Effect of Oils Categories on the Distribution of Polycyclic Aromatic Hydrocarbons and Derivatives in the Environment

International audience; Context and objective: The Migr’Hycar research project was initiated to provide decisional tools for risks connected to oil spill drifts in continental waters. This paper focuses on the distribution of polycyclic aromatic hydrocarbons (PAHs) from oils in water, air and oil slicks. Material and methods: Six petroleum oils covering a representative range of commercially available products were tested. Dynamic tests at laboratory scale were performed to study 41 PAHs and derivates, among them 16 EPA priority pollutants. Water soluble fraction protocol, stir bar sorptive extraction (SBSE) and high performance gas chromatography mass spectrometry (HPGC-MS) was used. Limit of quantification were lower than 1 ng.L-1 for each compounds. Results: A large variation in composition of the water soluble fraction depending on oil type and mixing time has been highlighted. Results have shown that evaporation is the primary mechanism of PAHs loss from spilled oil. The subsequent fate of hydrocarbons deposited in surface water is further influenced by volatilisation behaviour because of possible slick loss to the atmosphere. The water soluble fraction remains very low and is dominated by low molecular weight PAHS (e.g. naphthalenes).