Oxygen determination in the Ti certified reference material ERM-EB090b by instrumental photon activation analysis

For mechanical properties of titanium, oxygen content is important. In re-certifying O mass fraction in the Ti certified reference material ERM-EB090b, instrumental photon activation analysis (IPAA) was used as an alternative to the inert gas fusion technique. IPAA utilizes 15O measurable only via the nonspecific annihilation gamma line 511 keV. Interferences from other radionuclides can be suppressed by optimizing photon energy and irradiation-decay-counting times, and for most interfering radionuclides corrected via their specific gamma lines. The present re-evaluated IPAA results for O content 3.56 ± 0.59 g/kg matches closely the assigned certified value 3.57 ± 0.19 g/kg.