Butyl

Pre-slit Crimp-top Cap with butyl/PTFE silicone GC vial septa are commonly used in gas chromatography applications to provide a reliable and inert seal for sample vials.
These septa are typically composed of three layers: a butyl rubber backing, a PTFE (polytetrafluoroethylene) middle layer, and a silicone top layer.
When purchasing septa, it’s important to ensure that they are compatible with your specific GC vials and instruments.

10ml Top empty bottles have a round bottom or a flat bottom.
Both types are suitable for injection but round-bottomed bottles tend to be stronger in storing samples. Therefore, the more reliable work should be the automatic sampler of the round bottom bottle. Round-bottomed bottles also tend to withstand higher pressures and are more suitable for temperature increases and are compatible with applications such as derivatization.The round bottom sample bottle is compatible with most automatic samplers, and the sample arm is convenient for carrying the sample bottle from the tray
The flat-bottled sample bottle can achieve a high level of heating efficiency during manual head space injection and is suitable for certain types of instruments