Syringe Filters
Selection Guide for Syringe Filters
To find the right syringe filter for your application, follow the steps below:
1. Determine the filter size:
3 mm: for sample volumes < 1 ml
15 mm: for sample volumes 1 - 10 ml
25 mm: for sample volumes > 10 ml
2. Determine the pore size:
0.20 μm: recommended for UHPLC and HPLC columns with pore sizes < 3 μm
0.45 μm: recommended for HPLC columns with pore sizes < 3.5 μm
3. Do you need a glass fibre membrane?
If so, choose a filter with glass fibre (GF) membrane, e.g. GF / PTFE.
4. Select the appropriate membrane
Further information on the properties and application areas of the membranes can be found in the table below.
Properties of Syringe Filters
The properties of syringe filters made from different materials are very different. Therefore, the choice of the filter depends greatly on the chemicals used.
The following table provides an overview of the most common materials (incl. abbreviations) for syringe filters, the application areas as well as the chemical resistance of each synthetic.
Filter material
|
|
Properties
|
Cellulose acetate (CA) |
|
- hydrophilic membrane - excellent dimensional stability in aqueous solutions - extremely low binding capacity for proteins of 21 μg/filter at a membrane diameter of 25 mm - especially suitable for filtration of tissue cultures and biological macromolecules
|
|
|
|
Glass fiber (GF) |
|
- inert filter - for solutions with high suspended solids content or high viscosity - as pre-filters for other filters they prevent clogging of the membrane
|
|
|
|
Nylon (PA) |
|
- hydrophilic membrane - suitable for organic/ aqueous, medium polar liquids - resistant to many organic solvents - not resistant to acids and bases - high retention value for proteins
|
|
|
|
Polyethersulfone (PES) |
|
- hydrophilic membrane - very low adsorption of pharmaceuticals and proteins - very stable to bases, alcohols and acids (except oxidizing acids) - well suited for aqueous and slightly organic solutions with higher flow rates - binding capacity for proteins: 29 μg/ filter at a membrane diameter of 25 mm - mechanically very stable
|
|
|
|
Polyester (PET) |
|
- hydrophilic Allround Membrane - suitable for polar as well as non-polar solvents - not cytotoxic
|
|
|
|
Teflon (PTFE) |
|
- hydrophobic membrane - for nonpolar liquids and gases - very resistant to acids, bases and solvents of all kinds - by rinsing with alcohol and water the hydrophobic membrane can be made water-wettable - when using a wetting agent, PTFE can be used with aqueous solutions
|
|
|
|
Polyvinlyde difluoride (PVDF) |
|
- hydrophilic membrane - for polar as well as non-polar solutions - binding capacity for proteins: 82 μg/ filter with a membrane diameter of 25 mm - ideal for use in HPLC - unsuitable for aqueous solutions
|
|
|
|
Regenerated cellulose (RC) |
|
- hydrophilic membrane with very low adsorbtion - for aqueous/ organic liquids (polar - medium polar) - binding capacity for proteins: 84μg/ filter - with a membrane diameter of 25 mm - ideal for biological samples - high chemical resistance - high flow rates
|
|
|
|
Glass fibre / regenerated cellulose (GF/RC) |
|
- syringe filters with prefilters are recommended for solutions with high particle loads or for highly viscous solutions - these filters combine a coarse glass fibre prefilter and a narrow-pored regenerated cellulose membrane as the main filter - the hydrophilic RC membrane is used for filtration of aqueous and organic-aqueous liquids, i.e. polar and medium polar sample solutions
|
Syringe Filters - Sartorius, Pall, Merck
Information on the specific properties of each manufacturer for selected syringe filters (filter medium, diameter) can be found at Whatman syringe filter, Sartorius syringe filter, Pall Acrodisc syringe filter and Merck Millipore syringe filter.
Select the desired specifications available:
- Pore size: 0.1 µm - 10.0 µm
- Filter diameter: 3.0 mm - 50.0 mm
- Material: CA, CN, GF, PA, PES, PTFE, PVDF, RC