Why should I use an Inline Solvent Filter?

An inline solvent filter can make a very useful and protective addition to your system. Placing it between the pump and the injector, an inline solvent filter can protect your injector and the rest of your system—including your column and flowcell—from most particulate matter that exists in your solvent stream.

Where does this particulate matter come from? One source is from your solvent itself. If you have not pre-filtered your solvents, or if you don’t use a solvent filter in your reservoir(s), there is a good chance that some particles are present. Another source of contaminants is the pump seals themselves. As your pump’s pistons move back and forth through the seals, the friction created can cause small particles of seal material to fleck off and enter the solvent stream.

When any of this particulate matter passes on to your injector valve, it may get held up within the small passageways built into the valve’s seal. Once this occurs, it can cause flow blockages which may result in poor or no sample being injected. It may also result in the blocking of the solvent stream, which would be evident in a high pressure build up. One of the worst scenarios that can occur, however, is that the contaminant lodges between the seal and the inner face of the valve itself. As the valve rotates back and forth on subsequent injections with this particulate matter between the seal and valve face, both the seal and the valve face can become scored permanently. A scoring on either of these surfaces can allow fluid—either the sample or the solvent stream—to begin flowing in places it should not, usually resulting in a leak of fluid from the valve itself.

If the contaminants should happen to pass through the injection valve and continue on along the flow path, they could possibly enter the column, where they can ultimately cause poor chromatography.