Abstract: A cartridge holder includes a holder body having a cavity along a longitudinal axis of the holder body. A floating screw has a longitudinal axis and a hole through the length of the floating screw. The floating screw is adapted to engage with the cavity in such a way that the floating screw is movable relative to the holder body along the longitudinal axis of the holder body. But rotary movement of the floating screw around the longitudinal axis of the holder body is confined by a restriction of the cavity. An outlet unit having a stem with a central hole and a length greater than that of the floating screw is adapted to be movably inserted into the hole of the floating screw, so that a first end of the outlet unit extends out of the hole and a second end of the outlet unit is engaged with the cavity. An end cap is provided to engage with the cavity. In use a cartridge is placed inside the cavity of the holder body between the end cap and the outlet unit.

Abstract: A new type of guard cartridge has been provided to prevent contamination of liquid chromatography (LC) columns by particulate and soluble contaminants. The cartridge is prepared by packing an empty tube with a chromatographic stationary phase and the packed tube is then sealed on both ends with porus sheets held in place by two collars. The cartridge gives minimum disturbance on column performance and significantly decreases the cost of production.