard addition method.
Khaled Elsherif; Ashraf El Hashani; Ibrahim Haider
Volume 5, Issue 2 , September 2018, , Pages 31-38
Abstract
Biosorption of Cu(II) ions from aqueous solutions onto waste Tea and Coffee powder (WTCP) has been investigated in a batch biosorption process. The biosorption process was found to be dependent on pH of solution, initial metal ion concentration, biosorbent dose, and contact time. The experimental equilibrium ...
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Biosorption of Cu(II) ions from aqueous solutions onto waste Tea and Coffee powder (WTCP) has been investigated in a batch biosorption process. The biosorption process was found to be dependent on pH of solution, initial metal ion concentration, biosorbent dose, and contact time. The experimental equilibrium biosorption data were analyzed by Langmuir, Freundlich, Temkin and Dubinin ̶ Radushkevic isotherms models. The Langmuir model gave a better fit than the other three models by higher correlation coefficient, R2. The maximum biosorption capacities calculated from the Langmuir isotherm model were 526 and 417 mg/g, for coffee and tea, respectively at optimum conditions. The kinetic studies indicated that the biosorption process of the metal ions followed well pseudo-second-order model. According to the biosorption capacity, waste coffee and tea powder considered as an effective, low cost, and environmentally friendly biosorbent for the removal of Cu (II) ions from aqueous solutions.
Massoud Kaykhaii; Sayedeh Samaneh Hasheminasab; Sayyed Hossein Hashemi; Mojtaba Sasani
Abstract
In this research, Sistan sand was used as a natural and inexpensive sorbent for removal of cephalexin and tetracycline antibiotics from water and wastewater samples. For a concentration 60.0 mg L-1 of cephalexin, optimum removal conditions were: pH of the sample 3.0, adsorbent amount 1.0 g, contact time ...
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In this research, Sistan sand was used as a natural and inexpensive sorbent for removal of cephalexin and tetracycline antibiotics from water and wastewater samples. For a concentration 60.0 mg L-1 of cephalexin, optimum removal conditions were: pH of the sample 3.0, adsorbent amount 1.0 g, contact time 20.0 min, added amount of sodium chloride to adjust the ionic strength of the solution 7.0 g L-1. Langmuir isotherm was the best fitted model for this adsorption process and adsorbent capacity was calculated to be 0.26 g g-1. This adsorbent was able to remove up to 68.1% of cephalexin from wastewater. In case of tetracycline, for a 90.0 mg L-1 of the analyte, the optimum adsorption conditions were achieved at pH 8.0, 1.0 g of sorbent, contact time of 35.0 min and ionic strength of the solution as sodium chloride of 7.0 g L-1. The isotherm was best in agreement with Freundlich model. Adsorbent capacity was 0.76 g g-1 and up to 76.2% of this antibiotic could be removed from wastewater.
Milan Modi; Punit Parejiya; Nikunj Patel; Rakesh Sutariya
Volume 4, Issue 2 , September 2017, , Pages 33-41
Abstract
A rapid, selective and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) assay has been proposed for the determination of Clavulanic acid (CA) in human plasma using Diclofenac sodium as internal standard (IS). The analyte and IS were extracted from human plasma via ...
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A rapid, selective and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) assay has been proposed for the determination of Clavulanic acid (CA) in human plasma using Diclofenac sodium as internal standard (IS). The analyte and IS were extracted from human plasma via solid phase extraction and the chromatographic separation was achieved on Inertsil ODS-3, 50 x 4.6 mm, 5µ column under isocratic conditions. Detection of CA and IS was done by tandem mass spectrometry, operating in positive ionization and multiple reaction monitoring (MRM) acquisition mode. The protonated precursor to product ion transitions monitored for CA and IS were m/z 365.2→240.2 and 409.2→228.2, respectively. The method was fully validated as per the US FDA guidelines. The linear dynamic range of CA was 7.564 - 897.893 ng/mL. The intra-batch and inter-batch precision (%CV) was ≤ 14.1% while the mean extraction recovery was 84.48 % across quality control levels. It was successfully applied to a bioequivalence study of Cefdinir/CA (125 mg/62.5 mg) suspension formulation in 32 healthy Indian male subjects under fasting condition.
Fatemeh Sabermahani; Leyli Irannejad; Nosrat Madadi Mahani
Volume 5, Issue 1 , March 2018, , Pages 33-38
Abstract
Polyaniline/maghemite magnetic nanocomposite (PANI/γ -Fe2O3 MNC) was used as active agents for removal of lead ions from aqueous media. Chemical co-precipitation method was used to prepare the maghemite nanoparticles. Subsequently, the MNC was synthesized through polymerization of aniline. ...
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Polyaniline/maghemite magnetic nanocomposite (PANI/γ -Fe2O3 MNC) was used as active agents for removal of lead ions from aqueous media. Chemical co-precipitation method was used to prepare the maghemite nanoparticles. Subsequently, the MNC was synthesized through polymerization of aniline. It was characterized by FT-IR.The efficiency of this MNC was estimated for Pb (II) removal by using batch method. The results showed that optimum conditions for lead removal were found to be at pH of 6, adsorbent dosage of 0.04 g and equilibrium contact time of 90 min. The kinetic of adsorption system have been studied based on the assumption of a pseudo-second order rate law. The adsorption isotherms were examined. The Freundlich adsorption isotherm model was found to represent the equilibrium adsorption isotherm better than Langmuir isotherm. The thermodynamic studies indicated that the adsorption was spontaneous and endothermic process for lead.
Tahereh Rohani; Moghadase Yahyapoor
Volume 4, Issue 1 , March 2017, , Pages 34-39
Abstract
In this work, a new method was developed for the catalytic reduction of hydrogen peroxide at glassy carbon electrode modified with silver nanoparticles and multi-wall carbon nanotubes. Silver incorporated in this modified electrode acted as catalyst to reduce hydrogen peroxide. First, the electrochemical ...
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In this work, a new method was developed for the catalytic reduction of hydrogen peroxide at glassy carbon electrode modified with silver nanoparticles and multi-wall carbon nanotubes. Silver incorporated in this modified electrode acted as catalyst to reduce hydrogen peroxide. First, the electrochemical behavior of silver, incorporated in modified electrode, was studied. The results illustrated the adsorption-controlled reaction at the modified electrode. Then, the behavior of catalytic reduction of hydrogen peroxide at the modified electrode was investigated. A linear calibration graph was obtained for hydrogen peroxide over the concentration range of 4.04×10−3 – 1.5×10−6 molL-1. The detection limit for hydrogen peroxide was estimated 1.42×10−7 molL-1. The relative standard deviation of ten replicate measurements (performed on a single electrode at hydrogen peroxide concentration of 1.5×10-4 molL−1) was 2.36%. The proposed electrode was used for the determination of hydrogen peroxide in real samples which led to satisfactory results.
Mohammadreza Hadjmohammadi; Maede Asadi
Volume 2, Issue 1 , March 2015, , Pages 36-42
Abstract
A simple, inexpensive and efficient method was used for extraction and determination of Fexofenadine and Levocetirizine with three–phase hollow fiber liquid-phase microextraction and high-performance liquid chromatography. Several parameters influencing the extraction recoveries such as the nature ...
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A simple, inexpensive and efficient method was used for extraction and determination of Fexofenadine and Levocetirizine with three–phase hollow fiber liquid-phase microextraction and high-performance liquid chromatography. Several parameters influencing the extraction recoveries such as the nature of organic extraction solvent, pH of donor and acceptor phases, stirring rate, extraction time and salt addition to the sample solution (donor phase) were investigated and optimized. Under the optimized conditions (toluene as organic solvent, pHdonor = 2.5, pHacceptor = 12.0, stirring rate of 1000 rpm, extraction time of 30 min, with no salt addition), extraction recoveries were 64% for Fexofenadine and 79% for Levocetirizine. A good clean-up sample with excellent linearities in the range of 1–500 ng/mL for Fexofenadine (R2=0.997) and 0.6-600 ng/mlfor Levocetirizine (R2=0.998) were obtained. The limits of detection were 0.3 ng/mL for Fexofenadine and 0.2 ng/mL for Levocetirizine.
Alireza Mohadesi; Somayeh Parvaresh; Zarrin Eshaghi; Mohammad Ali Karimi
Abstract
A chemically modified glassy carbon electrode was developed using multi-walled carbon nanotubes covalently immobilized with 2,6-dichlorophenolindophenol. The immobilization of 2,6-dichlorophenolindophenol with multi-walled carbon nanotubes was characterized by UV–visible absorption spectroscopy ...
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A chemically modified glassy carbon electrode was developed using multi-walled carbon nanotubes covalently immobilized with 2,6-dichlorophenolindophenol. The immobilization of 2,6-dichlorophenolindophenol with multi-walled carbon nanotubes was characterized by UV–visible absorption spectroscopy and Fourier transform infrared spectroscopy, and was determined using cyclic voltammetry. The cyclic voltammetric response of 2,6-dichlorophenolindophenol grafted onto multi-walled carbon nanotubes indicated that it promoted the electrocatalytic, sensitive and stable determination of sulfide ions. Meanwhile, the dependence of response currents on the concentration of sulfide was also examined and was linear in the range of 1.8 µM – 2.5 mM. The detection limit of sulfide was 1.1 µM, and RSD for 10 and 1000 µM sulfide was 1.8 and 1.3 %, respectively. Many interfering species had little or no effect on the determination of sulfide. This procedure was applied for determination of sulfide in water samples.
Seyed Mohsen Sadeghzadeh; Rahele Zhiani; Ali Es-haghi
Abstract
Food waste is one of the main issues for international organisms. It is not only an ethical and economic issue but it also depletes the environment of limited natural resources. Among strategies suitable for fighting such challenge, intelligent packaging is an interesting tool to reduce waste derived ...
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Food waste is one of the main issues for international organisms. It is not only an ethical and economic issue but it also depletes the environment of limited natural resources. Among strategies suitable for fighting such challenge, intelligent packaging is an interesting tool to reduce waste derived from households and retailers. Colorimetric detection of biogenic amines, well-known criterions of food corruption, shows the main role for monitoring of food safety. A novel colorimetric sensor based on hydrolysis-induced mercury metallization reaction to tune the localized surface plasmon resonance (LSPR) adsorption of Au nanoparticles sensitive to total volatile basic nitrogen (TVBN) released from meat has been created for real-time supervision of meat quality. Sensors were kept in atmosphere of ammonia simulating which changed its colour with changing of pH. This is the case of highly volatile amines, produced in food spoilage, specifically in the deterioration of meat, for which the color development of the smart labels can be used as a visual test for food freshness.
mehdi mossaddegh; Hanif Kazerooni
Abstract
Generally, traditional bioanalytical methods including in vitro or ex vivo are associated with the limitations and drawbacks in the living systems analysis. However, the in vivo sampling technique is an excellent procedure to improve accuracy and performing the on–line and in–situ biological ...
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Generally, traditional bioanalytical methods including in vitro or ex vivo are associated with the limitations and drawbacks in the living systems analysis. However, the in vivo sampling technique is an excellent procedure to improve accuracy and performing the on–line and in–situ biological analyses. In this regard, solid–phase microextraction (SPME) as a simple, sensitive, solventless and noninvasive sample preparation technique has been considered by researchers in in vivo sampling, in recent years. This review briefly describes the use of in vivo SPME as a sample preparation method to study the living systems involving plants and animals (especially metabolomics and clinical researches). Also, biocompatible coatings and design innovations that use to enhance the sensitivity and functioning of the method have been investigated. Finally, the challenges facing the development in vivo SPME method are investigated and forthcoming trends for the better performance of bioanalytical method are offered.
Mehdi Hosseini
Abstract
A simple, green and sensitive method namely in situ solvent formation microextraction (ISFME) based on the use of 1-Octyl-3-methylimidazolium hexafluorophosphate [Omim][PF6] as an ionic liquid/green extractant (eco-friendly) was proposed for the concentration and deternination trace levels of cadmium(II) ...
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A simple, green and sensitive method namely in situ solvent formation microextraction (ISFME) based on the use of 1-Octyl-3-methylimidazolium hexafluorophosphate [Omim][PF6] as an ionic liquid/green extractant (eco-friendly) was proposed for the concentration and deternination trace levels of cadmium(II) ions as dangerous pollution agent in some real and saline samples. In this method, cadmium(II) ions was complexed with a Schiff bases ligand (L) as complexing agent and then extracted into an ionic liquid phase (secoundary phase) as green/eco-friendly extractant. After phases separation, the enriched Cd(II) ions in the secoundary phase was determined by flame atomic absorption spectrometer (FAAS). The effect of some analytical parameters were investigated and optimized. In the optimum conditions, the limit of detection (LOD), relative standard deviation (RSD) and enhancement factor (EF) were 0.05 µg L−1, 1.2% and 93, respectively. The accuracy of the method was confirmed by analyzing of a certified reference matter. Based on the obtained results, the method was successfully applied for the determination of cadmium(II) ions in several real and saline samples.
Haleh Omoori Sarabi; Zarrin Eshaghi; Javad Feizy
Abstract
For the first time, hollow fiber-solid liquid phase microextraction (HF-SLPME) using multiwalled carbon nanotube- ion exchange polyurethane foam (MWCNT-PUFIX) as adsorbent along with graphite furnace atomic absorption spectrometry was used to extract and measure the anticancer drug cisplatin. In this ...
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For the first time, hollow fiber-solid liquid phase microextraction (HF-SLPME) using multiwalled carbon nanotube- ion exchange polyurethane foam (MWCNT-PUFIX) as adsorbent along with graphite furnace atomic absorption spectrometry was used to extract and measure the anticancer drug cisplatin. In this method, the nanocomposite dispersed in octanol, is located in the pores and lumen of a porous polypropylene hollow fiber, was used as the extracting phase, this method benefits from high selectivity, high sample purification and enrichment, and reducing the consumption of organic solvents. The major factors affecting the extraction efficiency were investigated. The validation of the method was assessed by linearity, limit of detection, and accuracy calculated as relative recovery percent. The calibration curve was constructed under the optimal conditions was linear in the range of 1.00-55.0 µg/mL and the detection limit was 0.5 µg/mL. This method was successfully used for analysis of biological samples and the obtained results showed that the method has good accuracy and precision.
Sohrab Ershad; Lotf-Ali Saghatfroush; Fereshteh Azarm
Volume 3, Issue 1 , March 2016, , Pages 49-54
Abstract
A new optode for the sensitive and selective determination of copper (II) ion based on a change in absorption spectrum of a polymeric thin film in aqueous solution was proposed. A composed membrane of polyvinylchloride, different plasticizers and oleic acid as anionic additive was prepared. The influence ...
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A new optode for the sensitive and selective determination of copper (II) ion based on a change in absorption spectrum of a polymeric thin film in aqueous solution was proposed. A composed membrane of polyvinylchloride, different plasticizers and oleic acid as anionic additive was prepared. The influence of different plasticizers on sensitivity, linear range and selectivity of the membrane film were studied. Satisfactorily, analytical sensing characteristics, to determine of the copper ion in terms of the selectivity, reversibility and reproducibility in a good detecting range were obtained. In addition, the optical film responds to copper (II) ion, irreversibly, over a wide dynamic range 3.1×10-10 to 2.3×10-4 M with a response time ≈ 5 Min obtained confidently. The optode membrane was successfully, applied to determination of copper (II) ion in spiked samples.
Asghar Amiri; Marzieh Shabani
Volume 2, Issue 2 , September 2015, , Pages 108-111
Abstract
Recent studies have reported that metal sulfide nanoparticles had potential adverse effects. In this research, lead (II) sulfide nanoparticles have been synthesized under different reaction conditions. Scanning electron microscopy and X-ray diffraction were used to characterize the particle size ...
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Recent studies have reported that metal sulfide nanoparticles had potential adverse effects. In this research, lead (II) sulfide nanoparticles have been synthesized under different reaction conditions. Scanning electron microscopy and X-ray diffraction were used to characterize the particle size and morphology. Distribution, accumulation and toxic effects of nanoparticles on rats as a biological model were studied. Lead (II) sulfide nanoparticles (less than 50 nm in diameter) were administered orally in two doses (15 or 60 mg/Kg body weight/day) to Wister rats for 28 consecutive days. Lead concentrations and iron parameters in soft tissues were measured using inductively coupled plasma optical emission spectroscopy. The lead levels were highest in the liver, followed in decreasing order by the levels in the spleen, kidney and brain. There were no significant levels of lead in kidney and brain at low dose of administration. Iron concentration was lowest in the group that had the highest lead level, which is probably due to an interference that could take place by lead through iron uptake mechanism.
