Petrogenic families and biogenic loners · o-cymene p-cymene m-cymene Three closely related...
Transcript of Petrogenic families and biogenic loners · o-cymene p-cymene m-cymene Three closely related...
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Making environmental data meaningful
Where does toluene come from? Petrogenic families and biogenic loners
Watertech 2017
April 3-5, 2017
Where does toluene come from? Petrogenic families and biogenic loners
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Biogenic Toluene? Are you sure?
2Where does toluene come from? Petrogenic families and biogenic loners
Sample B T E X F1 F2 F3 F4
1 ND 0.297 ND ND ND ND 1300 ND
2 ND 0.116 ND ND ND ND 780 ND
3 ND 0.439 ND ND ND 81 870 ND
4 ND 0.090 ND ND ND 290 2300 800
5 ND 0.182 ND ND ND ND 1400 ND
6 ND 0.262 ND ND ND ND 1300 ND
7 ND 0.015 ND ND ND ND 1000 ND
0.078 0.120 0.210 28 210 150 300 2800AB T1 – Coarse, Surface, Natural Areas
Example from poor bog (i1)
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Biogenic Toluene? Are you sure?
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• Not discussed in peer-reviewed literature
• Formation mechanism not understood
• Observed by standard analytical methods• But no legally-defensible method for
demonstration of origin
Where does toluene come from? Petrogenic families and biogenic loners
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Biogenic Toluene? Are you sure?
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Regulatory understanding…•Constituent of petroleum and products•Highly mobile chemical•Health-based guidelines
Where does toluene come from? Petrogenic families and biogenic loners
How does a regulator acknowledge biogenic toluene at an investigation on that basis?
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Biogenic Toluene? Are you sure?
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Method already well described.• Arson investigation for ‘ignitable liquids’• ASTM method• AGAT is the forensic laboratory for arson analysis
for Govt of AB, and AB Forestry.
Where does toluene come from? Petrogenic families and biogenic loners
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Gasoline
6Where does toluene come from? Petrogenic families and biogenic loners
Toluene
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Gasoline
7Where does toluene come from? Petrogenic families and biogenic loners
Toluene
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Weathered gasoline in soil
8Where does toluene come from? Petrogenic families and biogenic loners
Toluene
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Weathered gasoline in soil
9Where does toluene come from? Petrogenic families and biogenic loners
Toluene
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Peat from treed poor bog (i1)
10Where does toluene come from? Petrogenic families and biogenic loners
Toluene p-cymene
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Gasoline
11Where does toluene come from? Petrogenic families and biogenic loners
Toluene
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Peat from treed poor bog (i1)
12Where does toluene come from? Petrogenic families and biogenic loners
Toluene p-cymene
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Decomposition Pathways
13Where does toluene come from? Petrogenic families and biogenic loners
pinene p-cymene toluene
phenylalanine phenylacetate toluene
An amino acid
A terpene
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Peat from treed poor bog (i1) & poor fen (j1)
14Where does toluene come from? Petrogenic families and biogenic loners
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Diagnostic Groups
Focus on 2 key groups.
• BTEX
• Cymenes
15Where does toluene come from? Petrogenic families and biogenic loners
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Diagnostic Groups - BTEX
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A standard forensic method for analysis of VOCs is the ratio
of BTEX.
Six closely related chemicals.
In petroleum all 6 may be present.
In natural wetlands only 1 is present.
benzene ethylbenzene xylenes (3)
Where does toluene come from? Petrogenic families and biogenic loners
toluene
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The BTEX
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Natural Petroleum
Where does toluene come from? Petrogenic families and biogenic loners
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Diagnostic Groups – The Cymenes
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p-cymeneo-cymene m-cymene
Three closely related chemicals.
In petroleum all 3 are present.
In natural wetlands only 1 is present.
Where does toluene come from? Petrogenic families and biogenic loners
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The Cymenes
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Natural Petroleum
Where does toluene come from? Petrogenic families and biogenic loners
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Diagnostic Chemical Ratios
20Where does toluene come from? Petrogenic families and biogenic loners
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Diagnostic Chemical Ratios
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Peat
SAGD
Light RefinedOils &
Heavy Refined
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Diagnostic Chemical Ratios
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Biogenic Toluene
Petrogenic Toluene
Where does toluene come from? Petrogenic families and biogenic loners
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Where does biogenic toluene come from?
Where does toluene come from? Petrogenic families and biogenic loners
© 2017 Chemistry Matters Inc. 24Where does toluene come from? Petrogenic families and biogenic loners
Very rich organic environment
Limited nutrients and oxygen
Anaerobic water
Limited ‘decomposition’ pathways
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Source: geogratis.gc.ca
Wetlands
Fort McMurray
Edmonton
Peace RiverCold Lake
High Level
Where does toluene come from? Petrogenic families and biogenic loners
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Ecosite type?
26Where does toluene come from? Petrogenic families and biogenic loners
Site 1poor bog i1 – pH 3.6 to 5.6, low TDS, low EC
Site 2poor fen j1 – pH 7.6 to 8.2, high TDS, high EC (adjacent poor bog)
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Ecosite type?
27Where does toluene come from? Petrogenic families and biogenic loners
poor bog i1 poor fen j1
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Peat from treed poor bog (i1) & poor fen (j1)
28Where does toluene come from? Petrogenic families and biogenic loners
Toluene p-cymene
poor bog i1 poor fen j1
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Seasonality?
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0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0.045
0.05
May July August September October
TolueneConcentra
on(mg/L)
Site 2 – a poor fen (j1). Strong seasonality in water samples.
•Production or movement?
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Toluene in snowpack
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Conclusions
Natural toluene concentrations are present in peat samples.• Highly specific pattern of chemicals.• Clear diagnostic ratios.
Wetland environment correlates with likely formation mechanisms.
Likely seasonality effects as well as ecosite type.
Where does toluene come from? Petrogenic families and biogenic loners
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Thank You
Where does toluene come from? Petrogenic families and biogenic loners
Where does toluene come from? Petrogenic families and biogenic loners
Look out for the paper soon…
Forensic source attribution for toluene in environmental samples