Phase Separator filter paper is impregnated with a stabilized silicone that renders it hydrophobic, retaining the aqueous phase and passing the solvent phase through.

After being shaken, the mixed phases are simply poured directly into the phase separatory filter which is quadrant-folded in a funnel. The separation is extremely rapid so it is unnecessary to wait until the two phases have settled into separate layers. Droplets are automatically separated after only a few moments, giving a solvent phase completely free of the aqueous phase. We feature and recommend the Whatman® 1PS grade of phase separator filter paper.