More Related Content Similar to Profiling ignitable liquid residues (ILRs) and potential interfering compounds during arson and arsonous wildfire investigations - 8th Multidimensional Chromatography Workshop 2017 (20) More from Chemistry Matters Inc. (20) Profiling ignitable liquid residues (ILRs) and potential interfering compounds during arson and arsonous wildfire investigations - 8th Multidimensional Chromatography Workshop 20171. Profiling ignitable liquid residues (ILRs)
and potential interfering compounds
during arson and arsonous wildfire
investigations
January 8 & 9, 2017
8th Multidimensional Chromatography Workshop
Court Sandau, PhD
2. 2© 2016
Chemistry Matters Inc.
Copyright Statement
All rights reserved. No part of this publication may
be reproduced, distributed, or transmitted in any
form or by any means, including photocopying,
recording, or other electronic or mechanical
methods, without the prior written permission of
Chemistry Matters Inc.
3. Collaborators
• Phil Richards, Lisa Kates, and Lacey
Harbicht - Chemistry Matters Inc.
• James Harynuk and Paulina de la Mata -
University of Alberta
• Frank Dorman - Penn State University
3© 2016
Chemistry Matters Inc.
6. “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.”
6
Stauffer, E., Newman, R., Dolan, JA
Handbook Fire Debris Analysis (2007)
8th Multidimensional Chromatography Workshop
Jan 8 & 9, 2017
8. The Process of Sampling and
Analysis
8© 2016
Chemistry Matters Inc.
9. Data Analysis and Interpretation
• Stauffer 2008, “Fire Debris Analysis”
• Detection of specific chemical groups…
1. Alkanes
2. The Three Musketeers
3. The Castle Group
4. The Gang of Four
5. The Twin Towers
6. The Five Fingers
7. Pristane and Phytane
8. Hash and Trash
9. Aromatic Petroleum Profile
benzenes
naphthalenes
‘branched’ alkanes
9© 2016
Chemistry Matters Inc.
• Routine analysis looks at compound
presence/absence and relative abundance
using SIM focused on benzenes
11. ILR Identification in Arson Samples
• Use targeted GC-MS analysis of 63
marker compounds
• Developed based on experience,
standard availability and presence
in accelerants
• Is 63 compounds enough to
fingerprint ILR source in samples
with potential interferences?
11© 2016
Chemistry Matters Inc.
13. Burnt baseboardsChar debris
Burnt Flooring Control Flooring
Soil and humusForest debris
ILRs are readily extracted from all types of material.
Analysis patterns can be compared irrespective of sample type.
13© 2016
Chemistry Matters Inc.
14. Gasoline - No Matrix
14© 2016
Chemistry Matters Inc.
Three Musketeers
C2-benzenes
Castle Group
C3-benzenes
Gang of Four
C4-benzenes
17. ILR Analysis on Arsonous
Wildfires
• ILR confirmation and identification is
hardest for soil/vegetation samples
due to natural interferences
• Conclusion:
– Need clean up of extracts to remove
interferences (may have very limited
improvement)
– Need better chromatography
17© 2016
Chemistry Matters Inc.
2D-GC?
18. Is 2D better than 1D?
Castle Group
Benzene, propyl
Benzene, 1,3,5-trimethyl
Toluene, 2-
ethyl
Toluene, 4-ethyl
Toluene, 3-ethyl Benzene, 1,2,4-trimethyl
Benzene,
tert-butyl
Benzene, isobutyl
Benzene, sec-butyl
Benzene, 1,2,3-trimethyl
18© 2016
Chemistry Matters Inc.
19. Is 2D better than 1D?
Group of 4 (i.e. 7)
19© 2016
Chemistry Matters Inc.
20. 2D-GC TOF Analysis of ILR
• Sample from fire investigation
analyzed by 2D-GC
• 200-1700 compounds identified in
ILR samples
20© 2016
Chemistry Matters Inc.
21. 2D-GC Chromatogram
• Benzene
• Toluene
• C2-benzenes
• C3-benzenes
• C4-benzenes
• C5-benzenes
Total of 63 individual compounds used
• C1-Naphthalenes
• Indanes (throughout)
21© 2016
Chemistry Matters Inc.
22. Arsonous Wildfire Investigations
• Positive results for ILR (based on 1D-
GC-MS) in vegetation samples (n=78)
were analyzed by 2D-GC-MS
• Used targeted analysis on 63 selected
compounds
• Used percentage mass spectral match to
standards or library (>70%) for
confirmation of presence/absence of
targeted compound
– Provides secondary confirmation of presence
/ absence of targeted compounds
22© 2016
Chemistry Matters Inc.
23. 2D vs. 1D – 70%+ Mass Spectral Match
(n=78 fire debris samples +ve of ILR)
23© 2016
Chemistry Matters Inc.
24. 2D-GC ILR Analysis on Arsonous
Wildfires
• Conclusion:
– 2D-GC provides better
chromatographic resolution for ILR
targeted compound analysis
• Can 2D-GC ILR Targeted Analysis
Provide Fingerprinting of Source of
Gasoline?
24© 2016
Chemistry Matters Inc.
The Experiment:
25. Fingerprinting Experiment
• Collected 23 gasoline samples
• Analyzed (neat) by PONA analysis
and conducted statistical analysis
– Used as the gold standard
• Analyzed (neat) by 2D-GC -
Targeted ILR analysis
• Added matrix and spiked gasoline
to woodchips and analyzed by 2D-
GC - Targeted ILR analysis
25© 2016
Chemistry Matters Inc.
26. PONA GC-MS Analysis - Gasoline
• 652 compounds reported in PONA
results
• Removed compounds with missing
values
• Substituted ½ DL for non-detects
• 349 compounds used in PCA/HCA
26© 2016
Chemistry Matters Inc.
Paraffins/Isoparaffins
Olefins
Naphthenes
Aliphatics
28. 2D-GC-TOFMS Analysis - Gasoline
• 63 compounds analyzed in neat
gasoline samples (target list)
• Removed compounds with zeros for
more than 50% of the samples
• Substituted ½ detection limit for
samples with non detects
• 55 compounds remained and used
in PCA and HCA
28© 2016
Chemistry Matters Inc.
30. Conclusions for Neat Gasoline
Analysis
• With PONA analysis, can easily
distinguish different sources of
gasoline
• With targeted 2D-GCTOF analysis,
can distinguish sources of gasoline
– Maybe not the same resolution as with
PONA
• What about when matrix is added?
– Woodchips
30© 2016
Chemistry Matters Inc.
31. 2D-GC-TOFMS Analysis - Fuel
Added to Wood Chips
• 64 compounds analyzed
• Removed compounds with zeros for
more than 50% of the samples
• 48 compounds remaining
• PCA and HCA completed
31© 2016
Chemistry Matters Inc.
33. Conclusions
• For successful identification of sources of
gasoline during arson investigations,
need MORE data
• True untargeted analysis may provide
enough compounds to distinguish
between sources of gasoline in fire
debris samples
– Determining the source will aid investigators
to find those responsible
33© 2016
Chemistry Matters Inc.
34. 34
Thank You
Contact Info:
Chemistry Matters Inc.
Court Sandau
Cell: 403.669.8566
URL: chemistry-matters.com
Twitter: @Chem_Matters
LinkedIn: ca.linkedin.com/in/courtsandau
Slideshare: www.slideshare.net/csandau