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.
