Potential of external (in air) particle induced gamma-ray emission method for the preparation of isotopic composition of boron in-house reference standard in boron carbide matrix for quality control work

The quality control (QC) of an analytical method for any analytical data measurement depends directly on the matrix matching standard and certified reference material (CRM). In many cases, obtaining a matrix match standard and an RM or CRM as a control sample in sufficient amounts for QC analysis is difficult. It is also not advised to use a CRM as a standard for routine analysis owing to its high cost and availability in lower quantities. In view of this, in-house reference standards/materials for isotopic compositions of boron (IC, ¹⁰B/¹¹B atom ratio) in natural and enriched boron carbide matrix were prepared in the present work. These in-house reference standards/materials will be helpful for method validation, quality control and quality assurance in the IC determination of boron carbide samples using particle induced gamma-ray emission (PIGE) method. A total of five different isotopic compositions, namely natural (19.8 atom% of ¹⁰B) and 30, 40, 50 and 67 atom% of ¹⁰B-enriched B₄C, were prepared in sufficient quantities (0.8 kg each). Homogeneity and stability tests were performed for the prepared materials with respect to their isotopic composition by analysing direct powder samples using the external PIGE method, and they were found sufficiently homogeneous and stable for the property value for use as in-house reference standards. Assigned values of isotopic compositions were determined through external PIGE using both powder and pellet samples. The obtained values of the isotopic compositions are 0.247(1), 0.427(2), 0.662(3), 0.991(4), and 2.028(7) for the natural and 30, 40, 50 and 67 atom% of ¹⁰B-enriched boron carbide, respectively.