Separation of 71,72As from alpha-particle induced reaction on gallium oxide target using naturally occurring alkaloid caffeine

Abstract

Abstract Gallium oxide target was irradiated with 46 MeV alpha-particle beam, which produced 71,72As and 67Ga radioisotopes in the matrix. Separation of radio-arsenics from the bulk gallium target was carried out by caffeine, a nature-resourced reagent, extracted from black tea leaves. 71,72As radionuclides were preferentially attached with caffeine and precipitated with caffeine in 2 M Na2SO4 solution as caffeine was insoluble in aqueous medium under this condition. With increase in weight of caffeine, extraction of 71,72As and bulk gallium significantly increased. Bulk Ga along with 67Ga remained in the supernatant. Geometry optimization of caffeine–metal complex was carried out by theoretical computational analysis. DFT calculation corroborated with the experimental findings where As3+ preferentially binds with caffeine in presence of gallium and arsenic. As evidenced by the short As–O and As–N distances, the high binding energies are a result of the metal ion’s strong binding to the carbonyl and nitrogen centres, whereas no such result could be obtained in case of bulk gallium.