Distribution of polycyclic aromatic hydrocarbons in surficial sediments of the Vigo estuary, Spain, central axis and adjacent shelf

For the first time, 13 polycyclic aromatic hydrocarbons (PAHs) have been identified in samples of surface sediments at 17 stations on the Vigo estuary (northwest Spain) and its adjacent shelf. The separation and quantification of the analyzed compounds were performed using high-performance liquid chromatography, and a fluorescence detector with wavelength programming. The values found, for the sum of the 13 PAHs, varied between 28 and 2,150 mug/kg dry weight. These concentrations may be considered to be between very low and medium when compared with other estuaries. A concentration gradient with lower values on the continental shear that increase as the distance to the city of Vigo decreases, may be appreciated. Variations also can be noted in the participation of each PAH in the total sum, as a consequence of the differing degradability levels of each compound.