Determination of uranium and thorium in geological materials using extraction chromatography

Abstract

A procedure has been developed for the determination of uranium and thorium in geological samples using extraction chromatography. Following sample preparation, uranium and thorium are pre-concentrated by precipitation with iron(iii) hydroxide and then separated using UTEVA resin. The separated uranium and thorium are electrodeposited onto stainless-steel discs and then measured by alpha spectrometry. The procedure was evaluated using uraninite ore, coral and granite reference materials. The uranium and thorium concentrations and the 234 U/ 238 U and 230 Th/ 234 U activity ratio values determined for the reference materials were in good agreement with the certified values. The presence of plutonium was found to interfere with the separation, but the inclusion of a reduction step using iron(ii) sulfamate eliminated the problem. Chemical recoveries for the procedure are similar to those for an anion-exchange procedure, but the extraction-chromatography procedure provides a more rapid separation using less reagents.

Systematic study of trace radioactive impurities in candidate construction materials for EXO-200

“…One way of overcoming this drawback is to undertake prior separation of the analytes from the matrix. Several methods have been used for this purpose including coprecipitation [5][6][7], liquidliquid extraction [8][9][10], distillation [11], and ion-exchange [12,13] which was used in this work (see Section 3.1). These techniques often require longer analysis times and give rise to additional analytical problems, including contamination during sample pretreatment and increased blank levels, which must be carefully controlled.…”

Comparison of sorption behavior of Th(IV) and U(VI) on modified impregnated resin containing quinizarin with that conventional prepared impregnated resin

“…In contrast with the liquid-liquid extraction, which results in huge environmental problem due to toxic organic diluents, solid phase extraction technique using eco friendly materials has been widely used in the preconcentration/separation of trace and ultra trace amounts these ions [9][10][11][12][13]. In treatment with this method, generally, suitable chelating agents can be chemically bonded to a polymeric matrix as a support for the solid phase extraction of metal ions from aqueous solution [14][15][16][17][18].…”

pH dependent separation of uranium by chelation chromatography using pyridine 2,6-dimethanol as a chelator: Single crystal X-ray structural confirmation of the chelated uranium complex

“…Several authors have used a number of solid sorbents viz. octadecyl silica membrane disk [6], empore (TM) chelating resin disk [7], commercial resin [8,9], Dowex 1 × 8 and Dowex 50W × 8 [10,11], neutral polymer Amberlite XAD series [12], silica [13], activated silica gel [14], controlled pore glass [15], polyurethane foam [16] and cation or anion exchange resins [17] for the enrichment of uranium(VI) from dilute solutions prior to determination by a variety of analytical techniques. Selective binding of uranyl cation using different chelating ligands, either immobilized or chemically attached on the inert solid support like silica, alumina, naphthalene, benzophenone, polystyrene-DVB resin or activated charcoal matrix have also been reported [18][19][20][21][22][23][24][25][26].…”