Filter paper (circle) impregnated with a stabilised silicone that renders it hydrophobic, retaining the aqueous phase and passing the solvent phase through.- Any number of separations can be processed together.- Cut-off is automatic and complete just as soon as the solvent phase has passed through. Filter paper (circle) impregnated with a stabilised silicone that renders it hydrophobic, retaining the aqueous phase and passing the solvent phase through.- Any number of separations can be processed together.- Cut-off is automatic and complete just as soon as the solvent phase has passed through.