Hossein Tavallali; Gohar Deilamy-Rad; Abolfath Parhami; Sajedeh Lohrasbi
Volume 3, Issue 2 , September 2016, Pages 76-87
Abstract
A new diazo based, Congo-Red-Cu , was developed to act as an ‘Off–On’ reversible fluorescent probe for CN− detection. The changes in solvent composition has been shown greatly effective on selectivity of anion sensing through eliminate of sulfite interference. Increasing the amount ...
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A new diazo based, Congo-Red-Cu , was developed to act as an ‘Off–On’ reversible fluorescent probe for CN− detection. The changes in solvent composition has been shown greatly effective on selectivity of anion sensing through eliminate of sulfite interference. Increasing the amount of ethanol up to 5% (v/v) cause a dramatic development in selectivity of CN−via inhibitory effect on sulfite interferent. The chemosensing behavior of the CR-Cu has been demonstrated through fluorescence, absorption, visual color changes and FT-IR studies. This chemosensor (CR-Cu) has been shown a significant visible color change and displays a remarkable fluorescent switch on in the presence of CN− ions. The ‘in situ’ prepared CN− complexes of CR-Cu shows high “Turn-Off” selectivity toward CO32− over the other anions. The detection limits for CN− were 90 and 20 nM for colorimetric and fluorometric methods respectively, that is far lower than the WHO guideline of 1.9 µM. The complex of CN− with CR-Cu also displayed ability to detect up to 15 nM CO32− among other competing anions through a fast response time of less than 30 s which is much lower than most recently reported chemosensor probes. It has been possible to build an INHIBIT logic gate for two binary inputs viz., CN− and CO32− by monitoring the fluorescence emission band at 446 nm as output. The development of fluorometric an ‘‘Off–On’’ reversible switch for three chemical inputs Cu2+, CN− and CO32− ions and mimics a molecular level keypad lock.
Ali Yeganeh-Faal; Ghazal Parvan
Volume 3, Issue 2 , September 2016, Pages 88-95
Abstract
In this work, the first, intense and efficient POCL arising from the reaction of bis (2, 4, 6-trichlrophenyl) oxalate (TCPO) with hydrogen peroxide in the presence of N-[4-(dimethyl amino) benzylidene] benzoxide (Nitrone) as a new luminophor has been reported. The relationships between the chemiluminescence ...
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In this work, the first, intense and efficient POCL arising from the reaction of bis (2, 4, 6-trichlrophenyl) oxalate (TCPO) with hydrogen peroxide in the presence of N-[4-(dimethyl amino) benzylidene] benzoxide (Nitrone) as a new luminophor has been reported. The relationships between the chemiluminescence intensity and concentrations of all reagents were investigated. The quenching effect of some cations and compounds such as Fe3+, Co2+, Cu2+, Mn2+, Ni2+, Cd2+ ions and imidazole, L-Histidine, L-Tyrosine, D-(+)-Lactose, and D-(+)-Sucrose, on the POCL system were investigated. The KQ values were calculated from Stern–Volmer equation. It was found that the KQ values decreases in the order: Co2+ > Fe3+ > Cu2+ > Mn2+ > Ni2+ > Cd2+ and D-(+)-Lactose > Imidazole > L-Tyrosine > L-Histidine > D-(+)-Sucrose. Dynamic range and detection limit of all quencher were determined. Sucrose has the best dynamic range and low detection limit, so sucrose considered as an analyte and then the total sucrose extracted from sugar beet as real sample was measured by this proposed method. Dynamic range, detection limit, mean intra-day and inter-day relative standard deviation (RSD%) were 6.67×10-7- 1.20×10-5, 1.0×10-8, 5.62%, 7.25% (n=3) respectively. For accuracy determination, the percentage recovery was found 97.4%- 104.3%. All interferences were investigated and Co2+, D-(+)-Lactose had most interference. Sucrose percentage of the measured sample was 17 percent. These results are comparable with the results of the standard method to determine the sucrose and is acceptable.
Mohammad Mazloum-Ardakani; Azimeh Mandegari; Alireza Khoshroo Khoshroo; Saeed Masoum; Hadi Kargar
Volume 3, Issue 2 , September 2016, Pages 96-104
Abstract
In this work, response surface methodology in conjunction with central composite design for modeling and optimization of the influence of some process variables (polyvinyl chloride (F1), ionophore (F2), additive (F3) and plasticizer (F4) amounts), on the performance of polyvinyl chloride membrane lead ...
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In this work, response surface methodology in conjunction with central composite design for modeling and optimization of the influence of some process variables (polyvinyl chloride (F1), ionophore (F2), additive (F3) and plasticizer (F4) amounts), on the performance of polyvinyl chloride membrane lead (ІІ) ion-selective electrode is discussed. The slope of 29.1 ± 0.1 mV at the optimal amounts of polyvinyl chloride (0.0283 g), ionophore (0.0074 g), additive (0.002 g) and plasticizer (0.060 g) has been achieved. The electrode exhibited a linear potential response to lead (II) in the concentration range of 1.0 × 10-5 mol L-1 to 1.0 × 10-1 mol L-1 over pH range of 3.0 - 5.5. Greatly, the alternating current impedance technique was applied to investigate the response mechanism of the electrode. The results were obtained from electrochemical impedance spectroscopy shows a linear concentrations range of 1.0 × 10-6 mol L-1 to 1.0×10-1 mol L-1 and in comparison with potentiometry, the pH range increased to 2.5 − 6.0.
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.
Zahra Garkani-Nejad; Marziyeh Poshteh-Shirani
Volume 3, Issue 2 , September 2016, Pages 116-126
Abstract
A 2D image approach has been used to predict 13C NMR chemical shifts of β-naphthalene derivatives. In multivariate image analysis-Quantitative structure property relationship (MIA-QSPR) study, descriptors correlating with dependent variable are pixels (binaries) of 2D chemical structures; Variant ...
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A 2D image approach has been used to predict 13C NMR chemical shifts of β-naphthalene derivatives. In multivariate image analysis-Quantitative structure property relationship (MIA-QSPR) study, descriptors correlating with dependent variable are pixels (binaries) of 2D chemical structures; Variant pixels in the structures (substitutes) account to explained variance in the property (chemical shifts). A case study is carried out in order to predict 13C NMR chemical shifts of 10 carbon positions of 24 mono substituted β-naphthalenes. The resulted descriptors were subjected to principal component analysis (PCA) and the most significant principal components (PCs) were extracted. Then, MIA-QSPR modeling was done by means of principal component regression (PCR) and principal component –artificial neural network (PC-ANN) methods. A correlation ranking procedure is proposed here to select the most relevant set of PCs as inputs for PCR and PC-ANN modeling methods. Here, the 13C chemical shifts of studied compounds were predicted using density functional theory (DFT) calculations, too. The widely applied method of gauge included atomic orbital (GIAO) B3LYP/6-311++ G have been used. The performance of the GIAO was also compared with PCR and PC-ANN models. Results showed the superiority of the PC-ANN over GIAO and PCR models. Finally, 13C NMR chemical shifts of studied compounds were calculated using ChemDraw program.
Naser Samadi; Reza Ansari; Bakhtiar Khodavirdilo
Volume 3, Issue 2 , September 2016, Pages 127-136
Abstract
In this study chelating resins have been considered to be suitable materials for the recovery of Manganese(II) ions in water treatments. These modified resins were further reacted with 1,2-diaminoethan in the presence of ultrasonic irradiation for the preparation of a tridimensional chelating resin ...
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In this study chelating resins have been considered to be suitable materials for the recovery of Manganese(II) ions in water treatments. These modified resins were further reacted with 1,2-diaminoethan in the presence of ultrasonic irradiation for the preparation of a tridimensional chelating resin on the Nano scale for the recovery of Manganese II) ions from aqueous solutions. In this work we used copolymers derivate resin of poly (styrene – Alternative - Maleic Anhydride) and Atomic Absorption Spectroscopy for removing and determining Manganese(II) ions .The method is simple, sensitive, inexpensive and fast. The adsorption behavior of Manganese(II) ions were investigated by the synthesis of chelating resins at various pH’s. The prepared resins showed a good tendency for removing the selected metal ions from aqueous solution, even at acidic pH. Also, the prepared resins were examined for the removal of Manganese(II) ions from real samples such as industrial wastewater and were shown to be very efficient at adsorption in the cases of Manganese(II) ions . The pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetics equations were used for modeling of adsorption data and it was shown that pseudo-second-order kinetic equation could best describe the adsorption kinetics. The intra-particle diffusion study revealed that external diffusion might be involved in this case. The resins were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction analysis.
Fatemeh Sabermahani; Fatemeh Ziaaddini; Zahra Hassani
Volume 3, Issue 2 , September 2016, Pages 137-144
Abstract
Removal of Pb(II) and Zn(II) ions from aqueous solutions using naphthalene modified with 2-(3,4,5-trimethoxybenzylidene) malononitrile(TMBM) as synthetic adsorbent was investigated. It was characterized by FT-IR. Batch method was applied for testing of adsorption behavior. Adsorption experiments showed, ...
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Removal of Pb(II) and Zn(II) ions from aqueous solutions using naphthalene modified with 2-(3,4,5-trimethoxybenzylidene) malononitrile(TMBM) as synthetic adsorbent was investigated. It was characterized by FT-IR. Batch method was applied for testing of adsorption behavior. Adsorption experiments showed, the new sorbent has high selectivity and good adsorption for removal of lead and zinc ions from aqueous solutions. Equilibration time was 5 min for zinc and 15 min for lead. There was little effect of salt on removal of the ions. The maximum adsorption capacities for Pb(II) and Zn(II) were 88.5 and 38.9 mg g-1, respectively. The thermodynamic studies indicated that the adsorption was spontaneous, exothermic and endothermic process for lead and zinc, respectively.
Habibollah Khajehsharifi; Aida Solhjoo; Mohammad Mahdi Bordbar
Volume 3, Issue 2 , September 2016, Pages 145-152
Abstract
A selective optical sensor based on immobilization of Eriochrome Cyanine R for the determination of Al(III) ions in aqueous solution has been developed. The method is based on the spectrophotometric measurement of complex Eriochrome Cyanine R-aluminium at 537 nm. The sensing membrane is made of a triacetylcellulose ...
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A selective optical sensor based on immobilization of Eriochrome Cyanine R for the determination of Al(III) ions in aqueous solution has been developed. The method is based on the spectrophotometric measurement of complex Eriochrome Cyanine R-aluminium at 537 nm. The sensing membrane is made of a triacetylcellulose film containing Eriochrome Cyanine R colorimetric reagent immobilized as an ion pair with methyltrioctylammonium chloride. The response of the sensor is based on the Eriochrome Cyanine R absorbance decrease by the coordination of Al(III) ions. At pH= 6.0, the linear dynamic rangeis varied from 3.22×10-8 to 4.10×10-5 mol L-1 with a detection limit of 1.2× 10-8 mol L-1. A dynamic working range, detection limit, sensitivity, selectivity and the response time were discussed in detail. The response was pH dependent. The membrane responds to Al(III) ions irreversibly by changing color from pink to blue. The membrane was regenerated in less than 30 seconds with 0.1 mol L-1 EDTA solution and was ready for further measurements. The response time of the sensor was within 16 min depending on the concentration of Al (III) ions. The sensor response was found to have a repeatability and reproducibility of 1.62% and 3%, respectively. The sensor provides appropriate selectivity to Al(III) ions over transition metal cations, including Co(II), Ni(II), Fe(III), Cu(II) and Zn(II). The sensor has been used for the determination of Al(III) ions in potable water and aluminium – magnesium syrup.
