More Related Content Similar to Fixing False Negatives, Using 2DGC-TOFMS to Correctly Identify Ignitable Liquid Residues (ILRs) in Wildfire Investigations - Pittcon 2019 (20) More from Chemistry Matters Inc. (20) Fixing False Negatives, Using 2DGC-TOFMS to Correctly Identify Ignitable Liquid Residues (ILRs) in Wildfire Investigations - Pittcon 20191. © 2019
Chemistry Matters Inc.
Fixing False Negatives, Using 2DGC-TOFMS to Correctly Identify
Ignitable Liquid Residues (ILRs) in Wildfire Investigations
March 18, 2019
Pittcon 2019, Philadelphia, PA
Court Sandau, PhD
Principal, Chemistry Matters Inc., Calgary, AB
Adjunct Professor, Mount Royal University, Calgary, AB
2. © 2019
Chemistry Matters Inc.
Chemistry Matters Inc. Co-Authors
Dr. Lisa Kates
Dr. Phil Richards
Michelle Misselwitz
Acknowledgements
2
Mount Royal University
Dr. Gwen O’Sullivan
Nadin Bogelsak
University of Alberta
Dr. James Harynuk
Dr. Paulina de la Mata
PennState University
Dr. Frank Dorman
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Victoria, Australia
Year: 2009
Causes: Arson, Lighting, Power Lines
Fatalities: 173 Individuals
Damage: Over 3,500 Buildings Destroyed
Burned Area: 450,000 Hectares
Attica, Greece
Year: 2018
Causes: Suspected Arson
Fatalities: 100 Individuals, 172 Injured
Damage: Over 1,000 Buildings
British Columbia, Canada
Year: 2018
Causes: Human Cause and Lightning
Fatalities: Unknown
Damage: 50 Buildings Destroyed
Burned Area: 1,350,000 Hectares
Slave Lake, Alberta, Canada
Year: 2011
Cause: Arson
Fatalities: 1 Individual
Damage: Over 500 Buildings Destroyed
Or Damaged
Burned Area: ~5,000 Hectares
California, USA (Camp Fire)
Year: 2018
Causes: Power Infrastructure, Negligence,
Human Causes, Under Investigation
Fatalities: ~90 Individuals
Damage: ~19,000 Buildings Destroyed
Burned Area: 62,000 Hectares
Fort McMurray, Alberta, Canada
Year: 2016
Causes: Suspected Human Cause,
Under Investigation
Fatalities: 2 Individuals
Damage:~3,200 Buildings Destroyed
Burned Area: 590,000 Hectares
2.5x for acres
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Chemistry Matters Inc. 4
History of 2DGC-TOFMS and Fire Debris Analysis
• 1994 - ASTM E1618 first approved
• 1994 - First reported use of MDGC for ILR (Jayatilaka & Poole) - Heart-cut, FID,
simulated samples
• 1996 - First conference report of GCxGC for ILR at Pittcon (Phillips et al.)
• 2002 - First reported use of GCxGC-FID for ILR (Frysinger & Gaines) – simulated
samples
• In 2012, first known application of 2DGC-TOFMS to actual wildfire investigation
(PennState University)
• 2015 – CMI presented on application to real wildfire investigation for fire debris
analysis at multidimensional chromatography workshop
• In 2016, largest 2DGC-TOFMS application for wildfire debris analysis (UofAlberta)
• 2017 and 2019 - CMI presented on use of 2DGC-TOFMS for fingerprinting ILRs on
wildfire debris samples at multidimensional chromatography workshops
• “GCxGC–TOFMS offers an extremely promising future in the field of fire debris
analysis. It permits better separation, and, therefore, better specificity of the analysis
of ILR. This will be the change of technique that will lead to a significant improvement
of the analysis of fire debris samples in the future.”
Stauffer, E., Newman, R., Dolan, JA. Handbook Fire Debris Analysis (2007)
PITTCON 2019 Philadelphia
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Arson Investigations – Laboratory Perspective
• Identify the presence or absence of ignitable liquid
residue (ILR) in fire debris samples collected at
suspected arson investigation
1. Extract fire debris samples (building materials or wood,
soil, leaf litter)
2. Analyze extract for ILR
3. Identify presence/absence of ILR based on target
compounds and extracted ion chromatograms
4. Identify type of ILR used
• ILR can be any chemical substance that can ignite
– Acetone, toluene
– Lighter fluid, gasoline, diesel
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ASTM Extraction Method
• Extraction is non-specific – no clean-up, need good chromatography
7
Heat
volatilizes
target
compounds
into headspace
Carbon strip
adsorbs
compounds
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• Add clean carbon strip, heat 50-80oC for 2-24 hours, elute with 50-1000 µL
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Identification of ILR by GC-MS
8
• ASTM E1618, developed primarily for structural fires
• Reference chromatogram comparison to identify ILR type
• Use extracted ion chromatograms to visually identify characteristic peaks/groups
• Find “must have compounds”, peak list table (~40 compounds)
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Three Musketeers
C2-benzenes
Castle Group
C3-benzenes
Gang of Four
C4-benzenes
Twin Towers
C1-naphthalenes
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Limitations of ASTM Method E1618 for Wildfire Debris
Analysis
9
• Very heavy focus on visual pattern matching to identify ILRs in samples
• Uses limited number of marker compounds of common accelerants
– Why be limited? There are 700-1500 compounds in gasoline
• Dispersion of ignitable liquid higher in wildfire scenario
– Need lower detection limits (10x lower with GCxGC-TOFMS – Abel et al. 2018)
• More interference potential with wildfire debris
– Need better chromatography
Fire Debris Wildfire Debris
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Three Musketeers
C2-benzenes
Castle Group
C3-benzenes
Gang of Four
C4-benzenes
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Gasoline - No Matrix
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Pinene
Limonene
4-isopropyl toluene
secbutyl benzene
Lots of natural chemicals, difficult to
see gasoline pattern
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Matrix – Vegetation + Gasoline
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2DGC-TOFMS Eliminates Matrix Interferences
13
Looking for this - gasoline Wildfire debris sample – positive for gasoline
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GC-MS vs. 2DGC-TOFMS for ILR Detection
• Retention time match
• Mass spectral match
• Lots of co-elution issues with matrix
• Limited to target compounds in ASTM
• Visual based for identification
• Libraries and 25 years of experience
• Two retention time matches
• Higher mass spectral match factor
(resolution of chromatography)
• Can eliminate co-elution issues with
matrix
• Lower detection limits (10x, Abel et al.
2018)
• Unlimited peak capacity and can expand
targeted compound list (700-1500
compounds in gasoline)
• Visuals not the same
• Re-build libraries, new kid on the block
Routine GC-MS 2DGC-TOFMS
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Wildfire Investigation Samples – Suspected Arson
• Samples submitted for ILR analysis from wildfire investigations
• Positive bias for results, identified by accelerant detection canine
(n = 164 samples)
• Analyzed samples by routine GC-MS (ASTM E1618) and by 2DGC-
TOFMS
• Experiment included trip blanks (n=7) and comparison reference
samples (n=15)
• Used ASTM E1618 method target compounds only for
identification of presence/absence of gasoline for both methods
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Method Comparison – Three Muskateers
• Provides little value for identification of gasoline/ILRs
– Detected in all samples
• Background and trip blanks are an issue
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Method Comparison – Castle Group + 1
• ”Must have compounds” almost 100% detection rate with 2DGC-TOFMS
Castle
Group
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Method Comparison – Twin Towers
• Substantial increase in detectability of methyl-naphthalenes
• Lowest concentration in extracts due to volatility (extraction efficiency) and lowest
abundance in gasoline
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Conclusions
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• Using 2DGC-TOFMS for ILR analysis increased detectability
of gasoline in suspected arsonous wildfire investigations.
– Decreased ‘tentative’ classification
• Method is more sensitive and the resolution power of the
chromatography makes identification of ILRs easier in high
matrix samples, such as wildfire debris.
• Missing a positive classification can have implications on
prosecution outcomes
n=164 suspected arson wildfire debris samples
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Thank you for your attention
Contact Info:
Chemistry Matters Inc.
Court Sandau
Cell: 403.669.8566
Email: csandau@chemistry-matters.com
www.chemistry-matters.com
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