Choice of material
The right frit material depends on the solvents you use. PE frits are the standard bed support for EZ columns when used with aqueous systems and common chromatography solvents. They are available with a porosity of 25 µm and are suitable for agarose, dextran and other polymer-based packing media.
PTFE frits offer considerably higher chemical resistance than PE frits and are the standard bed support for EZ SolventPlus columns. They are suitable for organic solvents such as toluene, DMSO, chloroform and other aggressive liquids. PTFE frits are available in porosities of 5, 10, 20, 30 and 50 µm, making them suitable for a wide range of packing media with different particle sizes.
Choosing the porosity
The right porosity depends on the particle size of your packing media. As a rule of thumb, the frit porosity should be smaller than the minimum particle size of the packing media, so the bed is well supported without restricting flow.
Availability
All Omnifit frits are available as separate replacement parts and are compatible with both EZ columns and EZ SolventPlus columns. They are available for column diameters from 5.0 mm to 50 mm. A complete column comes with a frit kit containing several frits in different porosities and materials, so you immediately have the most common combinations at hand.
O-rings
The O-rings in Omnifit columns provide an additional seal between the PTFE end piece and the glass column body. As with the frits, the choice of material depends on the solvents you use.
FKM/FPM O-rings are available for standard EZ columns. They are suitable for aqueous systems and most common chromatography solvents. Chemraz O-rings are available for EZ SolventPlus columns. Chemraz offers considerably broader chemical resistance than FKM/FPM and withstands aggressive organic solvents that can degrade or swell standard elastomers.
Replacement O-rings are available for all EZ column diameters from 5.0 mm to 50 mm and are supplied as a set.