20191203 imhasly presentation - eth z · 2020. 1. 6. · ammonium nitrate / fuel oil •always...
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Analytical StrategyForensic Analysis - Explosives
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Dr. Sandro Imhasly
Head of Analytics/Explosives Unit
Bomb Disposal Expert
sandro.imhasly@for-zh.ch
Organigramm FOR
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FOR-ZED
Koordination
PyrotechnikEntwicklung Analytik/Sprengstoffe
Organization ZED
ZEDBEXNEDEX
Entschärferstützpunkte CH
Service duties ZED
Explosion / Detonation
Explosions
mechanical explosion
gas/air explosion
detonation
Mechanical explosion
Gas/air explosion
Gas/air explosion
Gas/air explosion - trace pattern
large wreckage
no crater formation
Detonation
Detonation - trace pattern
Explosion centre with crater
Detonation
Detonation
Pressure/Push effect
Pull effect
Detonation
Question / Discussion
Question / Discussion
• What analytical methods would you propose for the determination of the diverse explosives components? What are the advantages and disadvantages of the proposed methods?
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bulk / trace
Bulk explosives
• Explosive Testing Kits
• IMS
• IR
• Raman
• Flame test
• XRD / XRF
• Microscopy
• TLC
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Raman – Attention!
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• Do not use for bulk explosives! The added energy of the laser can cause the substance to explode.
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Trace explosives
• IC-MS
• GC-(MS)
• HPLC-DAD
• HPLC-MS
• ICP-MS
• AAS
• IMS
• DART-TOF-MS
• ect.
Question / Discussion
• What analytical methods would you propose for the determination of the diverse explosives components? What are the advantages and disadvantages of the proposed methods?
• How would you prepare the gathered evidence for instrumental analysis using the proposed methods?
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bulk / trace
extractionwater/org. solvent
Explosives
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Chlorate/Perchlorate mixtures Ammonium nitrate / fuel oil
• Always mixtures:• Al, Mg• Sugar• Fuel • Sulfur
• Black powder, flash powder
• Widely used in fireworks
• XRD/XRF
• IC-MS
• AAS
• ICP-MS
• IMS
Explosives
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Hexamethylene triperoxide diamine (HMTD)
Triacetone triperoxide (TATP) Mannitol hexanitrate
• HPLC-MS (ESI/APCI)• GC-MS • IMS
• HME – homemade explosives
• Unsafe to handle
Explosives
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Trinitrotoluene (TNT) Pentaerythritol tetranitrate (PETN) Cyclotrimethylenetrinitramine (RDX) Nitroglycerine (NG)
• HPLC-MS (ESI/APCI)
• GC-MS
• IMS
Explosives
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Nitrocellulose
• Problem: not a "clear defined" molecule
• Trace analysis only possible by determination of additives• Camphor• Akardite• Centralite• Diphenylamine
• HPLC-MS / GC-MS
Question / Discussion• How would you proceed gathering evidence? What do you consider
important points?
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Gathering evidence - Blown upmailbox
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Sampling material
Explosives residues set
2 m2
Documentation
Documentation
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Question / Discussion• How would you proceed gathering evidence? What do you consider
important points?
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Prevention of Mix-up
Prevention of Contamination
Gathering Reference Samples
Prevention of Degradation
Question / Discussion• How would you proceed gathering evidence? What do you consider
important points?
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Prevention of Mix-up
Prevention of Contamination
Gathering Reference Samples
Prevention of Degradation
Reference Samples
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August 2014: Einsatz Burg AG
Samples (???)
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Question / Discussion• What is the point of quantitative analysis of traces of explosives in
offences?
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Question / Discussion• What is the point of quantitative analysis of traces of explosives in
offences?
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Conclusions on the quantity of explosives used can only bedrawn from the damage pattern.
Questions?
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