Chromatographic separation of germanium and arsenic for the production of high purity 77As

• Simple, rapid 77As/76,77Ge separation developed.
• No carrier added 77As was separated from neutron irradiated 76Ge using silica gel.
• ∼74% arsenate eluted with methanol with minimal to no Ge breakthrough.
• >80–90% arsenate eluted with 12 M HCl:EtOH (1:1200) without Ge breakthrough.
• 98% 76Ge recovered by elution with 3 mL of aqueous solution (pH ≥ 7).

A simple column chromatographic method was developed to isolate 77As (94 ± 6% (EtOH/HCl); 74 ± 11 (MeOH)) from germanium for potential use in radioimmunotherapy. The separation of arsenic from germanium was based on their relative affinities for different chromatographic materials in aqueous and organic environments. Using an organic or mixed mobile phase, germanium was selectively retained on a silica gel column as germanate, while arsenic was eluted from the column as arsenate. Subsequently, enriched 76Ge (98 ± 2) was recovered for reuse by elution with aqueous solution (neutral to basic). Greater than 98% radiolabeling yield of a 77As-trithiol was observed from methanol separated [77As]arsenate [17].