About the Features, Classifications, and Use Methods of Syringe Filter

With beautiful appearance, high cleanliness and light weight, the laboratory filters is a fast, convenient and reliable filter tool that is routinely used in the laboratory. It saves complicated and time-consuming preparations. Syringe filter is mainly used for sample pre-filtration, clarification and removal of particles, liquid and gas sterilization filtration. It is suitable for the filtration of a small amount of samples in the laboratory. HPLC syringe filter has low adsorption of samples, thus ensuring the recovery of small or high-value samples. The housing of the filter is made of polypropylene material, welded by ultrasonic, and does not contain adhesives.

HEPA syringe filter are common consumables in laboratories, which is frequently used on HPLC and IC analysis. There are many types of syringe filters that are widely used. HAWACH has provided the features and classifications of syringe filters for your reference.

Sterile Polypropylene Syringe FiltersWinstar Series PES Syringe FiltersSterile CA syringe filters


·The housing material of the filter head is made of high-quality sanitary polypropylene material.
·The precisely designed structure with rational internal space ensures smooth filtration, very low residual rate, and reducing sample waste.
·The edge of the filter is threaded, which plays a role of anti-skid, and the user-friendly design makes the operator handy.
·Stable filter membrane quality and zero difference between batches ensure the accuracy of analysis results.
·A clear specification mark, avoiding confusion and mistake


1. There are gas and liquid phase syringe filters, based on the filtering phase classification;

2. Based on the filtered solvent’s properties, the syringe filter can be classifed into water, organic and water organic general syringe filter;

3. According to whether it can be sterilized, it can be divided into two types: sterilization which contains gas and liqiud filters and non-sterilization. No matter before or after use, the syringe filters are required to complete the sterilization on the basis of sterile filter integrity test procedures. The sterilization methods are divided into steam sterilization and ethylene oxide gas sterilization, and steam sterilization is the most commonly used method.

4. There are single-layer, multilayer and capillary structure syringe filters based on the filter layer structure. For the syringe filter which uses monolayer(single-layer) microporous membrane, it can be used for general filtration. The sample is economical and practical; the multi-layer membrane structure adds a pre-filtration membrane, which can filter the coarser particulate impurities in the air. During production, transportation, and use, it can well protect the main filter material and prevent the damage of the main filter membrane.

5. The syringe filter has a variety of membrane materials, including cellulose acetate (CA), hydrophilic polyvinylidene fluoride (PVDF), nylon (Nylon), polyethersulfone (PES) and hydrophobic polytetrafluoroethylene ( PTFE) etc.;

6. There are three sizes commonly used, 33mm, 25mm and 13mm based on the shape and size.13mm is recommended for the filtration of 1-10ml solvent, and 25mm is recommended for the filtration of 10-100ml solvent. There are two pore sizes for the syringe filter membrane, 0.45μm and 0.22μm. The smaller pore size, the better filtration. So the 0.22μm membrane is able to filter very small impurities in the samples and meet meet the requirements of 99.99% sterilization specified by GMP or Pharmacopoeia; 0.45μm can filter In addition to most bacteria and microorganisms, it can meet the requirements of routine samples and mobile phase filtration, and can meet general chromatographic requirements. For chromatographic column systems using 3μm or larger particles, 0.45μm syringe filters or membranes can be used; for chromatography systems using less than 3μm fillers or chromatographic systems involving microbial growth, 0.22μm membranes are recommended.

Filter membranes

The syringe filter has good temperature resistance, 121°C, saturated steam autoclave sterilization for 30 minutes, working temperature 60°C, good chemical stability, and can withstand a variety of organic and inorganic compounds and solvents such as dilute acids and alkalis. It can be used in many industries, such as the filtration of tissue culture media, high-purity chemicals and water filtration, organic solvent mobile phases and so on. Syringe filters have different performances and uses depending on different membrane materials.

1) Hydrophilic samples: choose hydrophilic membranes, like the Nylon and PES, which have affinity for water and are suitable for filtering water-based.
2) Strongly corrosive organic solvents: choose hydrophobic membranes, for instance, PP, PTFE and so on.
3) Protein solution: choose a low protein adsorption membrane, like the PVDF membrane.


1. Suck about 1ml of air into the syringe before putting samples to minimize the liquid residue.
2. Get samples into syringe, turn it upside down and clear all residues on the top.
3. Connect the filter to the syringe and tighten gently to ensure a good seal.
4. Filter the sample in the syringe and inject it into the sample bottle, then follow the steps to increase the recovery rate, remove the filter, suck air into the syringe, reconnect the tip and get rid of all residual samples.