50 research outputs found

    Physical Properties and Chemical Composition of Pistacia atlantica subsp. kurdica (Zohary) Rech. F. gum: Effect of Geographical Region and Tree Gender

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    Pistacia atlantica subsp. kurdica (PAK) is one of three species in Iran and is indigenous to Kurdistan province. The aim of this reaserch was survey of the chemical composition and physical properties of oleoresin gum extracted from different gender of trees in six regions of Kurdistan province (Armardeh, Kanisoor, Marivan, Dezli, Hawraman and Sarvabad). Principal component analysis (PCA) assisted in analyzing the dependence of geographical regions and tree gender with the variations of chemical components of gum. Significant differences (P < 0.05) were observed in the surface tension, interfacial tension and intrinsic viscosity contents according to gender and geographic region. Spearman rank correlation coefficient results showed significantly positive and negative correlations between gum chemical components and physical characteristics. According to the obtained results and also various medical, cosmetic and food applications of oleoresin, when collecting, the separating extracted oleoresins from trees different regions andgenera is necessary

    A novel electrochemical sensor based on Co3O4-CeO2-ZnO multi metal oxide nanocomposite for simultaneous detection of nanomolar Pb2+ and Hg2+ in different kind of spices

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    Simultaneous and individual determination of Pb2+ and Hg2+ ions were carried out based on the synergistic effect of Co3O4, CeO2 and ZnO nanoparticles into the carbon paste electrode. The morphology of synthesized nanocomposite (Co3O4-CeO2-ZnO) was investigated by Scanning Electron Microscope, Transmission Electron Microscope, X-ray diffraction and Fourier Transform Infrared spectroscopy. The voltammetric current has increased linearly by increasing the concentration of Pb2+ and Hg2+ ions. The linear ranges of the Co3O4-CeO2-ZnO/CPE sensor were obtained 0.27-18.42 (for Pb2+ ions) and 0.42-31.30 nM (for Hg2+ ions), under optimum condition. The detection limits (3Sb/m) were obtained 0.054 nM for Pb2+ and 0.097 nM for Hg2+, respectively. The proposed electrochemical sensor acts as a sensitive and selective method for simultaneous determination of two heavy metal ions and shows excellent repeatability, reproducibility, and stability, with relative standard deviation (RSD) less than 3%. Finally, Co3O4-CeO2-ZnO/CPE was successfully applied for the determination of Pb2+ and Hg2+ in different kind of spices

    A comprehensive study on removal of cadmium from aqueous solution by using mesoporous SBA-15 functionalized by 1,5-diphenyl carbazide: experimental design, kinetic, thermodynamic, and isotherm aspects

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    In this study, a new adsorbent, which was synthesized by using SBA-15Santa Barbara Amorphous. modified with 1,5-diphenyl carbazide, was employed to extract cadmium (Cd) from aquatic systems. First, the sorbent was identified via various characterization techniques, and then the response surface methodology approach was applied for modeling and optimizing the adsorption performance of the sorbent. Under optimum conditions (pH=5.75\mathrm{pH}=5.75, an adsorbent dose of 4.55 mg, and a Cd concentration of 25.39 mg/L), an adsorption capacity of 160 mg/g was obtained. In addition, the sorption process was fast; it attained equilibrium in 25.39 min. Furthermore, the sorbent regenerated by nitric acid was reused without any significant loss of adsorption capacity. Finally, the experimental data were studied by different isotherm models and well described by the Langmuir model

    A comprehensive study on removal of cadmium from aqueous solution by using mesoporous SBA-15 functionalized by 1,5-diphenyl carbazide: experimental design, kinetic, thermodynamic, and isotherm aspects

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    In this study, a new adsorbent, which was synthesized by using SBA-15Santa Barbara Amorphous. modified with 1,5-diphenyl carbazide, was employed to extract cadmium (Cd) from aquatic systems. First, the sorbent was identified via various characterization techniques, and then the response surface methodology approach was applied for modeling and optimizing the adsorption performance of the sorbent. Under optimum conditions (pH=5.75\mathrm{pH}=5.75, an adsorbent dose of 4.55 mg, and a Cd concentration of 25.39 mg/L), an adsorption capacity of 160 mg/g was obtained. In addition, the sorption process was fast; it attained equilibrium in 25.39 min. Furthermore, the sorbent regenerated by nitric acid was reused without any significant loss of adsorption capacity. Finally, the experimental data were studied by different isotherm models and well described by the Langmuir model

    Biosynthesis and characterization of silver nanoparticles by using brown marine seaweed <em>Nizimuddiniazanardinii</em>

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    2497-2503In this study, the green synthesis of nanoparticles by using both fresh and dry marine macro alga of Nizimuddiniazanardinii was investigated. The Surface Plasmon Resonance bands of silver nanoparticles obtained were characterized by using UV-Vis spectrophotometer with characteristic absorption peaks at 413 and 414 nm. Maximum synthesis of silver nanoparticles was attained within 30 min at pH 8.5, 70&deg;C and 1mM concentration of AgNO3. Also maximum synthesis of silver nanoparticles reveals by characteristic absorption peaks at 432 and 441 nm within 2h at pH 7.5, 70&deg;C and 1mM Ag2SO4. The SEM images demonstrated these nanoparticles as spherical structures with average size of 60 nm. EDX study showed the major signal of silver metal with concentration of 50.06% in the fresh seaweed. The structure of Ag-NPs was determined by X-ray diffraction (XRD). FTIR showed that the function groups of hydroxyl, carbonyl and amine compounds in Nizimuddiniazanardinii extracts were involved in the reduction of aqueous AgNO3. This method of Ag-NPs synthesis is environmentally safe with potential utilization in biomedical and agriculture applications

    Spectrophotometric determination of selenium in Spirulina algae using Diaminotoluene reagent

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    Due to the progress of science and technology in health and medicine, selenium is mentioned as an excellent antioxidant in preventing the growth of cancers cell and even helping the process of cell growth. In most countries, plant foods are the main source of selenium. Among these plant sources, a kind of green-blue algae from the species of cyanobacteria should be mentioned, which is introduced as Spirulina algae. In addition to providing the body with the selenium it needs, spirulina is an excellent source of essential proteins, minerals, vitamins and amino acids. However, the amount of selenium required by the body and the fact that its excessive increase causes toxicity doubles the need to pay attention to its accurate quantitative measurement. These measurements are usually performed with costly and long-term methods such as ICP-AES. Therefore, in this study, the suitable specific ligand (Diaminotoluene) for selenium was used with low cost and high availability, using simple, low cost and fast technique as UV-spectrophotometric method.The results of the analytical method validation indicated that this ligand has high productivity and also this method should be quite suitable for replacement with high cost methods such as ICP-AES. In addition, this method used can provide all the parameters required to analytical method validation

    Removal of dye contamination from real textile wastewater by zero-valent iron nanoparticles@chitosan (nZVI@CS) nanocomposite

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    Abstract S. In this study, the nZVI@CS nano-absorbent was synthesized with a chemical reduction method and then characterized by FTIR, XRD, FESEM, EDS mapping, and BET analyses. The nZVI@CS had a uniform morphology and suitable functional groups for dye removal. After characterization, the nZVI@CS nano-absorbent was used to remove the dye from real and synthetic wastewater. For this goal, the operation condition was optimized by array L16 of the Taguchi design experiment. The results indicated that the dosage of nano-absorbent with 52% impact had the most effect on the dye removal efficiency. At the optimum condition (pH = 6, T = 25 °C, nanocomposite dosage = 0.01 g, and t = 60 min), the nZVI@CS nano-absorbent could be removed 99%, 96% and 88% of reactive red 81, real wastewater and reactive blue 41, respectively. Additionally, isotherms, the kinetic and thermodynamic of the adsorption reaction were assessed. The kinetic reaction has been similar to the pseudo-first-order model. Also, the isotherm followed the Langmuir isotherm. Moreover, thermodynamic investigation outcomes indicated absorption reactions were exothermic. The reuse ability experiment indicated that the synthesized nZVI@CS nano-absorbent could be used several times without remarkable loss of the sorption ability. Finally, it confirmed that the nZVI@CS nanocomposite has sufficient sorption capacity for dye wastewater on a large scale

    Genetic algorithm-based wavelength selection in multicomponent spectrophotometric determination by PLS: Application on sulfamethoxazole and trimethoprim mixture in bovine milk

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    The simultaneous determination of sulfamethoxazole (SMX) and trimethoprim (TMP) mixtures in bovine milk by spectrophotometric method is a difficult problem in analytical chemistry, due to spectral interferences. By means of multivariate calibration methods, such as partial least square (PLS) regression, it is possible to obtain a model adjusted to the concentration values of the mixtures used in the calibration range. Genetic algorithm (GA) is a suitable method for selecting wavelengths for PLS calibration of mixtures with almost identical spectra without loss of prediction capacity using the spectrophotometric method. In this study, the calibration model based on absorption spectra in the 200-400 nm range for 25 different mixtures of SMX and TMP Calibration matrices were formed form samples containing 0.25-20 and 0.3-21 μg mL-1 for SMX and TMP, at pH=10, respectively. The root mean squared error of deviation (RMSED) for SMX and TMP with PLS and genetic algorithm partial least square (GAPLS) were 0.242, 0.066 μgmL-1 and 0.074, 0.027 μg mL-1, respectively. This procedure was allowed the simultaneous determination of SMX and TMP in synthetic and real samples and good reliability of the determination was proved
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