Isolation and quantification of a ⁹³Mo isotope solution from proton irradiated niobium

⁹³Mo (4000 y half-life) formed through the ⁹³Nb(p,n)⁹³Mo reaction was isolated from a niobium target foil previously used in a low energy medical cyclotron. ⁹³Mo has identical characteristic x-ray emission and mass as the isomer ^93mNb and stable Nb present in the target foil at much higher concentrations. This makes distinction between ⁹³Mo, ^93mNb and stable Nb difficult using radiometric or mass spectrometric methods. An anion exchange method in combination with x-ray spectrometry and ICP-MS/OES enabled quantitative isolation of about 0.4 μg ⁹³Mo (14 kBq) from ^93mNb with a separation factor >10⁴ on a single column. An extraction chromatography column (TEVA) was used to reach a^93mNb/⁹³Mo activity ratio of <10^-6 and an atom ratio ⁹³Nb/⁹³Mo <1% making the ⁹³Mo suitable for both radiometric and mass spectrometric testing. ⁹³Mo is the only radioisotope of molybdenum with a long enough half-life suitable for this purpose. Calibration of the ⁹³Mo isotope solution was done through x-ray spectrometry using a characterized BEGe-detector in combination with a^99mTc solution. This is the first reported isolation of a⁹³Mo solution in the literature and the first time a LSC-spectrum of ⁹³Mo is shown.