The 1H nuclear spin–lattice and spin–spin relaxation times at BEarth of some liquids associated with environmental spills

Assessing the extent of an environmental spill is the first step in soil remediation. Near-surface nuclear magnetic resonance (NMR) imaging is proposed as a possible technique for in situ imaging the extent of a spill because of the hydrogen or proton NMR signal associated with the most commonly spilled liquids. Before such a technique is developed, the available signal needs to be assessed. The hydrogen spin–lattice and spin–spin relaxation times of the spilled liquids are the best indicator of the signal. These relaxation times were measured for a variety of hydrocarbons that might be associated with spills. The relaxation times are measured at the Earth’s magnetic field, as these times are field dependent and a near-surface MRI will most likely operate at this magnetic field. With the exception of the more viscous hydrocarbons such as diesel fuel and motor oil, the lower viscosity liquids possess relaxation time values which should yield a good NMR signal from a near-surface MRI operating at the Earth’s magnetic field.