Selecting the correct septum type is essential for maintaining seal integrity, minimizing contamination risk, and ensuring reproducible results in headspace analysis. Pharmafix™ septa offer certain performance benefits, but they also come with trade‑offs that users should understand before adopting them into routine workflows.

Improved Seal Performance

The primary advantage of using a Pharmafix™‑style septum is its superior sealing capability. This design enhances closure tightness and helps maintain vial integrity throughout pressurization, heating, and multiple autosampler needle punctures.
A stronger seal can lead to:

• Reduced sample loss through vapor leakage
• Improved pressure retention stability
• More consistent headspace equilibrium conditions

Considerations About Chemical Inertness

While Pharmafix™ septa provide improved mechanical sealing, they may not be as chemically inert as traditional silicone / PTFE (duplex) septa, which are specifically engineered for headspace applications.
Potential concerns include:

• Slightly higher interaction potential between sample vapors and the septum surface
• Increased risk of extractables under aggressive chemical conditions
• Reduced suitability for ultra‑sensitive analyses requiring the lowest possible background levels

When to Use Pharmafix™ Septa

Pharmafix™ septa may be a good choice when:

• Mechanical seal integrity is more critical than maximum inertness
• The application does not involve highly reactive solvents or extremely low‑level analytes
• Additional sealing robustness is needed to prevent leaks at elevated temperatures

When to Choose Silicone/PTFE Septa Instead

Silicone/PTFE septa remain the preferred option when:

• Maximum inertness is required
• You are working with volatile organics, low‑level contaminants, or trace‑analysis workflows
• You want to minimize contact contamination as much as possible

These septa are specifically formulated for headspace analysis and have a proven performance profile for minimal sample interaction.