Unlined Metal Can
Definition
The standard evidence container for fire debris analysis. 'Unlined' refers to the absence of internal plastic or epoxy coating, which would contribute volatile organic contaminants to the headspace and interfere with GC-MS ignitable liquid residue analysis.
- Standard use
- Fire debris evidence container
- Meaning of unlined
- No internal plastic or epoxy coating
- Risk avoided
- Contaminant volatiles in the headspace
- Analysis affected
- GC-MS ignitable liquid residue analysis
Common questions
Why would a coated can specifically ruin an ignitable liquid residue result?+
Plastic or epoxy linings can off-gas their own volatile compounds into the sealed headspace over time, and those compounds can overlap with or mask the target ignitable liquid signatures the GC-MS analysis is trying to detect.
Can an unlined can be reused for fire debris collection?+
No, standard practice treats them as single-use, new and unused containers, since any residue or contamination from a prior sample would compromise the headspace analysis of the next one.
Related terms
- ASTM E2998
- Standard Guide for Sampling Improvised Explosive Devices and Post-Blast Debris for Explosive Residue Analysis. Specifies cotton swabs, isopropanol or methanol pre-wetting, swabbing...
- Chain of Custody
- The documented chronological record of who collected, handled, transferred, and examined a piece of evidence. For digital evidence, chain of custody includes...
- Friction Lid
- The press-on metal lid used to seal evidence cans for fire debris. Seated by pressing firmly around the rim; allows field packaging...
- 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...
- LC-MS/MS
- Liquid chromatography coupled to tandem mass spectrometry. The preferred confirmatory method for non-volatile organic explosives (PETN, RDX, TNT, NG) because it avoids...
- Mahazar
- The formal seizure list used in Indian criminal procedure (BNSS 2023) to document the collection of physical evidence at a scene. Prepared...
- Passive Headspace Concentration (PHC)
- ASTM E1412 extraction method. The sealed evidence container is heated at 60-80°C; volatilised hydrocarbons adsorb onto an activated charcoal strip suspended in...
- Selected Ion Monitoring (SIM)
- A GC-MS operating mode in which the mass spectrometer monitors only a set of pre-selected diagnostic m/z values, rather than scanning the...
- Tamper-Evident Sticker
- A self-adhesive label applied across the lid-rim or closure interface of an evidence container. Any disturbance of the container after sealing leaves...