Solvation of dilute, high value targets such as rare earth elements (REEs) and fluorinated contaminants from aqueous samples is a critical challenge in separation science. Important solvent parameters, including pH and ionic strength, influence the chemical speciation and solubility of these molecular targets. These hinder the effectiveness and reproducibility of current separation processes including capture, especially when recovery from waste streams is sought. Recently, magnetic (B) field treatment of complex liquid mixtures and soft materials was shown to exhibit extraordinary impacts on resulting properties such as material durability, filter lifetime, and plant metabolism, over wide-ranging pH and ionic strength conditions. While the mechanisms underlying these behavior changes are unknown, the observed B-field effects clearly depend on solute-solvent interactions and solute identity. This project aims to elucidate how magnetic fields alter the solvation and aggregation behavior of high value separation targets such as REEs and fluorinated contaminants in complex aqueous systems and to subsequently exploit this B-field control to modulate separation efficiency and reproducibility. Spectroscopic tools and neutron and X-ray scattering measurements are expected to reveal how B-fields alter solvent orientation and hydrogen bonding, change the solvent and solute electric and magnetic dipolar character, and distort the solute molecular conformation and hydration shell, both in bulk solution and at solid-liquid interfaces. Beyond developing an understanding of how the chemical, structural, and dynamical properties of the system change, the alteration of solubility and solute aggregation at or near ambient conditions using B-fields could yield a novel, non-thermal separation mechanism that overcomes current challenges offered by traditional, energy-intensive separation processes.