کاربردهای شیمی تجزیه
Mehdi Hosseini; Ebba Adnan Azooz
Abstract
The process of interesterification is one of the most important alternative ways of hydrogenating oils, which is of particular importance by providing the possibility of changing the functional, physical and chemical properties of oils in a favorable way. In this work, a pyrrolidinium-based acidic ionic ...
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The process of interesterification is one of the most important alternative ways of hydrogenating oils, which is of particular importance by providing the possibility of changing the functional, physical and chemical properties of oils in a favorable way. In this work, a pyrrolidinium-based acidic ionic liquid, N-methylpyrrolidinium bisulfate ([Mpyr][HSO4]), was synthesized and characterized, and its catalytic performance was evaluated in the interesterification (glycerolysis) of triglyceride oils. Common analyzing techniques such as Fourier Transfer Infra-red (FTIR) and Nuclear Magnetic Resonance (NMR) techniques were used to catalyst characterization, structure and different bonds evaluation in catalyst structure. The catalytic activity of [Mpyr][ HSO4] during interesterification process of soy oil as raw material of triglycerides and glycerol reagents was investigated. For evaluation of interesterification procedure, the effects of several important parameters such as reaction time and temperature, molar ratio of oil: glycerol and catalyst dosage were investigated. The results obtain showed that the catalyst of [Mpyr][HSO4] is suitable for the interesterification (glycerolysis) of triglyceride oils and it has a conversion of about 97.5%. A simple and accurate titration method was used to evaluate the rate raw materials conversion into ester. Furthermore, in order to reuse the catalyst, the catalyst can be reused up to seven times.
Mehdi Hosseini; Saeedeh Shakibafar; Tayebeh Saki
Abstract
An environmentally friendly and safe method has been developed for synthesizing Azoarene and Azoxyarene derivatives from readily available nitrobenzene. This process utilizes a deep eutectic solvent (DES) composed of choline chloride (ChCl) and zinc chloride (ZnCl2), which functions as both the catalyst ...
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An environmentally friendly and safe method has been developed for synthesizing Azoarene and Azoxyarene derivatives from readily available nitrobenzene. This process utilizes a deep eutectic solvent (DES) composed of choline chloride (ChCl) and zinc chloride (ZnCl2), which functions as both the catalyst and reaction medium. The methodology is leveraging the dual role of the ChCl/ZnCl2 DES. Using this approach, various Azo and Azoxy compounds have been successfully synthesized starting from nitrobenzene derivatives. The reaction proceeded efficiently under mild conditions (3 h at 60 °C). Notably, the system exhibited strong selectivity toward Azoxy products, which were obtained in high yields of 73-78%. In contrast, Azo derivatives were formed only in moderate yield (42%), highlighting the selective nature of the ChCl/ZnCl2 DES catalytic medium. This method not only simplifies the synthesis but also aligns with the principles of green chemistry, offering an efficient and sustainable approach to producing Azoarene and Azoxyarene derivatives.
Pourya Abbasi; Keyvan Shayesteh; Vahid Vahidfard; Mehdi Hosseini
Abstract
Nickel is one of the metallic impurities that should be removed from the electrolyte solution before the electrowinning of zinc. This study investigated the parameters affecting the process of nickel removal in an Iranian zinc smelter plant by the response surface methodology. According to the results ...
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Nickel is one of the metallic impurities that should be removed from the electrolyte solution before the electrowinning of zinc. This study investigated the parameters affecting the process of nickel removal in an Iranian zinc smelter plant by the response surface methodology. According to the results of experiments, the optimum condition for removal of nickel was obtained at temperature of 85 °C, the residence time of 60 minutes, zinc powder of 2.5 g/l, mixing speed of 500 rpm, and pH of 5. With regards to the resulting model from the Design-Expert software, the significant parameters were concentration, residence time, and temperature, respectively.
Mehdi Hosseini; Arman Naderi; Zeinab Fazli
Abstract
In the present research, the application of a functionalized ionic liquid with a specific role to simultaneous extraction and preconcentration of cadmium and lead ions in aqueous media by in-situ solvent formation microextraction (ISFME) technique was developed. The task-specific functionalized ionic ...
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In the present research, the application of a functionalized ionic liquid with a specific role to simultaneous extraction and preconcentration of cadmium and lead ions in aqueous media by in-situ solvent formation microextraction (ISFME) technique was developed. The task-specific functionalized ionic liquid of 3-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)ethyl)-1-methylimidazolium chloride ([Tamim][Cl]) as a complexing agent utilized for the formation of metal chelates with Cd(II) and Pb(II) ions in aqueous solutions. Finally, determination of concentrated or separated metal ions contents after dilution step was carried out by flame atomic absorption spectrometry (FAAS). To obtain optimum extraction conditions, analytical parameters including the various range of sample solution pH, chelating agent amount, ionic strength of solution, solution temperature and counter ion dosage were investigated. Furthermore, parameters represent figures of merit of the method such as limit of detection (LOD), relative standard deviation (RSD), linear dynamic range (LDR) and the enhancement factor (EF) were 0.64;0.76 µg L-1, 1.5;1.8%, 50-2500;50-2000 µg L-1 and 85;80 for cadmium and lead, respectively. The ability of the method for analyzing of real water and saline samples were evaluated and good results were obtained.
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.
Mehdi Hosseini; Mousa Soleymani; Hossein Dashti Khavidaki
Abstract
A simple, new and low-cost design of Li-air battery was introduced. An effective synthesized nanocatalyst for modifiying of air cathode, filter paper as a simple separator and a conductive ionic liquid namely 1-Octyl-3-methyl imidazolium hexafluorophosphate abbreviated [Omim][PF6] as a non-aqueous and ...
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A simple, new and low-cost design of Li-air battery was introduced. An effective synthesized nanocatalyst for modifiying of air cathode, filter paper as a simple separator and a conductive ionic liquid namely 1-Octyl-3-methyl imidazolium hexafluorophosphate abbreviated [Omim][PF6] as a non-aqueous and green electrolyte in battery were used. The MnFe2O4 nanoparticles (NP-MnFe2O4) which consistingof transition metal-metal oxide components was synthesized in our labrature. High discharge capacity, non-flammability of electrolyte, high reversibility, long lifetime and low over potential were observed in electrochemical tests of the battery. Synthesized nanocatalyst was characterized using XRD, FTIR and SEM techniques. XRD results show that a nanocatalyst have a particle sizes of 16-28 nm that distributed on cathode uniformly and performance of battery was improved to more than 1000 cycles compared to battery without any catalyst. The discharge capacity at current density of 0.2 mA cm-2 and charge potential range of 2.0-4.2 V for battery with catalyst/green electrolyte and without catalyst/common organic electrolyte were 3391 and 1012 mAh g-1,respectively. Furthermore, the usage of an ionic liquid as electrolyte leads to the increase the safety and lifetime of battery. Because of used electrolyte have high boiling point amount (>350 Celcius), so if it released to the environment due to the destruction or life expires of battery, don’t seriously damage to the environment because it is not easily evaporated.
Narges Vaezi; Nasser Dalali; Mehdi Hosseini
Volume 4, Issue 1 , March 2017, , Pages 59-66
Abstract
A simple, novel, accurate and selective method for the determination of trace amounts of Cu2+ ions in water and soil samples is proposed. The method is based on the separation and preconcentration of Cu2+ on a nano-SiO2 modified by a cetyltrimethylammonium bromide as surfactant and indane-1,2,3-trione-1,2-dioxime ...
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A simple, novel, accurate and selective method for the determination of trace amounts of Cu2+ ions in water and soil samples is proposed. The method is based on the separation and preconcentration of Cu2+ on a nano-SiO2 modified by a cetyltrimethylammonium bromide as surfactant and indane-1,2,3-trione-1,2-dioxime as complexing agent. The retained copper on the nano-sorbent was eluted with 1.5 mL of 1.0 mol L-1 HNO3 and measured by flame atomic absorption spectrometry. The synthesis of this nano-sorbent is also described and certified by FTIR, XRD and TEM techniques. Furthermore, several effective analytical parameters were evaluated and optimized. Under the best optimum conditions maximum absorption capacity, enrichment factor and limit of detection were 7.04 mg g-1, 333.3 and 4.4 µg L-1, respectively. The relative standard deviation of the preconcentration method was 0.28% (n=7) and calibration curve gave good level of linearity with correlation coefficient value 0.997. Finally, the feasibility and performance of the method was evaluated by determination of copper (II) ions in several water and soil samples with satisfied results.
