Matrix solid-phase microextraction for measuring freely dissolved concentrations and chemical activities of PAHs in sediment cores from the western Baltic Sea

Influence of historical industrial epochs on pore water and partitioning profiles of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in Oslo Harbor, Norway, sediment cores

“…Immediately after the POM strips were removed, 50:10:40 ml heptane:acetone:water was added to the samples along with an internal standard of five 13 C-PCBs and six d-PAHs. Sediments were reflux extracted, and the extract was reduced and purified by successive solvent exchange with dimethylformamide followed by cyclohexane and eluted over a deactivated silica column [32].…”

“…However, for organic contaminants, it has been shown that freely dissolved sediment porewater concentrations, C pw (mol/L pw ), are more appropriate for such assessments than C sed , because C pw is more closely linked with toxic endpoints and bioaccumulation [9][10][11][12]. To date, however, sediment core studies measuring C pw are only just emerging [13], most likely because methods needed for determining C pw in thin sediment layers have only recently been developed [14,15]. One implication of this is that, even if C sed levels are found to be decreasing with time as a result of burial by cleaner, recent sediments, this does not by itself imply that environmental recovery is occurring, insofar as there may be no change or an increase in C pw .…”

Chemical activity as an integrating concept in environmental assessment and management of contaminants

“…Horstmann and McLachlan (1992) developed a ''fugacity meter'' for vegetation samples. Mayer and colleagues have pioneered the use of solid-phase microextraction techniques or equilibrium sampling methods for measuring chemical activities in sediments and soils (Reichenberg et al 2010;Witt et al 2009). The fundamental differences between accessible quantity of chemical and chemical activity has been discussed by Reichenberg and Mayer (2006), especially with respect to bioavailability and the potential for toxic effects.…”

“…This degree of accuracy obtained using activity is often sufficient for screening level assessments and for identifying the need for more detailed analysis. Witt et al (2009) have used chemical activity to assess the toxic potential of PAH mixtures in marine sediments. A test of the Ferguson Principle for a number of chemicals is to plot log LC50 versus log liquid or subcooled liquid solubility in water or in air.…”

The Role of Sediments in Coastal Monitoring

“…It has frequently been applied to marine sediments (Yang et al ., 2007;Trimble et al ., 2008;Witt et al ., 2009) and provides a matrix-and chemical-independent estimation of bioaccumulation for hydrophobic contaminants without extensive biotransformation (You et al ., 2006). For heavy metals, modelling approaches are of increasing interest when predicting potential risk due to metal concentration in the environment, the most accepted being the biotic ligand model.…”