The separation of arsenic-77 in a carrier-free state from the parent nuclide germanium-77 by a thin-layer chromatographic method

⁷⁷As(III) and⁷⁷As(V) were separated from neutron-irradiated GeO₂ by a thin-layer chromatographic method, in which silica gel was used as adsorbent and a 2∶1 mixture of methanol and 5N HCl as developer. The Rf values of these nuclides were as follows: 0.00 for⁷⁷Ge, 0.50 for⁷⁷As(III) and 0.94 for⁷⁷As(V). The influence of As(III) carrier added before the separation was investigated on the oxidation state of⁷⁷As recoiled from the parent nuclide. The radiochemical purity of⁷⁷As thus separated was more than 99.9% and the activity due to⁷⁷As could easily be eluted with water from the adsorbent, with 93% recovery.