Macroreticular p-(omega-sulfonic-perfluoroalkylated) polystyrene ion-exchange resins: a new type of selective solid acid catalyst

Macroreticular p-(omega-sulfonic-perfluoroalkylated) polystyrene (FPS) cation-exchange resins have been synthesized by sequential p-perfluoroalkylation of macroreticular polystyrene (PS) with omega-fluorosulfonylperfluorodiacyl peroxide 2, hydrolysis and acidification; the fluorinated mesoporous resins exhibited higher activity and selectivity than commercial Amberlyst 36 and Nafion NR50 in the cyclization of pseudoionone.     

Final purification and concentration of americium/curium separated from high-level reprocessing waste

A cation-exchange cycle has been developed for the recovery and concentration of the Am/Cm product from a DTPA/lactic acid solution used in an extraction process for the isolation and separation of the actinides from lanthanide fission products. The optimum pH region for the sorption of Am³⁺ from 0.05M DTPA/1M lactic acid solutions by strongly acidic cation-exchange resins is pH 0.9–1.0. Maximum usable capacities, heights of the exchange zone, and concentration factors for different resins, cross-linkages and temperatures have been determined. Decontamination factors are given for some fission products, as well as U, Np and Pu.     

Ion-exchange resins in non-aqueous solvents-III Solvent-uptake properties of ion-exchange resins and related adsorbents

Solvent-uptake properties for several synthetic resins and common adsorbents were determined by the centrifugation method. Data are reported for eighteen different solvents, which include water and the common polar and non-polar organic solvents. The cation-exchange resins are of two varieties: the microreticular or gel type and the macroreticular or porous type. The latter resin being rigid and porous takes up all types of solvents, whereas the former resin, which relies on swelling of the resin matrix, does not take up the nonpolar solvents. Data for the H(+) form and Na(+) form macroreticular resin are compared. Unsulphonated polystyrene-divinylbenzene polymers which possess similar micro- and macroreticular properties to the cation-exchange resins were also studied in the same solvents. The swelling properties of these non-polar resins are compared with each other and with the polar cation resins. Other adsorbents, which are frequently used as supports in chromatography were also examined in the same solvents. Several of these have large average pore diameters and surface areas like the macroreticular resin.     

Uricase-like catalytic activity of ion-exchange resins modified with metalloporphyrins

The uricase-like catalytic activity of the ion-exchange resins modified with metalloporphyrins has been investigated through the oxidation of uric acid. The anion-exchange resins modified with Mn(3+)-tetrakis(sulfophenyl)porphine and the cation-exchange resin modified with Mn(3+)-tetrakis(1-methylpyridinium-4-yl)porphine exhibited the highest uricase-like activity among the modified resins tested. The fact that these resins accelerated the oxidation of uric acid even after ten cycles of use indicates that the modified resins act as catalysts in the reaction catalysed by uricase. Some of the modified resins may be effectively used for the determination of uric acid in place of uricase.     

Cation-exchange resins and non-ionic cross-linked polymers in analysis of aqueous solutions for organic contaminants

Cyclohexane derivatives with a hydroxyl or carboxylic acid group separated by one or two methylene groups from the ring are, in acidified aqueous solution, adsorbed more strongly than the corresponding aromatic compounds both on sulfonated styrene—divinylbenzene resins and on non-ionic styrene—divinylbenzene resins. These observations and the lower temperature dependence observed for the cyclohexane derivatives indicate that hydrophobic interactions have a marked influence on the adsorption. Possible losses of non-ionic compounds by adsorption on cation-exchange resins and by leakage through columns packed with non-ionic resins used for concentration of organic compounds are discussed.     

The isolation of olitoriside from jute seeds

Summary 1. The possibility of using ion-exchange resins for the purification of extracts in the isolation of cardiac glycosides has been shown.2. A method is proposed for obtaining olitoriside by using a mixture of anion-exchange and cation-exchange resins to purify the extract, this method giving an increased yield of the preparation.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 81–83, January–February, 1972.     

烷基十八胺在离子交换树脂上的吸附及影响研究

研究发现，各种离子交换树脂对烷基十八胺均有较强的吸附作用，阳树脂吸附作用最强，可以近似100％吸附，吸附烷基十八胺后的树脂强度降低，沉降速度改变。常用的无机复苏液无法将吸附的十八胺洗脱出来。     

Utilization of ion exchangers in analytical chemistry XXVI : Application of the ion-exchange method to solutions containing oxidants

The free acid form of a cation-exchange resin of the sulfonated hydrocarbon type (Dowex 50) can be used for a quantitative liberation of the corresponding acids from salt solutions containing oxidants that are reduced by phenolic resins. Positive results have been obtained with solutions containing bromate, iodate, periodate, molybdate, and chromate. With permanganate a partial reduction occurs which prevents the application of the ion-exchange method for quantitative separation of solutions containing permanganate.     

Scope,limitations and mechanism of nucleotide separation by thin-layer chromatography with strong cation-exchange resin containing layers

Summary The scope and limitations of the application of the commercially available cation-exchange thin-layer chromatoplate (Fixion 50-X8) for the resolution of nucleotide mixtures is presented. A possible separation mechanism is proposed and discussed.Publication No. 11 in the series dealing with the separation of nucleic acid bases, nucleosides and nucleotides on thin-layers consisting of strong cation-exchange resins.     

Facile isomerization of glucose into fructose using anion-exchange resins in organic solvents and application to direct conversion of glucose into furan compounds

The facile isomerization of glucose into fructose has been developed using commercially available anion-exchange resins (AERs) in organic solvents. Following extensive screening for the amount and type of AERs, solvents and reaction time, glucose was transformed into fructose in yields of up to 50% using Amberlite A-26 with macroreticular morphology and tertiary amine functionality in a protic solvent (ethanol). AERs could be used five times without a significant loss of activity. This isomerization method could be applied to the direct conversion of glucose into furan compounds by integrating the dehydration of fructose with cation-exchange resins.     

Separation of amines by ligand exchange : Part III. A comparison of different cation exchangers

The elution behavior of 4 amines, ethanolamine, diethanolanine, dimethylamine and n-butylamine, was studied on 4 cation-exchange resins and zirconium phosphate, all loaded with nickel ions. Aqueous ammonia was used for clution. Different selectivity orders were found with exchangers of different types. The carboxylic cation-exchange resin gave the sharpest bands, but 2% cross-linked sulfonic resin gave the best separation of these amines.     

Separation of nucleoside 5′-phosphordiamidates by thin-layer chromatography with strong cation-exchange resin containing layers

Summary The application of the commercially available cation-exchange thin-layer chromatoplate (Fixion 50-X8) for the separation of nucleoside 5-phosphordiamidates is described.Publication No. 12 in the series dealing with the separation of nucleic acid bases, nucleosides and nucleotides on thin layers consisting of strong cation-exchange resins.     

Uptake of iodine and bromine by ion-exchange resins in aqueous solution

The uptakes of molecular iodine and bromine by both strong acid cation (Dowex 50W-X4 and X8) and strong base anion (Dowex 1-X4 and X8) exchange resins have been studied in aqueous solutions at 25 degrees C. An empirical formula for the amount of solute taken up by the resin in mmol per gram of dry resin, Q, as a function of the solute concentration in M (mol dm(-3)), C, was derived. Direct proportional relationships between Q and C have been found, except for the bromine-anion exchanger system. In contrast to the cation-exchange resin, the anion exchanger exhibits extremely high affinity for I(2) and Br(2).     

Styrylation of phenol in the presence of cation-exchange resins. Influence of the product composition on its stabilizing performance in rubber

Methylbenzylated phenols were prepared by catalytic reaction of phenol with styrenes. The effect of a series of cation-exchange resins on the product composition was examined, and the stabilizing performance of the products in rubber was evaluated.

     

Mixed-Bed Ion-Exchange Papers

Abstract

Retention of some cations and anions on ion-exchange resin-loaded disks has been reported to be less than quantitative. A mixed-bed resin-loaded paper was made in which mixed cation-exchange and anion-exchange resins were incorporated into the paper to take advantage of the ‘crossed equilibria’ effect and improve ion retention. The use of mixed-bed paper disks in analysis for cesium by X-ray fluorescence spectrometry is described.     

强酸阳离子交换树脂催化性能的研究

通过叔丁醇脱水生成异丁烯的反应研究对比了国内外常见种类的凝胶型和大孔型强酸阳离子交换树脂的催化性能，并对树脂的性质，预处理方法，以及其用量和再生程度等因素对树脂催化活性的影响进行了研究。在此基础上，合成了具有较高催化活性的新型大孔强酸阳离子交换树脂。     

Esterification of pyridinecarboxylic acids in the presence of cation-exchange resins

Pyridinecarboxylic acids undergo esterification on refluxing with alcohols in the presence of cation-exchange resins. In the case of pyridine-2,6-dicarboxylic acid, in which the basicity of the nitrogen atom is reduced, esterification products are obtained in high yields. In the case of pyridinecarboxylic acids, in which the pyridine nitrogen atom displays considerable basicity, the cations of the acids are tied up by the cation-exchange resin, and the yields of preparatively isolable esters do not exceed 60%.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 233–237, February, 1976.     

Factorial screening of antibody purification processes using three chromatography steps without protein A

Protein A affinity chromatography is often employed as a capture step to meet the purity, yield, and throughput requirements for pharmaceutical antibody purification. However, a trade-off exists between step performance and price. Protein A resin removes 99.9% of feed stream impurities; however, its price is significantly greater than those of non-affinity media. With many therapeutic indications for antibodies requiring high doses and/or chronic administration, the consideration of process economics is critical. We have systematically evaluated the purification performance of cation-exchange, anion-exchange, hydroxyapatite, hydrophobic interaction, hydrophobic charge induction, and small-molecule ligand resins in each step of a three-step chromatographic purification process for a CHO-derived monoclonal antibody. Host cell proteins were removed to less-than-detectable for three processes (cation-exchange-anion-exchange-hydrophobic interaction chromatography, cation-exchange-anion-exchange-mixed cation-exchange chromatography, and cation-exchange-mixed cation-exchange-anion-exchange chromatography). The order of the process steps affected purification performance significantly.     

Ion-exchange thin-layer chromatography of metal lons in organic solvent — Hydrochloric acid — Complexing agent media

Summary Thin-layers of strongly basic or strongly acidic ionexchange resins (Dowex 1 or Dowex 50), mixed with a plain cellulose, Avicel SF, have been used to investigate the chromatographic behaviour of 40 metal ions in acetic acid — hydrochloric acid — complexing agent media. The CIESE (combined ion-exchange-solvent extraction) effect, proposed by Korkisch, is noticed for scandium and thorium in the anion-exchange system involving trioctylphosphine oxide (TOPO) as the complexing agent, the system providing a basis on the specific separation of both elements. In the cation-exchange system involving TOPO, the metal ions are distributed chromatographically, so that the system allows multicomponent separations to be carried out. The system also reveals the CIESE effect for zirconium and hafnium.     

Retention behavior of carboyxlic acids on highly cross-linked poly(styrene-divinylbenzene)-based and silica-based cation exchangers

A highly cross-linked porous poly(styrene-divinylbenzene) resin was reacted with sulfuric acid to give strong cation-exchange resins with capacities from 0.2 to 1.9 mequiv./g. The retention behavior of mono- and dicar☐ylic acids on these resins was compared with results obtained from silica-based cation exchangers functionalized with alkylsulfonic acid or phenylsulfonic acid groups. The contribution of different retention mechanisms like ion exclusion, hydrophobic interaction and adsorption to the separation of the analytes on these chromatographic supports was discussed. Additionally the applicability of silica-based cation exchangers was tested in the field of silage analysis.