Sublimation (TATP Context)
Definition
The transition of a solid directly to vapour without passing through a liquid phase. TATP sublimes at room temperature (vapour pressure ~6.9 Pa at 25 degrees Celsius), which causes evidence loss if samples are not refrigerated, but also creates the detectable vapour signature exploited by IMS trace detection at security checkpoints.
- Compound
- TATP, triacetone triperoxide
- Vapour pressure
- About 6.9 Pa at 25 degrees Celsius
- Consequence for evidence
- Loss of trace residue if not refrigerated
- Detection exploited
- IMS trace detection at security checkpoints
Common questions
How can the same property be both an evidence problem and a detection advantage?+
The high vapour pressure that removes TATP from an evidence sample over time is the same property that fills the air around a concealed device with detectable vapour. Security screening exploits that vapour signature for ion mobility spectrometry detection, while forensic recovery has to work against it by refrigerating and analysing samples quickly.
Why is TATP's sublimation unusual compared with most military explosives?+
Conventional military explosives such as TNT or RDX have much lower vapour pressures and are comparatively stable as solids at room temperature. TATP's peroxide-based structure gives it an unusually high vapour pressure for a solid explosive, which is part of why it behaves so differently in storage and evidence handling.
Related terms
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- HMTD (Hexamethylene Triperoxide Diamine)
- A peroxide explosive analogue of TATP, synthesised from hexamine (hexamethylenetetramine), hydrogen peroxide, and citric acid. Similar sensitivity profile. Detected by LC-MS/MS as...
- Ion Mobility Spectrometry (IMS)
- A field-deployable analytical technique that separates ions by their mobility in an electric field at atmospheric pressure. Used for trace explosive detection...
- Nitramine
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- Nitro Compound
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- Organic Peroxide Explosive
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- Oxygen Balance
- A percentage expressing the surplus or deficit of oxygen in an explosive molecule relative to stoichiometric complete oxidation of carbon to CO2...