Simulation Study of High-Gradient Magnetic Chromatography

Abstract

High-gradient magnetic chromatography (HGMC) is a technique for selectively separating magnetic particles (MPs) according to their magnetic susceptibilities. We develop a mathematical model for HGMC that includes the effects of magnetic force, Brownian motion, gravity, and viscous drag. We then use this model to interpret recently reported experimental results and to distinguish these efforts from other work on high-gradient magnetic separation (HGMS) in the literature. Special emphasis is given to analyzing the main limitations of HGMC with regards to particle size and magnetic susceptibility. Our simulations show that HGMC can separate paramagnetic particles with magnetic susceptibilities as low as $10^{-4}$ to $10^{-3}$ and diameters down to a few tens of nanometers. Finally, we propose and discuss various alternative HGMC designs.