Plenary talk at ISPAC conference on the use of polycyclic aromatic hydrocarbons (PAHs) in environmental forensics. Covers basics of what enviromental forensics investigations (EFIs) are and how PAHs can be used to help determine sources of releases (creosote, railway ties), oil sands development and oil spill releases (Macondo oil spill, gulf oil spill).
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ISPAC2013 plenary talk - Environmental Forensics and PAHs
1. Use of PAHs in Environmental
Forensics
Presented by:
Court Sandau, PhD, PChem
ISPAC 2013
Corvallis, OR
2. Environmental Forensics
• What is it?
• Analytical issues with PAHs and EFI
• Expanding PAHs (beyond 16)
• PAHs and EFIs – examples and case
studies
2
For case study on PAHs and a pipeline oil spill, see a part blog on our website:
http://chemistry-matters.com/pipeline-spill/
For more information on PAHs, click here to see our website page on PAHs.
3. Environmental Forensic Investigation
The systematic examination of historical and
environmental information (which may be used in
litigation) to allocate responsibility for contamination
“The application of
scientific methods used to
identify the origin and
timing of a contaminant
release”
See our website for more information on environmental forensic investigations.
5. Birthplace of Environmental Forensics
Exxon Valdez 1989
Term “Environmental Forensics”
coined in Dr. Robert Morrison’s
first books since it was used in a
peer reviewed publication. 5
10. Litigation and Liability Driven EFIs
• Adversarial process
• Goal – make you look bad or incompetent while making
themselves look good/sympathetic
• They are trying to tell if you are telling the truth or not
• Good science does not necessarily prevail
• Unfortunately, science is complicated (scientific literacy
28% in 2007)
• Need to prove it beyond a reasonable doubt
10
11. Differences Between Legal and
Research
• Documentation,
Documentation,
Documentation
Project id.
Address
Project id.DateDate
Date
Notes and pictures/videos
13. Differences Between Legal and
Research
• Documentation
• Sample Handling
• Chain of Custody
• Laboratory Competence
• Standard Procedures
• Communicating Results
14. Carpet Dust Sampling
• Must follow
standardized
procedures where
available
• Difficult to change
approaches
• Validation required if
methodology changes
Designation: D 5438 – 05
Standard Practice for
Collection of Floor Dust for Chemical Analysis1
This standard is issued under the fixed designation D 5438; the number immediately following the desig
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates th
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice covers a procedure for the collection of a
sample of dust from carpets and bare floors that can be
analyzed for lead, pesticides, or other chemical compounds and
elements.
1.2 This practice is applicable to a variety of carpeted and
bare floor surfaces. It has been tested for level loop and plush
pile carpets and bare wood floors, specifically.
1.3 This practice is not intended for the collection and
evaluation of dust for the presence of asbestos fibers.
1.4 The values stated in SI units are to be regarded as the
standard.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards: 2
D 422 Test Method for Particle-Size Analysis of Soils
D 1356 Terminology Relating to Sampling and Analysis of
Atmospheres
E 1 Specification for ASTM Thermometers
E 337 Test Method for Measuring Humidity with a Psy-
larger, embedded in carpet
household vacuum cleaners
3.1.2 surface dust—soil
proximately 5-µm equivalen
adhering to floor surfaces a
hold vacuum cleaners.
4. Summary of Practice
4.1 The sampling metho
from work published in Rob
(4).
4.2 Particulate matter is
floor by means of vacuu
through a sampling nozzle
and the particles are separat
cyclone is designed to effic
approximately 5-µm mean
However, much smaller par
efficiencies. The sampling
and suction adjustments to
air velocity for the removal
and bare floor surfaces, so
be repeated.
NOTE 1—Side-by-side compa
upright vacuum cleaner revealed
Designation: D 422 – 63 (Reapproved 2002)e 1
Standard Test Method for
Particle-Size Analysis of Soils1
This standard is issued under the fixed designation D 422; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
HVS-3 Vacuum Cleaner
15. Commercial Laboratory
PAH Analysis
• Methods vary from lab to lab
• Quantification
– Semi-quantitative methods with surrogates
– Quantitative methods with labeled internal
standards
• Analytes measured
– Routine EPA
– Routine EPA+
– Deluxe EPA compounds with substituted PAHs
and then some (up to 63 compounds in an
analysis)
18. Interlaboratory Comparisons
Method 8270C
• Interlaboratory study conducted
• Each lab measured homogeneous
soil sample 4 times over a ~ week
• Requested standard PAH method
• Compared variability amoung labs
and within each laboratory
22. Results
• Laboratory variability issues amoung
laboratories
• Sample to sample variability within
the laboratories
Variability can be measured and controlled with
a good data validation program
23. Method Comparison - PAHs
Low Resolution MS Method
• EPA Method 8270C
• Full Scan analysis
• No confirmation ions or
ratios
• Inappropriate surrogate
standards
• Many versions of method
High Resolution MS Method
• Modified California Method
(Carb 429)
• IDMS quantitation
• Less likely to have
interferences present
• Isotopically labeled
standards
• More accurate and precise
• Better data = better
decisions
24. PAH Analysis
• Many interferences exist in low molecular
weight range
– Depends on matrix, clean up method
• Specificity of HRMS allows better accuracy
and precision
• Comes at a cost – 4-6x
Difference in measuring
252 versus 252.30928
Benzo(a)pyrene
25. Internal Standards vs. Surrogates
naphthalene phenanthrene benzo(a)pyrene
N+
O
O-
F
*
*
*
*
*
*13
C
*
* *
*
**
* *
*
*
26. Isotope Dilution Quantification
• Standards behave exactly like compounds
being analyzed
• Loss of analytes during method, included
in measurement
• Matrix interferences in method, can usually
be seen with standards as well
• THE most accurate measurement
available
27. Is more expensive better?
Experiment:
• SRM – determine accuracy
• Duplicate – determine precision
• Unknown duplicates to compare
results
Compared methods, not laboratories
Lab A – ID-HRMS
Lab B- LRMS, surrogates
31. Causes of Overestimation
• Incomplete cleanup, residue matrix in
extracts
• Co-elution of other PAHs not being
monitored
32. Data Quality for PAHs
• Low resolution surrogate MS methods for
PAHs can be highly variable between
laboratories
• Sites driven by PAH risk require IDMS
– Sensitivity – for the guidelines
– Specificity – for the interferences that are
naturally present in samples
• IDMS methods are suggested for forensics
investigations
– May reduce variability of diagnostic ratios
33. Diagnostic Ratios
Ratios Values / Sources References
Phenanthrene /
Anthracene
< 5 = Pyrogenic; > 5 =
Petrogenic
Neff et al., 2005
Fluorene / Pyrene
+ 1 = Pyrogenic. < 1 =
Petrogenic
Neff et al., 2005
Indeno(1,2,3-cd)pyrene /
(Indeno(1,2,3-cd)pyrene
+ Benzo(g,h,i)perylene
> 0.1 = Combustion
Motelay-Massei et al
2007; Yunker et al.,
2002
Fluoranthrene/ Pyrene
< 1 = Petrogenic; >1
Pyrogenic
Motelay-Massei et al
2007
LMW / HMW < 1 = Combustion Zhang et al 2005;
Benzo(a)pyrene /
Benzo(a)pyrene +
Chrysene
< 0.2 = Petrogenic; >
0.35 = Combustion
Zhang et al 2005;
Zhang et al 2007
• Decrease analytical variability with better methods
• Some good, some not as good – use what fits?
• Good for bulk characterization – what about further
distinction of sources
34. Expanding the List of PAHs
Alkylated-PAHs and Other PAHs
C1-Phenanthrenes
1
2
3456
7
8
9 10
CH3
C2-Phenanthrenes
Phenanthrene
CH3
CH3
CH3
H3C
CH2 CH3
C3-Phenanthrenes
C4-Phenanthrenes… (?)
CH3
CH3
CH3
CH2
H2C
CH3
(5)
(30) (?)
36. Additional PAHs
– Biogenic (transformation of natural
precursors)
• Yulin et al. (1996) Biogenic Polycyclic Aromatic
Hydrocarbons in an Alaskan Arctic Lake Sediment,
Polycyclic Aromatic Compounds, 9(1-4).
– Petrogenic (fossil fuels)
– Pyrogenic (burning of organic materials)
Phenanthrene Retene Perylene
Click here for past blog on retene.
38. Advanced – 2D-GC-TOF-MS
• Cost – Highest
• Interpretation – Difficult
• Time – slow
• Can look for anything organic
• Advantage – separation + mass spectra id +
sensitivity
• Can be qualitative or semi-quantitative
Diesel – Gas Station - Canada
40. Middle East Crude Oil 1
Saskatchewan Crude
Middle East Crude Oil 2
Middle East Crude Oil 3
Middle East Crude Oil Investigation
41. www.chemistry-matters.com 41
Stable Isotopes – CSIA
“DNA” Fingerprinting
-40
-35
-30
-25
-20
-15
δ13
C(‰)
Compound
• Stable isotope data gives a “signature” to samples
• Samples may be linked or differentiated
O
42. Case Study
Residents have
allegedly been
exposed to PAHs
released from a local
industry. Exposure
pathways include
inhalation of ambient
air and incidental
ingestion of soil
43. Investigation
A number of techniques were
completed including:
– Chemical fingerprinting
– Molecular diagnostic ratios
– Statistical Analysis
• Cosine Theta Analysis
46. Molecular Diagnostic Ratios
0
2
4
6
8
10
12
14
16
18
20
0.0 0.5 1.0 1.5 2.0 2.5
FLRN/PYR
PHEN/ANTH
Unknown Human Habitation Suspected Source
Petrogenic
Sources
After Sicre et al 1987, Budzinski et al 1997, Tam et al 2001 and Neff et al 2005
Mixed Sources
Pyrolytic SourcesMixed Sources
47. Cosine Theta Analysis
An analysis of the matrix of similarity
coefficients between several different
samplesOrthogonal
Dissimilar
Co-linear, similar compositions
Theoretical Vector
1.00, 0o
Theoretical Vector
0.00, 90o
Human Habitation/Background
0.995
Suspected Source
0.586
Unknown
48. Results of Study
–Independent lines of evidence were
developed to indicate the potential
source of PAHs in soils
–Multiple forensic techniques supported
these lines of evidence
–Conclusion: PAHs found at residence
shared similar properties to those of
human habitation or background
– Not similar to the suspected source
49. Environmental Forensics in the Gulf
Oil Spill
• Reddy et al. sampled oil directly above well to conduct
comprehensive characterization
– Gas isotopes, GOR, fluid characteristics, API etc.
– Fingerprinted with 2D-GC-TOF
– Could distinguish between crudes
Reddy et al. 2011, PNAS Early Edition, p.1-6
50. Environmental Forensics in the Gulf
Oil Spill
• Hall et al. took 41 samples (slicks, scrapings off rocks,
grasses and debris, sand patties etc)
• Oxidized hydrocarbons comprised of more than 50% of
extractable hydrocarbons
• Used 2D-GC-TOF of samples compared to oil to assess
weathering of oil spill using chemometric techniques
Hall et al. 2013, Marine
Pollution Bulletin, in
press
53. Alberta Oil Sands
• Discovered by aboriginals and used to
waterproof canoes – “tar sands”
– “Tar sands” is a dirty term
• In 1719, European fur traders received
sample at Hudson’s Bay Company
• In 1783, first European saw them
personally
• Development began in 1967 by (now
known as) Suncor
54. Environmental Forensics in the Oil
Sands
• 2009 Kelly et al. (Schindler)
examined water and snow
PAHs near oil sands
development
• Upstream [PAC] <
downstream [PAC] (p<0.05)
• Study was generally ignored
by industry but is cited as the
first attempt to assess
environmental impacts from
oil sands development
Kelly et al. 2009, PNAS, 106, 52, p.22346
55. Environmental Forensics in the Oil
Sands
• Kurek et al. sampled local
lake sediments (no flow)
• Sediment dating (Pb/Cs)
combined with PAH analysis
• PAHs sharply increased in
lake sediments in ~1970 (but
are still well below guidelines)
• Important study:
– Demonstrated that inputs were
occurring
– Established historical baseline
(hadn’t been done previously)
• No longer a question of if, now
it is question of how much
Kurek et al. 2013, PNAS, 110, 5, p.1761
56. Environmental Forensics in the Oil
Sands
• Jautzy et al. sampled
local lake sediments (no
flow)
• Sediment dating (Pb/Cs)
combined with PAH
analysis & compound
specific isotopic analysis
• Additional line of
evidence showing isotope
shift in DBT
• Increase due to
deposition of bitumen in
dust particles with erosion
of open pit mines
Jautzy et al. 2013, ES&T, 47, p.6155
57. Environmental Forensics in the Oil
Sands
• Lundin et al. sampled scat
from wolf, moose and caribou
around SAGD facilities
• DNA testing, hormone testing,
scat detection dogs, etc.
• Higher concentrations of
PAHs (NAP and alkyl-NAP) in
moose scat near SAGD
compared to control locations
• Suggests that SAGD facilities
may still be implicated
Lundin et al. 2013, ISPAC 2013, Tues,11:00 AM
59. Societies and Organizations
• International Network of Environmental Forensics
(INEF)
• Association for Environmental Health & Sciences
(AEHS) Foundation
• International Society of Environmental
Forensics (ISEF)
60. University Degrees and Training
• Masters degree – University of Strathclyde
• Bachelor Degree – Bangor University
• University of Florida – Certificate program
• Many courses on Environmental Forensics
offered at Universities
• Environmental Forensics certification
(AEHS Foundation and others)
61. Questions?
Contact Info:
Chemistry Matters
Court Sandau
Email: csandau@chemistry-matters.com
Twitter: @Chem_Matters
Slideshare: www.slideshare.net/csandau
Please visit our website for related information, case
studies and blogs. www.chemistry-matters.com
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