Aijiren Screw Caps with Septa for 8-425 Screw Neck Vial is a screw cap designed for 8-425 screw neck vials with PTFE or silicone septums for high performance liquid chromatography (HPLC) and gas chromatography (GC) sample vials. These caps ensure a good seal and chemical compatibility, while offering a wide selection of sizes and materials to meet different laboratory needs and autosampler compatibility requirements.
Pre-slit PTFE/Silicone Septa is designed for applications where larger sample volumes need to be injected from a vial to avoid aspiration. This septa allows ambient gas to balance the gas in the vial, reducing the vacuum created by a tight seal around the needle. The pre-slit design makes the septa easier to penetrate with a needle and releases the vacuum created when removing large samples from the vial, while maintaining chromatographic properties similar to un-slit septa.