Sarin (GB)
Definition
Isopropyl methylphosphonofluoridate, a G-series nerve agent. Highly volatile, AChE inhibitor. LCt50 ~35 mg.min/m3 by inhalation. Key degradation products: IMPA (isopropyl methylphosphonic acid) and MPA (methylphosphonic acid), both OPCW confirmation analytes.
- Chemical name
- Isopropyl methylphosphonofluoridate
- Class
- G-series nerve agent
- Mechanism
- AChE inhibitor
- LCt50 (inhalation)
- Approximately 35 mg.min/m3
- Key degradation products
- IMPA, MPA
Common questions
Why are IMPA and MPA important analytes rather than sarin itself in a confirmatory test?+
Sarin is highly volatile and degrades quickly in the environment and in the body, so by the time samples reach a laboratory the parent compound may be largely gone, while its stable hydrolysis products IMPA and MPA persist and serve as reliable confirmatory markers of exposure or use.
How does sarin's volatility affect how a scene or exposure site is investigated?+
Its high volatility means airborne concentrations can dissipate rapidly, so environmental and biomedical sampling has to happen quickly after a suspected release, and investigators rely heavily on degradation product analysis of surfaces, clothing, or biological samples rather than assuming the agent itself is still detectable.
What role does the OPCW play in confirming a sarin exposure case?+
The OPCW coordinates a network of designated laboratories that apply standardised, validated analytical methods, including detection of IMPA and MPA, so that findings from an incident can be independently corroborated and hold up to international scrutiny.
Related terms
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- Phosphorus-31 nuclear magnetic resonance spectroscopy, used to confirm the presence of phosphorus-containing OP nerve agents and their degradation products. Diagnostic: chemical shift...
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- IMPA (Isopropyl Methylphosphonic Acid)
- The primary hydrolysis product of sarin (GB). Detected in urine of sarin-exposed individuals and in environmental matrices by GC-MS and LC-MS/MS. The...
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