Characterization of magnetic nanoparticles using quadrupole magnetic field-flow fractionation
Cleveland Clinic, US
Keywords: field-flow fractionation, magnetic nanoparticles
Abstract:Quadrupole magnetic field-flow fractionation (QMgFFF) is an analytical and characterization technique for magnetic nanoparticles, such as those used for cell labeling and for targeted drug therapy. These nanoparticles are generally composite materials consisting of magnetic cores with biocompatible coatings carrying antibodies or therapeutic drugs. The coatings stabilize the particles in suspension and also reduce the magnetic dipole-dipole interactions between the particles in a magnetic field. QMgFFF is capable of determining not only the mean magnetite mass per particle but also the mass distribution of magnetite among the particles. The particles are separated as they elute through a thin helical channel that is mounted in an axisymmetric magnetic field gradient provided by a quadrupole electromagnet. The mechanism of FFF, which exploits the opposition of field-driven and diffusion-driven transport, causes the particles to elute from the channel in times related to the strength of their interaction with the magnetic field gradient.