What Are Features and Classifications of Syringe Filters
Syringe filter is one of the most commonly used tools in many industries, like the medical, food, life science, and agricultural tests and so on. It is especially suitable for small volume samples in life science laboratories(such as proteins, additives, buffers), reagents and drugs) for sterilization operations. The syringe filter housing is made of medical grade polypropylene, one-time injection molding, high pressure resistance, no product leakage; easy-to-tear paper-plastic independent packaging. Syringe filter is DNA/RNase-free, pyrogen-free, and endotoxin-free, with larger effective membrane filtration area.
To be more specific, the syringe filter can be used for sample preparation whether liquid or gas phase, normal QC testing, protein precipitates removal, environmental test and dissolution assays and so on. It is fast and efficient. But please note do not contaminate it and pay attention to the seals when using or storing it to make sure all are clean before use. Cross-contamination is difficult to solve and difficult to handle.
Classifications of syringe filters by filter membranes
The syringe filter can be classified based on different standards. Today, we will discuss it from two aspects: filter membranes and sterilized or not.
1. PVDF (Polyvinylidene fluoride)
Performance: the PVDF membrane is hydrophobic, featuring chemical stability and inertia, and is suitable for chemically corrosive organic solvents, acid-base solutions, and sample preparation for liquid chromatography analysis. The PVDF syringe filter is laminated on the support mesh, which has strong strength and mobility, and can withstand high temperature of 130 degrees. It is widely used in sterilization and filtration in biopharmaceuticals due to its low protein adsorption and few precipitates. Positively charged PVDF can be used to remove endotoxins.
2. Nylon
Properties: it has good hydrophilicity and stable performance, high temperature resistance, acid and alkali resistance, and oxidation resistance. Nylon syringe filters is suitable not only for aqueous solutions containing acids and bases, but also for organic solvents such as alcohols, hydrocarbons, lipids, phenols and ketones.
3. PTFE (PTFE)
Performance: suitable for water system and various organic solvents, resistant to various solvents, low solubility. It has the characteristics of breathable and airtight, large gas flux, high particle interception rate, good temperature resistance, strong acid and alkali resistance, organic solvent and oxidant, anti-aging, non-stick, non-flammable, non-toxic, biocompatible and so on.
4. PES (polyethersulfone)
Properties: high chemical and thermal stability, high speed, strong acid and alkali resistance (pH range 1-14); high mechanical strength.
5. CA (Cellulose acetate)
Properties: it is a hydrophilic filter membrane with low protein binding. CA syringe filters is suitable for proteins and aqueous solutions filtration in biological samples, such as serum medium filtration.
Classifications of syringe filters by sterilized or non-sterilized
From another aspect, the syringe filter can be divided into sterilized syringe filters and non sterilized ones. For the sterilized syringe filters, it is Gamma-sterilized and packaged individually and are free of pyrogens and endotoxins, DNA and RNases. It is suitable for sterile filtration of small volume protein solutions and tissue culture fluids. It can improve the analytical results consistency and quality and reduce instrument downtime, by filtering samples properly.
Let's take a look at the characteristics of sterilized syringe filters:
1. With both high quality and economy, it is an ideal choice for fast and efficient filtration of samples with a volume of up to 100mL.
2. Specially designed for filtering environmental samples before COD and DOC analysis. To reduce the organic carbon content, the membranes used in these devices are pre-cleaned prior to assembly.
3. Disposable filter units for removing solids from liquid samples prior to analytical methods such as HPLC and UV/Vis spectrophotometry. They are available with a choice of filters in 0.2µm or 0.45µm pore sizes, feature polypropylene overmolded housings, and include sterile and non-sterile options.
4. Specially designed for resistance to organic solvents, ideal for clarifying aggressive organic solvents.
5. Reproducible filtration of organic solutions and aqueous solutions, suitable for sample preparation for high performance and ultra-high performance liquid chromatography (HCLP and UHPLC). For batch-to-batch consistency, these filters are tested and certified to be free of substances that form UV-absorbing at 210 and 254 nm with water, methanol, and acetonitrile.
6. Specially designed for automatic filtration system. It is equipped with a polypropylene casing to ensure smooth transport from the storage carousel to the filter location.
7. It adopts polypropylene shell and is equipped with a layer of inorganic alumina filter membrane, which is specially designed for sample preparation for subsequent ion chromatography and HPLC analysis. These units ensure very low levels of anion leaching when performing ion chromatography tests.
8. High-viscosity filter with pre-filter for filtration of viscous, high-density or other difficult-to-filter materials with high solids content (such as in environmental and food analysis samples).