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11.
An analytical method using alumina modified with water-soluble polyacrylic acid polymer for the simultaneous separation and
preconcentration of trace Cu and Cd in a column system, and their determination by flame atomic absorption spectrometry was
developed. The conditions for coating Al2O3 with polyacrylic acid were optimized, then the column was packed with 50 mg of this sorbent. Cd and Cu solution was passed
through a glass column at pH 4.5, and elution was carried out with 5 mL of 0.05 M HCl at a flow rate of 1 mL min−1. A sorption capacity of 10 mg Cu and 12 mg Cd was obtained for 1 g sorbent. The detection limit was calculated as 4.5 μg L−1 for Cu and 1.54 μg L−1 for Cd in the final solution. Enrichment factors of 300 for Cd and 400 for Cu were obtained. 相似文献
12.
Afsaneh Safavi Norouz Maleki Fatemeh Honarasa Fariba Tajabadi Fatemeh Sedaghatpour 《Electroanalysis》2007,19(5):582-586
A new type of potentiometric sensor based on a recently constructed carbon ionic liquid electrode (CILE) is described. Two kinds of ionic liquids, i.e., N‐octylpyridinium hexafluorophosphate (OPFP) and 1‐butyl‐3‐methylimidazoluim hexafluorophosphate (BMFP) were tested as binder for construction of the carbon composite electrode. The characteristics of these electrodes as potentiometric sensors were evaluated and compared with those of the traditional carbon paste electrode (CPE). The results indicate that potentiometric sensors constructed with ionic liquid show an increase in performance in terms of Nernstian slope, selectivity, response time, and response stability compared to CPE. 相似文献
13.
alpha-Glycylglycine in its actual crystalline phase is studied by ab initio calculated nuclear quadrupole coupling constants. These physical quantities are computed for 2H and 14N in the hydrogen bonds. The type of hydrogen bond is the N-H...O type. The computations are performed with the RHF and B3LYP methods and 6-31++G** and 6-311++G** basis sets using the Gaussian 98 program. Values of the calculated nuclear quadrupole coupling constants are shown in Tables 1-3. The aim of this work is the study of 2H and 14N quadrupole coupling constants which contribute in the CON2H...O=CN2H type of hydrogen bond. The computed nuclear quadrupole coupling constants of 2H nuclei meet the related experimental values. In addition, the computed chi value of 14N belonging to the -CO-14NH- group agrees well with values obtained experimentally. However, there are some discrepancies between calculated 14N chi values of the N+H3 residue and experiments. Also, the values of these physical parameters are calculated for >C2H2 of alpha-glycylglycine in its crystalline phase. Calculations for these parameters are carried out in a single molecule using X-ray diffraction coordinates, too. 相似文献
14.
Preparation and characterization of Cu (II) supported on poly(8‐hydroxyquinoline‐p‐styrene sulphonate) and its application as catalyst for the synthesis of hexahydroquinolines 下载免费PDF全文
Ardeshir Khazaei Mahsa Tavasoli Vahid Jamshidi Fatemeh Gohari Ghalil Ahmad Reza Moosavi‐Zare 《应用有机金属化学》2018,32(7)
Cu ( II ) supported on poly(8‐hydroxyquinoline‐p‐styrenesulfonate) (Cu ( II )@PHQSS) was prepared and fully characterized by the different techniques including fourier transform infrared spectroscopy (FT‐IR), 1H NMR, 13C NMR, thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG), differential thermal analysis (DTA), scanning electron microscope (SEM) and energy dispersive X‐ray analysis (EDS). Afterward, the Cu ( II )@PHQSS as nanostructured catalyst was used as catalyst for the synthesis of hexahydroquinolines. 相似文献
15.
A simple, inexpensive, environmentally friendly and efficient route for Michael addition of indoles to α,β-unsaturated ketones using pentafluorophenylammonium triflate (PFPAT) as a catalyst is described. Various indole derivatives were synthesized in good to excellent yields. The preparation of PFPAT catalyst from simple and readily available starting materials makes this method more affordable. 相似文献
16.
Maryam Mohammadikish Fatemeh Davar Mohammad Reza Loghman-Estarki 《Journal of Cluster Science》2013,24(1):217-231
In this work, we report a facile hydrothermal method for the preparation of three dimensional hollow ZnS nanostructures, using Zinc bis(salicyle aldehitato), Zn(Sal)2, thioacetamide (TAA) and thioglycolic acid (TGA) as Zn2+, sulfur source and capping agent, respectively. The ZnS solid and hollow sphere was produced from the self-assembly of nanoparticles with diameters of 11 ± 2 nm with TGA and TGA, TAA, respectively. Furthermore, with changing zinc precursor from Zn(Sal)2 to zinc acetate [Zn(OAC)2], ZnS nanorods were obtained. The products were characterized by XRD, SEM, TEM, selected area electron diffraction, and FT-IR spectra. The influence of surfactant (Polyethylene glycol) on the morphology of the products was also investigated. Possible formation mechanism and optical properties of these architectures were also reported. 相似文献
17.
Masoud Salavati-Niasari Bahareh Shoshtari-Yeganeh Fatemeh Mohandes 《Journal of Cluster Science》2013,24(3):657-667
In this work, Pb(II)N,N-bis(salicylidene)-ethylenediamine; [Pb(salen)]; was applied as lead precursor to synthesis PbSe nanostructures. Besides [Pb(salen)], SeCl4 and reducing agents like N2H4·H2O have been employed for the production of PbSe nanostructures via a solvothermal route at 180 °C for 3 h in propylene glycol. The effect of preparation factors such as temperature, reaction time, and surfactant on the morphology of PbSe nanostructures was investigated. The experimental results indicated that PbSe synthesized at 150 and 210 °C was composed of agglomerated particles. On the other hand, the use of KBH4 as reducing agent led to produce PbSe with higher particle size and agglomeration. The as-prepared PbSe nanostructures were characterized by XRD, SEM, TEM, EDS, and FT-IR. 相似文献
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Fatemeh Osanlou Firouzeh Nemati Samaneh Sabaqian 《Research on Chemical Intermediates》2017,43(4):2159-2174