A syringe filter (sometimes called a wheel filter if it has a wheel-like shape) is a single-use filter cartridge. It is attached to the end of a

syringe A syringe is a simple reciprocating pump consisting of a plunger (though in modern syringes, it is actually a piston) that fits tightly within a cylindrical tube called a barrel. The plunger can be linearly pulled and pushed along the inside ...

for use. Syringe filters may have

Luer lock The Luer taper is a standardization, standardized system of small-scale fluid Piping and plumbing fittings, fittings used for making leak-free connections between a male-taper fitting and its mating female part on medical and laboratory instrumen ...

fittings, though not universally so. The use of a needle is optional; where desired it may be fitted to the end of the syringe filter. A syringe filter generally consists of a plastic housing with a membrane that serves as a filter. The fluid to be purified may be cleaned by drawing it up the syringe through the filter, or by forcing the unfiltered fluid through the filter.

Forms

In scientific applications, the most common sizes available are 0.2 or 0.22 μm and 0.45 μm pores. These sizes are sufficient for

HPLC High-performance liquid chromatography (HPLC), formerly referred to as high-pressure liquid chromatography, is a technique in analytical chemistry used to separate, identify, and quantify each component in a mixture. It relies on pumps to pa ...

use. The smallest known sterile syringe microfilter have pore sizes of 0.02 μm. Membrane diameters of 10 mm, 13 mm, 25 mm are common as well. Some syringe filters for small volumes may not resemble a wheel at all. The syringe filter body may be made of such materials as

polypropylene Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer propylene. Polypropylene belongs to the group of polyolefins and ...

and

nylon Nylon is a generic designation for a family of synthetic polymers composed of polyamides ( repeating units linked by amide links).The polyamides may be aliphatic or semi-aromatic. Nylon is a silk-like thermoplastic, generally made from petro ...

. The filter membrane may be of

PTFE Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemour ...

, or other treated products for specific purposes. Most manufacturers publish compatibility wallcharts advising users of compatibility between their products and organic solvents or corrosive liquids (e.g.

trifluoroacetic acid Trifluoroacetic acid (TFA) is an organofluorine compound with the chemical formula CF3CO2H. It is a structural analogue of acetic acid with all three of the acetyl group's hydrogen atoms replaced by fluorine atoms and is a colorless liquid with ...

Application

Syringe filters may be used to remove particles from a sample, prior to analysis by

or other techniques involving expensive instruments. Particles easily damage an HPLC due to the narrow bore and high pressures within. Syringe filters are quite suitable for

Schlenk line The Schlenk line (also vacuum gas manifold) is a commonly used chemistry apparatus developed by Wilhelm Schlenk. It consists of a dual manifold with several ports. One manifold is connected to a source of purified inert gas, while the other is ...

work, which makes extensive use of needles and syringes (see

cannula transfer Cannula transfer or cannulation is a set of air-free techniques used with a Schlenk line, in transferring liquid or solution samples between reaction vessels via cannulae, avoiding atmospheric contamination. While the syringes are not the same as ...

). Being relatively affordable, they may be used for general purpose filtration, especially of smaller volumes where losses by soaking up filter paper are significant. Syringe filters are also available for the filtration of gases, and for the removal of bacteria from a sample. Disk filters are frequently used for the onsite manufacture of parenteral drugs and sterile eye drops, in order to remove microbiological contaminations (sterile filtration).

Harm reduction in recreational drug use

Filters with 0.1 μm compared with 0.2 μm pore size have enhanced bacterial removal according to one study. The solubility of diazepam, for example, is less than 1 mg/mL at 68 °F (20 °C).

Notes

References

* {{DEFAULTSORT:Syringe Filter Laboratory equipment Medical equipment

Forms

Application

Harm reduction in recreational drug use

See also

Notes

References