Separation of radiolabelled arsenic compounds produced by neutron irradiation of organoarsenic compounds

Abstract Results are presented for the separation of radiolabelled arsenic compounds obtained by the irradiation of organoarsenic compounds in a nuclear reactor. Previously developed chromatographic techniques with element-specific detection were used and further improved to measure the 76 As activities and As concentrations of the arsenic-containing decomposition products formed. Since the recoil energy available during irradiation is high enough to break molecular bonds, a range of radiolabelled arsenic compounds were produced, depending on the conditions (type of compound, matrix and irradiation time). The most extensively investigated compound, viz. arsenobetaine, yielded, when irradiated as solid material for 60 min, 11 radiolabelled arsenic compounds, of which eight could be identified. Theoretically, an overall specific activity of 3.7 GBq g −1 was expected, but experimentally specific activities were found from 0.5 GBq g −1 (for arsenobetaine) to more than 3800 GBq g −1 (for arsenate).