Selecting the Correct Septa
It's vital to choose the right septa for your application. The wrong septa can compromise the accuracy of your results and reduce the lifespan of your supplies (increasing overall costs).
The below chart shows some common septa materials along with their compatibilities, incompatibilities, and resealability.
However, please don't accept the below data as final! Real-world results depend on a complex array of factors, including the specifics of your application and the quality of the material. If in doubt, it's recommended that you your own testing with different septa materials to determine the perfect match for your application.
| Septa Material | Compatible | Incompatible | Resealability |
|---|---|---|---|
| Butyl Rubber | Acetone, alcohols, diethylamine, DMSO, MEK, sodium peroxide | Benzene, chloroform, DMF, HF, HCL, phenol, toluene, xylene | Very good |
| Butyl Rubber / PTFE | PTFE resistance until punctured, then septa or liner will have compatibility of butyl rubber | PTFE does not reseal after being punctured | |
| PTFE | Diethylamine, fluorine | Single injection use | |
| Red Rubber | Acetone, alcohols, diethylamine, DMSO, sodium peroxide | Chloroform, DMF, HF, HCL, MEK, phenol, toluene, xylene | Excellent |
| Red Rubber / PTFE | PTFE resistance until punctured, then septa or liner will have compatibility of red rubber | PTFE does not reseal after being punctured | |
| Silicone | Alcohol, DMF, DMSO, hydrogen peroxide, sodium hydroxide | ACN, benzene, chloroform, hexane, HCL, MEK, THF, toluene | |
| Silicone / PTFE | PTFE chemical resistance until punctured, then septa or liner will have compatibility of silicone | PTFE does not reseal after being punctured | |
| VitonĀ® | Alcohols, benzene, chlorinated solvents, HF, heptane, hexane | Acetone, ACN, DMF, dioxane, pyridine, ketones, MEK, THF | Good |
The above data is provided courtesy of Ace Glass, Inc.