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An analytical scheme is proposed which combines three speciation techniques for determination of particular Al species in soil extracts and percolating waters. A cation-exchange fast protein liquid chromatography — inductively coupled plasma atomic emission spectrometry (FPLC-ICP-AES) procedure, a microcolumn chelating ion-exchange chromatography- atomic absorption spectrometry (MCC-ETAAS) technique and the 8-hydroxyquinoline spectrophotometric method (8HQ-spectrophotometry) were employed. The FPLC-ICP-AES procedure offers determination of Al3+ (retention time 4.5 min) and Al(OH)2+ species (retention time 4.0 min) which are separated from Al(OH)+
2 (retention time 1.5min). AlF2+ coelutes with Al(OH)2+ species, while Al(SO4)+, AlF+
2 and negatively charged Al organic complexes coelute with Al(OH)+
2 species. The MCC-ETAAS technique enables determination of the sum of positively charged monomeric aqua- and hydroxy-Al species plus sulphate- and fluoro-Al complexes. Employing the 8HQ-spectrophotometry the sum of positively charged monomeric aqua- and hydroxy-Al species plus sulphato- and most of the labile organic Al species are determined. The sensitivities of these selected techniques were adequate for speciation of Al in the samples analyzed. On the basis of the specific selectivity of a particular technique various groups of Al species may be determined. Thus, the comparison of analytical data from complementary procedures provides more comprehensive information on Al species present in soil extracts and percolating waters. 相似文献
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Marija Vojnovi Draan Jozi Gerald Giester Berislav Peri Pavica Planini Nevenka Brni
evi 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(4):m219-m220
The novel title compound, [(CH3)4N]2[Ta6Br12(H2O)6]Br4·2H2O, with a [Ta6Br12]2+ cluster unit, has been prepared and structurally characterized. The compound crystallizes in space group C2/c, with a twofold axis passing through the cluster and the centre of symmetry located between the clusters. The nearest neighbouring cluster units are aligned along the crystallographic c axis, forming a one‐dimensional chain pattern. 相似文献
4.
M. Poje 《Tetrahedron letters》1980,21(16):1575-1576
The method for the synthesis of new 2-acyl-6-alkyl(aryl)-3-hydroxy-4H-pyran-4-ones (), is described, involving the oxidation of 1,3,4,6-tetraketones with iodosobenzene diacetate. 相似文献
5.
Marija Vojnovi Berislav Peri Pavica Planini Gerald Giester Nevenka Brni
evi 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(6):i71-i73
The title compound, [Ta6Br12(H2O)6](Br0.4Cl1.6)·8H2O, crystallizes in space group P. The structure contains two crystallographically independent [Ta6Br12(H2O)6]2+ cluster cations forming distinct layers parallel to the ab plane. The compound is isoconfigurational with the double salts [Ta6Br12(H2O)6]X2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O (X = Cl, Br). 相似文献
6.
Nevenka M. Antovic Perko Vukotic Nikola Svrkota Sergey K. Andrukhovich 《Journal of Radioanalytical and Nuclear Chemistry》2012,293(1):299-302
Plutonium-238 (238Pu) activity concentrations in soil samples from Montenegro (six samples from three localities) have been measured for the first time. The 238Pu/137Cs activity ratio was determined on the basis of alpha and gamma-spectrometric measurements, and found to be with an average of 0.0006 and standard deviation of 0.0003. By using the activity ratios determined in the present study, 238Pu activity concentrations were estimated for three localities in the central: one in the northern, and two in the eastern part of Montenegro. 相似文献
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Nevenka Rajic Djordje Stojakovic Aleksander Recnik 《Journal of Physics and Chemistry of Solids》2011,72(6):800-803
Nanoparticles of NiO, ZnO and Cu2O crystallize when the Ni-, Zn- and Cu-exchanged natural clinoptilolite, respectively, are dehydrated by heating in air at 550 °C. The dehydration of Mn-exchanged clinoptilolite does not lead to the crystallization of manganese oxide but affects the crystallinity of the host clinoptilolite lattice, which becomes amorphous. The NiO, ZnO and Cu2O nanoparticles are found to be randomly dispersed in the clinoptilolite matrix. The particle size varies from 2 to 5 nm and exceeds the aperture of the clinoptilolite channel (approximately 0.4 nm), suggesting that the crystallization of the oxide phases takes place on the surfaces of clinoptilolite microcrystals. 相似文献