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1.
R. B. Kadam G. G. Mali B. S. Mohite 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(1):501-511
A selective and effective chromatographic separation method for thorium(IV) has been developed by using poly [dibenzo-18-crown-6] as stationary phase. The separations are carried out from glycine medium. The sorption of thorium(IV) was quantitative from 1 × 10?2 to 1 × 10?4 M glycine. The elution of thorium(IV) was quantitative with 2.0–8.0 M HCl, 4.0–7.0 M HBr, 1.0–2.0 M HClO4 and 5.0 M H2SO4. The capacity of poly [dibenzo-18-crown-6] for thorium(IV) was found to be 0.215 ± 0.01 mmol/g of crown polymer. The effect of concentration of glycine, metal ion, foreign ion and eluents has been studied. Thorium(IV) was separated from a number of cations in ternary as well as in multicomponent mixtures. The applicability of the proposed method was checked for the determination of thorium(IV) in real as well as geological sample. The method is simple, rapid, and selective with good reproducibility (approximately ±2 %). 相似文献
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Sandip R. Sabale D. V. Jadhav B. S. Mohite 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(2):273-278
A simple and efficient column chromatographic method has been developed for the sequential separation of U(VI), Th(IV) and
Ce(III) using poly[dibenzo-18-crown-6] as stationary phase and l-arginine as a counter ion. The different elution patterns with various eluting agents were observed for individual element.
The capacity of poly[dibenzo-18-crown-6] for U(VI), Th(IV) and for Ce(III) was found to be 0.96, 0.86 and 1.49 (±0.01) mmol/g
of crown polymer, respectively. The method is efficient to separate the elements in multicomponent mixtures and has good recovery.
The method is extended to determine the U(VI), Th(IV) and Ce(III) from monazite sand. The method is simple, rapid and selective
having good reproducibility (~±2%). 相似文献
4.
A two-step short and efficient strategy for the synthesis of substituted piperidones and piperidines in high diastereoselectivity (only trans-configuration), by employing cascade type reaction using BF3·Et2O or by carrying out one pot deprotection of tBoc group followed by intramolecular aza-Michael addition of α,β-unsaturated beta keto esters has been developed. Using a similar strategy a short access to hydroxy pipecolic acid is also described. Very simple and rapid experimental procedures involving mild conditions and only one or two chromatographic purifications are the main features of the process. 相似文献
5.
Room‐temperature magnetization hysterisis measurements were conducted on Mn0.5Zn0.5GdxFe(2‐x)O4 ferrite nanoparticles, with x = 0, 0.5, 1.0, 1.5. The structure of this ferrite is normal spinel where the added of Gd3+ ions occupied the octahedral sites and replaces Fe3+ ions. The saturation magnetization was found to increase with the initial addition of the Gd3+ ions followed by a sharp decrease with further addition of Gd3+ ions. The Curie temperature was found to increase up to Gd3+ concentration of x = 1.0, and then decreases at x = 1.5. These results were attributed to the surface spins. Because the size of Gd3+ ions is larger than that of Fe3+ ions, the substitution of Fe3+ ions with the Gd3+ ions results in surface disorder which results in surface spins. A core‐shell magnetization model was introduced where several factors were combined to explain our results. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
6.
B. S. Mohite B. E. Mahadik A. S. Jadhav 《Journal of Radioanalytical and Nuclear Chemistry》2000,245(2):343-346
A simple column chromatographic method has been developed for the separation of thorium(IV) from associated elements using poly-(dibenzo-18-crown-6). The separations are carried out from picric acid medium. The adsorption of thorium(IV) was quantitative from 0.0005–0.05M picric acid. Amongst the various eluents tested, 2.0–8.0M HCl, HBr, 1.0–6.0M HClO4 and 5.0M acetic acid were found to be particularly efficient for the quantitative elution of thorium(IV). The capacity of poly-(dibenzo-18-crown-6) for thorium(IV) was found to be 1.29±0.01 mmol/g of crown polymer. Thorium(IV) was separated from a number of cations in binary mixtures in which most of the cations showed a very high tolerance limit. It was possible to separate thorium(IV) from a number of cations such as lanthanum(III), yttrium(III), uranium(VI), beryllium(II) and barium(II) in multicomponent mixtures. The method was extended to the determination of thorium in monazite sand. It is possible to separate and determine 5 ppm of thorium(IV) by this method. The method is very simple, rapid, selective and has good reproducibility (approximately ±2%). 相似文献
7.
A very simple column chromatographic separation method has been developed for molybdenum (VI) using poly-(dibenzo-18-crown-6). The separations are carried out from hydrochloric acid medium. The adsorption of molybdenum (VI) on a poly-(DB-18-C-6) was quantitative from 2.5 to 10.0M HCl. Amongst the various eluents tested, 0.5M ammonium hydroxide was found to be an efficient eluent. Molybdenum (VI) was separated from a large number of elements in binary form, as well as from multicomponent mixtures. The method was applied for the analysis of molybdenum from various alloy samples. The method is very simple, rapid, selective and reproducible. The reproducibility of the procedure is +/-2%. 相似文献
8.
A simple separation method has been developed for thorium(IV) using poly-(dibenzo-18-crown-6) and column chromatography. The separation was carried out from ascorbic acid medium. The adsorption of thorium(IV) was quantitative from 0.001-0.01M ascorbic acid. The elution of thorium(IV) was quantitative with 4.0-8.0M HCl, 3.0-6.0M HClO4, 4.0-8.0M H2SO4 and 1.0-8.0M HBr. The capacity of poly-(dibenzo-18-crown-6) for thorium(IV) was found to be 1.379±0.01 m.mol/g of crown polymer. Thorium(IV) was separated from a number of cations in binary as well as in multicomponent mixtures. The method was extended to the determination of thorium in monazite sand. It is possible to separate and determine 5 ppm of thorium(IV) by this method. The method is very simple, rapid, selective and has good reproducibility (approximately ±2%). 相似文献
9.
DB-18-C6 was used for the extractive separation analysis of molybdenum(VI) from a range of other elements. Molybdenum(VI) was quantitatively extracted from 8M hydrochloric acid with 0.01M DB-18-C6 in nitrobenzene. It was stripped from the organic phase with 2M nitric acid and determined spectrophotometrically with Tiron at 390 nm. Molybdenum was separated from a large number of elements in binary mixtures, the tolerance limit for most elements being very high. Selective extraction of molybdenum permits its separation from barium, thorium, cesium, rubidium, strontium, lanthanum, chromium(III) and cerium(III). The method was extended for the analysis of molybdenum in a soil sample. 相似文献
10.
B. S. Mohite J. M. Patil D. N. Zambare 《Journal of Radioanalytical and Nuclear Chemistry》1993,170(1):215-224
Uranium(VI) was quantitatively extracted with 0.01M DB-24-crown-8 in nitrobenzene from 6 to 10M hydrochloric acid. From the organic phase uranium was stripped with 2M nitric acid and determined spectrophotometrically with PAR at 530 nm. Uranium(VI) was separated from a large number of elements in binary mixtures as well as from multicomponent mixtures. The method was extended to the analysis of uranium in geological samples and animal bone. 相似文献