| 摘要 |
<p>Electrofocusing apparatus comprises a cell having spaced electrodes and a polyion mixture for producing a pH gradient between the electrodes, characterised in that the cell has at least one inlet and a plurality of outlets placed on opposite sides of the polyion mixture such that a flowpath for liquid is provided through the cell from the inlet(s), through the polyion mixture, to the outlets, the flowpath being transverse to the electric field and to the pH gradient and the outlets being spaced along said electric field and pH gradient, the polyions being positioned and immobilised to provide and maintain a pK gradient from one electrode to the other, so that when immersed in an aqueous medium, application of an electrical field by the electrodes will cause migration of protons to give the pH gradient between the electrodes corresponding to the pK gradient, whereby when an aqueous liquid mixture of separable components is caused to flow through the apparatus it may be at least partially divided by the electric field and pH gradient into its different components which leave the apparatus by different outlets. The immobilised polyions can be provided by ampholytes immobilised by reacting them with a reactive polymerisable material, applying an electric field to form a pH gradient, and polymerising the material. A cheaper alternative comprises a buffering mixture of acidic and basic ion exchange resins, the proportion of acidic to basic resins varying across the apparatus from one electrode to the other.</p> |
