Polymer supported calix[6]arene hydroxamic acid, a novel chelating resin

A new polymer-supported calix[6]arene hydroxamic acid has been synthesised by reacting the acid chloride 37,38,39,40,41,42 hexahydroxy 1,8,13,19,25,31 hexacarboxy calix[6]arene with poly(styrene β-hydroxylamine). The synthesised resin was characterised by elemental analysis, FT-IR and mass spectra. Physicochemical properties viz. swelling, wet-density, void-volume, exchange capacity etc. were determined. The resin has 4.46 mmol/g exchange capacity for rare elements. The resin was used for the chromatographic separation of U(VI), Th(IV) and Ce(IV) by the judicious adjustment of pH 4.0, 6.0 and 7.5, respectively. The thorium and cerium were eluted with 0.1 M HCl while uranium was eluted with 2 M HCl. These rare elements were preconcentrated and determined in the presence of each other, monazite sand and environmental samples.