Home About us Contact
|
Home About us Contact | ||
|
|
||
Ion Exchange Resin (ion + exchange_resin)
Selected AbstractsThree Secondary Reference Materials for Lithium Isotope Measurements: Li7-N, Li6-N and LiCl-N SolutionsGEOSTANDARDS & GEOANALYTICAL RESEARCH, Issue 1 2007Jean Carignan matériaux de référence; isotopes de Li; solutions de Li; QUAD-ICP-MS; MC-ICP-MS The CRPG (Nancy, France) has prepared secondary reference materials for Li isotope measurements by mixing 7Li or 6Li spikes and either L-SVEC or IRMM-016 certified reference materials to produce solutions having a known Li concentration and isotopic composition. The Li7-N and Li6-N solution samples (1.5 mol l,1 HNO3) have nominal ,7Li isotopic compositions of 30.1, and -9.7, respectively relative to L-SVEC and concentrations of 100 mg l,1. Repeated measurement of these samples using the QUAD-ICP-MS at the CRPG yielded ,7Li of 30.4 ± 1.1, (n = 13) and -8.9 ± 0.9, (n = 9) at the 2s level of confidence. An additional LiCl-N solution was measured and yielded a delta value of 9.5 ± 0.6, (n = 3). Identical results were obtained at the BRGM (Orléans, France) from determinations performed with a Neptune MC-ICP-MS (30.2 ± 0.3,, n = 89 for the Li7-N, -8.0 ± 0.3,, n = 38 for the Li6-N and 10.1 ± 0.2,, n = 46 for LiCl-N at the 2s level of confidence). The deviation of measured composition relative to the nominal value for the Li6-N solution might be explained by either contamination during preparation or an error during sample weighing. These secondary reference materials, previously passed through ion exchange resin or directly analysed, may be used for checking the accuracy of Li isotopic measurements over a range of almost 40, and will be available to the scientific community upon request to J. Carignan or N. Vigier, CRPG. Le CRPG (Nancy, France) a préparé des matériaux secondaires de référence pour l'analyse des isotopes du Li en mélangeant des spikes de 7Li ou 6Li avec les matériaux de référence certifiés L-SVEC ou IRMM-016, ceci afin de produire des solutions ayant des concentrations et compositions isotopiques de Li connues. Les solutions Li7-N et Li6-N (1.5 mol l,1 HNO3) ont des compositions isotopiques nominales de ,7Li, exprimées par rapport à L-SVEC, de 30.1, et de -9.7, respectivement, et des concentrations de 10 0 mg l,1. L'analyse répétée de ces solutions par QUAD-ICP-MS au CRPG donne des ,7Li de 30.4 ± 1.1, (n = 13) et -8.9 ± 0.9, (n = 9) avec une incertitude à 2s. Une solution additionnelle de LiCl-N a été analysée et a donné une valeur de delta de 9.5 ± 0.6, (n = 3). Des résultats identiques ont été obtenus au BRGM (Orléans, France) où les déterminations ont été effectuées sur le MC-ICP-MS Neptune (30.2 ± 0.3,, n = 89 pour Li7-N, -8.0 ± 0.3,, n = 38 pour Li6-N et 10.1 ± 0.2,, n = 46 pour LiCl-N, à 2s d'intervalle de confiance). Le biais entre les compositions mesurées et la valeur nominale, observé pour la solution Li6-N peut être expliqué par une contamination durant la préparation ou par une erreur durant la pesée. Ces matériaux secondaires de référence, préalablement passés sur résine échangeuse d'ions ou analysés directement, peuvent être utilisés pour vérifier la justesse des analyses isotopiques de Li sur une gamme de presque 40% et sont à la disposition de la communauté scientifique sur demande auprès de J. Carignan ou N. Vigier, CRPG. [source] Sorption properties of the iminodiacetate ion exchange resin, amberlite IRC-718, toward divalent metal ionsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008Charef Noureddine Abstract The sorption properties of the commercially available cationic exchange resin, Amberlite IRC-718, that has the iminodiacetic acid functionality, toward the divalent metal-ions, Fe2+, Cu2+, Zn2+, and Ni2+ were investigated by a batch equilibration technique at 25°C as a function of contact time, metal ion concentration, mass of resin used, and pH. Results of the study revealed that the resin exhibited higher capacities and a more pronounced adsorption toward Fe2+ and that the metal-ion uptake follows the order: Fe2+ > Cu2+> Zn2+ >Ni2+. The adsorption and binding capacity of the resin toward the various metal ions investigated are discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] A convenient synthesis of [11C]paraquat and other [N -methyl- 11C]bisquaternary ammonium compoundsJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 4 2002Douglas M. Jewett Abstract [11C]Paraquat was synthesized by the reaction of [11C]methyl triflate with the mono-triflate salt of 1-methyl-[4,4,]bipyridinyl. The product was selectively separated from the precursor by a microcolumn of Chelex 100 ion exchange resin. The method was applied to the synthesis of a variety of [N -methyl- 11C]bisquaternary ammonium compounds. This is the first reported use of a chelating cation exchange resin for the selective purification of organic dications. Copyright © 2002 John Wiley & Sons, Ltd. [source] Study of synthesised ecofriendly and biodegradable esters: fire resistance and lubricating propertiesLUBRICATION SCIENCE, Issue 3 2010Ponnekanti Nagendramma Abstract Biodegradable esters have been synthesised using Polyols such as 2-methyl-2-n-propyl 1,3-propane diol, 2,2-di methyl 1,3-propane diol, 1,1,1-[tris] hydroxyl methyl propane, 1,1,1-[tris] hydroxyl methyl ethane and carboxylic acids (C6-C12) both pure and their mixtures with indigenous ion exchange resin (Indion-130) catalyst. The products were characterised for their physico-chemical properties and were evaluated for their lubrication performance. These were then compared with VG-22 grade fire resistant hydraulic fluids (FRHFs). The products were found to have good potential for use as a base stock for formulations as FRHF of VG-22 grade. Copyright © 2010 John Wiley & Sons, Ltd. [source] Measurement and Correlation of Critical Gas and Liquid Velocities for Complete Circulation of Solid Particles in External Loop Airlift Bubble ColumnsTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 3-4 2003Katsumi Nakao Abstract The external loop airlift bubble column provides an easy way of good contacting among gas, liquid and solid phases due to a relatively high recirculating liquid velocity UL. The critical gas and liquid velocities for complete circulation of solid particles, UG,C and UL,C, were measured in two different scales of columns with air, tap water and aqueous CMC solutions, and ion exchange resin and glass beads (155,3834 µm) were employed. The UG,C was determined as the inflection point on the plot of the pressure drop due to the suspended solid particles in the downcomer as a function of the gas velocity UG. The critical liquid velocity UL,C corresponding to the UG,C was obtained from the measured relationship between UL and UG. As a result, a unified dimensionless empirical correlation of UL,C was obtained within an error of ±20% and a dimensionless empirical relationship between UL and UG was developed within an error of ±15%. La colonne à bulles de type airlift à boucle externe offre un moyen facile pour le contact entre les phases gazeuse, liquide et solide grâce à la vitesse de liquide en recirculation UL relativement élevée. Les vitesses de gaz et de liquide critiques pour la circulation complète des particules solides, UG,C et UL,C, ont été mesurées dans deux colonnes d'échelle différente avec de l'air, de l'eau du robinet et des solutions aqueuses de CMC, et des billes de verre et de résine échandeuse d'ions (155,3834 µm) ont été employées. La vitesse UG,C est déterminée comme étant le point d'inflexion sur la courbe de la perte de chgarge causée par les particules solides suspendues dans le déversoir en fonction de la vitesse de gaz UG. La vitesse de liquide critique UL.C correspondant à la vitesse UG.C est obtenue à partir de la relation mesurée entre UL et UG. Ainsi, on obtient une corrélation empirique adimensionnelle unifiée de UL.C avec une erreur de ± 20% et une relation empirique adimensionnelle entre UL et UG est établie avec une erreur de ±15%. [source] Liquid phase mineralization of gel-type anion exchange resin by a hybrid process of Fenton dissolution followed by sonication and wet air oxidationASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2009T. L. Gunale Abstract A hybrid process of Fenton dissolution followed by sonication and wet air oxidation (WAO), has been demonstrated to mineralize strongly basic anion exchange resin (gel type). The solid anion exchange resin beads could be dissolved in water by Fenton process wherein the copper-catalyzed hydrogen peroxide (H2O2) reaction makes the resin hydrophilic by the disintegration of polymer matrix. Sonication of the dissolved resin thus obtained made the waste stream more amenable to WAO. Parameters for Fenton dissolution and sonication were studied to aid effective mineralization by WAO. The kinetic studies of WAO were performed using copper sulfate (CuSO4) as the homogeneous catalyst, in the temperature range of 483,523 K. It is thus possible to address the disposal of solid ion exchange resin by the hybrid process, described here. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source] A Novel Catalyst for Isobutene Oligomerization to High Quality GasolineCHINESE JOURNAL OF CHEMISTRY, Issue 6 2003Zhou Peng Abstract Dimerization of isobutene in liquid state to form high-octane value gasoline components was investigated over a homemade novel ion exchange resin, SPPESK, which shows high activity and selectivity in isobutene dimerization under mild conditions. [source] A fluorimetric method for the determination of trace pentachlorophenol, based on its inhibitory effect on the redox reaction between the improved Fenton reagent and rhodamine BLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 5 2007Huiqin Guo Abstract A sensitive fluorimetric method is presented and discussed for the determination of pentachlorophenol in aqueous solutions. This method is based on the inhibitory effect of pentachlorophenol on the reaction of conventional Fenton [Fe(III) + H2O2] reagent with rhodamine B in the medium of perchloric acid, which results in the fluorescence quenching of rhodamine B. It was further found that the sensitivity for the determination was improved significantly when the molecular ligand EDTA was added. This improved system was therefore presented for the determination of pentachlorophenol. The characteristics of the excitation and emission spectra, optimization of the experimental conditions, the stability of the system and the influence of foreign matter have all been investigated. Under optimal conditions, the linear range for the determination of pentachlorophenol is 12,480 ng/mL with a 3, limit of detection of 0.96 ng/mL. Compared with the conventional Fenton system, the improved system shows obvious advantages in both sensitivity and selectivity. By combination with the pretreatment of samples using ion exchange resins and XDA-1 absorption resin, the improved Fenton method was used for the first time for the determination of pentachlorophenol in synthetic samples and natural water samples, and satisfactory results, in agreement with those of the HPLC method, were achieved. The possible mechanism of the reactions has also been discussed. Copyright © 2007 John Wiley & Sons, Ltd. [source] An exclusion mechanism in ion exchange chromatographyBIOTECHNOLOGY & BIOENGINEERING, Issue 5 2006C. Harinarayan Abstract Protein dynamic binding capacities on ion exchange resins are typically expected to decrease with increasing conductivity and decreasing protein charge. There are, however, conditions where capacity increases with increasing conductivity and decreasing protein charge. Capacity measurements on two different commercial ion exchange resins with three different monoclonal antibodies at various pH and conductivities exhibited two domains. In the first domain, the capacity unexpectedly increased with increasing conductivity and decreasing protein charge. The second domain exhibited traditional behavior. A mechanism to explain the first domain is postulated; proteins initially bind to the outer pore regions and electrostatically hinder subsequent protein transport. Such a mechanism is supported by protein capacity and confocal microscopy studies whose results suggest how knowledge of the two types of IEX behavior can be leveraged in optimizing resins and processes. © 2006 Wiley Periodicals, Inc. [source] | ||||||||||