| Summary: | Progress Code: completed These data relate to the Max Easton Honours project, carried out at Macquarie University in 2010, supervised by Simon George THE LONG-TERM DEGRADATION OF LUBRICANT OIL IN ANTARCTIC MARINE SEDIMENTS. A simulated marine spill has been carried out by the Australian Antarctic Division (AAD) over a five year period, in which Antarctic sea-bed sediments were doped with various petroleum products and left in a shallow marine environment to examine the extent and rate of natural degradation. Of these pollutants, unused Mobil lubricant oil (OW/40; Exxon Mobil) was analysed qualitatively and semi-quantitatively by gas chromatography-mass spectroscopy (GC-MS) to determine the composition of the oil and the rates and modes of degradation. The Mobil Lubricant Oil was found to consist of three dominant compound classes; 1) a series of branched alkanes with chain lengths of C25-26 and C33-34, 2) a series of long chain alkylnaphthalenes (formula C26H40), and 3) a series of bulky alkanoate esters. Other minor compounds were also identified. The alkanoate esters were depleted most readily, to less than 20% their initial values after 65 weeks. Branched alkanes and long chain alkylnaphthalenes were both recalcitrant over time, present at ~10% of their initial value after 260 weeks. Both the branched alkanes and long chain alkylnaphthalenes exhibited near identical behaviour through the sediment profile over time, depleting at the surface and increasing at depths consistent with migration through the sediment profile. Branched alkanes were depleted most rapidly relative to all other compounds, perhaps owing to preferred the biodegradation of long alkyl chains. No clear interpretation of the dominant mode of degradation was able to be defined, although it is believed that a multitude of removal mechanisms participate in the removal of lubricant oils in Antarctic marine sediments. 1) Retention time - Minutes 2) Region - It is a retention time window, labelled A to G as colours 3) Peak area - Peak area is in ...
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