Nuclear magnetic resonance imaging (MRI) of diesel oil migration in estuarine sediment samples

Magnetic resonance imaging (MRI) provides a means of monitoring the change in position and the eventual breakdown of oil within sediments. The multidi mensional technique allows the position of nuclei (most commonly protons) t o be located within a known volume of substrate, e.g. sediment, hence offer ing a method of assessing the harming potential of oils in near-shore envir onments. Two-dimensional (2D) and three-dimensional (3D) MRI analyses of th e measurement and movement of oil in estuarine sediments show that, using a ppropriate parameters, movement of the oil can be both observed and quantif ied. To aid the quantification a sample holder fabricated from polyvinylsil oxane, an inert material visible in magnetic resonance images has been used as an internal intensity standard. The results show the great potential of MRI in studying protonated contaminants in these materials, notwithstandin g the presence of paramagnetic species in estuarine sediments which might d istort the image. Sediments studied thus far have been collected from the T ay Estuary, Northeast Scotland.