Preparation and analytical properties of a chelating resin containing cysteine groups

A macroporous, cross-linked polyacrylonitrile copolymer was synthesized, the nitrile groups were converted to carboxylic acid by hydrolysis, and these carboxylic acid groups were treated with L-cysteine and 1,6-hexanediol (binding agent). Studies of the basic characteristics of this resin showed that it was highly selective for silver(I), mercury(II), gold(III) and platinum(IV) in aqueous acidic solution, the maximum capacities being 0.97, 0.65, 1.22 and 0.39 mmol g^-1 of dry resin, respectively. These four metal ions can be separated from each other, or concentrated from very dilute solutions, on a short column of the resin. The effects of different acids and of various common metal ions are reported.     

Preparation and analytical properties of a chelating resin containing phenylalanine groups

A polystyrene-based macroreticular resin containing phenylalanine groups has been prepared and its analytical properties have been investigated and compared with Dowex A-1. The phenylalanine resin shows high selectivity for mercury(II) and copper(II) in the pH region 2-3. The sorption behaviour of copper has been examined in detail, with the intention of using the resin analytically. The important characteristics of the resin are fast equilibration, high selectivity and small volume change between its hydrogen form and metal forms. These enable it to be applied for the rapid concentration of trace amounts of copper in the presence of large amounts of diverse metals. It may be used for the determination of copper in sea-water and the separation of copper/cobalt and copper/nickel.     

Preparation and analytical properties of a chelating resin containing bicine groups

A polystyrene divinyl benzene based resin containing bicine groups has been prepared and its analytical properties investigated. The pH dependence of sorption of metal on the resin has been determined for Cu(II), Fe(II), Ni(II), Co(II), Zn(II), Hg(II) and Pb(II). The important characteristics of the resin are fast equilibrium, high selectivity and small volume change between its hydrogen and metal forms. These enable it to be applied to the rapid concentration of trace amounts of these metal ions. It shows promise for the separation of lead from other metal ions.     

Synthesis and properties of a chelating resin containing triazolethiol groups

A macroreticular poly(acrylic acid)-based resin with triazolethiol as the functional group has been synthesized. The stability of the resin in acidic media and the behaviour in sorption and desorption of various metal ions have been investigated and compared with those of the acylthiosemicarbazide resin which is an intermediate in synthesis of the triazolethiol resin. Both resins show high affinity for copper(II) silver, cadmium and mercury(II), and high selectivity for silver and mercury(II) at low pH (1–2), and even at pH 7 if EDTA is present. The triazolethiol resin sorbs metal ions faster than the acylthiosemicarbazide resin does and sorbs mercury(II) from high concentrations of acids and neutral salt solutions. This resin has been applied to the concentration of silver and mercury(II) from sea-water samples by column operation.     

Preparation and properties of a new chelating resin containing 2-nitroso-1-naphthol

A new chelating ion-exchange resin based on a macroreticular polystyrene—divinyl benzene copolymer and containing 2-nitroso-1-naphthol as the functional species has been synthesized. It is highly stable in acidic and alkaline solutions. Its sorption characteristics for V(V), Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Hg(II), Pd(II) and U(VI) have been investigated over the pH range 1.0–7.0 and the exchange-capacities have been found to be generally higher than those of a similar resin containing 1-nitroso-2-naphthol.     

Preparation and properties of a chelating resin containing the nitrosoresorcinol group

A macroreticular polystyrene-based chelating resin with the nitrosoresorcinol group as the functional group has been synthesized. The resin shows selectivity for copper(II), iron(III), and cobalt(II). The sorption behaviour of cobalt(II) is examined in detail, with the intention of using the resin analytically. Iron(III) and cobalt(II) are separated in a column operation by stepwise elution with oxalic acid solution and hydrochloric acid respectively.     

Synthesis and properties of a new chelating resin containing the oxime group

A macroreticular polystyrene-based chelating resin with oxime and diethylamino functional groups has been synthesized. The resin is stable in acid and alkaline solutions; no decrease in nitrogen content or capacity for sorption of copper(II) is observed when it is exposed to 3M hydrochloric acid and 1M sodium hydroxide for 7 days. The resin has higher selectivity for copper(II) than for other metal ions tested and the time required for 50% uptake of copper(II) is 15 min. The highest capacity for copper(II) is 2.0 mmole/g at pH 6.0. In a column operation, quantitative recovery of copper(II) is achieved by elution with 1M hydrochloric acid, and the resin can be used repeatedly.     

Preparation and properties of a new chelating resin containing 1-nitroso-2-naphthol as the functional group

A macroreticular polystyrene-based chelating ion-exchanger containing 1-nitroso-2-naphthol as the functional group has been synthesized. The exchange-capacity of the resin for a number of metal ions such as copper(II), iron(III), cobalt(II), nickel(II), palladium(II) and uranium(VI) as a function of pH has been determined. The sorption and elution characteristics for palladium(II) and uranium(VI) have been thoroughly examined with a view to utilizing the resin for separation and concentration of uranium and palladium. Uranium(VI) has been separated from a mixture of ten other metal ions by sorption on the chelating resin and selective elution with 0.5M sodium carbonate. Palladium(II) has been separated from various metal ions by selective sorption on the resin in 1M hydrochloric acid medium.     

Synthesis and properties of new chelating resin with a spacer containing alpha-nitroso-beta-naphthol as the functional group

A new chelating ion-exchange resin with a spacer CH₂-NH-C₆H₄- based on a microreticular chloromethylated styrene-divinylbenzene copolymer containing α-nitroso-β-naphthol as a functional group has been synthesized. The sorption characteristics for manganese(II), iron(III), cobalt(II), nickel(II), copper(II), and zinc(II) have been investigated over the pH range 1.0–7.0. The resin is highly stable in acidic and alkaline medium. Iron(III) and cobalt(II); copper(II) and iron(III) are separated very effectively in a column operation by stepwise elution.     

Chromatographic separation by a new chelating resin containing β-hydroxydithiocinnamic acid

Summary The distribution coefficients of Ag(I), Au(III), Cd(II), Cu(II), Fe(III), Hg(II), Ni(II), Pb(II), Pt(IV), and Zn(II) on a new chelating resin containing -hydroxydithiocinnamic acid at various acidity were studied. In the strongly acidic region, the resin shows high affinity for Ag(I), Hg(II), Au(III) and Pt(IV) and high resistance against air oxidation. The effect of diverse foreign ligands on the sorption of metal ions and the possibility of application to speciation studies with this resin were also considered. Some quantitative separations of Cd-Cu-Pb, Cu-Au and Au-Pt with this resin column were described. Detection of the chromatography system was carried out via post column derivatisation of the column effluent with PAR at 520 nm or direct UV detection of the chloride complexes at 215 nm.     

Four new chelating agents containing vicinal thioether groups

Four new chelating agents containing vicinal thioether groups have been prepared by the addition of the appropriate thiols to acetylenedicarboxylic acid. These new compounds are 4,5-Dicarboxy-3,6-dithiaoctanedioic acid, 2,9-Diamino-5,6-dicarboxy-4,7-dithiadecanedioic acid, 3,6-Dithiaoctanediamine-4,5-dicarboxylic acid dihydrochloride, and Disodium-3,6-dithia-1,8-octanediol-4,5-dicarboxylate. Reasonably stable complexes are formed with several divalent metal ions, through precipitation interfered with the complete characterization of the mercury(II) complexes in some cases. For all of these, the stability constants of the mercury(II) complexes were appreciably lower than the stability constants of structurally similar complexes containing vicinal mercaptal groups and the degree of selectivity for mercury(II) was also less. These chelating agents exhibit a very minimal tendency to bind calcium ions.     

Use of chelating resin containing thioacetamide groups for the separation of copper

Summary A new chelating resin containing thioacetamide incorporated into the weakly acidic polymeric matrix Amberlite IRC-50, has been synthesised and investigated for its metal exchange characteristics. Among the various cations studied, copper(II) was found to have the highest capacity. On the basis of experimental results, the resin was employed for the separation and preconcentration of copper from several synthetic mixtures and also from a few analysed alloy samples.     

Preparation and analytical properties of a chelating resin functionalized with 1-hydrazinophthalazine ligand

A poly[styrene-co-(divinylbenzene)] resin (XAD-4) functionalized with 1-hydrazinophthalazine ligand has been prepared and its analytical properties investigated. The pH dependence of sorption of metal ion on the resin has been determined for Cu(II), Ni(II), Co(II), Zn(II), Cd(II), Pb(II), Fe(III) and Cr(III). Trace amounts of these metal ions were quantitatively retained on the resin and recovered by eluting with 1 mol l(-1) hydrochloric acid. The resin was found to be selective for Fe(III) and its separation from other metal ions was carried out effectively. Metal ions concentrations were determined using AAS.     

A spectral study of transition-metal complexes on a chelating ion-exchange resin containing aminophosphonic acid groups

The coordination mode of a commercial chelating ion-exchange resin, ES 467, containing aminomethylphosphonic acid groups anchored on a macroporous styrenedivinylbenzene copolymer, with several metal ions, such as chromium(III), cobalt(II), nickel(II), copper(II) and zinc(II) has been studied with the aid of IR, ligand field and ESR spectra. The chelating group of ES 467, aminomethylphosphonic acid, appears to bind different metal ions mainly through oxygen atoms of the phosphonic acid group, though, in the case of those species containing low-loading of metal ions, the secondary amine nitrogen atom also appears to take part in coordination. Most of the metal ions studied seem to be present as six-coordinated species in the polymeric matrix, whereas cobalt(II) species show electronic spectra which are consistent with the presence of both four-coordinated (tetrahedral) and six-coordinated (octahedral) structures of these species. The distribution coefficients for cobalt(II), nickel(II), copper(II) and zinc(II) have been determined and it appears that the resin ES 467 binds copper(II) ions selectively. An attempt has been made to find a possible relationship between the selectivity of the chelating resin and the stereochemistry of the adsorbed metal ions.     

Preparation and properties of polybenzimidazoles containing cardo groups

Several polybenzimidazoles containing cardo groups were prepared: A cardodicarboxylic acid, 9,9-bis(4-carboxyphenyl)fluorene, and two cardotetramines, 9,9-bis(3,4-diaminophenyl)fluorene and 9,9-bis(3,4-diaminophenyl)10-anthrone. The cardodicarboxylic acid was condensed with aromatic tetramines and the cardotetramines were condensed with aromatic dicarboxylic acids. Prior to polymer synthesis two model compounds, 9,9-bis[4,(2-benzimidazolyl)phenyl]fluorene and 2,2′-diphenyl-5,5′-(9,9-fluorenediyl)-bibenzimidazole were prepared and characterized by spectral methods. The polymers were obtained in 60–70% yield and showed reduced viscosity in the range of 0.7–1.1 dL/g. They were soluble in dimethyl formamide (DMF) and chlorinated solvents like tetrachlorethane. The thermal stabilities of these cardopolymers were superior to noncardopoly-benzimidazoles.     

Preparation and analytical properties of chelating resins containing heterocyclic formazane derivatives

Chromatographia - By introducing pyridine and thiazole rings into polyacrolein, poly[1-(2-pyridyl)-3-(vinyl)-5-(phenyl)-formazane] (PPF), poly[1-(2-pyridyl)-3-(vinyl)-5-(2-arsonophenyl)-formazane]...