Non-Polar Electrical Field Flow Fractionation

Document Type

Student Presentation

Presentation Date


Faculty Sponsor

Dale Russell


Electrical Field Flow Fractionation (EFFF) is a method of separating particles by applying an electric field across a flow of solvent with some sort of detector. As the samples pass through the field charged particles will be separated from each other based on their attraction to the field (their surface charge) and their size. Non polar EFFF is performed in a non polar fluid. Nonpolar solvents generate very diffuse electrical double layers at surfaces and permit a constant field across the EFFF channel, as opposed to polar solvents like water which suppress the field. We propose to apply this novel method to the separation of lipophillic proteins. At present protein separation techniques are preformed in aqueous solvent and require very high voltages, causing large amounts of heat. This denatures proteins and endangers the user. With EFFF the gap between plates is very small so the applied voltage may be much smaller causing less heat, for the same filed strength. The instrument requires high precision parallel electrodes with very high surface smoothness. We will polish metal plates to a very lowroughness surface. The plates will be sandwiched together with a thin gasket that separates the plates and forms a thin, ribbonlike flow channel. The plates will be drilled and plumbed with inlet and outlet ports for the fluid flow. The design must ensure that there are no leaks and the inflow and outflow offer no resistance. The electrodes will be connected into an electrical control circuit. Dual detection of the effluent by UVVIS and light scattering detectors will permit identification and particle size information as the sample washes through the channel. When the instrument is constructed, it can be tested on particle size standards and ultimately used for the separation of proteins.

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