Forensic Identification of Seal Oils Using Lipid Profiles and Statistical Models

Authors

  • Margaret H. Broadwater Ph.D.,

    Corresponding author
    1. Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC
    • Center for Coastal Environmental Health and Biomolecular Research (CCEHBR), National Ocean Service (NOS), National Oceanic and Atmospheric Administration (NOAA), Charleston, SC
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  • Gloria T. Seaborn B.A.,

    1. Center for Coastal Environmental Health and Biomolecular Research (CCEHBR), National Ocean Service (NOS), National Oceanic and Atmospheric Administration (NOAA), Charleston, SC
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  • John H. Schwacke Ph.D.

    1. Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC
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Additional information and reprint requests:

Margaret Broadwater, Ph.D.

Center for Coastal Environmental Health and Biomolecular Research (CCEHBR)

National Ocean Service (NOS)

National Oceanic and Atmospheric Administration (NOAA)

219 Fort Johnson Rd

Charleston, SC 29412

E-mail: maggie.broadwater@noaa.gov

Abstract

Seal blubber oils are used as a source of omega-3 polyunsaturated fatty acids in Canada but prohibited in the United States and (FA) European Union. Thus, a reliable method is needed to identify oils originating from seals versus fish. Two lipid profiling methods, fatty acid analysis using gas chromatography and triacylglycerol (TAG) analysis using liquid chromatography and mass spectrometry, were applied with statistical models to discriminate commercial oils and blubber samples harvested from marine fish and seals. Significant differences were observed among FA profiles, and seal samples differed from each of the fish oils (p ≤ 0.001). FA and TAG profiles were used to discriminate sample groups using a random forest classifier; all samples were classified correctly as seals versus fish using both methods. We propose a two-step method for the accurate identification of seal oils, with preliminary identification based on FA profile analysis and confirmation with TAG profiles.

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