Technetium speciation: non-size effects in size-exclusion chromatography

he predominant separation technique used in technetium speciation, e.g., in plant material, is size-exclusion chromatography. However, interactions of technetium compounds with the stationary phase, i.e., non-size effects, have been reported. To evaluate these effects, the interaction of three technetium compounds, the pertechnetate anion (TcO4-), the anionic Tc-diethylenetriaminepentaacetate complex (Tc-DTPA), and the cationic [Tc(V)O2(1,4,8,11-tetraazacyclotetradecane)]+ complex (Tc-cyclam) with three different types of size-exclusion packing material, Sephadex G-25, Zorbax GF-250 and HEMA-SEC BIO 1000 has been studied. The effects of the composition of the mobile phase and the column temperature on the distribution coefficients of the three technetium compounds was measured. It is shown that non-size effects play a dominant role in the separation of these technetium compounds.