Septa selection
PTFE:
- Exceptional solvent resistance and chemical compatibility
- Recommended for single injection applications
- The most economical septa
- Not recommended for long term sample storage
- Maximum temperature 260°C
Rubber / PTFE:
- Routine analysis
- Moderate resealing and excellent chemical inertness before puncture
- Excellent chemicals inertness
- Not recommended for multiple injections or storage of samples
- Least expensive
- Maximum temperature 150°C
Silicone / PTFE:
- Recommended for multiple injections and sample storage: excellent resealing
- Autoclavable
- Excellent resistance to coring
- Maximum temperature 200°C
Silicone / PTFE Pre-slit:
- Reduces the possibility of coring
- Used to prevent vacuum from forming inside the vial
- Maximum temperature 200°C
PTFE / Silicone / PTFE:
- Superior performance for ultra-traces analysis
- Above average resealing
- Most resistant to coring
- Least evaporation
- Autoclavable
- Maximum temperature 200°C
Septa Chemical Compatibility
| Solvents | PTFE | PTFE/Butyl | PTFE/Silicone | PTFE/Silicone/PTFE* | PTFE/Red Rubber |
| Acetonitrile |  |
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| Acetic Acid |  |
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| Acetone | |
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| Alcohols (ethanol) | |
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| Benzene | |
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| Chlorinated Solvents (methylene chloride) |
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| Cyclohexane | |
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| DMSO | |
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| Ether | |
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| Methanol | |
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| THF | |
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| Toluene | |
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| *PTFE/silicone/ PTFE has the same chemical compatibility of PTFE ONLY UNTIL PUNCTURED. | |||||