Knowledge and How to Select Syringe Filters

Syringe filter is separation equipment which can be combined with a injector to filter out the impurities from the sample of chemically turbid solution. Syringe filter generally consists of a plastic housing and a membrane. The body of syringe filter (plastic housing) is usually made of materials such as polypropylene and nylon; the filter membrane may be of PTFE, nylon or other treated products for specific purposes.

Types of syringe filter

Here the syringe filter is mainly divided into three series: FILTSTAR, WINSTAR and PURSTAR. FILTSTAR and PURSTAR are high-end products with transparent color. Among the 3 types, Filtstar and Winstar are more commonly applied with active demands. Unlike the Filtstar including both sterilization and non-sterilization types, Winstar only supports the non-sterilization syringe filters, such as non sterile PTFE syringe filter. Furthermore, Filtstar is of high quality and variety, meeting the needs of research specialists; in comparison, Winstar is a low-end product which is suitable for price-sensitive customers. Such as MCE syringe filter, disposable Nylon Syringe Filters.

What is a syringe filter used for?

Syringe filters are normally used for chemical experiments. For example, prior to analysis by HPLC, we can remove particles from a sample via syringe filter. HPLC can be easily damaged and blocked by the impurity particles due to the small packing size and high pressure. Thus the sample and solvents need to be pre-filtered to remove particulate contaminants and protect the instrument, and then the syringe filter is going come in handy. Similarly, the syringe filters are also suitable for IC analysis.

Also, syringe filters are frequently used for the on-site manufacture of parenteral drugs and sterile eye drops, in order to remove microbiological contamination.

Syringe filters are used to filter chemically turbid solution samples. Most commonly used for chemical HPLC-MS / GC-MS analysis of liquid and gas dust removal, sterilization filtration, biological sample preparation, tissue culture media, microbial media, Decontamination filtration of buffer solutions, etc.

Nylon Syringe FiltersDisposable Series Nylon Syringe FiltersSterile PP Syringe Filters

How to select syringe filters?

As a membrane-based device used to provide you with cleaner sample extracts, syringe filters can remove interfering materials, fine particles, and microorganisms from small liquid samples.

Syringe filters can be figured out by two basic parts: the membrane and housing. When you select filters, you should ensure both parts are compatible with your desired application. You can tell syringe filter housings are matched or not by the composition and format, and membranes are matched to end applications or not by composition, filter diameter, and pore size as well.

The two most popular membrane pore sizes for medical applications in the labs are 0.45 μm and 0.2/0.22 μm. 0.45 μm membranes can be used for applications of general filtering and particle removing, and 0.2/0.22 μm membranes can be commonly used for solution sterilization.

Based on your application, Hawach provides disposable syringe filter which are commonly selected for fast and efficient filtration, material purification, or sterilization in the labs. For a wide range of samples and applications, you can always find Hawach's high-quality sample filtration solutions in a variety of syringe filter sizes, membranes, and housings.

The main function of the microporous filtration membrane and syringe filter is to trap and filtering of the particles, bacteria and other impurities from the gas phase or liquid phase for separation, purification and purification purposes.

The following factors should be considered when selecting a syringe filter:

1. Filter media (chemical compatibility):
The first factor to be considered is the chemical compatibility of the filter media.
If the filter is resistant to organic solvents such as acids and alkalis. See our syringe filter chemical compatibility table for details of each.

2. Diameter
For column systems using 3um or larger particle size, 0.45um syringe filter or membrane can be used; for chromatographic system with less than 3um packing, or chromatographic system involving microbial growth, it is recommended A 0.20 um filter was used. For viscous solutions, pre-filtration can be carried out using a 1-5 um filter and then continually filtered with the corresponding filter.
0.22um, 0.45um

3. Characteristics of the sample
1) Hydrophilic sample: A hydrophilic membrane is used. It has an affinity for aqueous based samples. Membranes also used such as: mixed cellulose esters, polyethersulfone (PES), Nylon, and the like.
2) Strong corrosive organic solvent: a hydrophobic film is generally used. Filters such as PTFE, polypropylene (PP)
3) Protein solution: Select a low protein adsorption filter, such as a PVDF filter.
4) Ion Chromatography: PES membranes are generally considered to be suitable for filtration of solutions with low inorganic ions.

4. Sample Volume
When selecting the syringe filter, consider the volume of the sample (that is, what size of the syringe filter is selected): Generally, when the sample amount is less than 2 ml, a 4 mm diameter micro-filter is used. The sample volume is between 2-10ml, and the 13mm diameter filter is suggested to use. When the sample amount is more than 10ml, the 25mm diameter syringe filter is suggested to use.

How to use of syringe filters membrane?

1. Before inhaling the sample, first suck about 1ml of air into the syringe, which can minimize the liquid residue.
2. Inhale the sample into the syringe, invert the syringe and clear all the residue on the top.
3. Connect the needle filter to the syringe and tighten it 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 maximize the recovery rate.
5. Remove the filter, draw air into the syringe, reconnect the filter, and push out any remaining samples.

Syringe filters membrane precautions

Use a syringe with a volume of less than 10 ml with caution, as such syringe pressure is sufficient to burst the syringe filter. It is best to choose the filter membrane recommended in the operating procedures.

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