Antimony isotope-delta values of pure mono-elemental solutions measured by Instrumental Neutron Activation Analysis

A method based on Instrumental Neutron Activation Analysis was established for the determination of isotope-delta values of pure Sb mono-elemental solutions. The measurement equation was developed to model all quantities related to the physical principles of nuclear neutron activation and instrumental effects of γ-spectrometry. The method was applied and tested in case the isotope-delta value is known to be zero to highlight systematic errors and evaluate the achievable uncertainty. A negligible 0.01 ‰ deviation was observed from the expected zero value with a 0.24 ‰ combined uncertainty due to counting statistics and pointed out to be the main contributor by the budget compiled using the developed measurement equation. The achieved uncertainty, close to the ultimate limit of INAA in isotopic abundance determinations, makes the method competitive for linking secondary to primary Sb isotopic reference solutions.