AAS (Atomic Absorption Spectrometry)
Definition
An analytical technique measuring the absorption of element-specific wavelengths by atomised sample. For GSR, it quantifies dissolved Pb, Ba and Sb in hand-wash or HNO3 swab extracts. Cannot confirm particle co-localisation; has lower specificity than SEM-EDS.
Related terms
- 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...
- NAA (Neutron Activation Analysis)
- A nuclear analytical technique in which sample irradiation in a research reactor converts stable isotopes to radioactive ones, which are identified by...
- 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 GriessAn analytical technique measuring the absorption of element-specific wavelengths by atomised sample. For GSR, it quantifies dissolved Pb, Ba and Sb in hand-was...