Assessing the microscale heterogeneity in Standard Reference Material 4600 Surrogate Post-detonation Urban Debris

Nondestructive microbeam X-ray fluorescence (μXRF) spectrometry has been used to investigate the elemental microheterogeneity in a nuclear forensics reference material (RM), NIST SRM 4600 Surrogate Post-detonation Urban Debris. Using a principal component analysis (PCA) model, results indicate the majority of elements appear homogeneous; however, zinc (Zn) exhibits microscale heterogeneity for this SRM. To minimize contributions to the measurement uncertainty from elemental microheterogeneity, a minimum sample mass of 24 mg is recommended for analysis. •Majority of elements appear homogeneous.•Zinc (Zn) exhibits microscale heterogeneity for this Standard Reference Material.•Sample mass of 24 mg is advised to minimize contribution to measurement uncertainty.