Solid phase extraction of trace elements

Solid phase extraction and determination of ultra trace amounts of mercury(II) using octadecyl silica membrane disks modified by hexathia-18-crown-6-tetraone and cold vapour atomic absorption spectrometry

Solid-phase extraction

Chelating Resins and Their Applications in the Analysis of Trace Metal Ions

Recent highlights in stationary phase design for open-tubular capillary electrochromatography.

Solid phase extraction of metal ions using immobilised chelating calixarene tetrahydroxamates

Silica-bonded calixarenes in chromatography: I. Synthesis and characterization by solid-state NMR spectroscopy

Silica-bonded calixarenes in chromatography: II. Chromatographic retention of metal ions and amino acid ester hydrochlorides

A silica bonded tetrameric calix[4]arene ester stationary phase has been used in the chromatographic separation of alkali metal ions and amino acid esters. Under reversed phase conditions, baseline resolution of a standard test mixture of benzamide, benzophenone and biphenyl was achieved using an MeOH—H2O mobile phase. In the chromatography of the amino acid ester hydrochlorides, retention appears to be related to the hydrophobicity of the esters studied, with tryptophan methyl ester being the longest retained.

Chromatographic selectivity for amino acid esters and alkali metal ions on a silica bonded calix[4]arene tetraester stationary phase

The functionalisation of macrocyclic p-tertbutylcalix[4]arenes at the lower rim withhydroxamic acid and proline hydroxamic acid groups gives the calixarenes chelatingproperties similar to siderophores. The H 1 NMR spectrum of p-tertbutylcalix[4]arenetetrahydroxamic acid shows a broad band at 10.8 ppm in DMSO- d 6 attributed to NHOH protons. Diffuse reflectance spectral analysis of PVC membranes containing thecalixarene hydroxamic acids show absorption bands at 485 nm and 504 nm followingcontact with aqueous solutions of Fe(III) and V(V) respectively. The pH dependency ofthis extractive selectivity is examined for Fe(III), Co(II), Pb(II), Mn(II), Cu(II) and Ni(II)using a solid phase extraction approach. Spectrophotometric evidence for thecomplexation of Cu(II) in methanol by p-tertbutylcalix[4]arene tetraproline acid is alsoprovided.

https://downloads.hindawi.com/archive/1994/947142.pdf

Elizabeth Horne

Papers

Solid phase extraction of metal ions using immobilised chelating calixarene tetrahydroxamates

Silica-bonded calixarenes in chromatography: I. Synthesis and characterization by solid-state NMR spectroscopy

Silica-bonded calixarenes in chromatography: II. Chromatographic retention of metal ions and amino acid ester hydrochlorides

Chromatographic selectivity for amino acid esters and alkali metal ions on a silica bonded calix[4]arene tetraester stationary phase

Transition Metal Ion Complexation and Extraction by HydroxamateFunctionalised p-Tert-Butylcalix[4]Arenes