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  • 1 Comenius University Department of Nuclear Chemistry, Faculty of Natural Sciences SK-842 15 Bratislava Slovakia
  • 2 Comenius University Department of Nuclear Chemistry, Faculty of Natural Sciences SK-842 15 Bratislava Slovakia
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Abstract  

The complexation of technetium with humic acid is usually done by a reduction of pertechnetate by Sn2+ ions. A Tc-HA complex can be scavenged in a Sn-HA complex, if tin is present as reductant. The main aim of the study was a preparation of the Tc-HA complex without impurities of Sn ions or other metal reductant, which was performed by a ligand exchange with hexakis(thiourea-S)technetium(III) under nitrogen atmosphere at pH 5.5. The [Tc(tu)6]3+ complex was prepared from TcO4- in acidic solution with thiourea as a reductant. Presence of the Tc-HA complex and other technetium species was determined by gel chromatography, paper chromatography and dialysis. Yield of Tc-HA complex was about 80% and reaction mixture contains about 20% of technetium dioxide, which is a side product of ligand-exchange.