Vahid Vahid Fard; Keivan Shayesteh; Pourya Abbasi; Mohammad Javad Khani
Abstract
Removal of cobalt from zinc electrolyte solution is one of the most important and difficult steps in zinc production using hydrometallurgy method. The impact of initial concentrations of cobalt, manganese, and Fe and amounts of potassium permanganate on the efficiency of cobalt removal by potassium permanganate ...
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Removal of cobalt from zinc electrolyte solution is one of the most important and difficult steps in zinc production using hydrometallurgy method. The impact of initial concentrations of cobalt, manganese, and Fe and amounts of potassium permanganate on the efficiency of cobalt removal by potassium permanganate from zinc electrolyte solution was investigated in this research. The results indicated that the higher the initial concentration of cobalt, manganese, and Fe is, the lower the cobalt removal amount will be; however, as the amount of potassium permanganate increases, the efficiency of cobalt removal will enhance. It was also found that, in order to make a permissible level of the dissolved cobalt, the consumption of potassium permanganate should be increased as the concentration of cobalt, Fe, and manganese increases. If the concentration of manganese is more than 500 mg/L, it can impact the reduction of the efficiency of cobalt removal to a great extent; but when the initial concentration of cobalt is high, the significance of the impact of the initial amounts of manganese would decrease. Additionally, if the manganese concentration is less than 200 mg/L, the optimal removal of cobalt (less than 2 ppm) will not occur under any circumstances. The results also indicate that if the potassium permanganate concentration is 1 g/L or lower, the Fe ions in the solution will drastically reduce the cobalt removal efficiency.
Robab Mohammadi; Milad Alizadehlarijan
Abstract
In this research, Fe3O4 and Fe3O4/Graphene materials were prepared and characterized via different techniques such as X-ray diffractometer (XRD), Vibrating Sample Magnetometer (VSM), and energy-dispersive X-ray spectroscopy (EDX). The efficiency of prepared samples were investigated by elimination of ...
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In this research, Fe3O4 and Fe3O4/Graphene materials were prepared and characterized via different techniques such as X-ray diffractometer (XRD), Vibrating Sample Magnetometer (VSM), and energy-dispersive X-ray spectroscopy (EDX). The efficiency of prepared samples were investigated by elimination of methylene blue as a cationic dye from aqueous solutions via different methods such as adsorption, photodegradation and sonodegradation processes. The results indicated that the degradation rate of methylene blue by Fe3O4/Graphene nanocomposite under sonocatalytic process was considerably higher than the adsorption and photocatalytic procedures. Sonocatalytic degradation of methylene blue by Fe3O4/Graphene nanocomposite could be explained by the mechanisms of hot spots and sonoluminescence. The degradation pathways between sonocatalytic oxidation and methylene blue solution was described. The results showed that the conjugate structure of nitrogen-sulfur heterocyclic material was broken and aromatic ring was oxidized to open the ring. Methylene blue molecules were finally mineralized to H2O and CO2 in the sonocatalytic degradation process. Furthermore, the figures-of-merit based on electric energy consumption (electrical energy per order (EEO)) were estimated in the degradation of methylene blue in the presence of Fe3O4/Graphene nanocomposite. The results showed that less energy is consumed during the sonodegradation of methylene blue in the presence of Fe3O4/Graphene nanocomposite in comparison with photodegradation procedure.
Hassan Karami; Seyyed Kazem Kazemi
Abstract
The work is a feasible study about the performance of woody skin and outer soft shell of Hazelnut for the removal of lead ions from water. The Hazelnut woody skin and soft outer shell are crushed by an innovative ball mill to prepare micro and nano powders. TEM images show that the produced nano powder ...
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The work is a feasible study about the performance of woody skin and outer soft shell of Hazelnut for the removal of lead ions from water. The Hazelnut woody skin and soft outer shell are crushed by an innovative ball mill to prepare micro and nano powders. TEM images show that the produced nano powder includes uniform nanoparticles with 8-10 nm average diameters. The produced nanoparticles were used as a suitable and effective biosorbent to remove lead ions from water. Experimental data shows that the adsorption of lead ions on the surface of hazelnut skin nanoparticles is acceptably fitted to Langmuir isotherm model. Based on the Langmuir isotherm, a maximum adsorption capacity of 91 mg g-1 is achieved for adsorption of lead ions on the surface of hazelnut skin nanoparticles. The obtained results showed that the best removal of lead ions can be done under conditions includes 50 ml initial solution, pH=4, 120 mg L-1 initial concentration of lead ions per 70 mg biosorbent for contact time of 20 minutes at room temperature. The adsorbed ions are easily eluted by 1.5 ml 0.7 M HNO3 solution. Under the optimal conditions, preconcentration factor of 200, %RSD of less than 5% with detection limit of 100 ppb are obtained. The effects of some interfering ions such as Fe2+, Cu2+, Mg2+, Zn2+, Mn2+ and Ni2+ on the removal efficiency of lead ions were studied. The presented method is successfully applied for removal and determination of lead ions from real samples.
Zahra Nazari; Zarrin Eshaghi
Abstract
In this study, an electrochemical sensor for simultaneous measurement of morphine and fentanyl based on a modified pencil graphite electrode with a semiconductor nanocrystalline structure was developed.The first layer of the sensor has a core of thioglycolic acid-bonded cadmium selenidequantum dot (TGA-CdSe), ...
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In this study, an electrochemical sensor for simultaneous measurement of morphine and fentanyl based on a modified pencil graphite electrode with a semiconductor nanocrystalline structure was developed.The first layer of the sensor has a core of thioglycolic acid-bonded cadmium selenidequantum dot (TGA-CdSe), surrounded by a second layer, zinc sulfide quantum dot (ZnS). Functionalized carbon nanotubes (FCNT) have also been used to reinforce the sensor structure (TGA-CdSe/ZnS@FCNT). Measurements were performed by differential pulse voltammetry (DPV) and cyclic voltammetry (CV).The synthesis of nanostructures was confirmed by FTIR, EDX, SEM and XRD. In order to optimize the effective factors in the performance of this sensor, the Taguchi orthogonal array (OA16) design has been utilized. TheCV voltammograms showed irreversible oxidation peaks at potentials of 0.9 V and 0.38 V for fentanyl and morphine respectively. The transfer coefficients (α) of 0.96for morphine and 0.95 for fentanyl obtained. The diffusion coefficients gained on the electrode surface by chronoamperometrywere 3.84×10-6cm2 s-1and1.615×10-6cm2s-1 for morphine and fentanyl, respectively. Under optimal conditions, the linear concentration range and detection limit for morphine were 0.08-100 μM, and 0.024 μM. For fentanyl two linear ranges of 0.02-8μM, 8-100 μM and 0.006 μM were obtained. The fabricated sensor can be well used for the simultaneous measurement of morphine and fentanyl in biological samples with acceptable relative recoveries in the range of 98.3-102.
Alaa S. Amin; Hesham El-Feky
Abstract
A highly selective optical sensor for V(IV) ions was established depended on entrapment of a sensitive reagent, 5-(2`,4`-dimethylphenylazo)-6-hydroxy-pyrimidine-2,4-dione (DMPAHPD), in a silica sol–gel thin film coated on a glass substrate. The thin films fabricated depended on tetraethoxysilane ...
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A highly selective optical sensor for V(IV) ions was established depended on entrapment of a sensitive reagent, 5-(2`,4`-dimethylphenylazo)-6-hydroxy-pyrimidine-2,4-dione (DMPAHPD), in a silica sol–gel thin film coated on a glass substrate. The thin films fabricated depended on tetraethoxysilane (TEOS) as precursor, sol–gel of pH = 2.5, water: alkoxyde ratio of 4: 1 and DMPAHPD concentration of 2.5 × 10−4 M. The effect of sol–gel parameters on sensing behavior of the fabricated sensor was also illustrated. The fabricated sensor can be used to detect V(IV) ion with an outstanding high selectivity over a wider dynamic range of 5.0–145 ng mL−1 and a detection limit of 1.35 ng mL−1. It also recorded reproducible results with relative standard deviation of 1.75% and 1.02% for 20 and 70 ng mL−1 of V(IV), respectively, along with a fast response time of two min. Total vanadium was determined after reduction of V(V) to V(IV) using ascorbic acid as reducing agent. The V(V) amounts were estimated by subtracting the concentration of V(IV) from the total vanadium concentration. Interference studies reported a good selectivity for V(IV) with trapping DMPAHPD into sol–gel matrix and appropriately adjusting the structure of doped sol–gel. The proposed sensor was compared with others and was applied to define vanadium in different environmental samples with good results.
Kobra Moteabbed; Jafar Burromandpiroze; Vahid Zare-Shahabadi; Soheil Sayyahi
Abstract
In this study, we used a prepared from chitosan-capped AuNPs for the determination of trace amount acetaminophen drug in various matrices such human fluids by kinetic spectrophotometric method. The calibration curve was linear in the range of (0.05 to 10.0 µg L−1). The standard deviation ...
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In this study, we used a prepared from chitosan-capped AuNPs for the determination of trace amount acetaminophen drug in various matrices such human fluids by kinetic spectrophotometric method. The calibration curve was linear in the range of (0.05 to 10.0 µg L−1). The standard deviation of (1.9%), and detection limit of the method (0.05 µg L−1 in time 6 min, 325 nm) were obtained for Sensor level response chitosan-capped AuNPs with (95%) confidence evaluated. Observed outcomes confirmed the suitability recovery, and a very low detection limit for measuring the acetaminophen drug. The method introduced to measure acetaminophen drug in real samples such as urine, and blood can be used for other drugs, and hospital samples.
Fatemeh Moeinpour; Danial Moodi; Haleh Sarabi-Omoori; Zarrin Eshaghi
Abstract
The aim of the present study was to develop electrochemical sensors based on pencil graphite electrode modified with green-caped ZnO, CdO nano particles and potassium tetra chloroplatinate (II), for a simple and fast simultaneous microextraction and determination of Aspirin (ASA) and Ibuprofen (IBU). ...
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The aim of the present study was to develop electrochemical sensors based on pencil graphite electrode modified with green-caped ZnO, CdO nano particles and potassium tetra chloroplatinate (II), for a simple and fast simultaneous microextraction and determination of Aspirin (ASA) and Ibuprofen (IBU). The nanoparticles were initially synthesized by the use of four vegetable extracts including garlic, onion, green onion and cabbage. The fabricated nanoparticles and platinum were then deposited on the surface of a pencil graphite electrode and was used as a working electrode in a three electrodes system. The Taguchi experimental design was employed for investigating the effects different parameters. For this purpose, a Taguchi L16 orthogonal array (OA) design was applied and the results were confirmed by the ANOVA test. The electrochemical behavior of ASA and IBU at the modified electrodes, were studied. The calibration curves were linear in the range of 5.17to 134.0 µg.mL-1 and 3.13 to 231.0 µg.mL-1 for ASA and IBU respectively. The limits of detection for ASA and IBU was calculated to be 0.50 and 0.42 µg.mL-1 respectively. The modified sensor showed good performance for simultaneous analysis of ASA and IBU in biological and pharmaceutical samples.
Mahboubeh Masrournia; Marjan Shahinfar; Radhwan Alsaeedi; Zahra Ahmadabadi
Abstract
In this paper, liquid phase microextraction technique based on deep eutectic solvent was used for preconcentration of trace levels of Cu2+ followed by its determination by flame atomic absorption spectrometry (FAAS). 8-Hydroxy quinolone (oxine) was used as a complexing agent and the mixture of choline ...
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In this paper, liquid phase microextraction technique based on deep eutectic solvent was used for preconcentration of trace levels of Cu2+ followed by its determination by flame atomic absorption spectrometry (FAAS). 8-Hydroxy quinolone (oxine) was used as a complexing agent and the mixture of choline chloride-phenol with a mole ratio of 1:3 was used as an extraction solvent. By using ultrasonicated dispersive liquid phase microextraction technique, the extraction solvent was dispersed in the sample solution and extracted the hydrophobic complex in a short time. Different parameters affecting the relative recovery including pH of sample solution, concentration of complexing agent, mole ratio of extraction solvent component, volume of extraction solvent, extraction time and volume of aprotic solvent (tetrahydrofuran) were completely investigated and optimized. Under the optimum conditions, the calibration curve was linear in the range of 20-300 µg L-1 Cu2+ with a limit of detection of 4.5 µg L-1 Cu2+ (n=8). Also, the relative standard deviation based on seven replicate analysis of solution containing 50 µg L-1 Cu2+ was 3.1%. Finally, the proposed efficient, rapid and green liquid phase microextraction was successfully used for determination of trace levels of Cu2+ in different water samples.
Mina Akbarpour; Azizollah Nezhadali
Abstract
A head space solid-phase microextraction (HS-SPME) method coupled to gas chromatography/mass spectrometry (GC/MS) has been developed and applied for profiling of volatile compounds released from Ocimum sanctum L. during plant growth. Three types of different SPME fibers including polydimethylsiloxane ...
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A head space solid-phase microextraction (HS-SPME) method coupled to gas chromatography/mass spectrometry (GC/MS) has been developed and applied for profiling of volatile compounds released from Ocimum sanctum L. during plant growth. Three types of different SPME fibers including polydimethylsiloxane (PDMS),divinylbenzene/carboxen/polydimethylsiloxane(DVB/CAR/PDMS),carboxen/polydimethylsiloxane(CAR/PDMS) and carbowax/polyethylene glycol (CW/PEG) were used as an adsorption phase and the best extraction was achieved with the mixed fiber 2. A gas chromatography coupled with mass spectrometer was employed for identification of the volatiles extracted from the head space of sampling vials by SPME. As a result, 23 compounds were detected using this method. Esdragol (70.33-90.57%), L-carrol ( 0.07-4.66%), α-citral (0.28-6.76%), caryophyllene ( 0.33-2.12%), β-citral (0.14-9.63%) and methyl eugenol (0.33-3.11%) were dominate volatile components, the relative content of which was found to enable differentiating between the seasonal examined. The oxygenated terpens were the most aroma compounds of O. sanctum L. in head space of the sample vial.
Majid Haji Hosseini
Abstract
In the present study a combined analytical method involving ultrasonic extraction (USE) and headspace liquid phase micro extraction (HS- LPME) was used to extract methyl tert-butyl ether (MTBE) in fish tissue for analysis by gas chromatography (GC). Extraction of MTBE from 2 g of fresh fish tissue was ...
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In the present study a combined analytical method involving ultrasonic extraction (USE) and headspace liquid phase micro extraction (HS- LPME) was used to extract methyl tert-butyl ether (MTBE) in fish tissue for analysis by gas chromatography (GC). Extraction of MTBE from 2 g of fresh fish tissue was performed by ultrasonication for 10 min (in 25 ºC after 3.5 h maceration) in the glass barrel that was filled with water and sealed. Headspace solvent microextraction was done for the extraction of MTBE after centrifuge of sonicated sample. The optimized method (under the optimal experimental conditions: ultrasonic extraction time: 10 min, ultrasonic extraction temperature: 25 °C, fish particle size: a particle of 2 grams, media: distilled water, maceration time: 3.5 h and centrifuge of sonicated sample: 2500 rpm in 15 ˚C for 10 min) had good linearity (R2 >0.99) over the range 0.5- 50 µg g-1, and showed satisfactory level of precision, with RSD values in the range of 1.1 to 9.7 %. The LOD about 0.2 µg g-1 was obtained.
Javad Feizy; Sima Ahmadi; Moslem Jahani; R. Lakshmipathy
Abstract
The present investigation reports a quantitative analysis of metals in the saffron samples collected from seven different saffron production areas in the Khorasan Razavi province, Iran. Khorasan Razavi is the leading producer of saffron in Iran, and more than 95% of the global production of this expensive ...
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The present investigation reports a quantitative analysis of metals in the saffron samples collected from seven different saffron production areas in the Khorasan Razavi province, Iran. Khorasan Razavi is the leading producer of saffron in Iran, and more than 95% of the global production of this expensive spice is attributed to Iran. Since environmental pollution is increasing, saffron is contaminated with various organic and inorganic contaminants such as heavy metals. Twenty-one saffron samples were collected in the flowering season of 2018 and analyzed for metal content. The concentration of microelements and heavy metals including Zn, Fe, Ca, Mn, Mg, Na, K, Pb, Cd, Cu, and Cr was determined in the samples collected from three farms in each production area with graphite furnace and flame atomic absorption spectroscopy. The results revealed that the collected saffron stigmas contain a wide range of minerals and heavy metals with different concentrations. Potassium is the most abundant element, and Cd had the least concentration in the saffron. It can be concluded that ecological management plans such as reducing chemical fertilizers and improving organic fertilizers can decline the extent of heavy metals in the saffron.
Mohammad Mazloum-Ardakani; Hamed Arabi; Zahra Alizadeh; Mahnoosh Haghshenas; Fatemeh Farbod; Sahar Saadat HosseiniKhah; Bibifatemeh Mirjalili
Abstract
In this research, a novel modified glassy carbon electrode (GCE) was successfully fabricated with a tri-component nanocomposite consisting of 5-(3,4-dihydroxyphenyl)8,8-dimethyl-2-(methyl thio)-7,8,9,10-tetrahydropyrimido [4,5-b]quinolone-4,6(3H,5H)-dione (PQ23) and Nitrogen-doped reduced graphene oxide ...
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In this research, a novel modified glassy carbon electrode (GCE) was successfully fabricated with a tri-component nanocomposite consisting of 5-(3,4-dihydroxyphenyl)8,8-dimethyl-2-(methyl thio)-7,8,9,10-tetrahydropyrimido [4,5-b]quinolone-4,6(3H,5H)-dione (PQ23) and Nitrogen-doped reduced graphene oxide aerogel/molybdenum oxide nanorods (PQ23/N-doped-rGO/MoO2 /GCE) as sensing platform toward hydrazine (HDZ). The nanocomposite is characterized by MAP analysis, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Through electrochemical investigations, the electron transfer coefficient between PQ23 and the N-doped-rGO/MoO2 /GCE (glassy carbon electrode which was modified with reduce graphene oxide decorated by molybdenum oxide nanorods) and the apparent charge transfer rate constant, ks, and diffusion coefficient (D) were calculated. Electrochemical behavior and electrocatalytic activity of the nanocomposite modified GCE were studied by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). Under the optimum experimental condition, the designed sensor exhibited high sensitivity and suitable selectivity for hydrazine oxidation, enabling the detection of hydrazine with a linear range of 25.0-1000.0 µM and a good detection limit (3σ) was 4.2 µM. The designed electrochemical sensor shows good repeatability, reproducibility, and acceptable stability with an RSD less than 3.2%.
Hossein Tavalali; Abolfath Parhami; Mohammad Ali Karimi; Jamshid Askari
Abstract
In this study, a novel mixed ligand (Dithizone-Co(II)-Alizarin red S: DTZ-Co-ALR-) ensemble is designed and developed ultra-sensitive, and highly selective to UV-Vis absorption and for naked-eye detection of Arginine (Arg), and Glutathione (GSH). The out coming high sensitivity and selectivity for new ...
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In this study, a novel mixed ligand (Dithizone-Co(II)-Alizarin red S: DTZ-Co-ALR-) ensemble is designed and developed ultra-sensitive, and highly selective to UV-Vis absorption and for naked-eye detection of Arginine (Arg), and Glutathione (GSH). The out coming high sensitivity and selectivity for new receptor (DTZ-Co(II)-ALRs-Arg) was attained by adding Glutathione. The indicator is released due to its displacement from the mixed ligand (DTZ-Co-ALRs-Arg) by Glutathione and the change in absorbance may be due to the further complexation of GSH with the additional coordination sites present in the Arg bonded with the mixed ligand (DTZ-Co-ALRs). The label-free DTZ-Co-ALRs receptor provided sensitive and selective detection of L-Arginine, and Glutathione with detection limits of 0.03, and 0.009µmol L-1, respectively. The protocol especially offers high selectivity for the determination of Arg, and GSH among amino acids found in real samples. Moreover, the investigation of the logic behavior of the proposed DTZ-Co-ALRs receptor indicated its capability of functioning as an INHIBIT-type colorimetric chemosensor with the chemical inputs and UV-Vis absorbance signal as the output. This mixed ligand receptor could also behave as a molecular “keypad lock” with the correct sequential addition of Arg and GSH inputs.
Mehdi Taghdiri; Farzaneh Ghanei; Marzieh Ardakania; Hossein Banitaba; Hossein Aarabi Ardakani
Abstract
Two new organic hybrids of phosphomolybdic acid (PMA) were prepared by means of hexamine (HMT) and HMT-Ni2+ complex. The effects of hybridization of HMT and Ni2+ were investigated on the photocatalytic activity of PMA. Characterization of hybrids were carried out by elemental analyses, Fourier transform ...
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Two new organic hybrids of phosphomolybdic acid (PMA) were prepared by means of hexamine (HMT) and HMT-Ni2+ complex. The effects of hybridization of HMT and Ni2+ were investigated on the photocatalytic activity of PMA. Characterization of hybrids were carried out by elemental analyses, Fourier transform infrared spectroscopy, powder X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry. The band gaps of PMA, phosphomolybdate-hexamine (PMA-HMT) and phosphomolybdate-hexamine-nickel (PMA-HMT-Ni) were determined from the diffuse reflectance spectra using the Tauc plots. Dye adsorption and photocatalytic properties of PMA-HMT and PMA-HMT-Ni hybrids were examined by studying the decolorization of model dyes methylene blue (MB), rhodamine B (RhB) and mixtures of MB and methyl orange (MO) solutions. The results show that the band gap of PMA-HMT-Ni is narrower and hence, its photocatalytic activity is higher for the degradation of dyes under sunlight irradiation. Mechanism of photodegradation was studied by adding scavengers. Removal is via combination of adsorption and then photocatalytic degradation through oxidation by radicals.
Farideh Shamsi; Ali Sheibani; M. Reza Shishehbore
Abstract
In this study, a dispersive magnetic solid phase extraction (DMSPE) was described by combining graphene oxide (GO) with Fe3O4 and CuO (Fe3O4@CuO&GO) for extraction and preconcentration of aspirin (ASP) in biological samples. The morphology and structure of the prepared nanocomposite was characterized ...
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In this study, a dispersive magnetic solid phase extraction (DMSPE) was described by combining graphene oxide (GO) with Fe3O4 and CuO (Fe3O4@CuO&GO) for extraction and preconcentration of aspirin (ASP) in biological samples. The morphology and structure of the prepared nanocomposite was characterized and analyzed by XRD, SEM and FTIR techniques. Ion mobility spectrometry (IMS) method equipped to a corona discharge ionization source was exploited to determine ASA. The extraction parameters (desorption solvent, pH, adsorbent amount, extraction time and temperature) and also the operational parameters of IMS were investigated and optimized. Under the optimum conditions, the DMSPE–IMS method provided a linear range 6.0–40.0 ng for ASA with coefficient of determination R2 = 0.99. The LOD and LOQ values were 0.9 and 3.0 ng for ASA, respectively. The repeatability of developed method was evaluated as relative standard deviation (RSD% = 2.7). The proposed method was also used to determine ASA in human plasma and serum as biological samples, which recovery results were within 89.0–100.0%.
Majid Haji Hosseini
Abstract
Minimizing a drug’s size is an effective means to increase its dissolution and hence the bioavailability, which can be achieved by specialized dispersion techniques. This strategy results in increased surface area, the potential to increase saturation solubility, and decreased diffusional distance, ...
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Minimizing a drug’s size is an effective means to increase its dissolution and hence the bioavailability, which can be achieved by specialized dispersion techniques. This strategy results in increased surface area, the potential to increase saturation solubility, and decreased diffusional distance, all of which lead to an increase in the extent and the rate of dissolution. The purpose of this research was to develop antisolvent precipitation system for the preparation of stable aqueous suspension from ultrafine particles of lamotrigine as a poorly water soluble drug. Use of high stream velocities enhances mixing of lamotrigine acetic acid solution with water, that water was containing of polymer or surfactant inhibitor, was prepared a solution with lamotrigine particles with size <250 nm. Several experimental parameters, such as the type of stabilizer, the concentration of stabilizer, the concentration of salt (NaCl) and the concentration of drug that affected on size of the particles were optimized by undertaking Taguchi experimental design methodology. Using different analytical tools, such as X-ray diffraction (XRD), dynamic light scattering (DLS) and differential scanning calorimetry (DSC), the effect of different parameters on the size of the produced particles was investigated. The results showed that the best stabilizer is PEG (poly ethylene glocal) 4 mg ml-1, concentration of lamotrigine 10 mg ml-1 and NaCl concentration: 2 mol L-1, that the produced submicrometer suspension had a mean particle size of 248.5 nm and size distribution 243.9 – 252.2 nm.
Amirkhosro Beheshti; Tahereh Rohani; Sayed Zia Mohammadi; Maryam Dadkhodazadeh
Abstract
Molybdenum disulfide as a transition metal dichalcogenide was prepared by a hydrothermal method and hybridized with graphene oxide (MoS2/GO). The as-prepared materials were investigated by Fourier transform infra-red spectroscopy (FT-IR), X-ray diffraction (XRD), energy dispersive X-ray elemental analysis ...
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Molybdenum disulfide as a transition metal dichalcogenide was prepared by a hydrothermal method and hybridized with graphene oxide (MoS2/GO). The as-prepared materials were investigated by Fourier transform infra-red spectroscopy (FT-IR), X-ray diffraction (XRD), energy dispersive X-ray elemental analysis (EDX) techniques as well transmission electron microscopy (TEM) image. The nanomaterial with its electrocatalytic properties was applied as an electro-nanocatalyst for loading on a glassy carbon electrode (MoS2/GO-GCE) for detection of carbamazepine as an anti-epileptic in real body samples. The simple and low-cost developed electrochemical sensor detected carbamazepine with a vast linear concentration range(30-350nM), very low detection limit about 6.0nM and significant sensitivity equal to 0.134µA/nM.
Fatemeh Nourpishe; Ali Asghar Amiri; Ali Sheibani; Masoud Reza Shishehbore
Abstract
In this study, a simple and sensitive method was developed for pre-concentration of spirotetramat (SPT) using the ionic liquid-based dispersive liquid-liquid microextraction. After extracting of SPT into 1-butyl-3-methylimidazolium hexafluorophosphate (ionic liquid), the insecticide was injected into ...
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In this study, a simple and sensitive method was developed for pre-concentration of spirotetramat (SPT) using the ionic liquid-based dispersive liquid-liquid microextraction. After extracting of SPT into 1-butyl-3-methylimidazolium hexafluorophosphate (ionic liquid), the insecticide was injected into HPLC system for determining. Under the optimum conditions, the developed method provided a linearity in the range of 0.05–2.0 µg mL-1 with R2= 0.9987, and also enrichment factor was 250. The detection limit and relative standard deviation of the developed method were 0.01 µg mL-1 and 2.7%, respectively. The proposed method was successfully applied to the pre-concentration and determination of SPT in spiked water samples with mean recoveries 94.0-96.0%.
Afroozeh Arabi; Alireza Mohadesi; Mohammad Ali Karimi; Mehdi Ranjbar
Abstract
In this study, a new Zeolite Al/Na (ZAN) was synthesized and characterized and then a new modified Carbon Paste Electrode with ZAN was made to determine Acetaminophen. Electrochemical studies using Linear Sweep Voltammetry and differential pulse voltammetry were used to determine electrochemical Acetaminophen ...
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In this study, a new Zeolite Al/Na (ZAN) was synthesized and characterized and then a new modified Carbon Paste Electrode with ZAN was made to determine Acetaminophen. Electrochemical studies using Linear Sweep Voltammetry and differential pulse voltammetry were used to determine electrochemical Acetaminophen . In the presence of Acetaminophen , modified electrode with ZAN shows a specific anodic peak at ~ 0.59 volts which is the result of using electrocatalytic oxidation of Acetaminophen . The determination limit of this method to measure Acetaminophen was 5.8 µM, the relative standard deviation for 7 repeated measurements was 1.1 % and linear range of the calibration to measure Acetaminophen was 10 up to 115 µM . for the characterization of ZAN nanostructures we used SEM (Scanning Electron Microscopy), DLS (Dynamic Light Scattering) and FT-IR (Fourier-Transform Infrared spectroscopy).
Mahdi Shahriarinour; Faten Divsar; Leila Youseftabar-Miri; Mohammad Banimahd Keivani
Abstract
Herein, the date palm pollen (DPP) grain was used as an amikacin (AMK) delivery vehicle for the first time. The AMK-loaded DPP was characterized using scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy, and surface area (BET) analysis. The pore size of DPP was obtained ...
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Herein, the date palm pollen (DPP) grain was used as an amikacin (AMK) delivery vehicle for the first time. The AMK-loaded DPP was characterized using scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy, and surface area (BET) analysis. The pore size of DPP was obtained 80–200 nm that was favorable to the drug uptake. The effects of pH and temperature were studied on the AMK loading in DPP. The study of drug release kinetics in phosphate buffer pH 7.4 at 37 oC suggested that the best kinetic model was the Higuchi equation. The antibacterial activity of AMK-loaded DPP (AMK-DPP) was investigated on Staphylococcus aureus and Escherichia coli bacteria by the agar-well diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for AMK were also carried out by using broth dilution method. The similarity of the results between MIC and MBC is considerable. However, an intense reduction in the MBC was observed after AMK loaded on palm pollen. Moreover, the AMK-DPP was utilized to improve the effectiveness of AMK against the dangerous forms of antibiotic-resistant bacteria. In general, AMK-DPP shows to be a new favorable method allowing in the management of Gram-positive and Gram-negative bacterial infections and may be further evaluated in in-vivo experiments.
Reyhaneh Rahnama; Saideh Fatemeh Shafeii Darabi; Mohammad Reza Jamali
Abstract
This work presents a fast, feasible, and sensitive method for the preconcentration and separation of cobalt in various real samples through the use of deep eutectic solvent-based dispersive liquid-liquid microextraction (DES-DLLME) in which deep eutectic solvent, methanol, and 1-(2-pyridylazo)-2-naphthole ...
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This work presents a fast, feasible, and sensitive method for the preconcentration and separation of cobalt in various real samples through the use of deep eutectic solvent-based dispersive liquid-liquid microextraction (DES-DLLME) in which deep eutectic solvent, methanol, and 1-(2-pyridylazo)-2-naphthole (PAN) were employed as extraction solvent, dispersive solvent, and complexing agent, respectively. Co concentration was measured by flame atomic absorption spectrometer. Effective parameters which may influence the extraction efficiencies (like type and volume of the dispersive and extraction solvent, pH, PAN concentration, and salt concentration) were examined and the optimal values were determined. The use of optimal conditions resulted in a limit of detection equal to 1.5 μg/L with a preconcentration factor of 40. RSD value, after measuring 20.0 μg/L of cobalt for 10 times, resulted in a value of 3.0 %. The methodʼ s accuracy and applicability were assessed through the evaluation of Co content in water certified reference materials and different agricultural and water specimen.
Hossein Tavallali; Abolfath Parhami; Abbas Karimpour; Mohammad Ali Karimi
Abstract
In this study, a new colorimetric sensor based on a couple of Congo Red (CR) and Alizarin Red S (ALRs) was ready for the detection of the carbonate in tracing levels in aqueous media. The linear range of carbonate derived from the results of this simple, selective, and rapid determination, was 1.21 × ...
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In this study, a new colorimetric sensor based on a couple of Congo Red (CR) and Alizarin Red S (ALRs) was ready for the detection of the carbonate in tracing levels in aqueous media. The linear range of carbonate derived from the results of this simple, selective, and rapid determination, was 1.21 × 10-6–9.51 × 10-5 mol L-1 with the detection limit of 1.31 × 10-7 mol L-1. In the examined cases, the concomitant cations, anions, and weak acids ( I-, Br-, F-, Cl-, SCN-, SO32-, S2O32-, S2O82-, OAc-, H2PO4-, HPO42-, NO3-, C2O42-, HCO3-, BrO3-, IO3-, Cit3-), ( K+, Na+, <1.5 × 10-4 mol L-1 ) did not curb the analysis by creating the disturbance of chemical ions. The recoveries shown in the range of 98.6–102.5% indicate the high validity of the method in water samples. Typically, this compound presented was affordable and fast, with a trouble-free operation, which can consider as a good carbonate receiver in running water greenhouses and arable land. In addition, due to the sophisticated modifications made to filter paper strips, this chemical sensor has the potential capacity to be used as a carbonate solid colorimetric indicator.
Tesfu Hailu; Yaw-Kuen Li; Merid Tessema
Abstract
An analytical method that offers fast response with a cheap instrument and simple sample preparation is an ideal technique that is required in scientific analysis. Electrochemical sensing is an analytical method that suits the above criteria to determine various samples using different electrode material. ...
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An analytical method that offers fast response with a cheap instrument and simple sample preparation is an ideal technique that is required in scientific analysis. Electrochemical sensing is an analytical method that suits the above criteria to determine various samples using different electrode material. Detection of chloramphenicol in agricultural products and drug samples using cheap electrode materials is highly required due to its wide application in agriculture. In this study a cost-effective activated SPCE was made electrochemically to determine chloramphenicol in eye-drop and pasteurized milk. The activation of the SPCE was straightforward and done by cycling 0.5 M KOH using LSV techniques. Surface imaging, spectroscopy, and electrochemical analyses showed that there is an effective formation of new functional groups during the activation. The activated SPCE gave a higher peak current for Chloramphenicol during the CV and SWV study using PBS pH 6.5 compared to that of the bare one. Utilizing the optimal SWV conditions, a linear calibration curve was obtained in the range of 0.05‒100 µM with quite a small detection limit of 20 nM. In addition to the high sensitivity, stability, and remarkable recovery, the excellent reproducibility makes the activated SPCE applicable in real sample analysis.
Vahid Vahid Fard; Keivan Shayesteh; Pourya Abbasi; Saeid Salimi
Abstract
One of the effective and important steps of the production of Zn in zinc factories is the purification step to remove the general impurities such as cobalt, nickel, and cadmium that can cause the creation of problems in the electrowinning process. In Iran's zinc factories, firstly, at the hot purification ...
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One of the effective and important steps of the production of Zn in zinc factories is the purification step to remove the general impurities such as cobalt, nickel, and cadmium that can cause the creation of problems in the electrowinning process. In Iran's zinc factories, firstly, at the hot purification step cobalt using the manganometry method, and then at the cold purification step nickel & cadmium using the cementation method with the help of Zn powder removed. In the aim of this study is evaluated the usability of the cementation method instead of the manganometry method. In this paper, important and effective parameters such as temperature, Zn powder dosage, mixing time, amount of trioxide antimony, copper sulfate effect, particle size, zinc ions concentration, mixing speed, and pH of zinc sulfate solution were studied and optimized. The Optimal state is obtained at 85 °C, pH= 4.5, 20 mg/L Sb2O3 concentration, 8 g/L zinc dust, 600 rpm mixing speed in 75 minutes. Decreasing the particle size of zinc dust increased the removal efficiency, but increasing the amounts of copper sulfate and zinc ions caused decreasing in efficiency. Results showed that cobalt, nickel, and cadmium removal efficiencies for the manganomery method were 99%, 0%, and 20% and for the cementation method were 99.5%, 99.7%, and 99.9%, respectively. Also, results indicated that the cementation method due to the increase of soluble zinc concentration; not being removes of manganese ions; simultaneous removal of impurities such as cobalt, nickel, and cadmium in a single step; and saving time and cost, has a higher performance rather than to manganometry method.
Amirkhosro Beheshti; Sayed Zia Mohammadi; Mahdokht Arjmand Kermani; Tahereh Rohani
Abstract
Addressed herein, Bismuth sulfide (Bi2S3) as a synthetic semiconductor chalcogenide applied in fabrication process of an aptasensor as a signal promoter for ultra-trace detection of aflatoxin B1(AFB1). The analytical signal was improved by using optimized amounts of Bi2S3 for electrode modification. ...
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Addressed herein, Bismuth sulfide (Bi2S3) as a synthetic semiconductor chalcogenide applied in fabrication process of an aptasensor as a signal promoter for ultra-trace detection of aflatoxin B1(AFB1). The analytical signal was improved by using optimized amounts of Bi2S3 for electrode modification. The AFB1 Aptamer single strand type(SSDNA) was simply immobilized on the cross section of a pencil lead through polydopamine layers. A wide concentration range of trace amounts of AFB1(0.3-630nM) was supported by the fabricated aptasensor (pencil/polydopamine@Bi2S3/aptamer) using differential pulse voltammetry. Simple fabrication and no needing to electrode refreshment were part of the advantages of the suggested aptasensor. Finally, very low resulted detection limit(0.04nM) with a great sensitivity (0.076µA/nM) and also appropriate stability and repeatability led to application of the aptasensor in real sample analysis such as wheat flour with brilliant recovery percentages.
