Strong Base Ion Exchange Resin Research Articles

Cu II—diamine complex catalyzed hydrolysis of phosphate triesters adsorbed on strong-base ion exchange resins. 31P NMR relaxation measurements

The Cu II—diamine complexes, (bipy)CuSO 4 and (tmen)CuSO 4, catalyze the hydrolysis of p-nitrophenyl diphenyl phosphate (PNDP) adsorbed on a strong-base ion exchange resin. Turnover is observed. The major hydrolysis products are diphenyl phosphate, p-nitrophenyl phenyl phosphate, and the ethanolysis product ethyl diphenyl phosphate (EDPP) which are observed in similar amounts in both the presence and absence of the Cu II—diamine catalysts. The apparent bimolecular rate constants found for the (bipy) CuSO 4 and (tmen)CuSO 4 catalysts are 0.023 and 0.024 M −1 s −1, respectively. CuSO 4 is inactive as a catalyst. 31P MAS NMR relaxation measurements of the stable EDPP product reveal that the Cu II—diamine complexes greatly enhance T 1 relaxation, whereas CuSO 4 has only minimal effect. These results are consistent with the complexation of neutral phosphorus esters by the Cu II—diamine catalysts. 31P T 1 measurements of hydrolytically-stable dimethyl methylphosphonate (DMMP) in water solutions of Cu 2+, (tmen)Cu 2+, and Mn 2+ suggest that DMMP exchanges rapidly between inner-sphere and outer-sphere complexes in a nearly identical manner with each of these paramagnetic species.

Removal of uranium from acidic sulfate solution by ion exchange on poly(4-vinylpyridine) and polybenzimidazole in protonated sulfate form

Microporous polybenzimidazole (PBI) of 0.25–0.50 mm spherical bead size from Celanese and spherical crosslinked poly(4-vinyl-pyridine), Reillex 425 PVP, of diameter 0.5–1.5 mm from Reilly Industries Inc. were used in the protonated sulfate form for the sorption of uranium from acidic sulfate solution and compared with conventional strong-acid and strong-base ion-exchange resins Dowex-50(H+) and Dowex-1 (SO42−) for the same application. Both PBI(H2SO4) and PVP(H2SO4) exhibit significantly greater acid tolerance than both Dowex-50(H+) and Dowex-1(SO42−), on which the uranium uptake drops drastically at low pH with the result that at pH values below 1.0, PVP(H2SO4) has considerably greater uranium sorption than both Dowex-50(H+) and Dowex-1(SO42−). The uranium capacity of PBI(H2SO4) is, however, less than half that of PVP(H2SO4). The protonated PVP also has considerably greater salt tolerance than the Dowex resins and exhibits high uranium selectivity in the presence of large excesses of NaCl and Na2SO4, while in comparison the uranium selectivity on Dowex-1(SO42−) is sharply reduced by NaCl and that on Dowex-50(H+) by both NaCl and Na2SO4. Thus, for uranium sorption against high salt background, PVP(H2SO4) exhibits higher capacity than the Dowex resins. Of the three resins, however, PVP(H2SO4) has the slowest sorption kinetics, the approximate half times for exchange being 4, 21 and 65 min for Dowex-50(H+), Dowex-1(SO42−) and PVP(H2SO4), respectively. The sorbed uranium species can be stripped with HCl, H2SO4, NaCl or Na2SO4 which give different stripping rates. The fastest stripping for all the sorbents is obtained with HCl.

Resin-in-leach cyanidation of a carbonaceous gold ore

Resin-in-leach (RIL) cyanidation experiments were performed on a refractory carbonaceous gold ore. The objective of this investigation was to determine if strong-base ion exchange resins could adsorb the soluble aurocyanide complex in preference to natural “preg robbing” organic constituents. Direct cyanidation of the carbonaceous gold ore used in this study resulted in less than 2% gold extraction in 24 hr. RIL cyanidation resulted in about 70% gold recovery onto the resin. Kinetic experiments indicated that 50% of the gold is extracted after 1 hr of leaching. Resin breakage was investigated for as-received and preattrited resins. Similar results were obtained with three different strong base resins.

Denitratation des eaux a potabiliser sur resines echangeuses d'ions—Impact sur la qualite chimique de l'eau traitee

The increase in nitrate concentration in public water supplies is becoming an important problem in certain countries. Among the treatment processes available, the removal of nitrates by ion exchange has been thoroughly studied in recent years with regard to problems of capacity and selectivity. The use of anionic resins in drinking water treatment imply that these compounds do not induce secondary degradation in the quality of the treated water. The purpose of this paper is to examine the chemical quality of water treated by a strong base ion exchange resin (IRA 400) regenerated by sodium chloride. Two sources of organic compounds can be found in water treated with a filter of ion exchange resin: The constitution monomers leached from IRA 400 (styrene, divinylbenzene, trimethylamine and their derivatives). The micropollutants liable to be adsorbed, desorbed or produced during the exhaustion cycles of denitratation. The evolution of the concentration synthesis monomers in treated water was studied during the conditioning and the exhaustion cycles of the resin. Moreover the adsorption isotherms of the IRA 400 for different kinds of micropollutants (aromatic compounds, chlorinated solvents, herbicides, nitrosamines) were determined and the concentration of an added micropollutant (phenol) was measured during an exhaustion cycle. As for the formation of organic compounds during the treatment, we have limited our study to the analysis of N-dimethylnitrosamine during the exhaustion cycle, since this compound has been detected in water demineralized by an ion exchange resin.

ChemInform Abstract: CATALYTIC DEACYLATION OF SUGARS WITH STRONG BASE ION‐EXCHANGE RESINS; AN ALTERNATIVE TO THE ZEMPLEN PROCEDURE

AbstractIn Gegenwart katalytischer Mengen eines Ionenaustauscherharzes (II) werden die benzoylierten und acetylierten Zucker (I), (IV) und (VI) unter Bildung von (III), (V) und (VII) desacyliert.

Catalytic deacylation of sugars with strong base ion-exchange resins; an alternative to the Zemplén procedure

Strong base ion-exchange resins may be used for the catalytic deacylation of sugars; this new technique permits the facile isolation of water-soluble products without deionization.

High Pressure Liquid Chromatographic Determination of Saccharides in Corn Sirups: Collaborative Study

Abstract A liquid chromatographic method for quantitative analysis of saccharides in corn sirup was investigated. Fructose, glucose, and related saccharides are separated on an Aminex 50W-X4, calcium form, cation exchange column or, alternatively, on an Aminex Q15-S, calcium form, cation exchange column. Water is the solvent. All carbohydrate components in the sirup elute from the column, permitting normalized computation vs. synthetically prepared standards. The corn sirup samples are diluted to an approximate dry substance and injected directly into the chromatograph. When required, interfering ionic material is removed with the aid of a mixed strong acid-weak base ion exchange resin. The reproducibility and repeatability coefficients of variation for fructose (on samples ranging from 15 to 90% fructose) are 0.9 and 0.3%, respectively. The reproducibility and repeatability coefficients of variation for glucose (on samples ranging from 8 to 50% glucose) are 1.4 and 0.5%, respectively. The method has been adopted as official first action.

Radioisotope studies of carboxyl sites on strong acid and strong base ion-exchange resins derived from polystyrene

The pH-dependent distribution of carrier-free radioisotopes between aqueous phases at constant ionic strength and polystyrene-divinylbenzene type exchangers reveals the presence of a secondary exchange function attributable to carboxyl groups. Cation- and anion-exchangers of the sulphonate and quaternary ammonium types possess this additional cation-exchange capacity which is, however, relatively very low in currently available commercial resins. Its influence on separations involving radioisotopes of high specific activity is discussed.

Some aspects of ion-exchange in non-aqueous and mixed solvents

The author's published work has been used to illustrate certain aspects of ion-exchange resin stability and sorption behaviour in non-aqueous and mixed solvent media. Solvent and thermal stability have confirmed that even strong-base ion-exchange resins are sufficiently stable in methanol and heptne media at ambient temperature to permit their use in analytical separations. The enhanced selectivity differences of ion-exchange resins for inorganic ions in mixed media is illustrated by the sorption of alkali metal ions on Zeo-Karb 225 (hydrogen form) from aqueous methanol, aqueous ethanol, and aqueous acetone. Finally, on the organic side, the discussion of work on the separation principles of phenols from methanolic media with De-Acidite FF (acetate form) is extended to the wider context of ion-exchange fractionation of peat and petroleum constituents.

Cyclitols. Part XXIII. Suppression of epoxide migration. Synthesis of mucoinositol

A strong-base ion-exchange resin converts 1-O-toluene-p-sulphonylmyoinositol into 1,2-anhydro-(±)-inositol but, unlike sodium hydroxide, does not cause subsequent epoxide migration. Acid hydrolysis of the anhydro-compound gives mainly mucoinositol. The configurations of “bromoscylloquercitol” and “bromoviboquercitol” have been established.

Chromatographic separation of phenols on ion-exchange paper

Paper loaded with strong base ion-exchange resin in Cl − form was used to accomplish the chromatographic separation of a number of monohydric and dihydric phenols and their derivatives by the use of two solvent systems. Data obtained confirmed the results of others who found that there is good correlation between p K a values of some phenols and their R F values for separation on paper that contains a highly polar stationary phase. This is not true for other phenols, suggesting that several factors may affect these chromatographic separations.

Ion Exchange Separation of Uranium from Thorium

S>Uranium has been separated and concentrated from sodium carbonate solutions of monazite sand residues using strong base ion-exchange resins, particularly amberlite IRA-400. The uranyl tricarbonate anion, (UO/sub 2/(CO/sub 3/)/sub 3/!/sup -4/, is believed to be the active species in t his exchange. The interference of anions present in monazite bonate complex was evaluated, and exchange data were obtained on a solution prepared from a typical sample of concentrates of Brazilian sand. The use of strong base exchangers in carbonate systems as a means of exhaustive removal of uranium from thorium is indicated. (auth)