The Main Type and Selection of Syringe Filter Materials

The syringe filter is mainly applied for filtration of the mobile phase and sample when in chromatographic analysis. It has good effects on protecting the chromatographic columns, infusion pump pipe, and sample valve from being polluted. The syringe filter is widely used for gravimetric analysis, microanalysis, colloid separation, and sterility test.

Syringe filters could be mainly divided into two types which are hydrophobic and hydrophilic respectively. It is a good way to encode according to the color of the filter shell so that filter material could be easily recognized and unnecessary laboratory mistakes could be avoided. There are different membrane materials that are used for making syringe filters, and many of them have their own characteristics.

Nylon thin membrane is the cheapest and most harshness-tolerant chemical for normal filtration. The nylon membrane syringe filter has good hydrophily and is resistant to acids, alkalis, and antioxidants. It is not only suitable for water solution, but also organic solvent.

The other popular material is PTFE which is also segmented into two types- hydrophobicity and hydrophile. The Poly Tetra Fluoro Ethylene (PTFE) membrane is suitable for hydrophilic and all sorts of organic solvents. It is resistant to all solvents with low solubility. Moreover, the PTFE membrane syringe filter is breathable and impermeable, with the advantages of a large air flow rate, high particle filtration efficiency, good thermal endurance, excellent aging resistance, non-stick performance, noninflammability, and biocompatibility. The syringe filter with PTFE membrane is widely applied in the areas of the chemical industry, pharmaceutical industry, environmental protection, electronic industry, food industry, and energy industry.

The PES Hydrophilic membrane has good chemical and heat stability, with a high flow rate, strong acid, and alkali resistance, and high mechanical strength.

In addition, there are some normal filter materials, such as CA Hydrophilic membrane, PVDF Hydrophobic membrane, Hydrophilic MCE membrane, Glass microfiber Hydrophilic materials, and so on.

When choosing the filter material, some instructions should be followed. First of all, the sample you are filtering should be compatible with the filter material. Second, it should be consistent with the filtration test. Then, the selection of filtration material should be confirmed with the S.O.P. of the proceeding test. Finally, the material could use the minimum pressure to filter most of the samples.