Demonstration of the principle of paramagnetic chromatography for resolving mixtures of particles

Particles which bind sufficient quantities of the paramagnetic cation Er³⁺ behave paramagnetically, and can be captured by a suitably-designed magnetic field. As the binding o Er³⁺ is ionic, the affinity of a given particle for Er³⁺ can be purposefully modulated by altering the ambient conditions. In the present communication, we describe one way in which these properties can be exploited to separate discrete populations of particles from heterogenous mixtures. We call this approach paramagnetic chromatography.