Syringe filters are often used in scientific research experiments. The type of membrane material and pore size used in the filter need to be considered when using it. The characteristics and scope of application of common filter membrane materials are briefly introduced as follows:
1. PTFE (Polytetrafluoroethylene)
Suitable for water systems and various organic solvents, resistant to all solvents, and low solubility. It has the characteristics of air permeability and water impermeability, large air flux, high particle retention rate, good temperature resistance, resistance to strong acids, alkalis, organic solvents and oxidants, resistance to aging, non-stickiness, non-flammability, non-toxicity, and biocompatibility. Its related products are widely used in chemical, pharmaceutical, environmental protection, electronics, food, energy and other fields. Polytetrafluoroethylene (PTFE) organic filter membrane, suitable for the filtration of organic solvent medium samples (including strong acids and alkalis) and organic solvents. Although it has a hydrophobic membrane, it can also be made hydrophilic by adding ethanol and deionized water.
2. PES (polyethersulfone):
It has high chemical and thermal stability, fast flow rate, strong acid and alkali resistance (pH range 1-14), and high mechanical strength. Polyethersulfone (PES) hydrophilic membrane has low resistance, fast filtration speed and low protein adsorption. It is especially suitable for the filtration of viscous biological and cell tissue samples. In addition, it also has good permeability, suitable for rapid filtration of large-volume aqueous samples.
3. PA (nylon, polyamide, often PA6 or PA66)
Nylon universal filter membrane is suitable for the filtration of most sample solutions and solvents. The filter membrane itself has hydrophobic properties, but it is also suitable for the filtration of water solvents, so it is often used for the filtration of HPLC and GC samples and solvents.
4. PVDF (polyvinylidene fluoride)
PVDF filters are chemically stable and inert (avoid using strong alkalis), and are used for impurity removal and sterilization filtration of organic solvents and solvents, and clarification and filtration of pharmaceuticals, beverages, and alcohol. The polyvinylidene fluoride film is laminated on the support net, which has strong strength and operability, and can withstand high temperatures of 130 degrees. The protein bound by PVDF membrane is far less than that of nitrocellulose, nylon and PTFE filter membranes. It is compatible with aqueous solutions and a variety of organic solvents. It has wide applicability, good oxidation resistance and heat resistance, and is very suitable for HPLC and GC preparation.
5. Mixed fiber membrane (MCE)
It is a mixture of nitrocellulose and cellulose acetate. It is hydrophilic, chemically compatible and has a high protein adsorption capacity. For particle analysis, particle removal, biochemical analysis, HPLC sample preparation and solvent filtration.
The Difference between Different Material Syringe Filters:
1. Water system is generally used to filter neutral and partial neutral aqueous solutions.
2. Organic systems generally filter organic solutions, but some organic solutions are not applicable. For details, please refer to the introduction of organic filters.
3. PTFE has the widest application range, which can filter aqueous solutions, organic solutions, acid and alkaline solutions.
Common application range of Syringe Filter:
1. Sample preparation, purification and pre-treatment of HPLC, MS, LCMS, GC, GCMS, IC and other instruments.
2. Preparation of biological products.
3. Filtration of tissue culture media, microbial media, buffer solutions and other liquid samples.
4. Purification and clarification of highly corrosive solutions.
5. Filtration of a small amount of sample to remove impurities and precipitation in the sample.
6. Ultra-clean polypropylene shell, low dissolution, suitable for trace analysis.