Iranian Journal of Chemistry and Chemical Engineering
Year:2017 | Volume:36 | Issue:3|Papers Count:19

Functionalized morpholines have attracted much attention due to their potential biological activities. Despite wide importance of morpholine derivatives in drug design of various pharmacological agents, the development of new approaches to their synthesis remains relatively unexplored. Given the low cost and easy availability of N-propargylamines, the synthesis of functionalized morpholines from these versatile building blocks have undergone an explosive growth in recent years. This review provides concise overview on the synthesis of morpholine cores from N-propargyalamines in recent years.

a-Bromoketals and acetals are important synthetic precursors in organic synthesis. In this work, some new α-bromoketals are synthesized by the reaction of aryl methyl ketones with diols in the presence of 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU) hydrobromide-perbromide in good isolated yields. The latter compound converts aldehydes to acetals and serves as a new and efficient reagent for the synthesis of acetals. Comparative studies of the preparation of a-bromoketal and acetals using some reported methods versus the present method show that DBUH-Br3 is one of the most efficient reagents for the preparation of these compounds. Conversion of carbonyl compounds to corresponding a-bromoketals and acetals in the presence of DBUH-Br3 under microwave irradiation is also described.

This study was aimed to investigate the amount of reactive blue 29 (RB29) dye removal from aqueous solution by Chitosan extracted from Persian Gulf shrimp shell. The effect of parameters such as pH, the concentration of reactive blue 29 dye, contact time, and adsorbent dosage in dye removal was studied. Isotherm, Thermodynamics, and kinetics of adsorption process were also investigated. The results of this study showed that the optimum condition of the adsorption process occurred in 50mg/L of RB29 dye concentration, pH=4, contact time of 90 minutes and adsorbent dosage of 0.2 g/L. The maximum adsorption capacity in optimum condition was estimated to 87.74 mg/g. Lab data displayed that the results were in compliance with Langmuir isotherm. According to the results of thermodynamic studies, standard entropy changes (DS°) was 66.67 J/mol K and standard enthalpy changes (DH°) was 19158.3 kJ/mol. Also, the standard Gibbs free energy (DG°) was negative and kinetics of adsorption process follows the pseudo-second-order model.

Application of SiO2@FeSO4 nano composite as a new nano catalyst in reduction area was investigated. Carboxylic acid simple and convenient reduction to alcohol by 0.75 mol of the nano composite, 3 mol sodium borohydride (NaBH4) as reduction reagent under solvent free condition at 30-65 min. The reaction happens in two stages - first to form an aldehyde and then a primary alcohol. Because sodium aluminum hydride reacts rapidly with aldehydes, it is impossible to stop at the halfway stage. The method does not require an anhydrous solvent, does not involve a hazardous reagent, has somewhat different selectivity than techniques in general use, and may sometimes be the method of choice.

Herein, it has been shown that the bismuth ferrite magnetic nanoparticles (BFO-MNPs) are new, efficient and recyclable catalysts for the synthesis of polyhydroquin oline derivatives by the Hantzsch reaction. The one-pot four-component cyclocondensation reaction of dimedone, aromatic aldehydes, ethyl acetoacetate and ammonium acetate was carried out under solvent-free conditions. The desired products were obtained in very short reaction times with high yields. The magnetic nanocatalyst was characterized by the X-Ray Diffraction (XRD) and FT-IR analysis. For the first time, the bismuth ferrite magnetic nanoparticles were used as a catalyst in the Hantzsch reaction. The catalyst was found to be reusable, which showed considerable catalytic activity after the third run.

This paper concerns the oxidative stability of experimental reduced-fat margarine (EM) enriched with canariensis red date peel powder extracts. For this, the two phases intended for obtaining the margarines were used first as extraction solvents. Both enriched phases thus obtained are then employed to formulate different margarine samples. In addition to color and rheological behavior, margarine samples were characterized in terms of oxidative stability which was evaluated through the peroxide value, Q10-factor and activation energy (Ea). Results showed that all the margarines formulated by addition of date peel extract presented high values of a* and b* parameters, compared with those of reference and commercial origin (p<0.05).The best oxidation resistance of different experimental margarines was obtained when the sample was added with: (i) the aqueous extract-ingredient, in the case of storage at 30°C, and (ii) the both aqueous and oil extract-ingredients, in the case of storage at 5°C. Results showed that the models applied (zero-order, first-order, polynomial, logarithmic and power law) differently described the oxidation kinetics (R2£0.993), according to the margarine type and storage temperature. Globally, Q10 and Ea parameters varied within wide intervals of values (0.8-4.0 and 3.4-95.9kJ.mol-1, respectively) according to margarine nature. So, the present study demonstrated the possible application of Phoenix canariensis red date peel extract as a natural colorant and antioxidant in margarine and other food formulations.

Composite films on the base of ZnO with different weight percentages of polypyrrole have been prepared using the hot pressing method and their current-voltage characteristics have been studied. Results show that the films have nonlinear varistor behavior and can be used to protect sensitive circuits from 110V up to 350V over voltages. It is found that the higher the content of polypyrrole in the varistor, the lower the breakdown voltage. Samples with higher polypyrrole content have less nonlinearity. The interesting result is that, unlike semiconductor-polyaniline based varistors, varistor hysteresis decreases through increasing polypyrrole content. Results have been analyzed with respect to SEM micrographs and XRD patterns of the samples. Energy gaps of varistors are evaluated using their UV spectra analysis regarding Tauc relation, which show that increasing polypyrrole content in varistors causes their absorption to increase and the corresponding band gap to decrease.

In current study, macro and micro element contents of oat grains were determined by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). P contents of grains were found between 2428.72 mg/kg (Arslanbey) and 4557.25 mg/kg (TL10). While K contents of oat samples change between 3055.99 mg/kg (TL63) and 5621.12 mg/kg (TL8), Ca contents of oats ranged from 568.50 mg/kg (TL63) to 1269.97 mg/kg (TL86). In addition, the highest and lowest Mg were determined in Kırklar (2024.88 mg/kg) and TL73 (1252.48 mg/kg) oat samples, respectively. Iron contents of oat changed between 29.98 mg/Kg (TL7) and 80.78 mg/Kg (Arslanbey). While Zn contents of oat samples change between 15.50 mg/kg (Arslanbey) and 37.68 mg/kg (TL/76), Mn contents ranged from 25.82 mg/kg (TL63) to 62.55 mg/kg (Kırklar). Also, the highest Zn and Cu contents of oat grains were found in TL76 (37.68 mg/kg) and TL67 (8.67 mg/kg). Locations had significant effect on all macro and micro nutrient concentrations of oat grains. The results presented here suggest that oat grains could serve as a good source of mineral elements.

Simultaneous determination of pharmaceutical compounds and accurate quantitative prediction of them are of great interest in the clinical and laboratory-based investigations. This work has focused on a comprehensive comparison of Partial Least-Squares (PLS-1) and Artificial Neural Networks (ANN) as two powerful types of chemometric methods. For this purpose, montelukast (MONT), fexofenadine (FEXO) and cetirizine (CET) were studied as three pharmaceuticals whose UV-Vis absorption spectra highly overlap each other. The cross-validation leave-one-sample-out procedure was applied and the optimum number of factors was determined. The developed models were subsequently validated through testing with an independent dataset. Furthermore, a simple and fast method for wavelength selection (WS-PLS-1) in the calibration step was presented which involved the calculation of the Net Analyte Signal Regression Plot (NASRP) for each test sample. Highest prediction accuracies corresponded to WS-PLS-1 method with R2 values of 0.994, 0.982 and 0.999 for MONT, FEXO and CET, respectively. The best values of detection limit was also provided by WS-PLS-1 method which obtained to be 0.029, 0.049 and 0.054 mg/L for MONT, FEXO and CET, respectively. According to the results obtained, WS-PLS-1 method was shown to have the potential to be utilized as a promising tool in clinical and pharmaceutical applications.

A simple and rapid solidified vortex assisted 1-undecanol based liquid–liquid microextraction technique was proposed for preconcentration of trace levels of lead ions. The extraction solvent (1-undecanol) was dispersed into the aqueous samples by the assistance of vortex agitator.100 mL of 1-undecanol containing ethyl (2Z) -3- [(5-chloro-7-methyl [1, 3] thiazolo [5, 4-d] pyrimidin-2-yl) amino] -2-cyano-3- (methylsulfanyl) prop-2-enoate (TPAS) as a new chelating agent (0.1%w/v) was transferred to the water samples containing lead ions. The hydrophobic complex was extracted into 1-undecanol and the sample vial was cooled in an ice bath for 5 min. The solidified extract was transferred into a conical vial where it was melted immediately, and 20 mL of this solution was injected and analyzed by Graphite Furnace Atomic Absorption Spectrometry (GFAAS). Several variables such as sample pH, concentration of TPAS, volume of 1-undecanol and extraction time were investigated in details and optimum conditions were obtained. Under the optimum conditions, the Limit Of Detection (LOD) was 0.02 mg L-1 for lead and Relative Standard Deviation (RSD %) for five replicate determinations of 1 mg/L of lead was 5.6%. The results for determination of lead in reference material, three samples of wastewater, well, tap, river and aqueduct water demonstrated the accuracy, recovery and applicability of the presented method.

Extraction and determination of naproxen from human plasma were performed using Vortex - Assisted Inverted Dispersive Liquid–Liquid MicroExtraction (VA−IDLLME) and High Performance Liquid Chromatography (HPLC). The parameters affecting extraction recovery such as type and volume of extraction and disperser solvents, pH of sample solution, stirring rate, extraction time and salt addition were optimized. Optimal extraction conditions were: 100 mL dodecane as extraction solvent, 350 mL methanol as disperser solvent, pH of sample=5, stirring rate: 500 rpm, with no effect of extraction time and no addition of NaCl to the sample solution. Under the optimal conditions a linear range of 1.0–1000.0 ng/mL (R2=0.9993) was obtained. Limit of detection, the extraction recovery and preconcentration factor were 0.32 ng/mL, 87% and 108 respectively.

A new analytical approach was developed involving magnetic solid–phase extraction and spectrofluorimetric determination of carvedilol in human plasma samples. A plasma sample was prepared and adjusted to pH 8.2–10, then carvedilol was quickly extracted using iron oxide magnetic nanoparticles modified by the surfactant cetyltrimethylammonium bromide and determined applying spectrofluorimetry at 354±3 nm after excitation at 241±3 nm. Experimental conditions, such as the amount of nanoparticles and cetyltrimethylammonium bromide, pH value, standing time and desorption solvent type and volume have been adjusted to optimize the extraction process and to obtain analytical characteristics of the method. Linearity was observed in the analyte concentration range of 2.0–125 ng/mL with correlation coefficients (r) of 0.999. The method showed good precision and accuracy, with intra– and inter–assay precisions of less than 7.0% at all concentrations. Standard addition recovery tests were carried out, and the recoveries ranged from 94.4% to 100.7%. The limits of detection and quantification were found to be 0.67 and 2.24 ng/mL. The method was applied to the determination of carvedilol in human plasma samples.

Surface Molecularly Imprinted Polymer (SMIP) for selective adsorption of di (2-ethylhexyl) phthalate (DEHP) was prepared on the surface of silica gel which was modified by aminopropyltriethoxysilane and acryloyl chloride in a two-step method. The prepared SMIP was used to prepare Molecularly Imprinted Solid-Phase Extraction (MISPE) column for selective extraction of DEHP from aqueous solution. The results suggested that MISPE column had high affinity and excellent selectivity for DEHP. And adsorption property of MISPE column was significantly superior to commercial C18 column. The MISPE column was reusable. An analytical method MISPE-HPLC was developed for extraction and determination of the DEHP residues in environmental water samples. The results showed that the linear relationship of the peak area and the concentration of DEHP were as follow: y=2354.6x+1663.5 with a good correlation coefficients (R2=0.9997) and the detection and quantification limits reached 0.012 mg/L and 0.039 mg/L, respectively. The spiked recoveries of DEHP in river water and lake water sample were in the range from 93.3% to 102.3 % at the spiked level of 50~1000 mg/L. The Relative Standard Deviations (RSD) were less than 5.2%.

The purpose of this study was the investigation of the removal of phenol with nanoparticles zero valent iron and iron powder. The effect of various parameters such as initial concentration, pH, contact time, and dosage of NZVI and Fe powder were examined, and a Central Composite Design (CCD) was then applied to appraisal the effect of these variables. The chemical and physical characteristics of NZVI were studied with Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) analysis. The results displayed that the adequate initial concentration for phenol sorption, pH, contact time, and sorbent dosage were 5 mg/L, pH 2, 54.75 min and 1.40 g in the case of NZVI and 5 mg/L, pH 2, 55.84 min and 2.5 g in the case of Fe powder. The Central Composite Design (CCD) showed that the fundamental parameters were pH and initial phenol concentration had the main effect on phenol removal.

The oil contents of linseeds were determined between 39.9% (Antares) and 43.3% (Railinus). The oleic acid contents of seed oils varied between 0.8% (Maroc) and 24.8 (Railinus). The linoleic acid contents of linseed oil change between 10.2% (Avangard) and 48.2% (Maroc), while the palmitic acid of oils ranged from 4.8% (Antares) to 6.1% (Maroc), stearic acid contents ranged between 4.7% (Avangard) to 23.5% (Maroc). Also, linolenic acid contents of Avangard oil was higher (59.9%) than those of results of other linseed oils. The P8 contents of linseed oil change between 1.1 mg/kg (Railinus) and 16.4 mg/kg (Avangard). Also, the d-tocopherol content of Railinus oil was also higher (262.7 mg/kg) than those of other linseed oils (0.3-0.4 mg/kg). The total tocopherol in Railinus seed oil was higher (437.4 mg/100 g) (p<0.05) than that of Maroc seed oil (30.3 mg/100 g).

Cooling is one of the most important challenges in industries especially in the automotive industry. Coolant which is used in engine radiators possess lower thermal conductivity. To enhance the thermal properties, coolant was dispersed in nano sized particles and the fluid is called as Nanofluid. In this Study, Silica Nanoparticle was dispersed in Paraflu Engine coolant using Bath Sonicator and Probe Sonicator. The effect of Sonication on thermal Conductivity and the effect of concentration on thermal conductivity was studied. Characterization Studies like UV-Vis Spectroscopy, XRD (X-Ray Diffraction) and TEM (Transmission Electron Microscopy) results confirmed the size of silica particles in the nanometer range. Stability time was also calculated by Sedimentation method for the fluids prepared by Bath sonicator and Probe Sonicator. For the commercial application purpose, an optimization process is required for the creation of nanofluids and the forces affecting it.

Ultrasound has been widely employed in food industry, while some of its working parameters are usually neglected to be described in its application, which caused the difficulty of reproducing and comparing the results obtained by different groups. So it is definitely not sufficient to simply state the ultrasound conditions such as ultrasound power, frequency and temperature, additionally, other parameters including the geometry of the reaction vessel, vessel distance, initial temperature of water, ultrasonic power density and positions used for fixing vessel are also very important for the actual/practical ultrasound power delivered to the targeted solution. Considering these facts, the above-mentioned factors were systematically conducted to study their effects on the actual ultrasound power, i.e. ultrasound power density for achieving maximum benefit, as a result, to highlight the importance of fully describing the ultrasound working parameters about its application. As Expected, the results confirmed our assumption that nearly all the studied parameters did have a great influence on the actual ultrasound power density dissipated into the targeted solution, excluding vessel position. In a word, this research would make this paper valuable to the scientific community, underline the importance of these neglected or rejected problems in the application of ultrasound bath, and persuade the readers to give some more thoughts to these issues.

Experimental designs were applied for optimizing media and process parameters for hydrogen production from maize stalk hydrolyzate by a newly isolated facultative strain. Plackett-Burman design was used to identify the significant components and using this method the media components - glucose, yeast extract, malt extract, peptone, and NaCl were identified as significant variables influencing the production of hydrogen. The concentrations of these components were optimized using Central Composite Design (CCD) and were found to be: glucose, 19.25g/L; peptone, 5.64g/L; malt extract, 1.64g/L; yeast extract, 3.16g/L and NaCl, 4.312g/L. For further maximizing the production of hydrogen, the process parameters including pH, temperature and fermentation time were optimized by adopting Box-Behnken design. A maximum hydrogen yield of 0.91 mol H2/mol substrate was achieved under the optimum conditions of pH, 7.0; temperature, 34.5oC and fermentation time, 42.5h.

It has been shown that the photocatalytic activity of doped semiconductor with some nonmetals is higher than pure semiconductor. Hence, with an attempt to achieve higher photocatalytic activity, doped ZnO with C, N, and S was prepared by a sedimentary process and used for the photocatalytic degradation of Fluocinolone Acetonidin as a drug in aqueus solutions. X-Ray Diffraction (XRD), Energy Dispersion X-ray (EDX), X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM) were used to characterize the microstructure and morphology of the precursor and the products. The photocatalytic degradation of drug was investigated using supported ZnO/C, N, and S photocatalyst under UV light irradiation. We also studied the influence of the basic photocatalytic parameters as well as irradiation time, initial concentration of drug, pH of solution, amount of nanoparticles and addition of oxidant on the reaction. The optimum conditions of degradation were obtained accordingly: concentration of Fluocinolone Acetonidin, 20 ppm; amount of photocatalyst, 7 mg; oxidant (K2S2O8), 5 mM; irradiation time, 6 h in pH=9. Kinetic analysis demonstrated that the amount of Fluocinolone Acetonidin photocatalytic degradation can be fitted by a pseudo- first- order model.