Agilent, 5182-0730, Septa, for screw top caps, certified, PTFE/silicone, 100/pk

Agilent certified PTFE/silicone septa provide a puncturable seal for compatible screw-top chromatography vial caps. The layered construction places a chemically resistant PTFE surface toward the sample while the silicone backing maintains compression and helps seal around the injection needle. These 12 mm septa are supplied in packs of 100 and are used in GC and LC sample handling. Proper septum selection affects evaporation, contamination, needle penetration and repeat injection performance, especially when volatile solvents or sensitive analytes are involved. Fit each septum in a matching cap without curling the edge, tighten the cap appropriately and verify that the closure seats evenly on the vial. Consider solvent compatibility, needle geometry and expected number of punctures when designing an autosampler sequence. Replace punctured septa when sealing performance is no longer reliable; the septa are supplied as a consumable, not as complete capped vials.