25th International Meeting on Organic Geochemistry IMOG 2011

O-03
Diamonds in the rough: identification of individual naphthenic
acids in petroleum and oil sands process water
Steven Rowland 1 , Charles West 1 , Alan Scarlett 1 , David Jones 1 , Richard Frank 2
1 Biogeochemistry Research Centre, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK,
Plymouth, United Kingdom, 2 Aquatic Ecosystems Protection Research Division / Water Science &
Technology Directorate, Environment Canada, 867 Lakesh, Burlington, Canada
Expansion of the oils sands industry of Canada has
seen a concomitant increase in the amount of process
water produced and stored in large lagoons.
Concerns have been raised, particularly about the
toxic complex mixtures of water–soluble naphthenic
acids (NA) in the process water, yet to date no
individual NA have been identified, despite numerous
attempts. Similarly, NA are also an integral part of
many biodegraded or partially biodegraded petroleum
systems.
The complexity of NA mixtures has prevented their
resolution and identification for over a century, except
in a minority of cases.
Here we describe the chromatographic resolution and
mass spectral identification of individual NA from
petroleum and in oil sands process waters. The
presence of tricyclic and pentacyclic diamondoid
acids, never before even considered as NA, revealed
the unprecedented biodegraded nature of some of the
samples. The identifications are supported by
analysis of numerous synthetic diamondoid acids and
should now be followed by quantitative studies and be
used to direct toxicity assays of relevant NA.
The novel two-dimensional comprehensive gas
chromatography-mass spectrometry method
described will also be important for helping to better
focus reclamation/remediation strategies for NA, as
well as in facilitating the identification of the sources
of NA in contaminated surface waters, offshore
produced waters and biodegraded petroleums.
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