A two-group separation scheme for the determination of eleven trace elements in biological material by neutron activation analysis

The applicability of solvent extraction with tri-n-octylphosphine oxide (TOPO) in the neutron activation analysis of biological material has been studied. A two-group radiochemical separation scheme is presented. After wet oxidation, As, Se, and Hg are removed by distillation and subsequent sulfide precipitation; Ca, Cd, Co, Fe, Mo, Sc, W, and Zn are then determined after extraction with TOPO. Chemical yield is determined for the volatile group by re-irradiation of the sulfide precipitate. No chemical yield determination is performed for the TOPO group. Results for six international biological standards are presented. The method is applicable to a wide variety of biological samples