Mobile phase inlet filter selection

Eluent inlet filters prevents dust and other foreign particulate matters from entering the flow path of your liquid chromatography instrument. Such particles would otherwise eventually reach the column inlet, increase the system backpressure and might then also introduce radial flow heterogeneity which could affect peak shape.

Biotech Fluidics offers a range of competently designed inlet filters in different materials and porosities for a variety of solvents and requirements. All of these have a defined homogenous pore size to effectively block particles above a certain size, while letting the mobile phase through without significant pressure increase. The Bottom-of-the-Bottle™ design of these inlet filters make it possible to use mobile phases very efficiently down to the last few millimetres from the bottom of your eluent bottle. Replacement of inlet filters should be performed a couple of times per year and during the regular instrument service routines.

The patented stainless-steel Bottom-of-the-Bottle™ inlet filter features a replaceable filter cup in either 2 or 10 µm pore size that allows solvents to be drawn down to 3.2 mm (1/8 inch) from the bottle bottom. They allow flow rates up to 40 ml/min (10 µm filter) or 10 ml/min (2 µm filter) making it a trusted choice for many situations.

The all-PEEK Bottom-of-the-Bottle™ biocompatible inlet filters are equipped with a bottom withdrawal filter (2 or 10 µm pore size) allowing solvents to be used down to 2 mm (0.08 inch) from the bottom. These inert biocompatible are connected without any fittings and are available for a variety of tubing diameters, while allowing flow rates up to 30 ml/min. In addition, these inlet filter enables the connection of an optional auxiliary helium sparging line.

The inert and biocompatible UHMWPE Bottom-of-the-Bottle™ filter assembly comes with a replaceable filter cup and is an economic alternative enabling solvent withdrawal down to 2.5 mm (0.1 inch) from the bottom of your eluent bottle. These filters allow flow rates up to 5 ml/min although the hydrophobic filter material might require some surface wetting with organic solvents such as methanol or acetonitrile for optimum performance.

Biotech Fluidics also offers additional filters for liquid chromatography, HPLC and other equipment handling delicate fluids. Browse the online catalogue of IDEX Health & Science LLC for more information or contact Biotech Fluidics for guidance and to discuss your application needs.