0.22μm / 0.45μm Hydrophobic PTFE Syringe Filters For HPLC And GC Sample

Product Specification

0.45μm Pore Size PTFE Syringe Filters Hydrophobic for Lab Filtration

In analytical chemistry experiments, especially those involving high-sensitivity techniques such as high-performance liquid chromatography (HPLC), gas chromatography (GC), and mass spectrometry (MS), the purity of the sample is crucial to the outcome. Syringe filters can effectively remove particles that may cause column blockage, sensor contamination, or signal interference.

For example, in HPLC analysis, using a syringe filter can significantly extend the lifespan of the chromatographic column and improve the consistency of the analytical data. Additionally, syringe filters are widely used in the preparation of biological samples, including blood, serum, urine, and tissue extracts, providing clean samples for biochemical analysis.

The following is a detailed guide for selecting PTFE (Polytetrafluoroethylene) syringe filters:

Filter Membrane Material & Chemical Compatibility

PTFE filter membranes are made from a perfluorinated material, offering excellent chemical compatibility, strong hydrophobicity, and high-temperature resistance. They are suitable for filtering nearly all organic solvents and corrosive solutions, as well as gases. PTFE is inherently hydrophobic; thus, when filtering aqueous solutions, it must first be pre-wetted with ethanol or isopropanol to allow the aqueous solution to pass through. This pre-wetting step is necessary due to the hydrophobic nature of the PTFE membrane to adapt it for specific solvent filtration. Pre-wetting is not required when it is used for gas filtration.

Pore Size

The pore size determines the particle size that can be removed by the filter membrane. Common pore sizes include 0.22 μm and 0.45 μm. For chromatographic columns with packing materials of 3 μm or less in diameter, it is recommended to use a filter product with a 0.22 μm pore size; for those with packing materials above 3 μm, a 0.45 μm filter product should be used.

Model and Size

The model of a syringe filter typically correlates with its diameter, with common sizes including 13 mm, 25 mm, and 33 mm. Smaller diameter filters are suitable for rapid filtration of small volume samples, while larger diameter filters are appropriate for larger sample volumes. Additionally, the type of filter connection needs to match the syringe being used.

Sample Properties

The nature of the sample also affects the choice of syringe filter. For hydrophilic samples: Hydrophilic membranes are chosen because they have an affinity for water and are suitable for filtering solutions based on water. For strongly corrosive organic solvents: Generally, hydrophobic membranes such as PTFE filters are used.

Key features of PTFE Syringe Filters

• Hydrophobic polytetrafluorethylene (PTFE) membrane 
• Very high flow rate
• Excellent chemical resistance to most solvents and acids
• Low dead volume
• Resistance to various chemical solvents
• Free from wetting agents
• Sterilization by autoclaving at 121ºC or by ethylene oxide
• They must be pre-wetted with a polar solvent such as ethanol or isopropanol before filtering aqueous samples

The PTFE membranes of the syringe filters are manufactured by ourselves in our 100,000 grade cleanrooms, and the housing production and product- assembly are done in our own automatic injection-molding facilites. This makes us stand out from other manufacturers who have to purchase the membranes and shells to complete the assembly, and makes us more flexible and competitive on pricing. And we offer free sample service, contact us and you'll get desirable products at amazing price!