Copper cation exchange resins

Theory. Conventional anion and cation exchange resins appear to be of limited use for concentrating trace metals from saline solutions such as sea water. The introduction of chelating resins, particularly those based on iminodiacetic acid, makes it possible to concentrate trace metals from brine solutions and separate them from the major components of the solution. Thus the elements cadmium, copper, cobalt, nickel and zinc are selectively retained by the resin Chelex-100 and can be recovered subsequently for determination by atomic absorption spectrophotometry.45 To enhance the sensitivity of the AAS procedure the eluate is evaporated to dryness and the residue dissolved in 90 per cent aqueous acetone. The use of the chelating resin offers the advantage over concentration by solvent extraction that, in principle, there is no limit to the volume of sample which can be used. 

The sluggish substitution properties of copper(III) and nickel(III) peptide complexes have permitted the isolation of complexes with these oxidation states (14, 15). Thus, the tri-valent peptide complexes pass through a cation exchange resin which readily strips copper(II) or nickel(II) from the corresponding complexes. We now have a little more information about the substitution characteristics of the trivalent metal complexes. 

A cation exchange resin column is saturated with copper(II) ions recovered from rinse waters from plating operations. 

Catalytic reduction, with Adams platinum oxide catalyst, 470 with copper-chromium oxide, 873 with Raney nickel, 566 Cation exchange resin, for esterification, 381, 387, 388 Cellosolve, 170, 265, 444 butyl, 170, 444 methyl, 170, 444 Cellulose, 458 ... 

Chakrabarti, C.L., Lu, Y., Gregoire, D.C., Back, M.H. and Schroeder, W.H. (1994) Kinetic studies of metal speciation using Che lex cation exchange resin application to cadmium, copper, and lead speciation in river water and snow. Environ. Sci. Technol, 28, 1957-1967. 

Toxic trace elements were isolated from water samples by extraction with di-ethyldithiocarbamate (Table 2.1.2). Following this pre-concentration step the metal ions were adsorbed on a cation-exchange resin using a mixture of tetrahydro-furan-methylglycol-6 M HCl as sorption solution. The succesive elution was treated with 6 M HCl, 1 M HCl and 2 M HNO3 for fractional separation. In another application hexane-isopropanol-HCl mixture was used as the adsorption medium An analytical scheme which provides quantitative results, is described for ion-exchange separation of fifteen major, minor and trace elements in silicates For concentration and separation of copper, chromium, lead and iron an ion-exchanger in phosphate or OH -form was used in various combinations ... 

By exploiting the differences in stability of various complexes of Cu and other metals, it is possible to achieve separations on ion-exchange columns. Owing to the different stability of the chloride complexes, copper has been separated from Ga, Fe(III), and Zn by ion-exchange on anion- or cation-exchange resins. The anionic chloride copper(I) complex (in the presence of ascorbic acid) has been retained on anion-exchanger Dowex 1 from 0.1 M HCl medium copper was then eluted with 1 M nitric acid [6]. 

D-Glucose and acetone, with a wide variety of catalysts, for example, 1-2% hydrogen chloride, zinc chloride and 85% phosphoric acid, anhydrous copper(II) sulfate, concentrated sulfuric acid, cation-exchange resins, or the ethyl ester of metaphosphoric acid, react to give 1,2 5,6-di-O-isopropylidene-a-D-glucofuranose (24). A comprehensive survey of the evidence, and confirmation of the furanose structure of the diacetal (24) was provided by Anderson, Charlton, and Haworth, nearly 30 years after the initial preparation of the diacetal. The diacetal has been used extensively for the preparation of C-3 substituted D-glucose derivatives and 3-a- and 3- 3-linked disaccharides. 

Experiment 12. Determination of the exchange capacity and exchange efficiency of a cation exchange resin Experiment 13. Complex elution of iron and copper using a cation exchange resin... 

Complex elution of iron and copper using a cation exchange resin. 

To separate a mixture of copper(II) and iron(III) on a cation exchange resin by elution using the technique of phosphate complexation. 

The separation involves the stepwise elution of iron(III) by phosphoric acid and then of copper(II) by hydrochloric acid, from a strongly acidic cation exchange resin such as ZeoKarb225, AmberliteIR-120 or Dowex50. If hydrochloric acid alone is used the order of removal of the ions from the columns is reversed, and poorer separation is obtained. The phosphoric acid eluant modifies the activities of the ions, possibly by complex formation, giving improved resolution. The order of elution is also reversed with a phosphate eluant, iron having the smaller retention volume. 

The factor most influential in determining the outcome of a condensation reaction is the catalyst. The catalysts most commonly employed are mineral acids, although copper(lI) sulfate, phosphorus pentaoxide, ethyl metaphosphate, cation-exchange resins in the acid form, and zinc chloride (alone - or in combination... 

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