Why is mass spectrometry used in forensics?
Mass spectrometry is used in forensics because it is a fast and highly sensitive analytical technique for the screening and identification of unknown substances from many different sources.
Its forensic uses include the identification of
- Drugs (forensic toxicology)
- Flammable liquids (arson investigations)
- Explosive residues
When it is combined with liquid chromatography (LC/MS) and gas chromatography (GC/MS) for preliminary separation, it can push the limits in toxicology and drug testing.
Sample preparation allows for a wide variety of compound classes to be screened using a single procedure for sample preparation and chromatographic analysis.
For example, here’s an LC/MS analysis of 19 drugs in a single sample. The total run time was 6 min.
GC/MS can even detect cocaine and heroin on bank notes that are used in the drug trade.
Arson investigators submit samples from a fire scene. The forensic lab uses an extraction followed by GC/MS to determine if an accelerant was used.
Forensic analysis of explosive residues is difficult because explosives are almost completely destroyed during the explosion. Specialized MS techniques allow the detection of tiny amounts of explosives.
It's all done with computers and software. That's why mass spectroscopy is such a fast and useful technique.