TRACKING OIL SPILLS IOANA G. PETRISOR OUR COAST TO KEEP: ENVIRONMENTAL LAW ENFORCEMENT IN SOUTHERN CALIFORNIA SEMINAR

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1 TRACKING OIL SPILLS OUR COAST TO KEEP: ENVIRONMENTAL LAW ENFORCEMENT IN SOUTHERN CALIFORNIA SEMINAR IOANA G. PETRISOR Great Ecology San Diego, CA September 5, 2014

2 Overview Brief Review of Crude Oil Tiered Fingerprinting Approach: Tier 1: Chemical fingerprinting GC/FID Tier 2: Chemical fingerprinting GC/MS Tier 3: Isotopic fingerprinting Distinguishing Spilled Oil From Seeps

3 Crude Oil Saturated Hydrocarbons: Alkanes (Parrafins) Isoalkanes (Isoparrafins) Cycloalkanes (Naphthenes) Aromatic Hydrocarbons: Monoaromatic (BTEX) PAHs (Parent and Alkylated) Polar Compounds: (With N, O, S, Trace Metals: Ni, V) Resins (Smaller Compounds) Asphaltenes Porphyrins

4 Analytical Detection Principle Separation Equipment coupled with /Detector Gas Chromatograph (GC)/Flame Ionization Detector (FID) Mass Spectrometer (MS) Individual compounds are separated based on their mass fragments and elute from chromatographic column at distinct times The separated compounds enter in the detector unit: Tier 1 GC/FID or GC/MS (TIC Total Ion Mass Chromatogram): captures all present compounds Tier 2 GC/MS (Selected Ion Monitoring -SIM mode): captures selected classes of compounds

5 Tier 1 Data GC/FID - May Distinguish Between Petroleum Products Automotive gasoline Heavy fuel oil #6 Jet fuel A Lubricating Lubricating oil oil Number of carbon atoms Diesel fuel #2 Petroleum asphalt Source: Wang, Z. and Stout, S. (Ed.) Oil Spill Environmental Forensics Fingerprinting and Source Identification. Elsevier Academic Press, ISBN 13:

6 Tier 1 Data GC/FID - May Distinguish the Source of Crude Oils Source: Wang, Z. and Stout, S. (Ed.) Oil Spill Environmental Forensics Fingerprinting and Source Identification. Elsevier Academic Press, ISBN 13:

7 Tier 1 Data GC/FID - May Distinguish the Type and Degree of Weathering GC/FID of Fresh Crude Oil Partially Weathered Crude Oil Highly Weathered Crude Oil Source: Mansuy, et al., 1997, Environmental Science & Technology, v. 31, n. 12)

8 Tier 2 Data Data GC/MS SIM PAHs To Be Analyzed in Forensic Investigations

9 Tier 2 Data Data GC/MS SIM - Biomarker Classes To Be Analyzed in Forensic Investigations

10 Tier 1 and 2 Data Crude Oil Fingerprinting: Two Samples (Left and Right) Same Source? TIC GC/FID Hopanes GC/MS m/z 191 Steranes GC/MS m/z 217 Source: Wang, Z. and Stout, S. (Ed.) Oil Spill Environmental Forensics Fingerprinting and Source Identification. Elsevier Academic Press, ISBN 13:

11 Tier 2 Data 1-P CS 12P C2P CYP 2MP 3MP P MYCP 22DMP 24DMP C6 CYH 2MYCP 3MH ISO C7 MCYH 24DMH 234TMP 233TMP 23DMH C8 12DCT ECYHE IPB C9 PROPB 1M3EB 1M4EB 135TMB 1M2E 124TMB C10 123TMB 13DEB 14DEB 13DESEB 1M2PB 12DM4EB 13DM2EB C npb C12 benzene toluene ethylbenzene m-xylene p-xylene o-xylene ethylbenzene p-xylene o-xylene 1-P CS 12P C2P CYP 2MP 3MP P C6 MYCP 22DMP 24DMP CYH 2MYCP 3MH ISO C7 MCYH 24DMH 234TMP 233TMP 23DMH C8 12DCT ECYHE 1M3EB 124TMB IPB PROPB 1M4EB 1M2E C10 123TMB 13DEB 14DEB 135TMB C9 toluene benzene Sample 1 Sample 2 Histogram Review/Gasoline Fingerprinting Same Source?

12 Tier 2 Data PAH Histograms (Alkylated Vs. Non-Alkylated) Petrogenic or Pyrogenic Sources? No 6. Crude Oil Creosote

13 Tier 2 Data Double-Ratio Scatter Plots of Diagnostic PAHs for Source Differentiation Fl/Py separates CWG tar/residuals from creosote and background BAA/Chr separates CWG tar/residuals from background BAA/BAP separates creosote from background Source: Costa, H. Presentation AEHS Conf, San Diego, March 2008

14 Analytical Methods for Petroleum Fingerprinting Analysis Forensic Relevance Cost* C 3 -C 10 (PIANO gasoline-range distribution) by high resolution GC/FID Oxygenated Blending Agents MtBE, DIPE, EtBE, tame, tba, ethanol by EPA 1625 Modified EDB, MMT, and Organic Lead Concentrations by GC/ECD C 3 -C 44 (whole oil) by high resolution GC/FID Full Scan GC/MS * Prices from Zymax Lab, Escondido, CA Identifies more than 90 compounds Compares compositional similarities among samples (relative %) Degradation ratios provide information on ageof product Quantifies oxygenated additives in gasoline Provides information on age of unleaded gasoline Quantifies alkyl lead compounds and EDB Provides information on age of leaded gasoline Identifies up to 149 compounds Includes gasoline-range PIANO analysis Assists in identification of types of free product orcrude oils Degree of degradation provides information on productage Provides alkanes, alkylbenzenes, PAHs (PNAs), and polycyclic biomarkers Degree of degradation provides information on the age of a product $250 $220 $200 $300 $450 (P) $575 (AQ)

15 Tier 1 and 3 Data Targeted Fingerprinting -20 C14i C15i C16i C18i PR PH Carbon Isotope Value B -32 Tier 3 Data: Isotopic Fingerprinting (CSIA for isoprenoids) Tier 1 Data: Chemical Fingerprinting (GC/FID) Source: EPA Applications of Stable Isotope Analyses to Environmental Forensics (Part 3) and to Understand Degradation of Chlorinated Organic Compounds. CLU-IN Internet Seminar. Presented by Paul Philp

16 Challenge: Distinguishing Petroleum Spills from Background Contamination In an environment rich with natural sources of hydrocarbons, such as natural oil seeps, how do you distinguish contributions from locally extracted oils? Typical Approach Challenges Compare chemical fingerprintsusing comprehensive evaluation of diagnostic compounds ( the more the better ) Seeps are similar with locally extracted oils Thissimilarity is better preserved in the diagnostic compounds typically used for forensic evaluation Innovative Approach Focused Fingerprinting: Uses few relevant compounds to generate fingerprints (e.g., stereoisomers)

17 Natural Seeps Versus Spilled Platform Oils Conceptual Specific Differences NATURAL SEEPS Fate & Transport Repeated releases Reach surface through natural conduits SPILLED OILS Fate & Transport Episodic releases Reach surface through manmade conduits Response actions/active remediation More affected by long-term biodegradation More affected by short-term physicalchemical weathering Compositional distinct traits Isomer pairs (compositional and stereoisomers)

18 Stereoisomers Same elemental composition Mirror image of each other Lack an internal symmetry; contain one or more asymmetric carbons or chiral centers (with 4 different substituents) Stereoisomers are biodegraded distinctly Many common oil biomarkers have stereoisomers

19 Case Study: Distinguish Natural Seeps from Marine Oil Spills Offshore Southern California Relevant Forensic Techniques Chemometric analysis on selected diagnostic ratios Presence/absence of n-alkanes and Pri/Phy Innovative Approach Degree of biodegradation used in differentiation of closely related oils samples to be collected within 1 month of a spill

20 Ratios with High-Diagnostic Power for Closely Related Oils from Southern California Source: USGS, 2009, Open-File Report

21 Fingerprinting Platform Oil and Seeps from Same Oil Family - Denote Distinct Biodegradation States Platform Oil Seep Source: USGS, 2011, Scientific Investigations Report

22 Useful Diagnostic Ratios for Seeps Vs. Platform Oils Stereoisomers (S vs. R) Isomers Diasterance (C27 (S+R)/Sterane C27 (S+R) 1-Methyl Dibenzothiophene/4- Methyl Dibenzothiophene

23 More Information: Recommended Reading

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