title: Biased cyclical electrical field-flow fractionation for separation of submicron particles.
abstract: The potential of biased cyclical electrical field-flow fractionation (BCyElFFF), which applies the positive cycle voltage longer than the negative cycle voltage, for characterization of submicron particles, was investigated. Parameters affecting separation and retention such as voltage, frequency, and duty cycle were examined. The results suggest that the separation mechanism in BCyElFFF in many cases is more related to the size of particles, as is the case with normal ElFFF, in the studied conditions, than the electrophoretic mobility, which is what the theory predicts for CyElFFF. However, better resolution was obtained when separating using BCyElFFF mode than when using normal CyElFFF. BCyElFFF was able to demonstrate simultaneous baseline separations of a mixture of 0.04-, 0.1-, and 0.2-μm particles and near separation of 0.5-μm particles. This study has shown the applicability of BCyElFFF for separation and characterization of submicron particles greater than 0.1-μm in size, which had not been demonstrated previously. The separation and retention results suggest that for particles of this size, retention is based more on particle size than on electrophoretic mobility, which is contrary to existing theory for CyElFFF.
authors.affiliation: Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.|Branches of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Bangna-Trad Rd, Samut Prakarn, 10540, Thailand.
authors.forename: Mathuros
authors.initials: M
authors.lastname: Ornthai
authors.affiliation: Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.
authors.forename: Atitaya
authors.initials: A
authors.lastname: Siripinyanond
authors.affiliation: Department of Mechanical Engineering, University of Utah, 50 S. Central Campus Drive, Rm. 2110, Salt Lake City, UT, 84112, USA. bruce.gale@utah.edu.
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Gale
mesh_terms: D031521:Fractionation, Field Flow / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size
keywords: Chromatography; Colloids; Electrical field-flow fractionation; Nanoparticles