Development of ⁷⁷Ge/⁷⁷As parent-daughter system for periodic removal of ⁷⁷As for environmental sanitation and biochemical purposes

A simple method was developed for the separation of radioactive ⁷⁷As from neutron irradiated natural GeO₂ samples for environmental and biochemical studies. The method is based on the volatility of GeCl₄. The GeCl₄ was co-evaporated from the reaction mixture with an azeotropic mixture of HCl and water, and immediately condensed into a separate finger part of the special glass apparatus which was cooled by liquid nitrogen. By inverting the room temperature and the deep frozen parts of the glass equipment after three half-lives of the ⁷⁷Ge the separation process can be repetitive, getting a special type of ⁷⁷Ge/⁷⁷As parent-daughter system. The radionuclidic purity of the remaining As fraction was found to be 99.95%. Its yield, however, drastically decreased in the second and subsequent separations.