What Are The Characteristics Of Commonly Used Filter Materials For Syringe Filters
As one of the most widely used tools in the laboratory, the syringer filters are able to filter the water or organic solutions fast and efficiently. It includes a top cover, a ring-shaped shell, and a bottom cover. The two sides of the annular shell are respectively covered with a top cover and a bottom cover. The inner plug of the annular shell is equipped with a filter membrane, the top cover is provided with a convex feed port, and the bottom cover is provided with a convex discharge port.
These devices are made of various membrane filters with polypropylene shells, and a special injection molding process increases the burst pressure and filtration speed. These syringe filters are suitable for many applications, such as medicine, environmental protection, biotechnology, food/beverage, agricultural products testing laboratories.
If it is an aqueous sample, use cellulose or polyethersulfone directly. If it is an acidic or alkaline sample, use PTFE. Use regenerated cellulose or nylon for organic. Although the style and color of each brand are different, the most important thing is the filter membrane inside. The quality of the filter membrane directly affects the filtering result.
HAWACH syringe filter is divided into one-time and multiple-use, organic or water-based, with specifications of Φ13 or Φ25, used for sample filtration in liquid or air phase analysis. The filter membranes with 0.22 micron and 0.45 micron pore diameters are frequently seen. For the 1.0, 1.3, and 2.5 cm filters, it is used with disposable syringes and needles and is placed between the two and the interface is standard and is suitable for filtering small amounts of liquid, large amount, or too much insoluble matter can cause clogging. It is often used to process HPLC samples. Pls, note according to the actual use, the filter material in the primary effect syringe filter is regularly removed for cleaning.
1. Polytetrafluoroethylene (PTFE)
The polytetrafluoroethylene membrane is made of PTFE, which is completely natural and hydrophobic. The PTFE membrane is chemically compatible and can filter almost all organic solvents and highly corrosive chemicals. When it is necessary to filter the aqueous solution with a PTFE syringe filter, it must be pre-soaked with ethanol or isopropanol before the aqueous solution can be filtered.
2. Glass fiber pre-filter membrane (GF)
It is used to improve the filtration rate and continuous filtration; glass fiber syringe filter belongs to deep-layer filtration, and its main purpose is to be used as a pre-filter layer and directly added to the filter membrane for use.
3. Polyamide filter membrane (Polyamide, Nylon)
With excellent mechanical strength and strong adsorption, the nylon syringe filter suitable for the organic solvent and alkaline solution filtration. Compared with the PTFE membrane, It is more practical and cost-saving when filtering organic solvent, like the HPLC mobile phase particle removal filtration. Plus, because of its relatively high adsorption ability, it can be taken as transfer membranes, but it’s not suggested be used for biological samples filtration, in order to avoid sample loss due to adsorption. In this case, a more suitable usually used is a low-adsorption cellulose acetate membrane (CA).