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 surface), then couples with NEDA to produce an orange-pink azo dye. Maps propellant residue distribution around a firearm entry wound.
Explained in these topics
- Gunshot Residue (GSR) Analysis: Detection Methods
- Determination of Range of Firing in Firearm Cases
- Firing Distance Chemistry: Griess Test and Sodium Rhodizonate
- Forensic Analysis of Explosives and Post-Blast Residues
- Instrumental GSR Analysis: SEM-EDS, AAS, NAA and Modified Griess
- Powder Tattooing, Stippling, Blackening and the Modified Griess Test