Recovery of ammonium99Tc-pertechnetate from its reaction waste

A method is described for the recovery of NH₄ ⁹⁹TcO₄ from its reaction waste. From the collected waste solution⁹⁹Tc was precipitated as⁹⁹Tc₂S₇ which on digestion with ammoniacal hydrogen peroxide produced a mixture of NH₄ ⁹⁹TcO₄ and (NH₄)₂SO₄ from which the latter was removed by treatment with Ba(OH)₂. The solution fumished NH₄ ⁹⁹TcO₄ as a crystalline material in 54% overall yield and with 96–98% purity after chromatographic purification over Dowex 50W column. Recrystallisation of this material from aqueous ammoniacal ethanol gave the analytical material which compared well with a standard sample and with literature data in terms of its -counts/mg and its molar extinction co-efficients () at 244 and 286 nm.