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1.
Mir Ali Farajzadeh Mortaza Ebrahimi Ali Ranji Elham Feyz Vali Bejani Amir Abbas Matin 《Mikrochimica acta》2006,153(1-2):73-78
High performance liquid chromatography (HPLC) and gas chromatography (GC) are introduced for analysis of polymer lubricants
(stearamide, oleamide and erucamide). In the HPLC method, a reverse phase octadecylsilane (ODS) column along with acetonitrile/methanol
(60:40) as a mobile phase were used. Detection of analytes was performed by a UV detector at 202 nm. The analysis time was
less than 8 min. In the GC method, polar capillary column and flame ionization detector (FID) were used for separations and
detection, respectively. The analysis time by GC was longer than HPLC and was about 30 min. Limits of detection, linear range
and repeatability of both methods are similar, but determination of oleamide in real samples by HPLC method is difficult due
to complexity of the initial part of HPLC chromatogram in polyethylene samples. That problem is not observed in the GC method.
Detection limits in both methods for all analytes are lower than 0.003% which are much lower than the amount of lubricants
in commercial polymers (0.05–0.2%). 相似文献
2.
S. G. Yunusova S. D. Gusakova A. I. Glushenkova U. K. Nadzhimov Sh. Turabekov SA. Musaev 《Chemistry of Natural Compounds》1991,27(2):147-150
A comparative analysis has been made of the amounts of lipids and their fatty-acid compositions in the seeds of the lines of agenetic collection of cotton plants of the speciesGossypium hirsutum and their hybrids and the variety Tashkent-1. The results obtained on the fatty-acid compositions of some hybrids make it possible to recommend the use of individual lines of cotton plants as donors for improving the food-value indices of cottonseed oil.Institute of Chemsitry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 173–176, March–April, 1991. 相似文献
3.
Hamideh Sharifi Noghabi Gholam Hossein Rounaghi Mohammad Hossein ArbabZavar Javad Ebrahimi 《Russian Journal of General Chemistry》2014,84(7):1429-1433
We report on conductometric study of complexation between benzylbisthiosemicarbazone [(2E,2′E)-2,2′-(1,2-diphenylethane-1,2-diylidene)bis(hydrazine-1-carbothioamide)] with Zn2+, Cr3+, Co2+, and Ni2+ cations at different temperatures in acetonitrile-dimethylformamide binary solvents of varied composition. The equilibrium constant and standard thermodynamic parameters (Δc H 0 and Δc S 0) of the complexes formation have been determined and found to be dependent on the binary solvent composition, the metal ion nature, and temperature. 相似文献
4.
Tahereh Naderi Joloudar Ali Akbar Saboury Marzieh Dehghan Shasaltaneh Seifollah Bahramikia Mohammad Ali Ebrahimi Atiyeh Ghasemi 《Journal of the Iranian Chemical Society》2017,14(11):2407-2416
A key feature in more than twenty amyloid-related diseases is the aggregation of intra-and/or extracellular misfolded proteins as amyloid fibrils. Therefore, preventing or reversing amyloid aggregation by using of small molecules is considered as useful approaches to the treatment of these diseases. We have evaluated the ability of safranal and crocin, to inhibit amyloid self-assembly of hen egg white lysozyme (HEWL), as an in vitro model system. Structural properties of HEWL in the presence of these compounds were investigated individually using thioflavin T, anilinonaphthalene-8-sulfonic acid fluorescence assays, far-UV circular dichroism and scanning electron microscopy as well as docking method. Our results showed that incubation of HEWL with either crocin or safranal at various concentrations leads a significant inhibition in the rate of amyloid formation. Docking analysis revealed crocin and safranal interact with the central hydrophobic region of lysozyme through van der Waals interaction. Hydroxyl group in crocin through hydrogen bonds connected to the several hydrophilic amino acids of lysozyme, while in safranal there are just one aldehyde group that through hydrogen bonds connected to aspartic acid in lysozyme. It can be concluded that both hydrophobic and hydrophilic groups contribute to lower lysozyme fibril accumulation. 相似文献
5.
Somayeh Hosseini Amir Charkhi Abdolhamid Minuchehr Seyyed Javad Ahmadi 《Chemical Papers》2017,71(6):1143-1153
Pervaporation (PV) separation of water–acetonitrile mixture using sodium alginate (NaAlg) based mixed matrix membranes (MMM) comprising different amounts of nano NaA zeolite (10, 20 and 30 wt%) is investigated in various concentrations of water and temperatures. The prepared membranes are modified by sulfosuccinic acid (SSA) as a crosslinking agent. NaAlg-NaA/SSA membranes are synthesized by a solution casting technique. The process and membrane performance including separation factor, flux and activation energy of permeation are determined. Results reveal that adding of nano zeolite may lead to an increase in the flux and the separation factor of sodium alginate membrane up to 123 and 169%. In addition, using MMM in dehydration of a feed containing 30 wt% of water shows much better performance than alginate membrane. Furthermore, the activation energy of water permeation through MMM is predicted lower than sodium alginate membrane which reflects the facilitated permeation of water through MMM. 相似文献
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Ahmad Shaabani Heshmatollah Sepahvand Seyyed Emad Hooshmand Mahmoud Borjian Boroujeni 《应用有机金属化学》2016,30(6):414-421
The synthesis and characterization of an efficient and reusable nanocatalyst, Cu/GA/Fe3O4@SiO2, obtained by ultrasonic‐assisted grafting of guanidineacetic acid on modified Fe3O4@SiO2 core–shell nanocomposite spheres and subsequent immobilization of Cu(II), are described. The catalyst was characterized by means of X‐ray diffraction, scanning and transmission electron microscopies, energy‐dispersive X‐ray spectroscopy, elemental analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy, vibrating sample magnetometry and inductively coupled plasma optical emission spectrometry. The prepared nanocatalyst facilitated an efficient and straightforward friendly procedure for the synthesis of benzodiazepines and imidazoles in ethanol and under solvent‐free conditions, respectively. The nanocatalyst can be easily recovered using a magnet and reused several times without any significant loss of activity. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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