A Comparison of Methods for the Analysis of Hydrocarbons in Marine Sediments

The ability of several methods to extract polycyclic aromatic hydrocarbons (PAHs) and other petroleum hydrocarbons from marine sediments was examined. Comparisons of soxhlet and methylene chloride reflux methods gave extraction efficiencies that showed no statistical difference in the return of PAHs; however, the return when using ball-mill tumbling was significantly lower. The relative content of individual parent PAH compounds, parent compound distributions (PCDs), and alkyl homologue distributions (AHDs) of PAHs was calculated using capillary column GC—MS. The similarities of the distributions showed that any of the three methods could have been used to calculate these distributions. An examination of several extraction methods commonly used for the extraction of petroleum hydrocarbon material from sediment samples showed differences in results that depended on the extraction method employed. In addition, the methods varied in their ability to extract resolved versus unresolved material and to return aliphatic and aromatic hydrocarbon compounds.