Determination of 99 mTc valent form in solids by measurement of internal conversion electrons

Abstract

The core-level internal conversion electron spectroscopy (ICES) was used to study no-carrier-added compounds of 99m Tc in the form of solid deposits. The following chemical shifts of the electron binding energies were determined: ΔE B(NH 4TcO 4NaTcO 4) = 0.0±0.3 eV, ΔE B(NH 4TcO 4TcO 2·2 H 2 O) = 3.±0.3 eV. Furthermore, two valent forms were distinguished in the decay-induced 99m Tc species created from the Na 2 99 MoO 4 in the NaOH matrix. The smallest detectaable amount of 99m Tc in the minor valent form was ∼30μCi (6 × 10 −12g). The observed shifts ΔE B(NH 4TcO 4NaTcO x) = ±0.0±3 eV and ΔE B(Nh 4TcO 4-NaTcO y ) = 2.1±0.3 eV indicate the chemical form NaTc(VII)O 4 for the NaTcO x and either Na 2Tc(Vi) or NaTc(V0O 3 for the NaTcO y. Shift calculations based on the ground -state potential model prefer NaTcO 3.