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51.
Amir Waseem Mohammad Yaqoob Masood Ahmed Siddiqui 《International journal of environmental analytical chemistry》2013,93(12):825-832
A flow-injection procedure is described for the determination of carbaryl based on its inhibition effect on luminol-cobalt(II) chemiluminescence reaction in alkaline medium in the presence of hydrogen peroxide. The calibration data over the range 5.0?×?10?7 to 20?×?10?6?M give a correlation coefficient (r 2) of 0.9972 with relative standard deviations (RSD; n?=?4) in the range of 1.0–2.1% with a limit of detection (3?×?blank noise) of 2.37?×?10?7?M for carbaryl. The sample throughput was 120?h?1. The effects of some carbamates, anions, and cations were studied on luminol CL system for carbaryl determination. The proposed method has been applied to determine carbaryl in natural waters. 相似文献
52.
Pezhman Kazemi Mohammad Peydayesh Alireza Bandegi Toraj Mohammadi Omid Bakhtiari 《Chemical Papers》2013,67(7):722-729
An experimental study on the pertraction of methylene blue (MB) through a supported liquid membrane (SLM) using a mixture of mono-(2-etylhexyl) ester of phosphoric acid (M2EHPA) and bis-(2-etylhexyl) ester of phosphoric acid (D2EHPA) and sesame oil as the liquid membrane (LM) was performed. Parameters affecting the pertraction of MB such as initial MB concentration, carrier concentration, feed phase pH, and stripping phase concentration were analyzed. Optimal experimental conditions for MB pertraction (permeability of 5.63 × 10?6) were obtained after a 7 h separation with the MB concentration in the feed phase of 80 mg L?1, D2EHPA/M2EHPA concentration in membrane phase of 40 vol. %, feed pH of 6, and acetic acid concentration in the stripping phase of 0.4 mol L?1. Kinetics of transport and stability of the SLM system were also studied and the mass transfer coefficient for this system was evaluated. Scanning electron microscopy (SEM) was used to morphologically characterize the membrane surface. 相似文献
53.
The low temperature perovskite-type calcium titanate (CaTiO3) thin films and powders with nanocrystalline and mesoporous structure were prepared by a straightforward particulate sol–gel route. The prepared sol had a narrow particle size distribution about 17 nm. X-ray diffraction and Fourier transform infrared spectroscopy revealed that, the synthesized powders had highly pure and crystallized CaTiO3 structure with preferable orientation growth along (1 2 1) direction at 400–800 °C. The activation energy of crystal growth was calculated 5.73 kJ/mol. Furthermore, transmission electron microscope images showed that the average crystallite size of the powders annealed at 400 °C was around 3.5 nm. Field emission scanning electron microscope analysis and atomic force microscope images revealed that, the deposited thin films had uniform, mesoporous and nanocrystalline structure with the average grain size in the range 33–39 nm depending on annealing temperature. Based on Brunauer–Emmett–Teller (BET) analysis, the synthesized powders showed mesoporous structure with BET surface area in the range 51–21 m2/g at 400–800 °C. One of the smallest crystallite size and one of the highest surface areas reported in the literature is obtained which can be used in many applications, such as photocatalysts. 相似文献
54.
Ghodsi Mohammadi Ziarani Sakineh Faramarzi Negar Lashgari Alireza Badiei 《Journal of the Iranian Chemical Society》2014,11(3):701-709
Sulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) as a new nanoporous solid acid catalyst was applied in the green one-pot synthesis of spiro[indole-tetrahydropyrano(2,3-d)pyrimidine] derivatives via three-component reaction of isatins, malononitrile or cyanoacetic esters and barbituric acids under solvent-free conditions. SBA-Pr-SO3H was proved to be an efficient heterogeneous nanoporous solid acid catalyst with a pore size of 6 nm, which could be easily handled and removed from the reaction mixture by simple filtration and can be recovered and reused several times without any loss of activity. The advantages of this methodology are high product yields, being environmentally benign, short reaction times, and easy handling. 相似文献
55.
Two new fluorescent BODIPY dyes have been designed and synthesized. They dyes differ in their meso substituents, which have different electronic properties. Their selective reactivity towards an Ar‐SN2 reaction has been explored as a potential basis for colorimetric and fluorescent discrimination of primary, secondary and tertiary aliphatic amines. This dual‐mode, instantaneous recognition event is unprecedented. 相似文献
56.
57.
Mohammadi Ziarani Ghodsi Khademi Mahdieh Mohajer Fatemeh Anafcheh Maryam Badiei Alireza Ghasemi Jahan B. 《Research on Chemical Intermediates》2022,48(5):2111-2133
Research on Chemical Intermediates - The synthesis of 4-Aryl-(3,5-dimethyl-1,4,7,8-tetrahydro-dipyrazolo[3,4b:4′,3′e]pyridine derivatives was accomplished using Fe3O4@SiO2@(BuSO3H)3... 相似文献
58.
Ebrahimiasl Hakimeh Azarifar Davood Mohammadi Mahsa Keypour Hassan Mahmood abadi Masoumeh 《Research on Chemical Intermediates》2021,47(2):683-707
Research on Chemical Intermediates - In this research, synthesis and characterization of a novel Schiff base Cu (II) complex immobilized on Fe3O4@SiO2 nanoparticles are reported. Then, the... 相似文献
59.
A novel organic-inorganic hybrid optical sensor (SBA-NCO) was designed and synthesized through immobilization of isocyanatopropyl-triethoxysilane and 1-amino-naphthalene onto the surface of SBA-15 by post-grafting method. The characterization of materials using XRD, TEM, N2 adsorption-desorption, and FT-IR techniques confirmed the successful attachment of organic moieties and preserving original structure of SBA-15 after modification step. Fluorescence experiments demonstrated that SBA-NCO was a highly selective optical sensor for the detection of Fe3+ directly in water over a wide range of metal cations including Na+, Mg2+, Al3+, K+, Ca2+, Cr3+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, and Pb2+ in a wide pH values. 相似文献
60.
Vahideh Masoumi Ali Mohammadi Mohsen Amini Mohammad Reza Khoshayand Rasoul Dinarvand 《Journal of Solid State Electrochemistry》2014,18(6):1763-1771
In this work, polyaniline, polypyrrole, and polyaniline/polypyrrole composite fibers were synthesized in the absence and presence of oxidized multiwalled carbon nanotubes using electrochemical cyclic voltammetry with CF3COOH as dopant. Thermal stability of these fibers was studied by differential scanning calorimetry. Then, headspace solid-phase microextraction process coupled with gas chromatography and flame ionization detector was used for comparing extraction capability of benzaldehyde from aqueous solution. Since polyaniline fiber showed better extraction efficiency than the other fibers, its preparation conditions including acid concentration, aniline concentration, scan rate, and amount of multiwalled carbon nanotubes were studied by means of the “one-factor-at-a-time method”. The analytical performance of polyaniline fibers were investigated to determine benzaldehyde from the aqueous solution. The morphology and texture of polyaniline fibers were examined by field emission scanning electron microscopy and Fourier transform infrared spectroscopy analyses. The attained results revealed that the perfect conditions for acid concentration, aniline concentration, scan rate, and multiwalled carbon nanotubes content were 0.5 M, 0.2 M, 25 mV s?1, and 0.02 wt%, respectively. The limit of detection for the proposed polyaniline fiber was 15 ng ml?1. 相似文献