NAA (Neutron Activation Analysis)
Definition
A nuclear analytical technique in which sample irradiation in a research reactor converts stable isotopes to radioactive ones, which are identified by gamma-ray spectroscopy. Provides sub-nanogram detection limits; used in forensic GSR research and very high-priority casework with reactor access (e.g. BARC Mumbai).
Related terms
- AAS (Atomic Absorption Spectrometry)
- An analytical technique measuring the absorption of element-specific wavelengths by atomised sample. For GSR, it quantifies dissolved Pb, Ba and Sb in...
- GFAAS (Graphite Furnace AAS)
- An AAS configuration using an electrically heated graphite furnace to atomise the sample, achieving approximately 100-fold lower detection limits than flame AAS....
- ICP-MS (Inductively Coupled Plasma Mass Spectrometry)
- A bulk elemental quantification technique that dissolves the entire hand swab or SEM stub and measures total element mass per sample. Complements...
- Modified Griess Test
- A contact-transfer colour chemistry test for nitrite-containing propellant combustion residue. Sulphanilic acid undergoes diazotisation with nitrous acid (from NO2 on the target...
- SEM-EDS (ASTM E1588-20)
- Scanning electron microscopy with energy-dispersive X-ray spectroscopy, operated under ASTM E1588-20. The reference method for individual GSR particle detection; provides simultaneous morphological...
- Sodium Rhodizonate
- A chelating agent producing a scarlet-to-red colour with lead ions at acid pH. Applied to entry-wound margins and garment entry holes to...
- SWGGSR Guide (2011)
- The Scientific Working Group for Gunshot Residue 'Guide for Primer Gunshot Residue Analysis by SEM/EDS.' Defines sampling, analysis and reporting requirements for...
Explained in
- Instrumental GSR Analysis: SEM-EDS, AAS, NAA and Modified GriessA nuclear analytical technique in which sample irradiation in a research reactor converts stable isotopes to radioactive ones, which are identified by gamma-ra...