Phase Separating Filters are hydrophobic filters that will separate aqueous and non-aqueous phases of a solution.  The filter retains the aqueous phase of the mixture while the non-aqueous phase passes through.  

Choice of materials: Grade No.2S is a silicone treated cellulose paper and Polyflon PF grades are pure PTFE fiber.  Grade PF filters are recommended when chemical interaction with the filter media must be minimize