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Limin Zhou Yuyan Jia Juan Peng Zhirong Liu Essam Al-Zaini 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(1):331-340
The triphosphate-crosslinked magnetic chitosan resins (TPP-MCR) with a diameter range of 200–350 nm were synthesized for the adsorption of U(VI) and Th(IV) ions from aqueous solutions. The adsorption experiments were conducted in both mono-component systems with pure actinide solution and bi-component systems with different U/Th mass ratios. The maximum adsorption capacities in mono-component systems determined by Langmuir model were 169.5 and 146.8 mg g?1 for U(VI) and Th(IV), respectively. In bi-component systems, U(VI) and Th(IV) adsorption capacities were reduced significantly, and the combined sorption capacities were substantially lower (almost halved) compared to those obtained by the addition of sorption capacities using mono-component solutions, indicating that U(VI) and Th(IV) compete for the same sorption sites. Adsorption–desorption experiments for five cycles illustrated the feasibility of the repeated use of TPP-MCR for the adsorption of U(VI) and Th(IV) ions. 相似文献
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Adel M. El-Menshawy M. E. Khalifa 《Journal of Radioanalytical and Nuclear Chemistry》2006,268(2):341-348
Summary Duolite
C20 resin modified with trimethylammonium acetosalycoylhydrazone has been
developed, for the selective separation and/or preconcentration of uranium. The
modified resin was characterized by elemental analysis and infrared spectra.
Batch and column modes were applied. The newly designed resin quantitatively
sorbs uranium ion at pH 3 when the flow rate equals to 2 ml . min
-1 . The sorption capacity was 0.750 mmol . g-1 for
uranium ion, whereas its preconcentration factor was 200. The lower limit of
detection was 5 ng . ml-1 and its desorption was
effective with 5 ml of 3 mol . l-1 HCl or HNO3
prior to detection spectrophotometry. The modified resin was highly
ion-selective in nature even in the presence of large concentrations of
electrolyte or organic media, with a preconcentrating ability for uranium ion.
The modified resin was tested on its utility with synthetic, real and certified
ore samples, showed RSD values of <2% reflecting the accuracy and
reproducibility of the newly modified resin.</p>
</p> 相似文献
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V. A. Pulhani S. Dafauti A. G. Hegde 《Journal of Radioanalytical and Nuclear Chemistry》2012,294(2):299-302
Uranium determination in environmental samples is faced with problems due to presence of iron and other major elements. Iron is also used many a times for pre-concentration of uranium and actinides. Separation of milligram quantity of Fe from microgram quantity of uranium becomes essential during the estimation step. A simple two step procedure has been standardized for separating uranium and iron using anion exchange in 0.025 M H2SO4. Quantitative recovery of uranium was obtained as well as good separation from iron. This method was applied for estimation of uranium in water samples. 相似文献
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Selective adsorption of modified nucleoside cancer biomarkers by hybrid molecularly imprinted adsorbents
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Agnieszka Iwanowska Shin‐Ichi Yusa Maria Nowakowska Krzysztof Szczubiałka 《Journal of separation science》2016,39(15):3072-3080
Modified adenosine nucleosides have been proposed to be potential DNA‐based biomarkers for early diagnosis of tumor and a promising tool for the development of noninvasive prediction systems. However, the low concentration of modified adenosine nucleosides in physiological fluids makes them challenging for both quantitative and qualitative determination. Therefore, materials, which are potentially useful for selective adsorption of nucleobase‐containing compounds, were obtained. To obtain the adsorbents, the silica gel particles were coated layer‐by‐layer with films of the polymers with different combinations of polymers containing thymine groups. Next, the microspheres were irradiated with UV light in the presence of 2’‐deoxyadenosine or 5’‐deoxy‐5’‐(methylthio)adenosine, as template molecules, which resulted in the photodimerization of thymine moieties and molecular imprinting of adsorbed modified adenosine compounds. The selectivity of the adsorption was significantly enhanced by the photoimprinting process. Eventually, the imprinted particles have shown an improved ability to recognize mainly 2’‐deoxyadenosine and 5’‐deoxy‐5’‐(methylthio)adenosine molecules. The best performing adsorbent was obtained using modified natural polysaccharides. The studied materials could serve as promising adsorbents of biomarkers for tumor diagnostics. 相似文献
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B.W. Budesinsky 《Microchemical Journal》1977,22(1):50-54
Uranium(VI) (10–100 μg) is extracted with 2% dibenzoylmethane in benzene at pH 6–7 while other cations are masked with CDTA (maximum of 8 μg/100 ml). Shaking with 6 M hydrochloric acid reintroduces uranium(VI) into the aqueous phase, where after evaporation and complexation with Arsenazo III in 0.02 M hydrochloric acid the final measurement of absorbance at 650 nm is performed. Iron(III), copper(II), aluminum, and zinc do not interfere even if present in amounts of 15–19 mmol. 相似文献
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Lattice models based on modified adsorption and interaction rules are suggested for heterogeneous CO oxidation. The advantage of these models over the conventional model is that they disavow the false prediction that the catalytic surface will be poisoned by oxygen at low CO concentrations in the reaction mixture. In the general case, the way the reaction rate and CO and O coverages vary with CO concentration is sensitive to the choice of adsorption rules.Translated from Kinetika i Kataliz, Vol. 46, No. 1, 2005, pp. 104–107.Original Russian Text Copyright © 2005 by Abramova, Baranov, Dulov. 相似文献
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Simultaneous metal adsorption on tannin resins 总被引:1,自引:0,他引:1
J. L. Santana L. Lima J. Torres F. Martínez S. Olivares 《Journal of Radioanalytical and Nuclear Chemistry》2002,251(3):467-471
Vegetable tannin sorbent is evaluated as ion exchange resin using a multitracer study on the adsorption behavior of various elements. Lisiloma latisiliqua L. tannins, polycondensated into spherical pellets were chosen as sorbent resin material. Sorption evaluation of Ce, Cu(II), U(VI), Eu, Fe(III), Th, Nd as representatives of different classes of metal ions were done at different pH values. The distribution ratio of the studied elements was calculated from laboratory experiments. Tannic ion exchange material shows excellent ability for actinides and rare earth elements adsorption from waters. Using radiotracers, the number of catechins subunits involve in each tannin-metal complex was determined. 相似文献
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Till now, Ionic liquid‐stabilized metal nanoparticles were investigated as catalytic materials, mostly in the hydrogenation of simple substrates like olefins or arenes. The adjustable hydrogenation products of aromatic compounds, including quinoline and relevant compounds, aromatic nitro compounds, aromatic ketones as well as aromatic aldehydes, are always of special interest, since they provide more choices for additional derivatization. Iridium nanoparticles (Ir NPs) were synthesized by the H2 reduction in imidazolium ionic liquid. TEM indicated that the Ir NPs is worm‐like shape with the diameter around 12.2 nm and IR confirmed the modification of phosphine‐functionalized ionic liquids (PFILs) to the Ir NPs. With the variation of the modifier, solvent and reaction temperature, substrate like quinoline and relevant compounds, aromatic nitro compounds, aromatic ketones as well as aromatic aldehydes could be hydrogenated by Ir NPs with interesting adjustable catalytic activity and chemoselectivity. Ir NPs modified by PFILs are simple and efficient catalysts in challenging chemoselective hydrogenation of quinoline and relevant compounds, aromatic nitro compounds, aromatic ketones as well as aromatic aldehydes. The activity and chemoselectivity of the Ir NPs could be obviously impacted or adjusted by altering the modifier, solvent and reaction temperature. 相似文献
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Cross-linked chitosan resins with catechol (catechol-type chitosan, type 1 and type 2), iminodiacetic acid (IDA-type chitosan), iminodimetylphosphonic acid (IDP-type chitosan), phenylarsonic acid (phenylarsonic acid-type chitosan), or serine (serine-type chitosan) were prepared for the collection and concentration of uranium(VI). The adsorption behavior of U(VI) and other ionic species, such as metal ions and oxo-acid ions, on the cross-linked chitosan (base material) and chitosan resins modified with chelating moieties was examined using a column procedure. Especially, the catechol-type chitosan (type 2) adsorbed U(VI) at pH 2-7, and selectively collected U(VI) at acidic pH regions by forming a stable chelate with hydroxyl groups of catechol moiety introduced to the chitosan. Also, the adsorption properties of cationic and anionic species present in aquatic media were elucidated. The adsorption ability for U(VI) was in the order: catechol-type chitosan (type 2) > serine-type chitosan > phenylarsonic acid-type chitosan > the others. The catechol-type chitosan (type 2) was useful for the collection and concentration of uranium(VI). 相似文献
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Chen Qiong Wang Hongqiang Hu Eming Lei Zhiwu Liu Wenjie Jiang Xiaoyu Hou Wei Wang Qingliang 《Journal of Radioanalytical and Nuclear Chemistry》2020,323(1):73-81
Journal of Radioanalytical and Nuclear Chemistry - Using steel slag as a raw material, a new type of adsorption material has been prepared by acid modification method. The preparation conditions of... 相似文献
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Journal of Radioanalytical and Nuclear Chemistry - Noble gas monitoring system is used to measure the volumetric activity of beta particles due to radioactive noble gases—41Ar, 85Kr and... 相似文献
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The packings most widely used for solid-phase extraction are hydrophobic and make poor surface contact with aqueous samples unless the resins are first treated with an activating organic solvent such as methanol. Insertion of an acetyl- or hydroxymethyl group into a porous polystyrene-divinylbenzene resin provides a more hydrophilic surface that is easily wetted by water alone. Small columns of the chemically modified resins were found to be very efficient for the solid-phase extraction of many types of organic solutes from aqueous samples. Comparative recovery studies showed that the modified resins are superior to both silica packings and unmodified organic resins for the solid-phase extraction of organic compounds, and especially for polar organics such as phenols. 相似文献
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Fan Meiqing Wang Xiao’e Song Qiong Zhang Liying Ren Bo Yang Xiaodong 《Journal of Radioanalytical and Nuclear Chemistry》2021,330(3):589-602
Journal of Radioanalytical and Nuclear Chemistry - Uranium is for a long time the main nuclear fuel on the global level. However, in nuclear energy mining and disposal, radioactive elements may... 相似文献
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S. N. Gladkikh L. I. Kuznetsova L. I. Naumova A. I. Vyalov 《Polymer Science Series D》2009,2(4):238-242
Main characteristics of heat-conducting adhesive materials used to withdraw heat from warming elements of devices and the
joints of electrotechnical equipment are presented. The developed materials, i.e., TsMK-TP adhesive pastes and TPK convenient
for application adhesives, are cold-curing compositions based on epoxy-diane resins modified with Laproxide products. They
have heat conductivity coefficients of no less than 1.8 W/(m K), are workable in the temperature range of −196 to 150°C (up
to 200°C for a short period of time), and do not contaminate optical elements due to minimal gas release under exposure to
vacuum and increased temperatures. 相似文献