Field flow fractionation sedimentation

Biomolecule Separations. Advances in chemical separation techniques such as capillary zone electrophoresis (cze) and sedimentation field flow fractionation (sfff) allow for the isolation of nanogram quantities of amino acids and proteins, as weU as the characterization of large biomolecules (63—68) (see Biopolymers, analytical techniques). The two aforementioned techniques, as weU as chromatography and centrifugation, ate all based upon the differential migration of materials. Trends in the area of separations are toward the manipulation of smaller sample volumes, more rapid purification and analysis of materials, higher resolution of complex mixtures, milder conditions, and higher recovery (69). 

Fig. 10. Centrifugal sedimentation field-flow fractionation equipment deposits particles along the circumference of the disk by size. The fluid enters and...

Currently, there are several molecular weight separation techniques, such as OTHdC, PCHdC, SEC, thermal field flow fractionation (ThFFF), and sedimentation field flow fractionation (SdFFF). The molecular weight separation range... 

Techniques which seem less suitable for routine size analysis are (1) analytical ultracentrifugation combined with a Schlieren optical system (Mason and Huang, 1978 Weder and Zumbuehl, 1984) (2) the sedimentation field flow fractionation (SFFF) technique to separate heterogeneous dispersions (e.g., Kirkland et al., 1982). 

VIGNETTE II ANALYTICAL SEPARATIONS AND CHROMATOGRAPHY Sedimentation Field Flow Fractionation... 

FIG. 2.1 Sedimentation field flow fractionation (SdFFF) (a) an illustration of the concentration profile and elutant velocity profile in an FFF chamber and (b) a schematic representation of an SdFFF apparatus and of the separation of particles in the flow channel. A typical fractionation obtained through SdFFF using a polydispersed suspension of polystyrene latex spheres is also shown. (Adapted from Giddings 1991.)... 

C. M. Frietch, and C. A. Kelly. Characterization of Submicron Aqueous Iron(lll) Colloids by Sedimentation Field Flow Fractionation, Anal Chem. 2001, 73.4815.)... 

Bio, G., Contado, C., Fagioli, F., Bollain Rodgiguez, M. H., and Dondi, F. (1995). Analysis of kaolin by sedimentation field-flow fractionation and electrothermal atomic absorption spectrometry detection. Chromatographia 41,715-721. 

Murphy, D.M., Garbarino, J.R., Taylor, H.E., Hart, B.T. and Beckett, R. (1993) Determination of size and element composition distributions of complex colloids by sedimentation field-flow fractionation-inductively coupled plasma mass spectrometry. /. Chromatogr., 642, 459M67. 

Fractionated Distributions. It will become apparent that the unambiguous determination of broad size distributions, be they multimodal or unimodal, presents the most problems for PCS. Therefore, a combination of PCS and a technique which fractionates a broad distribution has the potential for yielding the most information with the least ambiguity. Sedimentation field-flow fractionation (SFFF) is one such technique (12). 

This paper outlines the basic principles and theory of sedimentation field-flow fractionation (FFF) and shows how the method is used for various particle size measurements. For context, we compare sedimentation FFF with other fractionation methods using four criteria to judge effective particle characterization. The application of sedimentation FFF to monodisperse particle samples is then described, followed by a discussion of polydisperse populations and techniques for obtaining particle size distribution curves and particle densities. We then report on preliminary work with complex colloids which have particles of different chemical composition and density. It is shown, with the help of an example, that sedimentation FFF is sufficiently versatile to unscramble complex colloids, which should eventually provide not only particle size distributions, but simultaneous particle density distributions. 

Blaine, R. "New Applications and Techniques Sedimentation Field Flow Fractionation", The TA Hotline, DuPont Company, Summer 1986, 5. 

Colloid Characterization by Sedimentation Field-Flow Fractionation. I. Monodis-perse Populations, J. C. Giddings, G. Karaiskakis, K. D. Caldwell, and M. N. Myers, J. Colloid Interface Sci., 92, 66 (1983). 

Fractionating Power in Sedimentation Field-Flow Fractionation with Linear and Parabolic Field Decay Programming, P. S. Williams, J. C. Giddings, and R. Beckett, J. Liq. Chromatogr., 10, 1961 (1987). 

Separation and Size Characterization of Colloidal Particles in River Water by Sedimentation Field-Flow Fractionation, R. Beckett, G. Nicholson, B. T. Hart, M. Hansen, and J. C. Giddings, Wat. Res., 22, 1535 (1988). 

Retention Perturbations Due to Particle-Wall Interactions in Sedimentation Field-Flow Fractionation, M. E. Hansen and J. C. Giddings, Anal. Chem., 61, 811 (1989). 

Giddings JC, Caldwell KD, Jones HK (1987) Measuring particle size distribution of simple and complex colloids by sedimentation field-flow fractionation. In Provder T (ed) Particle size distribution assessment and characterization. American Chemical Society, Washington, DC,pp 215-230... 

Chianea, T., Assidjo, N.E., and Cardot, P.J.P., Sedimentation field-flow-fractionation Emergence of a new cell separation methodology, Talanta, 51, 835, 2000. 

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