Syringe filter Definition, Uses and Types

? What is a syringe filter ?

Syringe #filter is single-use #membrane device, attached to the end of a syringe. Used to remove particulate impurities from samples (liquid/gas) prior to some type of analysis to prevent damage to equipment (e.g. HPLC, #chromatography #ionic, ICP, dissolution tests etc.)

A?syringe filter?usually consists of a?housing?with a?membrane that serves as a filter?(classified according to #composition, filter diameter and pore size). Both components must be compatible with the application and solution being filtered.

Proper sample filtration improves the quality and #consistency of analytical results and reduces instrument downtime.

? What are syringe filters used for

Syringe filters can be used to remove particles from a sample, before it is used in techniques involving expensive #instruments that are easily damaged due to the narrow bore and high pressures inside .

Syringe filters?are quite suitable for Schlenk line work, which makes extensive use of needles and syringes

They may be used for general purpose #filtration, especially of smaller volumes where losses by soaking up filter paper are significant.

They are also available for the filtration of gases, and for the removal of bacteria from a sample.

? How to use a #syringefilter

• Load the #sample into the syringe.
• Fix the filter securely with a twisting motion. With a Luer Slip syringe, this is about a quarter turn when the filter is pushed in. If the syringe has a luer lock, attach it firmly but do not overtighten.
• Hold the assembled syringe and filter vertically to evenly wet the membrane (this promotes high flow rates).
• Gently depress the plunger of the syringe to push the sample through the filter. If possible discard the first 0.25-0.5ml of sample as if there is contamination present it is likely to be higher in those first microliters of sample.
• If the back pressure increases significantly, change the filter as it may have become clogged. Avoid pressing too hard as this may cause the filter housing to burst.
• Change filter and repeat for next sample

? Choosing a Syringe Filter

There are several aspects to choosing a syringe filter. Some of the main ones are:

??Filter body?: Disposable (polypropylene) or reusable (polycarbonate / stainless steel), Luer-lok or Luer-slip

??Pore Size: The pore size is determined by the size of the particles you need to filter out of your aqueous solution. Filters are available in a variety of pore sizes. The most commonly used are 0.13μm, 0.17μm, 0.25μm, 0.30μm and 0.45μm.

??Filter Material: There are many different filter materials used in syringe filters (Polyethersulfone (PES), Cellulose Acetate (CA),?Nylon,?RC,?GMF,?pp, etc.).

The main differences are :

Chemical compatibility : If the filter supports the chemical composition of the solution example :?#PH variations

• Flow rate : Speed of passage through the filter
• Burst pressure : Is the pressure at which the filter element is destroyed.
• Wettability : #Hydrophilic or #hydrophobic membrane.
• Binding properties : Membrane can bind analyte to varying degrees depending on membrane type and analyte type or concentration

??Filter Capacity

??Retention Volume

??Sterile or non sterile

? How to order a syringe filter

Sterile Syringe Filters from Membrane Solutions are manufactured with a polypropylene (PP) housing and are available with a wide variety of membranes and pore sizes, making it suitable for low #protein binding (eg: PES) or to a wide #chemical compatibility (eg: PTFE membrane).