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151.
A novel silica sorbent, silica gel-immobilized 5-aminoisophthalohydrazide (SiO2-APH), was prepared by the condensation of 3-chloropropyl-functionalized silica gel with 5-aminoisophthalohydrazide (APH) derived from dimethyl 5-aminoisophthalate as a starting material and used for separation and preconcentration of Cu, Zn, and Pb metals in water samples using Flame Atomic Absorption Spectrometry (FAAS). The characterization of the new sorbent was carried out by Elemental Analysis, Thermogravimetric Analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR). Important analytical parameters including as pH, amount of sorbent, type and amount of eluting solvent, sample volume, vortex and ultrasonic bath time, matrix ions that effect the developed SiO2-APH-solid phase extraction (SPE) method were investigated and optimum parameters were detected. Recoveries of examined metals were obtained as 98% for Cu and Pb and 101% for Zn. The relative standard deviation (RSD, n = 8) of Cu, Zn and Pb metals were 3.2, 2.8 and 1.6%, respectively. Limit of detections (LODs) (n = 10) were found as 2.7 μg L−1 for Cu, 7.4 μg L−1 for Zn and 3.5 μg L−1 for Pb μg L−1. The accuracy of the new method was assessed by analyzing of TMDA-51.4 and TMDA-70.2 certified reference materials. The results obtained for metals were in a good agreement with certified values. Addition/recovery test was applied to the real well, river, dam and stream water samples to check the accuracy of the method. The results showed that the developed SiO2-APH-SPE method can be effectively used as an alternative method for determination of Cu, Zn, and Pb metals in water samples. 相似文献
152.
Yesilyurt Murat Kadir Yilbasi Zeki Aydin Mustafa 《Journal of Thermal Analysis and Calorimetry》2020,140(6):2903-2942
Journal of Thermal Analysis and Calorimetry - The objective of the present study is to scrutinize the influence of a binary blend of diesel–safflower oil biodiesel and ternary blends of... 相似文献
153.
The interactions of Sc3+ and Y3+ ions with disodium 1,2-dihydroxybenzene-3,5-disulfonate (Na2H2L, where H2L2- = Tiron) were investigated in aqueous solution by means of potentiometric and spectroscopic methods. The coordination of Tiron to Sc3+ and Y3+ takes place through two phenolic oxygen atoms of catecholate ion in different stoichiometries. Thus, the binding of Tiron to Sc3+ occurs either in 1 : 1 or 1 : 2 molar ratios; they have resulted by the formation of [ScL]- and [ScL2]5- type complexes, respectively. On the other hand, Y3+ ion behaves like Th4+ and Ln3+ ions toward Tiron. It forms [YL]-type complex in 1 : 1 molar ratio; but in 1 : 2 or in higher molar ratios, only unique [Y2L3]6- type complex formation takes place. The formation constants of [ScL]-, [ScL2]5-, [YL]-, and [Y2L3]6- complexes were determined by analysis of the potentiometric data in ionic medium of 0.1 M KNO3 or NaClO4 at 25°C. The hydrolytic reactions of Sc(III) and Y(III) complexes with Tiron were determined from potentiometric data and the formation constants of [ScL(OH)]2- and [YL(OH)]2- were also calculated.From Koordinatsionnaya Khimiya, Vol. 31, No. 1, 2005, pp. 62–68.Original English Text Copyright © 2005 by Aydin, Türkel, Özer. 相似文献
154.
155.
Cemil Ibis Sibel Sahinler Ayla Şenol Yavuz Hatice Asar Funda Özkök Hakan Bahar 《Phosphorus, sulfur, and silicon and the related elements》2018,193(6):358-362
In this study, S-, S,S- and S,O-substituted novel nitrodiene compounds were synthesized. Cyclization products were formed when difunctional nucleophiles were used. The stereoisomerism of a heterocyclic nitrodiene is discussed with the help of XRD studies. The structures of all compounds were characterized by spectroscopic methods (FT-IR, 1H NMR, 13C NMR, 19F NMR, MS) and microanalysis. 相似文献
156.
Funda Yukruk 《Tetrahedron letters》2005,46(35):5931-5933
A novel perylenediimide derivative which has a bay region hydroxyl function behaves as a pH-sensitive dye. The deprotonation of the aryl-OH yields a green solution with a λmax of 692 nm and this deprotonated form has strong internal charge transfer characteristics. On reprotonation in acidic solutions, the typical PDI absorbance spectrum is restored. The experimentally determined pKa (7.45) is very close to physiological pH, therefore the most significant changes in color take place in the vicinity of this pH value. 相似文献
157.
Muhammed Aydin Mehmet Atilla Tasdelen Tamer Uyar Yusuf Yagci 《Journal of polymer science. Part A, Polymer chemistry》2013,51(24):5257-5262
A series of A3‐type star poly(methylmethacrylate)/clay nanocomposites is prepared by in situ atom transfer radical polymerization (ATRP) initiated from organomodified montmorillonite containing quaternary trifunctional ATRP initiator. The first order kinetic plot shows a linear behavior, indicating the controlled character of the polymerization. The resulting nanocomposites are characterized by spectroscopic (XRD), thermal (DSC and TGA), and microscopic (TEM) analyses. The exfoliated nanocomposite has been obtained when polymerization was conducted with 1% of organic clay loading. Thermal analyses show that all nanocomposites have higher glass transition values and thermal stabilities compared to neat polymer. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 5257–5262 相似文献
158.
In this study, new calculations on the excitation functions of 13C(p,n)13N, 14N(p,a)11C, 15N(p,n)15O, 16O(p,a)13N, 18O(p,n)18F, 62Ni(p,n)62Cu, 68Zn(p,n)68Ga and 72Ge(p,n)72 As reactions have been carried out in the 5–40 MeV incident proton energy range. In these calculations, the pre-equilibrium
and equilibrium effects have been investigated. The pre-equilibrium calculations involve hybrid model, geometry dependent
hybrid model, the cascade exciton model and full exciton model. Equilibrium effects were calculated according to Weisskopf-Ewing
model. The calculated results have been compared with experimental data taken from literature.
相似文献
159.
160.
A study has been made of the effect of orientation on the oxidative degradation of poly(vinylchloride) (PVC), low density polyethylene (LDPE) and high density polyethylene (HDPE) under the influence of γ- and u.v.-radiation. The effect of drawing in PVC is to increase the rate of oxidative degradation; in LDPE and HDPE, this rate decreases (especially for HDPE) both under u.v. and γ-radiation. 相似文献