Jul 31, 2020 · Pre-slit septa is ideal for automatic sampleing because Septa is kept sealed between Vials and Caps, and pre-slit processing makes it easy to puncture the sample feeder's injection into HPLC Vials for sampling. Despite the slit, Septa is also able to maintain the sample seal in HPLC Vial without creating a vacuum in the air pressure inside the