The complex permittivity of a solution-phase sample is a function of both the dipole moment and polarizability of all the molecules therein, and for dilute solutions, it may be expressed as the sum of contributions from the solvent and the solute. This relationship is simplified if the complex permittivity can be separated into its real and imaginary components (described by equation ( )) as the imaginary permittivity is only a function of the dipole moment.