Field-flow fractionation of magnetic particles in a cyclic magnetic field.

摘要: Although magnetic field-flow fractionation (MgFFF) is emerging as a promising technique for characterizing particles, it still suffers from limitations such low separation efficiency due to irreversible adsorption of particles on channel. Here we report novel approach based the use cyclic field overcome particle entrapment in MgFFF. This generated by rotating magnet top spiral channel so that and opposing gravitational forces alternately act suspended fluid flow. As result, migrate transversely between walls their at internal surface prevented short residence time which controlled rotation frequency. With recycling catch-release process, follow saw-tooth-like downstream migration trajectories exit velocities corresponding sedimentation coefficients. A retention model has been developed basis combined effects magnetic, fields hydrodynamic flow migration. Two types core-shell structured microspheres with diameters 6.04- 9.40-μm were synthesized used standard test proposed theory under varying conditions. The ratios these two measured function frequency, gap channel, carrier rate, sample loading. data obtained confirm optimum improved can be achieved tuning gradient, rate. In view widespread applications biological molecules, virus, cells, this new method might extended separate magnetically labeled proteins or organisms multiplex analyte identification purification.