Continuous two-dimensional field-flow fractionation: a novel technique for continuous separation and collection of macromolecules and particles

Abstract

Instrumental techniques to analyse macromolecular and particulate materials have undergone rapid development in response to the need for high resolution, precise identification and characterization, and enrichment and collection for further analysis. Continuous two-dimensional field-flow fractionation (2D-FFF), which is described in this article, is a novel technique for separation and collection of macromolecules and particles. 2D-FFF is based on the conventional field-flow fractionation principle but with carrier flow in two-dimensions. This overview discusses the principle of the technique, describes the instrumentation and suggests potential applications and further extensions. An overview of the basic field-flow fractionation principle is presented.

Retention in continuous two-dimensional thermal field-flow fractionation: comparison of experimental results with theory

“…The combination of these simultaneously acting mechanisms underlies the twodimensional continuous fractionation. 8,27,33 The sample components are separated by these two displacements into continuous laments that strike off at different angles over the 2D surface. The separated components are then collected at different locations around the perimeter of the channel.…”

Partition-induced vector chromatography in microfluidic devices

“…The spatial resolution that allows continuous operation in 2D methods could be achieved by a combination of transport in one direction with selective displacement in the perpendicular direction resulting in greater resolving power compared to 1D techniques [23]. An extension of FFF, for example, combines radial and tangential carrier flows between two parallel disks to allow for the continuous collection of separated bands in different locations of the fractionation cell [26]. Other examples of 2D fractionation use a flow field and an external force applied in the direction perpendicular to the flow as the selective displacement.…”

“…These methods fall in the category vector chromatography [24,25]−VC− tecniques, where the fractionation relies on differences in the average direction in which species being separated move. An extension of FFF, for example, combines radial and tangential carrier flows between two parallel disks to allow for the contin-uous collection of separated bands in different locations of the fractionation cell [26]. Other examples of 2D fractionation use a flow field and an external force applied in the direction perpendicular to the flow as the selective displacement.…”

Particle separation in alternating-current electro-osmotic micropumps using field-flow fractionation

“…In contrast to analytical chemical methods, hydrodynamic and size exclusion chromatography and electrophoretic and dielectrophoretic (DEP) techniques allow the collection of the separated sample (Radko Sergey 1999;Vastamäki et al 2005). The latter describe the forced translational movement of a polarizable colloidal in a nonuniform alternating-current (AC) electric field due to the electric interaction between field-induced polarization in the particle and the applied electric field (Pohl 1978).…”

“…Field-flow fractionation (FFF) describes the separation of particles suspended in a carrier flow, by a selective force due to an externally applied perpendicular field (Aldaeus et al 2006;Huh et al 2007;Myers 1997;Petersson et al 2007;Vastamäki et al 2005;Zhang et al 2005). Since the present forces, as diffusion, steric, gravitational, hydrodynamic and electrical forces are particle dependent, particles with different properties move in different fluid layers and therefore move at different velocities due to the parabolic velocity profile of the channel-flow.…”